1. School of Mathematical Sciences, Dalian University of Technology, Dalian 116024, Liaoning, P. R. China
2. School of Energy and Power Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P. R. China
3. Economics and Technology Research Institute, China National Petroleum Corporation, Beijing 100724, P. R. China
4. State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, Liaoning, P. R. China
5. School of Mathematics and Statistics, Nanyang Normal University, Nanyang 473061, Henan, P. R. China
6. College of Science, Dalian Minzu University, Dalian 116600, Liaoning, P. R. China
7. Department of Mathematics, School of Science, Dalian Maritime University, Dalian 116026, Liaoning, P. R. China
8. School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, Liaoning, P. R. China