1. National Engineering Research Center in Biomaterials College of Biomedical Engineering Sichuan University Chengdu Sichuan 610065 P. R. China
2. Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 P. R. China
3. Metrology Research Centre National Research Council Canada Ontario K1A 0R6 Canada
4. School of Physical and Chemical Sciences Queen Mary University of London London E1 4NS UK
5. Analytical & Testing Center Sichuan University Chengdu Sichuan 610065 P. R. China
6. Laboratory of Ethnopharmacology West China School of Medicine West China Hospita Sichuan University Chengdu Sichuan 610065 P. R. China
7. Department of Physicals Guizhou University of Engineering Science Bijie Guizhou 551700 P. R. China