The National Natural Science Foundation of China (10771001);the Special Research Fund for the Doctoral Program of Higher Education of China (20093401110001);the Natural Science Key Foundation of the Education Department of Anhui Province (KJ2010ZD02);the Natural Science Foundation of the Education Department of Anhui Province (KJ2008B152;KJ2009B098;KJ2011A197);the Foundation of Innovation Team of Anhui University