作者单位: | (1)Department of Mathematics and Physics, Henan University of Science and Technology, Luoyang 471039, China; (2)Department of Mathematics and Physics, Henan University of Science and Technology, Luoyang 471039, China; Department of Mathematics, Lanzhou University, Lanzhou 730000, China; (3)School of Mechanical and Electronic Engineering, Northwestern Polytechnic University, Xi'an 710072, China |