By 1852-53,Boston and New York think about this--Boston-- although we're getting close to that again Boston and New York had 50% foreign-born populations.

在1852年到1853年间,波士顿和纽约,你们听听这个数据,虽然我们现在又快接近这个比例了,那时移民占据波士顿和纽约人口的50%

耶鲁公开课 - 美国内战与重建课程节选

So you need first to take the liquid helium and cool it below 53 degrees Kelvin before you can do the Joule-Thomson to cool it even further to make liquid helium.

我们首先需要,把温度江都53k一下,然后利用焦耳-汤姆孙实验,来继续冷却它。

麻省理工公开课 - 热力学与动力学课程节选