1. State Key Laboratory of Supramolecular Structure and Materials College of Chemistry Jilin University Changchun 130012 P. R. China
2. State Key Laboratory of Superhard Materials College of Physics Jilin University Changchun 130012 P. R. China
3. College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University Chengdu 610065 P. R. China