1. State Key Laboratory of Applied Organic Chemistry; Key laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province; Department of Chemistry; Lanzhou University, Lanzhou, Gansu; China
2. Key laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province; Zhongwei High-Tech Institute of Lanzhou University, Zhongwei, Ningxia; 755500 China