1. College of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou 730050, China
2. Key Lab of Complementary Energy System of Biomass and Solar Energy Gansu Province, Lanzhou 730050, China
3. Western China Energy & Environment Research Center, Lanzhou University of Technology, Lanzhou 730000, China
4. State Key Laboratory of Permafrost Engineering, Northwest Institute of Ecological and Environmental Resources, Chinese Academy of Sciences, Lanzhou 730000, China