Affiliation: | College of Mathematics and Physics Science,ChongqingUniversity, Chongqing 400030, China; College of Software Engineering, Chongqing University,Chongqing 400030, China; Department of Mathematics, Leshan Teachers' College,Leshan 614004, China; State Key Laboratories of Mechanical Transmission,Chongqing University, Chongqing 400030, China |