1. School of Physical Science and Technology, Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China
2. Department of Chemistry, Jilin University, Changchun 130012, P. R. China
3. Department of Bioengineering, Zunyi Medical University, Zhuhai 519000, China
4. Department of Applied Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka, Shinjuku-ku, Tokyo 162-8601, Japan