同位素成分 meaning in English

isotope composition
isotopic composition
isotopic constituency

Determination of uranium and plutonium content and isotopic composition ; mass spectrometric method
铀.钚及同位素成分的测定.质谱测定法
Standard test method for determination of plutonium isotopic composition by gamma - ray spectrometry
用射线光谱法测定钚同位素成分的标准试验方法
Standard test method for determination of uranium content and isotopic composition by isotope dilution mass spectrometry
用同位素稀释质谱法测定铀含量和同位素成分的标准试验方法
Studies of the isotopic composition of the stardust samples , conducted by scientists from the carnegie institution in washington dc . , also point in the same direction
由华盛顿大学卡内基学会实施的对星尘样品同位素成分的研究同样指向这一方向。