The PM2.5 measurement means the particles are 2.5 microns or less in diameter.

PM2.5的测量的意思是颗粒物的直径小于或等于2.5微。

Their oil layer was about 10 microns, or about a hair's width thick.

油大约为10微，相当于头发丝的直径。

And I got it down from 20 microns down to 0.3 microns.

我把它从 20 微降低了 到0.3 微。

Wow. - Point five microns are stacked together very perfectly.

哇。- 5 微，非常完美地堆叠在一起。

The shorthand for that is PM2.5, which are fine particles that are 2.5 microns or smaller across.

其简称为“ PM2.5”，即直径为 2.5 微或更小的微粒。

As reference, your hair is 50 microns so this is point 3, it's a fraction of your hair.

作为参考，头发的直径有50微，所以只相当于头发的一小部分。

But in reality the oil was only 10 microns thick.

但事实上油只有10微。

Why is there a constant isometric force below 2.2 to 2.0 microns?

为什么在 2.2 到 2.0 微以下会有恒定的等距力？

When astronomers talk about dust, they mean tiny grains a micron across.

当天文家说到尘埃时，他们指的是直径一微的微小颗粒。

They noticed many of their pieces of debris sported surface pits around two microns across.

他们发现很多塑料碎片的运动表面周围有大约两微的凹坑。

And to put this into perspective: a human hair is 100 microns across.

一根头发的直径是100微。

" N95" means they block at least 95% of particles smaller than 0.3 microns across.

N95意味着它们至少能阻挡95%直径小于0.3微的粒子。

And that microscope will take images of what's in the water down to about five microns.

显微镜将摄取图像，可以看到水里5微左右的物体。

This is Steve Pawlowski from micron.

这是来美光的自史蒂夫·帕沃夫斯基。

We're looking at one clump of the Chinese purple pigment and the size is around 50 micron.

我们正在看的是一丛中国紫色素，大小约 50 微。

If you do the calculation for oil 10 microns thick the drop should move way slower.

如果你按10微油计算，那么水滴移动速应该慢很多。

The diameter of human hair, for example, is about 30 times larger than a particle of 2.5 microns.

例如，人类头发的直径大约是2.5微颗粒物的30倍。

The capsules were 10-15 microns across-large enough to disrupt the coatings, and thus do more harm than good.

而过去用的胶囊跨为10到15微，这种跨足以打乱覆盖的结构，因此对金属造成的弊大于利。

We're really good at that, but it's actually very hard to make things from 10 microns to 1,000 microns, the mesoscale.

我们这方面做得很好，但在10到1000微的范围内 制造物体是非常困难的，在这个中等尺范围。

(ie, smaller than five microns) that may carry viruses much farther through the air than droplets can manage.

（如小于5微），这些颗粒携带病毒在空气中传播的距离可能远远超过飞沫所能达到的距离。