1. Department of Mathematics and Physics, Chongqing University of Posts and Telecommunications, 2 Chongwen Road, Chongqing 400065, China
2. School of Material Science and Engineering, Chongqing University of Arts and Sciences, Chongqing 402160, China
3. The Institute of Chemical and Gas and Oil Technologies, T.F. Gorbachev Kuzbass State Technical University, 28, Vesennyaya Street, Kemerovo 650000, Russia