1. State Key Laboratory of Advanced Power Transmission Technology Global Energy Interconnection Research Institute No.18 Binhe Avenue Changping District Beijing 102209 P. R. China
2. Key Laboratory of Polymer Ecomaterials Changchun Institute of Applied Chemistry (CIAC) Chinese Academy of Sciences (CAS) No. 5625 Renmin Rd. Changchun Jilin 130022 P. R. China