1. School of Mathematics and Physics, Anhui Jianzhu University, Hefei 230601, P. R. China
2. School of Engineering Science, University of Science and Technology of China, Hefei 230026, P. R. China
3. School of Transportation Engineering, Hefei University of Technology, Hefei 230009, P. R. China
4. Department of Modern Physics, University of Science and Technology of China, Hefei 230026, P. R. China
5. Complex System Research Center, University of Shanghai for Science and Technology and Shanghai Academy of System Science, Shanghai 200093, P. R. China