Circadian rhythms show persistent, stable periodicities of about 24 hours . 昼夜节律表现出大约24小时的连续而稳定的周期性。
The state of knowledge in this field has been surveyed periodically in review papers . 在一些评论文中对这一领域的动态周期性地进行了评述。
Apparently as λ approaches infinity the resulting function will no longer appear periodic . 显然当趋于无穷大时所得到的函数将不再是周期性的。
A canister purge valve is opened periodically to vent the vapor back into induction system . 收集器的清除阀周期性地开启，泄放蒸气使之返回进气系统。
Among the first things a watcher of the sky becomes aware of is the cyclic nature of what is seen . 天空的观察者首先意识到的是所见现象的周期性特征。
Periodic crises wrack the capitalist system, and they grow in size and duration . 周期性的危机破坏着资本主义制度，这种危机的规模在扩大，时间在延长。
Economic dislocations such as "the panic of 1837" occurred periodically during the 19th century . 十九世纪曾周期性地发生象“一八三七年恐慌”那样的经济失调现象。
Periodically, the lamellae become enlarged, forming flattened, membrane-enclosed vesicles called thylakoids . 片层周期性地扩展，形成扁平的有膜为界的囊，称为类囊体。
The displacement at any point on the structure will vary periodically between specific limits in either direction . 结构上任何一点处的位移沿两个方向在一定界限内作周期性改变。
That there is a relationship of some kind between the moon and the rhythm of the tides was known even in ancient times . 甚至在古代，人们就知道在月球和潮汐的周期性变化之间，存在一定关系。
