1. Department of Power Engineering School of Energy Power and Mechanical Engineering North China Electric Power University Baoding 071003 China
2. Department of Chemical and Petroleum Engineering University of Calgary T2N 1N4 Calgary Alberta Canada
3. School of Mathematics and Physics North China Electric Power University Beijing 102206 China
4. Institute of Clusters and Low Dimensional Nanomaterials School of Mathematics and Physics North China Electric Power University Beijing 102206 China
5. State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources North China Electric Power University Beijing 102206 China
6. Beijing Key Laboratory of Energy Safety and Clean Utilization North China Electric Power University Beijing 102206 China
7. Advanced Institute for Materials Research (WPI-AIMR) Tohoku University Sendai 980-8577 Japan