1. Institute
of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, P. R. China
2. Engineering
Research Center in Biomaterials, Sichuan University, Chengdu 610065, P. R. China
3. National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada
4. School
of Chemical Engineering, Sichuan University, Chengdu 610065, P. R. China