接触阻力很难测量。

The contact resistance is difficult to measure.

youdao

在基于专家经验的方法中，精度来源于评估人员的知识和经验，很难测量和验证。

In expertise-based methods accuracy is a product of the estimator's expertise and experience, which cannot be easily measured and validated.

youdao

这对于那些依赖于流量读数的控制尤其是如此，这些流量读数在低流量速率下是很难测量的。

This is particularly true of controls relying on flow readings that are difficult to measure at low flow rates4.

youdao

This is real, unlike the Joule coefficient which is very small so that most gases have tiny Joule coefficients. So if you do a Joule experiment, you hardly measure a temperature change. With real gases, here you do actually measure it. You can feel it with your finger on your bicycle tire.

系数那样小以至于,大多数气体的焦耳系数,都很小，所以如果你做焦耳实验,很难测量出温度的变化,对于真实气体，你可以测量它，你能通过手指按在,自行车轮胎上来感觉到它。

麻省理工公开课 - 热力学与动力学课程节选