基金This work was supported by the National Basic Research Development Program of China (No. 2006CB504106)the NationalNatural Science Foundation of China (No. 30393130+4 种基金 30393133 30572086 30370536)the Special Foundation for the Doctoral Pointin High Educational Institute of China (No. 20060089009)the Knowledge Innovation Program of the Chinese Academy of Sciences(No. KSCX1-YW-R-75).