Affiliation: | 1. School of Resources and Environmental Science, Chongqing University, Chongqing 400044, P. R. China;2. State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, P. R. China;3. Faculty of Mechanical and Electrical Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, P. R. China |