If the time you are interested in is not zero, you're allowed to cancel it and get the time from here.

如果你们关注的解不是零时刻,那么就可以忽略它,然后从这里解出时间

耶鲁公开课 - 基础物理课程节选

infinitesimal interval of time not yet 0.

不为零的无穷小时间间隔

耶鲁公开课 - 基础物理课程节选

We can also do a similar thing, and I'll keep my distance from the board, but we can instead be holding x constant, for example, putting x to be equal to zero, and then all we're doing is considering the electric field as a function of t.

我们也可以做类似的事情,把x固定为一个常数,例如令x等于零，然后,考虑电场作为时间的函数,这种情况下，我们划掉。

麻省理工公开课 - 化学原理课程节选

Let's create a graph here that on the x axis it's going to be time, so time zero will be when you first take in a food and then one hour later, two hours later will be shown as you go from left to right, and then we'll have blood glucose level up on the y axis.

我们在这建立一个曲线图,X轴代表的是时间,所以零时间点是你第一次进食的时间,然后一小时以后,两小时以后,是从左到右呈现在图表上的,在Y轴上是你的血糖值

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选