1. State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200438, China
2. Division of Theoretical Chemistry and Biology School of Biotechnology, KTH Royal Institute of Technology, SE-10691 Stockholm, Sweden
3. College of Science, University of Shanghai for Science and Technology, Shanghai 200093, China
4. Key Laboratory of Coal Science and Technology, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024, China
5. Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
6. Tomsk State University, 36 Lenin Avenue, Tomsk, Russia