1. Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province and State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, PR China
2. School of Dentistry, Lanzhou University, Lanzhou 730000, PR China
3. School of Basic Medical Sciences, Lanzhou University, Lanzhou 730000, PR China
4. State Key Laboratory of Advanced Ceramic Fibers & Composites, College of Aerospace and Materials Engineering, National University of Defense Technology, Changsha 410073, PR China