1. Key Laboratory of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education, National Demonstration Center for Experimental Chemistry Education, College of Chemistry & Materials Science, Northwest University, 1 Xuefu Road, Xi’an, Shaanxi 710127, P. R. China
2. Shaanxi Key Laboratory of Low Rank Coal Pyrolysis, Shaanxi Coal and Chemical Technology Institute Co., Ltd., State Energy Key Lab of Clean Coal Grading Conversion Modern Chemical Technology Department, 2 Jinye Road, Xi’an, Shaanxi 710065, P. R. China