1. School of Management and Economics, Beijing Institute of Technology, Beijing 100081, China
2. Center for Energy & Environmental Policy Research, Beijing Institute of Technology, Beijing 100081, China
3. Institute for Interdisciplinary Information Sciences, Tsinghua University, Beijing 100084, China
4. State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China