1. State Key Laboratory of Applied Organic Chemistry, Institute of Biochemical Engineering & Environmental Technology, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Road, Lanzhou 730000, P. R. China
2. State Key Laboratory for Marine Corrosion and Protection, Luoyang Ship Material Research Institute (LSMRI), Xiamen 361101, P. R. China
3. The Second Clinical Medical College, Lanzhou University, Lanzhou 730030, P. R. China
4. Department of Chemistry, Minorities Teachers College, Qinghai Normal University, Xining 810008, P. R. China