Southwestern Institute of Physics;
Chengdu 610041;
People's Republic of China;
Laboratory for SpaceEnvironment and PhysicalSciences;
Harbin Institute ofTechnology;
Harbin 150001;
People's Republic of China;
Institute for Fusion Theory andSimulation and Department ofPhysics;
Zhejiang University;
Hangzhou 310027;
People'sRepublic of China;
Department of Physics andAstronomy;
University of California;
Irvine;
CA 92697-4575;
United States of America;