Improvement the Preparation of C4 Oolefin Through Ethanol Coupling and Optimization the Gray Correlation Degree Algorithm Journal title: Journal of Sustainability for Energy Authors: Pengyuan Li, Qingquan Xu, Cheng Huang, Haoqing Wang, Yisen Wang, Zibo Wang, Yibo Zhang, Ao Wang, Tia... Subject(s): Energy, Green & Sustainable Science & Technology