1. Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education, Jilin Normal UniversityChangchun 130103P.R. China
2. National Demonstration Center for Experimental Physics Education, Jilin Normal UniversitySiping 136000P.R. China
3. Key Laboratory of Preparation and Application of Environmental Friendly Materials, Jilin Normal University, Ministry of EducationChangchun 130103P.R. China