1. School of Materials Science and Engineering Qilu University of Technology (Shandong Academy of Sciences) No. 3501, Daxue Road, Changqing District Jinan 250353 P. R. China
2. School of Chemistry and Chemical Engineering and Environmental Engineering Weifang University Weifang 261061 P. R. China
3. State Key Laboratory of Heavy Oil Processing College of Chemical Engineering China University of Petroleum (East China) No. 66, West Changjiang Road, Huangdao District Qingdao 266580 P. R. China