Supported by the National Natural Science Foundation of China(11071002);the NFS of Anhui Province(11040606M14);the NSF of Department of Education of Anhui Province(KJ2011A195);the Program for New Century Excellent Talents in University(NCET-10-0001);the Key Project of Chinese Ministry of Education(210091);the Specialized Research Fund for the Doctoral Program of Higher Education(20103401110002);the Scientific Research Fund for Fostering Distinguished Young Scholars of Anhui University(KJJQ1001)