1. School of Geosciences, China University of Petroleum (East China), Qingdao, China
2. School of Geosciences and Info-Physics, Central South University, Changsha, China
3. China United Coalbed Methane Corporation Ltd., Beijing, China
4. School of Geosciences and Info-Physics and the Hunan Key Laboratory of Nonferrous Resources and Geological Hazards Exploration, Central South University, Changsha, China