1. State Key Laboratory of Heavy Oil ProcessingCollege of Chemical EngineeringChina University of Petroleum (Huadong) Qingdao 266580 P. R. China
2. Key Lab of Organic Optoelectronics andMolecular Engineering of the Ministry of EducationDepartment of ChemistryTsinghua University Beijing 100084 P. R. China
3. CAS Key Laboratory of ColloidInterface and Chemical ThermodynamicsInstitute of ChemistryChinese Academy of Science Beijing 100084 P. R. China
4. Department of ChemistryRenmin University Beijing 100084 P. R. China