1. College of Arts and ScienceNational University of Defense Technology Changsha 410073 P. R. China
2. Center for NanochemistryBeijing Science and Engineering Centre for NanocarbonsCollege of Chemistry and Molecular EngineeringPeking University Beijing 100871 P. R. China
3. Beijing Academy for Advanced Interdisciplinary StudiesPeking University Beijing 100871 P. R. China
4. College of Advanced Interdisciplinary StudiesNational University of Defense Technology Changsha 410073 P. R. China
5. College of Physical Science and TechnologyXiamen University Xiamen 361005 P. R. China