Supported by the National Natural Science Foundation of China(11071002,11126178);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 Science and Technological Fund of Anhui Province for Outstanding Youth(10040606Y33);the Project of Educational Department of Anhui Province (KJ2011A019);the Scientic Research Fund for Fostering Distinguished Young Scholars of Anhui University(KJJQ1001);the Academic Innovation Team of Anhui University Project(KJTD001B)