But our bodies have many chemical mechanisms in place to not only put us to sleep, but wake us up as well.

我们的身体有许多化学机制来控制睡眠，与清醒的时间。

They're corroding " not quickly, necessarily." He says the scientists need to learn " the chemical mechanisms."

它们腐蚀“不是很快， 而是必然的” 。 他说科学家们需要学习“化学机制” 。

" Chemical mechanisms, " then, are the processes that the chemicals in the daguerreotypes are going through and how they were produced to begin with.

那么，“化学机制”就是银版照片中化学物质所经历的过程， 以及它们最初是如何产生的。

Now, although the Spartinas have adapted several chemical and physical mechanisms that allow them to thrive in salt water and to feed oxygen to their roots.

现在，尽管 Spartinas 已经采用了几种化学和物理机制， 使它们能够在盐水中茁壮成长并为它们的根部提供氧气。