1. Department of Mechanical and Electronic Engineering, Chizhou University, Chizhou 247000, P. R. China
2. College of Optoelectronic Engineering, Changzhou Institute of Technology, Changzhou 213002, P. R. China
3. Department of Physics Electronic and Engineering, Chizhou University, Chizhou 247000, P. R. China
4. Department of Basic Course, Wuxi Institute of Technology, Wuxi 214121, P. R. China