1. Key Laboratory of Coal Science and TechnologyMinistry of Education and Shanxi ProvinceTaiyuan University of Technology Taiyuan 030024 China
2. State Key Laboratory of Molecular Engineering of PolymersDepartment of Macromolecular ScienceFudan University Shanghai 200438 China
3. Division of Theoretical Chemistry and Biology, School of BiotechnologyKTH Royal Institute of Technology 10691 Stockholm Sweden
4. Department of ChemistryFudan University Shanghai 200438 China
5. College of Chemistry and Chemical EngineeringDepartment of ChemistryHenan University Kaifeng Henan 475004 P. R. China