1. Department of Chemistry, University of Shanghai for Science and Technology, Shanghai 200093, P. R. China
2. Department of Physics, University of Shanghai for Science and Technology, Shanghai 200093, P. R. China
3. Eye & ENT Hospital of Fudan University, Fudan University, Shanghai 200031, P. R. China
4. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, P. R. China