1. School of Science, Xi’an University of Architecture and Technology, Xi’an, P. R. China
2. School of Mathematics and Information Science, Henan Polytechnic University, Jiaozuo, P. R. China
3. National Engineering Laboratory for Modern Silk, College of Textile and Clothing Engineering, Soochow University, Suzhou, P. R. China
4. School of Mathematics, China University of Mining and Technology, Xuzhou 221116, Jiangsu, P. R. China
5. School of Science, Inner Mongolia University of Technology, Hohhot 010051, P. R. China
6. School of Mathematics and Big Data, Hohhot University for Nationalities, Hohhot, P. R. China