The lower one captures longer wavelengths that have passed unperturbed through the upper, and also any lower-energy light that has been re-emitted within the top layer and somehow escaped.
较低的一层俘获通过上层的未经干扰的波长较长的光线，也能吸收顶层重新放射和侥幸逃脱的低能量的光。
2
When it relaxes, the energy it has absorbed is re-emitted as yellowish light.
放松之后，它所吸收的能量就以稍黄颜色的光重新释放出来。
3
The nanoprobe excites the sample with a strongly focused X-ray beam and collects the characteristic fluorescence signal that is re-emitted.