基金Project supported by the NSFC(No.10171111)and the Foundation of Advanced Research Center,zhongshan University.The second author is partially supported by a grant from Australia Research Council and NSF of Guangdong Province
基金The National science Foundation of the USA(Grant No.DMS 0400387)The University of Missouri Research Council(Grant No.URC-07-067)+1 种基金国家杰出青年基金(批准号:10425106)教育部“新世纪优秀人才”支持计划(批准号:04-0142)资助项目