还有环境方面的好处：在需要的时候租一辆车，而不是购买一辆，意味着汽车的需求量更少，用于制造汽车的资源也更少。

And there are environmental benefits, too: renting a car when you need it, rather than owning one, means fewer cars are required and fewer resources must be devoted to making them.

youdao

还有环境方面的好处：在需要的时候租一辆车，而不是购买一辆，意味着汽车的需求量更少，用于制造汽车的资源也更少。

There are environmental benefits, too: renting a car when you need it, rather than owning one, means fewer cars are required and fewer resources must be devoted to making them.

youdao

我们选择第一个方法，主要是因为该方法需要的时间和工作量更少。

We chose the first option, primarily because it required less time and effort.

youdao

The z effective is lower, so we have to put less energy in to get an ion out.

它的有效核电量更低，所以我们只需要更少的能量就能打出一个离子。

麻省理工公开课 - 化学原理课程节选

The reason it's aluminum is because aluminum has a lower z effective, so it's not being pulled in as tightly by the nucleus, and if it's not being pulled in as tightly, you're going to have to put in less energy in order to ionize it, so that's why it's actually going to have the smaller ionization energy.

原因是,铝的有效核电量更少，所以没有被原子核束缚得更紧，而如果没有被束缚得更紧，你为了电离它所需要注入的能量也就更少，这就是,它的电离能会更低的原因。

麻省理工公开课 - 化学原理课程节选