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

PM2.5测量意思是颗粒物直径小于或等于2.5。

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

油层厚度大约为10，于头发丝直径。

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

我把它从 20 降低了 到0.3 。

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

哇。- 5 ，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 或更小粒。

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

作为参考，头发直径有50，所以只于头发一小部分。

But in reality the oil was only 10 microns thick.

但事实上油层厚度只有10。

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

为什么在 2.2 到 2.0 以下会有恒定等距力？

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

天文学家说到尘埃时，他们指是直径一小颗粒。

" 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粒子。

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运动表面周围有大约两凹坑。

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

一根头发直径是100。

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

显镜将摄取图像，可以看到水里5左右物体。

This is Steve Pawlowski from micron.

这是来美光自史蒂夫·帕沃夫斯基。

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

我们正在看是一丛中国紫色素，大小约 50 。

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

如果你按10厚油层计算，那么水滴移动速度应该慢很多。

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

例如，人类头发直径大约是2.5颗粒物30倍。

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

而过去用胶囊跨度为10到15，这种跨度足以打乱覆盖层结构，因此对金属造成弊大于利。

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

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

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范围内 制造物体是非常困难，在这个中等尺度范围。