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- The isotope ratio is directly used for comparing oils or gases. 同位素比率直接用于比较各种石油或天然气。
- The atmospheric helium isotope ratio: Is it changing? 大气氦同位素比率在变化吗?
- Stable isotope ratio analysis is an effective method for the identification of fruit juice adulteration. 稳定同位素分析法就是根据这种差异对掺假果汁进行准确鉴别的有效方法。
- There are differences between natural and adulterated juices in stable isotope ratio. 天然果汁与掺假果汁之间在稳定同位素比率方面存在着差异。
- To be sure, some scientists suggest that life could have evolved differently on Titan than on Earth or that the inorganic isotope ratio may be different there. 不过，还是有些科学家指出，可能是泰坦和地球上的生命演化过程不同，或是无机同位素比率不一样。
- Analytical services include potassium-argon age determinations, stable isotope ratio analyses, radiocarbon age determinations as well as other radiometric analyses. 分析包括钾-氩测年，稳定同位素丰度分析，放射性碳测年，以及其他放射性分析。
- 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着一个明显的局限因素，就是要用质谱仪进行分析。
- CAN STABLE ISOTOPE RATIOS PROVIDE FOR COMMUNITY-WIDE MEASURES OF TROPHIC STRUCTURE? 稳定性同位素与群落营养结构?
- Isotope ratios of Pb contained in wares were measured using Time-Of-Flight Secondary Ion Mass Spectrometry(TOF-SIMS)without any references. 介绍了用飞行时间二次离子质谱法对器物中的铅同位素比值的测量。
- gas isotope ratio mass spectrometer 气体同位素比质谱计
- First, it is a global record: there is remarkably little variation in isotope ratios in sedimentary specimens taken from different continental locations. 第一，它是全球性的记录：来自不同大陆位置的沉积物样品其同位素比例变化非常之小。
- high precision isotope ratio mass spectrometer [化] 高精度同位素比质谱计
- A method by cumulative intensity of ion current to analyse isotopic ratio is proposed in present paper. 本文介绍了离子流强度累计测定同位素比的方法。
- The isotopic ratio of lithium was determined by cumulating intensity of ion current during evaporation of all samples on evaporation filament. 用热表面离子源测定了锂同位素丰度,在样品全耗尽过程中累计离子流强度。
- The stable isotopic research is established by studying the discrepancy in isotope ratio, which was caused by isotope fractionation, and the isotopic ratio difference can be determined by mass spectrometer. 稳定同位素的研究主要是建立在此同位素分化作用所造成的同位素比值差异，而此同位素比值差异可被质谱仪测知。
- A Lead Isotope Ratio Data Base of Ancient Chinese Bronzes 夏商周青铜器铅同位素示踪研究数据库的构建
- The ratio of students to teachers is 35:1. 学生和老师的比率是三十五比一。
- Precise determination of the platinum-group elements and Os isotopic ratios in low-level rock samples. 岩石样品中低含量铂族元素和锇同位素比值的高精度测量方法。
- A radioactive isotope of carbon, especially carbon 14. 放射性碳碳的一种放射性同位素，尤指碳14。
- The ratio of schoolboys to schoolgirls is 2 to 1. 男学生和女学生的比例是2比1。
