Nanocrystals, also known as quantum dots, are semiconducting particles with a diameter of a few millionths of a millimeter.

纳米晶体，也被称为量子点，是一种直径只有百万分之一毫米的半导体粒子。

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Atlas, the flatter of the two, has a diameter of only 18 kilometers from pole to pole but is almost 40 kilometers across its waist.

阿特拉斯是两者中较平整的一个，极点间的直径只有18公里，但它的赤道周长却有40公里。

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The largest terrestrial planet, Earth has a diameter only one quarter as great as the diameter of the smallest Jovian planet, Neptune, and its mass is only one seventeenth as great.

最大的类地行星地球的直径仅仅是最小的类木行星海王星的四分之一，而且地球的质量仅仅是其质量的十七分之一。

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That cabin is a 14-ton spherical steel capsule only two meters in diameter, with a single,half-meter-wide circular plastic window for viewing.

VOA: standard.2010.06.21

They might be 100 nanometers or so in diameter, whereas, a cell is ten microns or so in diameter.

直径只有一百纳米左右,而一个细胞的直径是十微米左右

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And, that's a good thing to know because if you come out with an answer that's somewhere near the diameter of the universe and it's supposed to be the diameter of an atom, then you will know that you probably made a mistake.

这是我们需要知道的,因为当你做一道题得到的答案,是宇宙的直径,而正确答案是原子直径时，你能很快发现你的错误。

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These channels, which have a diameter of 50 microns (about the width of a human hair) are etched using standard silicon-fabrication methods.

ECONOMIST: Monitor

DARPA's criteria, the craft, which has a diameter of 15cm (six inches) has managed a 16-minute flight at a top speed of nearly 70kph (45mph).

ECONOMIST: A personal eye in the sky

It uses a lens with a diameter of just a few millimeters and covers a much larger field of vision than a conventional rear-view mirror.

ENGADGET: Audi R8 e-tron to feature digital AMOLED rear-view mirror