1. Key Laboratory of Functional Materials Physics and Chemistry of the Ministry of Education Jilin Normal University Changchun 130103 P. R. China
2. National Demonstration Centre for Experimental Physics Education Jilin Normal University Siping 136000 P. R. China
3. Key Laboratory of Preparation and Application of Environmental Friendly Materials Jilin Normal University, Ministry of Education Changchun 130103 P. R. China
4. School of pharmaceutical sciences Jilin University Changchun 130012 P. R. China