1. Electric Power Research Institute of Guizhou Power Grid Co, Guiyang, China
2. Liupanshui Power Supply Bureau, Guizhou Power Grid Co., Ltd, Liupanshui, China
3. Kaili Power Supply Bureau, Guizhou Power Grid Co., Ltd, Kaili, China
4. School of Chemistry and Chemical Engineering, Guizhou University, Guiyang, Guizhou, China