1. State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
2. School of Energy Resources, China University of Geosciences, Beijing 100083, China
3. Coal Reservoir Laboratory of National Engineering Research Center of CBM Development & Utilization, China University of Geosciences, Beijing 100083, China
4. School of Minerals and Energy Resources Engineering, University of New South Wales, Sydney, New South Wales 2052, Australia