1 CAS Key Laboratory of Standardization and Measurement for Nanotechnology, CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology Beijing 100190 P. R. China fangxc@nanoctr.cn wangch@nanoctr.cn yangyl@nanoctr.cn +86-10-82545561 +86-10-82545559.
2 University of Chinese Academy of Sciences Beijing 100049 P. R. China.
3 Academy for Advanced Interdisciplinary Studies, Peking University Beijing 100871 P. R. China.