1. College of Science, Hebei United University, Tangshan 063009, China
2. College of Mechanical Engineering, Yanshan University, Qinhuangdao 066004, China
3. School of Materials and Metallurgy, Northeast University, Shenyang 110819, China
4. Department of Mathematics and Statistics, University of Victoria, Victoria, BC, Canada V8W 3R4
5. School of Mechanical Engineering, Northwestern Polytechnical University, Xi’an, Shaanxi 710048, China
6. Department of Mathematics and Mechanics, China University of Mining and Technology, Xuzhou, Jiangsu 221008, China