基金supported by the National Natural Science Foundation of China(Nos.51007031,51277194 and 61273154)the Specialized Research Fund for the Doctoral Program of Higher Education of China(No.20123227110012)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK2012711)the Priority Academic Program Development of Jiangsu Higher Education Institutionsthe Fund Program of Jiangsu University for Excellent Youth Teachers