1. College
of Resource and Safety Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Beijing 100083, P.R. China
2. College
of Geoscience and Surveying Engineering, China University of Mining and Technology (Beijing), D11, Xueyuan Road, Beijing 100083, P. R. China
3. No.
2 Coal Mine of Zhaogu, Jiaozuo Coal Industry Co., Ltd., Henan Energy and Chemical Industry Group Co., Ltd., Huixian 453633, China