Affiliation: | 1. Wuhan Center for Magnetic Resonance, State Key Laboratory, Magnetic Resonance and Atomic Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071 (P.R. China), Fax: (+86)?27‐87199291;2. State Key Laboratory of Heavy Oil Processing, CNPC Key Laboratory of Catalysis, China University of Petroleum‐Beijing, Beijing 102249 (P.R. China) |