因此我们要用到粉末状的焦亚硫酸钠。

For that, we use powdered sodium metabisulfite.

youdao

但是边缘上的冰比较容易融化，留下粉末状的沙土。

But at the edges, where the ice has had a chance to melt, all that's left is powdery sand.

youdao

一种专门研制的复合材料，一开始是粉末状的。

It's a specially engineered composite material that starts out as powder.

youdao

And then they found that they could freeze-dry this preparation of virus, and freeze-drying to lower the temperature, freeze it, then extract out all the water, so you're left with a powder, basically a powdered form of the virus, that could be shipped all over the world, and then reconstituted by adding water to it.

研究者们发现可以冷冻干燥这些病毒制剂,冷冻干燥就是就是降低温度,冷冻病毒,然后提取出所有水份,然后就剩下一些粉末,这主要是粉末状的病毒,这样就能将它运往全世界,并可以通过加水来恢复病毒的活性

耶鲁公开课 - 生物医学工程探索课程节选