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	The stress experience dependent long-term depression disassociated with stress effect on spatial memory task
	Xiong WY1,3; Yang YX1; Yang SC1; Xu L*1; Cao J1; Wei HM2; Liang CL1; lxu@vip.163.com
	2003
发表期刊	NEUROSCIENCE RESEARCH
卷号	46期号:4页码:415-421
摘要	Behavioral stress can either block or facilitate memory and affect the induction of long-term potentiation (LTP) and long-term depression (LTD). However, the relevance of the stress experience-dependent long-term depression (SLTD) to spatial memory task is unknown. Here we have investigated the effects of acute and sub-acute elevated platform (EP) and foot shock (FS) stress on LTD induction in CA1 region of the hippocampus of anesthetized rats and spatial memory in Morris water maze. We found that LTD was facilitated by acute EP stress, but not by sub-acute EP stress that may be due to the fast adaptation of the animals to this naturalistic mild stress. However, FS stress, an inadaptable strong stress, facilitated LTD induction both in acute and sub-acute treatment. In addition, with the same stress protocols, acute EP stress impaired spatial memory but the sub-acute EP stressed animals performed the spatial memory task as well as the controls, may due to the same reason of adaptation. However, acute FS stress slightly impaired learning but sub-acute FS even enhanced memory retrieval. Our results showed that SLTD was disassociated with the effect of stress on memory task but might be related to stress experience-dependent form of aberrant memory.
关键词	Long-term Depression Stress Water Maze Hippocampus Stress Experience
资助者	Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work.
收录类别	SCI
语种	英语
资助者	Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work. ; Basic Research Program G1999054000, National Natural Science grants 39870280, 39925011, 39930080 and Yunnan Science Foundation grant 98C111M of China to L. Xu supported this work.
文献类型	期刊论文
条目标识符	http://ir.kiz.ac.cn/handle/152453/10905
专题	科研部门_学习记忆的分子神经机制（徐林）
通讯作者	lxu@vip.163.com
作者单位	1.Laboratory of Learning and Memory, Kunming Institute of Zoology, The Chinese Academy of Sciences, Kunming 650223, Yunnan, China 2.Kunming General Hospital, Chengdu Area of Chengdu, Kunming 650032, China 3.Graduate School of the Chinese Academy of Sciences, Beijing 100039, China
推荐引用方式 GB/T 7714	Xiong WY,Yang YX,Yang SC,et al. The stress experience dependent long-term depression disassociated with stress effect on spatial memory task[J]. NEUROSCIENCE RESEARCH,2003,46(4):415-421.
APA	Xiong WY.,Yang YX.,Yang SC.,Xu L*.,Cao J.,...&lxu@vip.163.com.(2003).The stress experience dependent long-term depression disassociated with stress effect on spatial memory task.NEUROSCIENCE RESEARCH,46(4),415-421.
MLA	Xiong WY,et al."The stress experience dependent long-term depression disassociated with stress effect on spatial memory task".NEUROSCIENCE RESEARCH 46.4(2003):415-421.

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200346415.pdf（344KB）	期刊论文	出版稿	开放获取	CC BY-NC-SA	请求全文

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