ZHANG Qing1, YANG Xue-Ying2, BAI Yun-Shan2, WEI Yan-Lin3, LIU Huan-Huan3*
1. Xi'an Huashan Middle School, Xi'an 710043, China;
2. School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an 710062, China;
3. Basic Experimental Teaching Center, Shaanxi Normal University, Xi'an 710062, China