1. College of Mathematics and Information Science; North China University of Water Resources and Electric Power; Zhengzhou 450046 China
2. State Key Laboratory of Molecular Reaction Dynamics, Theoretical and Computational Chemistry, Dalian Institute of Chemical Physics; Chinese Academy of Sciences; Dalian 116023 China
3. Measurement and Testing Institute of Mongolian Autonomous County of Fuxin; Fuxin 123100 P. R. China