So, that researching on the flow of viscoelastic fluid in annulus with the inner cylinder executing a planetary motion has great significance in academic theory in the engineering.

因此研究粘弹性流体在内管做行星运动的环空中的流动具有学术理论意义和工程实际意义。

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In the early 17th century, Johannes Kepler worked out the laws of planetary motion as a result of years of analysis of the observations made by Tycho Brahe.

ECONOMIST: Mining the digital skies