1. School of Mathematics and Physics, North China Electric Power University, Beinong Road 2, Changping, Beijing, 102206, P. R. China
2. Institute of Clusters and Low Dimensional Nanomaterials, North China Electric Power University, Beinong Road 2, Changping, Beijing, 102206, P. R. China
3. School of New Energy, North China Electric Power University, Beinong Road 2, Changping, Beijing, 102206, P. R. China
4. Hebei Key Laboratory of Physics and Energy Technology, North China Electric Power University, Baoding, 071000, China