1. Institute for Advanced Study, Chengdu University, Chengdu 610106, P. R. China
2. School of Mechanical Engineering, Chengdu University, Chengdu 610106, P. R. China
3. Southwest Institute of Chemical Co., Ltd., Chengdu 610225, P. R. China
4. College of Chemistry, Sichuan University, Chengdu 610064, P. R. China