In a laboratory vault outside Paris is a small cylinder of platinum-iridium alloy that serves as the standard for all mass measurements worldwide.

在巴黎郊外的一个实验室地下室中，有一个铂铱合金作的圆筒，这个圆筒就是作为世界上所有质量测量的标准。

youdao

Each is, in essence, a layer of carbon atoms that has been coated with nitrogen-containing molecules called amines and rolled into a cylinder with the amines on the outside.

实质上，每个碳纳米管都是一层碳原子，这层碳原子被涂上了一种叫做胺的含氮分子，随后，将胺涂层朝外，把碳原则层卷成圆柱形，我们就得到了所要的碳纳米管。

youdao

Found outside Baghdad, Iraq in 1936, the Baghdad Battery is a small clay jar containing an iron rod suspended in a copper cylinder which is soldered shut and sealed with asphalt.

1936年在伊拉克巴格达郊外发现的巴格达电池由一根小铁棍悬空在一个由沥青密封的铜制容器中，该容器置于一个陶土罐里。

youdao