1. School of Mathematics and Information Science, Henan Polytechnic University, Jiaozuo, P. R. China
2. School of Physics and Electronic Information Engineering, Henan Polytechnic University, Jiaozuo, P. R. China
3. National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, 199 Ren-Ai Road, Suzhou, P. R. China