1. Key Laboratory of Green Chemistry & Technology Ministry of Education College of Chemistry, Sichuan University Chengdu 610064 P. R. China
2. Key Laboratory of Radiation Physics and Technology, Ministry of Education, Institute of Nuclear Science and Technology Sichuan University Chengdu 610064 P. R. China
3. Petrochemical research institute QaQing petrochemical research center Daqing 163000 P. R. China