1. School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, P. R. China
2. Shanghai Key Laboratory of Advanced Polymeric Materials, East China University of Science and Technology, Shanghai 200237, P. R. China
3. Shanghai Engineering Research Center of Cards & Identification Documents, Shanghai 200063, P. R. China
4. College of Humanities and Basic Education, Xinjiang Vocational & Technical College of Communications, Urumqi 831400, P. R. China