1. MIIT Key Laboratory of Thermal Control of Electronic Equipment School of Energy and Power Engineering Nanjing University of Science & Technology Nanjing 210094 P. R. China
2. Department of Mechanical Engineering The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong SAR P. R. China
3. Institute of Engineering Thermophysics School of Energy and Power Engineering Chongqing University Chongqing 400030 P. R. China