气体和液体中总的摩尔数之比。

The ratio of total moles in the gas to the liquid.

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当横流雷诺数与射流雷诺数之比大于0．5之后，有横流时的冲击射流冷却局部努赛尔数比无横流时有较为显著下降。

When the cross-flow to jet Reyuolds number ratios are greater than 0. 5, the jet impingement Nusselt numbers arc obviously lower than that without cross-flow.

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中国在出生率大幅度下降的情况下，每年出生人口数与人工流产数之比保持在1：0.3左右，相当于目前世界各国的中等水平。

When China's birth rate drops sharply, the annual ratio between the number of newly born babies and that of induced abortions has retained at around 1:0.3, equivalent to the medium level in the world.

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