1. Key Laboratory of Eco-Environment-Related Polymer Materials of Ministry of Education, Key Laboratory of Polymer Materials of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou 730070, China
2. College of Chemistry and Chemical Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
3. School of Electronic and Information Engineering, Lanzhou City University, Lanzhou, 730070, China