1. Dept. of Built Environment and Energy Application Engineering, Guilin Univ. of Aerospace Technology, Guilin, Guangxi 541004, PR China.
2. School of Environmental Science and Engineering, Shanghai Jiao Tong Univ., 800 Dongchuan Rd., Shanghai 200240, PR China.
3. Professor, School of Environmental Science and Engineering, Shanghai Jiao Tong Univ., 800 Dongchuan Rd., Shanghai 200240, PR China (corresponding author).