1. State Key Laboratory of Heavy Oil Processing College of Chemical Engineering China University of Petroleum East China–Qingdao Campus No. 66, West Changjiang Road Huangdao District P. R. China
2. Central Facility for Advanced Microscopy and Microanalysis University of California Riverside 900 University Avenue Riverside CA 92521 USA
3. “E. Djakov“Institute of Electronics Bulgarian Academy of Sciences 72 Tzarigradsko Chausee Blvd. 1784 Sofia Bulgaria
4. Laboratoire Catalyse et Spectrochimie Normandie Univ ENSICAEN UNICAEN CNRS 6 Bd Maréchal Juin 14000 Caen France
5. Faculty of Chemistry and Pharmacy University of Sofia 1126 Sofia Bulgaria
6. Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101 P. R. China