1. Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education, Key Laboratory of Eco-environmental Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
2. Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou 730000, China
3. Key Laboratory of Evidence Science Research and Application of Gansu Province, Gansu University of Political Science and Law, Lanzhou 730070, China