基金Supported by the DFCQNU(Nos.11XLB027,2011XLZ05)the Foundation of Chongqing Education Commission(Nos.KJ120624,KJ110614)the Tianyuan Fund for Mathematics(No.11226237)
基金The National Natural Science Foundation of China (No.71171046)the Scientific Research Innovation Project for College Graduates in Jiangsu Province(No.CXLX_0162)