1. Department
of Theoretical Chemistry and Biology, School of Biotechnology, Royal Institute of Technology, S-106 91 Stockholm, Sweden
2. Research
Center for Engineering Ecology and Nonlinear Science, North China Electric Power University, Beijing 102206, P. R. China
3. Heifei
National Laboratory for Physical Science at the Microscale, Department
of Chemical Physics, University of Science and Technology of China, Hefei, 230026 Anhui, P. R. China