1. Hunan Province Cooperative Innovation Center for the Construction and Development of Dongting Lake Ecological Economic Zone, College of Mathematics and Physics Science, Hunan University of Arts and Science, Changde 415000, People’s Republic of China
2. School of Mathematics and Statistics, Changsha University of Science and Technology, Changsha 410114, People’s Republic of China
3. College of Science, China University of Petroleum (East China), Qingdao 266580, People’s Republic of China