1. CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, National Center for Nanoscience and Technology, Beijing 100190, China
2. CAS Key Laboratory for Nuclear Analytical Techniques, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, China
3. Laboratory for Nanomaterials, National Center for Nanoscience and Technology, Beijing 100190, China
4. Photon Factory, High Energy Accelerator Research Organization, Oho 1-1, Tsukuba, Ibaraki, 305-0801, Japan