Affiliation: | 1. School of Mathematics and Computational Science, Hunan University of Science and Technology, Xiangtan, Hunan, China;2. Department of Mathematics, City University of Hong Kong, Kowloon, Hong Kong;3. School of Science and Engineering, Chinese University of Hong Kong, Shenzhen, Guangdong, China;4. Department of Mathematics, University of Louisiana at Lafayette, Lafayette, LA, USA |