1. Ocean College, Tangshan Normal University, Tangshan 063210, China
2. School of Metallurgy and Energy, North China University of Science and Technology, Tangshan 063210, China
3. Institute of Environmental Technology, Faculty III Process Sciences, Technische Universität Berlin, Berlin 10623, Germany
4. School of Economics and Management, Nanchang University, Nanchang 330031, P. R. China
5. The Bartlett School of Sustainable Construction, University College London, London WC1E 7HB, U.K.
6. School of Finance, Central University of Finance and Economics, Beijing 100081, China
7. College of Mechanical Engineering, North China University of Science and Technology, Tangshan 063210, China