1. State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun 130022, P. R. China
2. School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei 230026, P. R. China
3. Faculty of Materials Science and Chemistry, China University of Geoscience, Wuhan 430074, P. R. China
4. Zhejiang Institute, China University of Geosciences, Hangzhou 311305, P. R. China