1. College of Chemistry and Chemical Engineering, Southwest Petroleum Univ., Chengdu 610500, China.
2. College of Chemistry and Chemical Engineering, Southwest Petroleum Univ., Chengdu 610500, China; State Key Laboratory Oil and Gas Reservoir Geology and Exploitation, Chengdu Univ. of Technology, Chengdu 610500, China; College of Resource and Environment Science, Chongqing Univ., Chongqing 400044, China (corresponding author).