1. Institutes of Physical Science and Information Technology, Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of Education, Anhui University, Hefei 230601, P.R. China
2. Department of Physics, School of Physical Science and Technology, Ningbo University, Ningbo 315211, P.R. China
3. College of Materials and Chemical Engineering, West Anhui University, Lu’an, Anhui 237015, P.R. China