1. State Key Laboratory of Chemical Resource Engineering; Key Laboratory of Carbon Fiber and Functional Polymers of Ministry of Education; Beijing Laboratory of Biomedical Materials; Beijing University of Chemical Technology; Beijing 100029 P. R. China
2. College of Chemistry and Molecular Engineering; Peking University; Beijing 100871 P. R. China
3. State Key Laboratory of Superhard Materials; Jilin University; Jilin 130012 P. R. China