[1] Jiangxi Univ Sci & Technol, Sch Sci, Ganzhou 341000, Peoples R China
[2] Univ Elect Sci & Technol China, Sch Elect Sci & Engn, Natl Key Labo High Power Vacuum Elect, Chengdu 610054, Peoples R China
[3] Hunan Univ Arts & Sci, Sch Comp & Elect Engn, Changde 415000, Peoples R China