作者机构:[1]College of Engineering and Technology, Yangtze University, Hubei 434000, P. R. China, [2]School of Information and Mathematics, Yangtze University, Hubei 434000, P. R. China, [3]Department of Mathematics, University of Macau, Macau 999078, P. R. China
相关基金:Supported by the National Natural Science Foundation of China(Grant No.11401186); the Research Fund from Engineering and Technology College Yangtze University(Grant No.15J0802)Acknowledgements We thank all the referees for their time and comments to improve this paper. We also thank the editors for handling this paper.