1. The Key Laboratory of Applied SuperconductivityChinese Academy of SciencesBeijing100190People's Republic of China
2. The Institute of Electrical EngineeringChinese Academy of SciencesBeijing100190People's Republic of China
3. University of Chinese Academy of SciencesBeijing100049People's Republic of China
4. College of Electric EngineeringZheng Zhou UniversityZheng Zhou450001People's Republic of China