1. School of Mechanical Engineering and Automation, Harbin Institute of Technology, Shenzhen Graduate School; Shenzhen 518055 People's Republic of China
2. Department of Mathematics; East China Normal University, and Shanghai Key Laboratory of Pure Mathematics and Mathematical Practice; Shanghai People's Republic of China
3. Department of Mathematics; Southern University of Science and Technology; Shenzhen 518055 People's Republic of China
4. Department of Mathematics; Wayne State University; Detroit Michigan 48202