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。
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。
Invading woody vegetation, especially of the same species, should be controlled periodically to prevent confusion . 入侵的木本植物，特别是同一种类的，应当定期地除去，以防止混杂。
If we discipline ourselves to adopt periodically a "nonego" state, we can perceptively drink in the full meaning of a situation without imposing ourselves upon it . 如果我们训练自己定期地置身于“无我”状态，我们就能敏锐地领会形势的全部含义，而不会受骗上当。
Database maintenance should be performed periodically 数据库的维护应定期进行。
Dynamic ram ' s need to be refreshed periodically 动态ram则需要周期性地刷新数据。
These are data packets that are polled periodically 这些是定期轮询的数据包。
