Da-Wei Niu

College of Information and Business, Zhongyuan University of Technology, Zhengzhou City, Henan Province, China

Yue-Jin Zhang

College of Information and Business, Zhongyuan University of Technology, Zhengzhou City, Henan Province, China

Feng Qi

College of Mathematics, Inner Mongolia University for Nationalities, Tongliao City, Inner Mongolia Autonomous Region, China
Department of Mathematics, College of Science, Tianjin Polytechnic University, Tianjin City, China;Institute of Mathematics, Henan Polytechnic University, Jiaozuo City, Henan Province, China