1. Research Assistant, Sino-Canada Center of Energy and Environmental Research, Hunan Univ., Changsha 410082, China and Faculty of Engineering, Univ. of Regina, Regina SK, Canada S4S 0A2.
2. Professor, Sino-Canada Center of Energy and Environmental Research, Hunan Univ., Changsha 410082, China and Faculty of Engineering, Univ. of Regina, Regina SK, Canada S4S 0A2 (corresponding author).
3. Professor, Dept. of Chemical Engineering, Univ. of Waterloo, Waterloo ON, Canada N2L 3G1.