Affiliation: | [1]School of Mathematics, Sichuan University, Chengdu 610064, China [2]Department of Mathematics, Taiyuan Teachers College, Taiyuan 030012, China [3]Faculty of Science, Xian Jiaotong University, Xian 710049, China [4]Key Laboratory of Numberical Simulation of Sichuan Province, Neijiang 641112, China |