1. Guangxi Key Laboratory of Trusted Software, Guilin University of Electronic Technology, Guilin 541004, China
2. School of Mathematics and Computing Science, Guilin University of Electronic Technology, Guilin 541004, China
3. Center of Nonlinear Science Studies, Kunming University of Science and Technology, Kunming, Yunnan 650093, China
4. Department of Mathematics, Hezhou University, Hezhou, Guangxi 542800, China