作者机构:[1]School of Mathematical Sciences, Anhui University, Anhui 230039, P. R. China, [2]Department of Mathematics & Physics, Anhui University of Architecture, Anhui 230022, P. R. China
相关基金:Supported by the National Natural Science Foundation of China (Grant No. 10601001), the Natural Science Foundation of Anhui Province (Grant No. 070412065), Project of Anhui Province for Young Teachers Research Support in Universities (Grant No. 2008jq1083), Natural Science Foundation of Department of Education of Anhui Province (Grant No. 2005kj005zd), Project of Anhui University on Leading Researchers Construction and Foundation of Innovation Team on Basic Mathematics of Anhui University.