1. College of Electrical Engineering, Xinjiang University, Urumqi, Xinjiang 830046, China
2. Department of Mathematics and Statistics, University of Victoria, Victoria, BC, Canada V8W 3R4
3. Department of Mathematics and Computer Sciences, Faculty of Arts and Sciences, Cankaya University, 06530 Ankara, Turkey
4. Department of Chemical and Materials Engineering, Faculty of Engineering, King Abdulaziz University, P.O. Box 80204, Jeddah 21589, Saudi Arabia
5. Institute of Space Sciences, Magurele, 077125 Bucharest, Romania
6. Department of Mathematics and Mechanics, China University of Mining and Technology, Xuzhou Campus, Xuzhou, Jiangsu 221008, China