Uranus is circled by a blue ring - a colour that makes it almost unique among planetary rings, which are usually red.

行星光环通常为红色，这使得天王星的蓝色光环显得独树一帜。

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Work on Uranian rings and some general problems of the planetary rings including the collision process in the rings, the photometric theory and their origin are also elucidated.

F环。还评述了天王星环以及行星环中的碰撞、光度理论和起源等问题的研究。

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Secondly, the forces of inner cam rings, planetary bearings, counter weights and input shaft are solved after the acting force between the cam and the rollers has been calculated.

其次，本文在确定了凸轮-针轮副的啮合力的基础上，对整个机构的内齿板、行星轴承、配重及其输入轴进行了受力分析。

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