1. Assistant Professor, Institute of Thermal Science and Technology, Shandong Univ., Jinan, Shandong Province 250061, China.
2. Ph.D. Candidate, Dept. of Mechanical and Industrial Engineering, Northeastern Univ., Boston, MA 02115.
3. Professor, Dept. of Mechanical and Industrial Engineering, Northeastern Univ., Boston, MA 02115 (corresponding author).