We can then look at uranium 238 which has a relatively low absorption thermal energy range and essentially has no fission cross section which is why we call uranium 238 a fertile atom.
我们能看看铀238，它有一个，相对低的吸收热能范围，基本上没有裂变横截面，那就是为什么我们称铀238为可转换核素。
The big cross section of low speed shearing, should satisfy to request system flywheel energy enough, that is to optimize the flywheel structural parameter, and guarantee its step response.
低速大断面剪切时，应满足对系统飞轮能量足够大的要求，即通过优化驱动系统的飞轮结构参数，保证其阶跃激励特性。
The obtained integral cross section decreased quickly at low collision energy and then became flat, which reflected the general feature of such exothermic reactions.
计算得到的反应截面在碰撞能量很低时下降很快，然后变得比较平坦，其变化趋势与实验测量的结果相吻合，呈现出强放热反应的基本特征。
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