1. State
Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences, P.O. Box 165, Taiyuan, Shanxi 030001, P. R. China
2. Synfuels China, Beijing, 100195 P. R. China
3. Materials
Research and Technology Institute, UT-El Paso, El Paso, Texas 79902, United States
4. HiPSEC & Department of Physics, University of Nevada Las Vegas, Las Vegas, Nevada 89154, United States