Science Bulletin (Sci. Bull.) is a multidisciplinary academic journal supervised by the Chinese Academy of Sciences (CAS) and co-sponsored by the CAS and the National Natural Science Foundation of China (NSFC). Sci. Bull. is a semi-monthly international journal publishing high-caliber peer-reviewed research in a broad range of natural sciences and high-tech fields on the basis of its originality, scientific significance and whether it is of general interest. In addition, we are committed to serving the scientific community with immediate, authoritative news and valuable insights into upcoming trends around the globe. Sci. Bull. is indexed by Science Citation Index, Chemical Abstracts, Ei Compendex, Medline, Scopus, Google Scholar, Inspec, Academic Search Alumni Edition, Academic Search Complete, Academic Search Elite, Academic Search Premier, ASFA 1: Biological Sciences and Living Resources, ASFA 2: Ocean Technology, Policy and Non-Living Resources, Biological Sciences, Biological Abstracts, BIOSIS Previews, CAB Abstracts, Current Contents/Physical, Chemical and Earth Sciences, Current Mathematical Publications, Digital Mathematics Registry, EMBio, Environmental Engineering Abstracts, Environmental Sciences and Pollution Management, Mathematical Reviews, MathSciNet, Meteorological and Geoastrophysical Abstracts, Pollution Abstracts, Water Resources Abstracts, Zentralblatt MATH, and Zoological Record.