ZHANG Hong-Li1,2, SHI Bing1,3, ZHANG Ming-Jing4, ZHANG Ai-Ping4, WEI Rui1
1. College of Chemistry, Beijing Normal University, Beijing 100875, China;
2. Taiyuan Normal University, Jinzhong 030619, China;
3. Beijing Changping District Teachers Training School, Beijing 102208, China;
4. Yanhua Middle School Affiliated to Beijing Normal University, Beijing 102500, China