1. School of Chemistry
and Materials Science, Heilongjiang University, Harbin, Heilongjiang 150080, P. R. China.
2. Engineering Laboratory of Specialty Fibers and Nuclear Energy Materials, Ningbo Institute of Industrial Technology, Chinese Academy of Sciences, Ningbo, Zhejiang 315201, P. R. China
3. National Laboratory for Condensed Matter
Physics, Institute of Physics, Chinese Academy of Science, Beijing 100190, P. R. China
4. College of Power and Energy Engineering, Harbin Engineering University, Harbin, Heilongjiang 150001, P. R. China