thousandth

A micrometer is one thousandth of one millimeter.

一微米是一毫米的千分之一。

These high-energy gamma rays, detected by Fermi’s Large Area Telescope (LAT), have wavelengths one-thousandth the size of an atomic nucleus.

这些“费米大天区望远镜（LAT）”所侦测到的高能伽马射线的波长仅相当于原子核大小的千分之一。

As if that were not enough of an impact, sunscreens increasingly contain nanoparticles, smaller than one one-thousandth the diameter of a human hair.

就像是怕以前作用还不够似的，现在防晒霜遮阳剂包含的纳米粒子越来越多，比人类头发直径的千分之一还小。