1. Jiangxi Province Key Laboratory of Functional Organic Polymers, East China University of Technology, Nanchang 330013, P. R. China
2. State Key Laboratory of Materials Processing and Die & Mould Technology, Huazhong University of Science and Technology, Wuhan 430000, P. R. China
3. Key Laboratory of Rare Earths, Chinese Academy of Sciences, China Rare Earth Group Research Institute, Ganzhou, Jiangxi 341000, P. R. China