Lead isotope ratio的用法和樣例：
例句
- An obvious restraint in the use of isotope ratios results from the need to employ mass spectrometers.
使用同位素比值法有著(zhù)一個(gè)明顯的局限因素，就是要用質(zhì)譜儀進(jìn)行分析。 - Precise determination of the platinum-group elements and Os isotopic ratios in low-level rock samples.
巖石樣品中低含量鉑族元素和鋨同位素比值的高精度測量方法。
