Both of the observed radial velocity and separation being projective values, in order to determine the mass of binary galaxies the average projection factor may be derived by a statistical method.

双重星系或天体系统，用动力学方法测定其质量时，观测到的视向速度和距离间距，都是各自值的投影值，可用统计方法，求出一个关于它们的平均投影因子。

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Clear projection velocity and flight trajectory of explosion fragments in chemical industry parks help to reveal the Domino effect caused by the fragments.

明确爆炸碎片的抛射速度及飞行轨迹是分析化工园区中爆炸碎片导致的多米诺效应的前提和基础。

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According to the mapping relation of input and output of the parallel robot, Jacobian matrix of this robot was obtained on the basis of velocity projection method.

根据该并联机构的输入输出映射关系，推导出一种基于速度投影的雅可比矩阵求解方法。

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