人眼感受的光用流明时这个单位来衡量——燃烧一根蜡烛一个小时所产生的光的量就是一流明时。

The light perceived by the human eye is measured in units called lumen-hours. This is about the amount produced by burning a candle for an hour.

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为了计算出射光瞳，可将孔径(单位mm)除以目镜的放大倍数。

To calculate exit pupil, divide the aperture (in mm) by the power of the eyepiece being used.

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这些电梯由地面发射的激光束驱动，接收装置则是位于机械上的光伏单位——正如太阳能电池板中使用的一样——而这个过程被称做“能量束驱动”（power beaming）。

They are powered by laser beams on the ground firing at photovoltaic cells on the vehicles – like those used in solar panels – in a process called “power beaming”.

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