[1] Chengdu Univ Technol, Coll Geophys, Chengdu 610059, Peoples R China
[2] Chengdu Univ Technol, Engn & Tech Coll, Leshan 614000, Peoples R China
[3] Univ Adelaide, Sch Phys Chem & Earth Sci, Adelaide, SA 5000, Australia
[4] Southwest Univ, Coll Comp Informat Sci Coll Software, Chongqing 400700, Peoples R China