[1] Shaanxi Univ Sci & Technol, Sch Environm Sci & Engn, Xian 710021, Peoples R China
[2] Xi An Jiao Tong Univ, State Key Lab Elect Insulat & Power Equipment, Xian 710049, Peoples R China
[3] Chinese Acad Sci, Inst Earth Environm, State Key Lab Loess & Quaternary Geol, Xian 710061, Peoples R China
[4] Univ Ghent, Fac Engn & Architecture, Dept Appl Phys, Res Unit Plasma Technol RUPT, Sint Pietersnieuwst 41-B4, B-9000 Ghent, Belgium