Affiliation: | 1. Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024, China;Departments of Physics and Electrical Engineering, Weinan Normal University,Weinan 714000, China 2. Institute of Electrostatics and Special Power, Dalian University of Technology, Dalian 116024, China 3. Departments of Physics and Electrical Engineering, Weinan Normal University,Weinan 714000, China |