1. Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province, China West Normal University, Nanchong, Sichuan 637009, P. R. China
2. China Petroleum Engineering Company, Limited Southwest Company, Chengdu, Sichuan 610213, P. R. China
3. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, P. R. China