作者机构:[1]School of Mathematical Sciences, Dalian University of Technology, Liaoning 116024, P. R. China, [2]School of Mechanical Engineering, Dalian University of Technology, Liaoning 116024, P. R. China
相关基金:Supported by the National Natural Science Foundation of China (Grant No. 10671029) and the Research Fund for the Doctoral Programme of Higher Education (Grant No. 20060141029).