North China Electric Power University, North China Electric Power University, Beijing University of Technology, Tsinghua University - Tsinghua Shenzhen International Graduate School, affiliation not provided to SSRN, North China Electric Power University, North China Electric Power University, North China Electric Power University, North China Electric Power University, Tsinghua University - Shenzhen Geim Graphene Center, North China Electric Power University and Tsinghua University - Tsinghua Shenzhen International Graduate School