1. State Key Laboratory of Heavy Oil Processing, College of Chemical Engineering, China University of Petroleum (East China), Qingdao 266555, PR China; Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea e-mail:
2. School of Mechanical and Power Engineering, Nanjing University of Technology Nanjing, 210009, PR China
3. Neutron Science Division, Korea Atomic Energy Research Institute, Daejeon 305-353, South Korea
4. School of Mechanical and Power Engineering, Nanjing University of Technology, Nanjing, 210009, PR China
5. Key Laboratory of Pressure System and Safety (MOE), School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai 200237, PR China