1. 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, China
2. Petrochemical Research Institute, PetroChina Company Limited, Beijing 100195, P. R. China
3. West Pacific Petrochemical Company LTD, Dalian 116000, China
4. Université de Poitiers, UFR SFA, IC2MP, UMR 7285, Bât B27, 4 rue Michel Brunet, TSA 51106, 86073 Cedex 9 Poitiers, France
5. Laboratoire Catalyse et Spectrochimie, Normandie University, ENSICAEN, UNICAEN, CNRS, 6 Bd Marchal Juin, Caen 14000, France
6. SEM Application Team JEOL Ltd., 3-1-2 Musashino, Akishima, Tokyo 196-8558, Japan