1. National Key Laboratory of Science and Technology on Advanced Composites in Special Environments, Harbin Institute of Technology, Harbin 150080, P. R. China
2. Zhengzhou Research Institute, Harbin Institute of Technology, Zhengzhou 450000, P. R. China
3. School of Stomatology, Harbin Medical University, Harbin 150001, P. R. China
4. Beijing No. 80 High School, Beijing 100000, P. R. China