氡的同位素 meaning in English

emanation

Any of several radioactive gases that are isotopes of radon and are products of radioactive decay
射气几种氡的同位素的放射性气体，是放射性物质衰变的产物
Although thoron is one of isotopes of radon , and the characteristics of thoron and thoron progenies are similar to those of radon and radon progenies , because the half life of thoron is shorter ( 55 . 6s ) , the concentrations of thoron and thoron daughters in environment are lower , people usually think that the effective dose from thoron and its progenies can be eliminated , and the measurements of thoron progenies concentrations are difficulty , a little research work on the dose evaluation of thoron and thoron progenies in environment has been done
虽然(气土)是氡的同位素，它及其子体的特性也与氡及其子体的相似，但由于(气土)的半衰期短( 55 6s ) ，环境中(气土)浓度较低， (气土)及其子体浓度的测量较难，人们一般认为(气土)及其子体所致剂量可以忽略，所以对环境中(气土)及其子体剂量评价研究很少。