查询词典 isotopic

The sulfur isotopic composition of hydrothermal minerals and barite vary in a wide range too.

矿床中热液硫化物和重晶石的硫同位素组成变化范围也很宽。

Basanite and tephrite from Mt. Crater, Cape Bird and Bonney Lake exhibit similar composition in major elements and trace elements, rare earth elements . They are enriched in MgO, TiO〓, transitional elements and compatible elements , and depleted in SiO〓, Al〓O〓, Na〓O, K〓O, incompatible elements and rare earth elements; Latite from Cape Rodeys and Cape Evens are different from basanite and tephrite, they are enriched in SiO〓, Al〓O〓, Na〓O, K〓O, incompatible elements and rare earth elements, and depleted in Mgo, TiO〓, transitional elements and compatible elements. Volcanic rocks in five regions have the same isotopic ratio of 〓Sr/〓Sr (0.703115-0.703334) and 〓Nd/〓 Nd (0.512892-0.513076), however,〓Pb/〓Pb ratio in volanic rocks from Mt. Crater, Cape Bird and Bonney Lake is lower than those of Cape Rodeys and Cape Evens.

在主元素氧化物和微量元素、稀土元素含量上，克雷克特山、鸟角和博尼湖南岸的碧玄岩、碱玄岩成分比较类似，均具有较高的MgO、TiO〓、过渡元素和相容元素，较低的SiO〓、Al〓O〓、K〓O、Na〓O、不相容元素和稀土元素；罗德角和伊万思角安粗岩雷同，它们具有较高的SiO〓、Al〓O〓、Na〓O、K〓O、稀土元素和不相容元素，较低的MgO、TiO〓、过渡元素和相容元素，但五地区火山岩几乎具有一致的Sr、Nd同位素比值，〓Sr/〓Sr＝0.703115-0.703344、〓Nd/〓Nd＝0.512892-0.513076，在Pb同位素比值上，五地区的〓Pb/〓Pb＝18.664-19.913，其中碧玄岩和碱玄岩比安粗岩的比值稍低。

Biogenetic gas;origin of hydrogen;biochemical action;hydrogenase;isotopic composition

生物气；氢的来源；生物化学作用；氢化酶；同位素组成

The understanding of biogeochemical cycle of hydrogen, oxygen, carbon, nitrogen, and sulfur elements in nature ecosystem have increased substantially in the past two decades owing to the improvement of gas isotope ratio mass spectrometer and the wide application of isotopic studies with these elements.

近20年由於「气相同位素比值质谱仪」的改良和氢、氧、碳、氮和硫等稳定同位素的广泛研究，稳定同位素的研究技术已实质增加我们对於这些元素在自然生態系中生地化循环的瞭解。

Mo isotopic signatures in sediments can be used as an indicator for redox conditions of paleo-environment and corresponding paleo-oceanography. Therefore, molybdenum isotopes can be used as a powerful tool for understanding the redox conditions of local or regional depositional environment, the biogeochemical cycle of sulfur or carbon, and the geochemical evolution of ancient oceans.

沉积物中的Mo同位素既能指示古沉积环境的氧化还原条件，也能够指示与之相关的古海洋地理环境，因此，Mo同位素是了解局域至区域沉积环境的氧化还原条件、硫和碳地球化学循环及古海洋化学演化等的强有力工具。

This paper deals with the advance in the study of terrestrial Permian-Triassic boundary. At first, some index TPTB sections and their research backgrounds are introduced. Then, the research status on the synthesis of the TPTB, including biostratigraphy, eventostratigraphy, isotopic dating, magnetostratigraphy and sequence stratigraphy etc., is analyzed. Finally, the existing problems and the next research directions about the TPTB study are assessed.

着重介绍了几个目前陆相二叠系－三叠系界线研究的重点剖面及其生物地层学研究进展；分析了陆相二叠系－三叠系界线综合地层学研究现状，包括生物地层学、事件地层学、同位素年代学、磁性地层学和层序地层学等；剖析了陆相二叠系－三叠系界线地层学研究中存在的问题及进一步的研究方向。

And furthermore basing on the marks of biostratigraphy and chronostratigraphy and relatively reliable isotopic age of the 14 3rd-order sequences associated with time-space match relation of biostratigraphy and sedimental system, the formed time limits of the 3rd-order sequences is calculated primarily as 1.5-3Ma, mainly appearing at 2Ma.

进而，结合生物地层及沉积体系的时空匹配关系等多方面的综合分析，对14次三级海平面升降事件的生物地层和年代地层的标识和参考已发表的同位素年龄数据，初步估算出三级层序的形成时限为1.5-3Ma，集中出现在2Ma。

In addition, the boundary interval is clearly recognizable by the depletion of isotopic carbon ratios and the normal polarity zone appearing above the Late Wuchiapingian reversed polarity zone.

界线层的碳同位素存在明显的负漂移，正磁极性带出现在吴家坪晚期的反极性带之上。

Different secondary layers of fossil brachiopod shells have different preservation and the way by which the shells' primary isotope ratios be influenced by diagenesis: postdepositional alternation of δ〓O、δ〓C has no effect on the low-Mg calcite minerals of the shells, while it alters the whole shell's isotopic compositions by microcrack fillings, even with the well preserved shells.

1成岩后生作用对腕足化石壳体不同结构单元的改造方式及改造程度不同：成岩后生作用对保存较好的腕足化石壳体的改造是以微裂隙充填方式进行，而对低镁方解石本身并没有影响。

Features and innovations in this study:(1) Longest successive time scale of Precambrian samples is studied;(2) The environmental and biological significances of the difference between . the carbon isotopic compositions of kerogen and coexisted carbonate were discoved;(3) The difference of biogeochemical processes between Proterozoic closed and open sea system was considered in the disccussion;(5) It is first time to carry out the chemolysis and thermolysis of kerogen in Precambrian organic matter research.(6) It is first time to apply molecular organic geochemical data to the reconstruction of Proterozoic Rodinia Supercontinent.

此项研究具有以下特色和创新之处：(1)研究对象连续时间跨度最长；(2)研究内容涉及面较全面；(3)较早详细探讨了前寒武纪沉积有机质的分子特征与古环境和生物群落的演化关系；(4)独立推导和论证了δ〓C〓和δ〓C〓的差值的生物和环境的重要意义；(5)在前寒武纪有机质研究中区分了局部封闭环境下的生物地球化学循环过程与广域海环境下的生物地球化学过程的差异；(6)开展了前寒武纪干酪根化学和热降解研究；(7)开创性地将分子有机地球化学的数据应用于元古宙Rodinia超大陆的重建中。

The circulation, consumption and reproduction of the trilogy have not only testified to its historical significance and literariness, but also invested it with new meanings.

该三部曲的流通、消费与再生产不仅验证了其历史意义及文学性，而切还赋予它以新的意义。

If he thought that he could buy me off, he would be wrong.

如果他认为他可以收买我，那他就大错特错了。