1. State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, Chengdu University of Technology, Chengdu, P.R. China
2. College of Nuclear Technology and Automation Engineering, Chengdu University of Technology, Chengdu, P.R. China
3. Key Laboratory of Earth Exploration and Information Technology of Ministry of Education, Chengdu University of Technology, Chengdu, P.R. China