Supported by the Natural Science Foundation of Anhui Education Committee(KJ2007A003);the"211 Project"for Academic Innovative Teams of Anhui University(KJTD002B);the Doctoral Scientific Research Project for Anhui Medical University(XJ201022);the Key Project for Hefei Normal University(2010kj04zd);the Provincial Excellent Young Talents Foundation for Colleges and Universities of Anhui Province(2011SQRL126);the Academic Innovative Scientific Research Project of Postgraduates for Anhui University(yfc100020;yfc100028)