掌桥科研 NCBI Pubmed Central (全网免费下载) Europe PMC NCBI 查看更多 JSTOR Europe PMC (全网免费下载) adsabs.harvard.edu ResearchGate EBSCO pnas.org (全网免费下载) core.ac.uk mysciencework.com core.kmi.open.ac.uk The National Academy of Sciences of the United States of America (全网免费下载) mendeley.com pnas.org onAcademic