1. Department of Information Engineering, Weihai Vocational College, Weihai City, Shandong Province, 264210, China.
2. College of Mathematics, Inner Mongolia University for Nationalities, Tongliao City, Inner Mongolia Autonomous Region, 028043, China.
3. Department of Mathematics, College of Science, Tianjin Polytechnic University, Tianjin City, 300387, China.
4. Institute of Mathematics, Henan Polytechnic University, Jiaozuo City, Henan Province, 454010, China.