You could run the reaction, take solid iron gaseous oxygen, form iron oxide, measure the heat of formation of it, tabulate it.

你可以进行一个反应,用固态铁和氧气生成氧化铁，测量它的生成热，列成表格。

麻省理工公开课 - 热力学与动力学课程节选

And to measure the intensity of unequal sharing, we take the difference in electronegativity, which I am going to use the Greek symbol chi for.

要度量非平均的程度，我们考虑电负性的差异，我要用希腊语第22个字母chi来表示电负性。

麻省理工公开课 - 固态化学导论课程节选

Well, a cross-sectional study would mean that you'd get a random group of the population and measure them in 1970 and then take another random group five years later and measure them, but it wouldn't be the same people necessarily, it would be different groups of people.

那么,横断面研究就是,1970年你在人群中随意选择一组人,并记录下相关数据,然后,五年后再随意选择一组人记录数据,但这不需要是同一组人,通常是不同的人

耶鲁公开课 - 关于食物的心理学、生物学和政治学课程节选