  How does the published scientific literature used by scientific community?
Many previous studies make analysis on the static usage data. In this research,
we propose the concept of dynamic usage data. Based on the platform of
realtime.springer.com, we have been monitoring and recording the dynamic usage
data of Scientometrics articles round the clock. Our analysis find that papers
published in recent four years have many more downloads than papers published
four years ago. According to our quantitative calculation, papers down-loaded
on one day have an average lifetime of 4.1 years approximately. Classic papers
are still being downloaded frequently even long after their publication.
Additionally, we find that social media may reboot the attention of old
scientific literature in a short time.
