查询词典 isotopes

Nature, most elements have two or more isotopes, the same kinds of elements in the quality of the various isotopes of different, but the types and proportion constant (except for radioactive elements). In 1961, the carbon content of the most abundant in nature, a kind of isotope, carbon-12 atom of a quantity and quality of C as a 12 mass units to it as "benchmarks" for all isotopes of an element according to the average abundance The ratio of the benchmark is the atomic weight of this non-prime, that is listed in the periodic table of atomic weights.

自然界中大多数元素都有两种或更多的同位素，同种元素的各同位素质量不同，但其种类和比例是恒定的。1961年，把碳在自然界含量最丰富的一种同位素，碳12的一个原子的质C量定为12个质量单位，把它作为"基准"，某种元素的所有同位素按丰度的平均值与基准之比，就是这种无素的原子量，即元素周期表列出的原子量。

The MS showed that the ratio of relative abundance ratio of two main Se isotopes is about 2:1, which can give important information for identifying molecular or fragile ions of selenium.

所有化合物均可获得特徵质谱，表现出含单个硒原子的分子离子或碎片离子特徵峰簇，硒的两种主要同位素在峰簇中表现为主要峰M与(M-2)的相对丰度比约为2：1，可为鉴定含硒分子离子或碎片离子提供重要信息。

Its isotopes, all radioactive, are highly toxic radiological poisons because they give off alpha particle s and are specifically absorbed by bone marrow.

它的所有同位素都是放射性的，因其放出的α粒子易于被骨髓吸收而具有高度的放射性毒性。尽管具有潜在的致命性，它的毒性通常是被夸大了的。

History of each element, atomic number, symbol, electron configuration, isotopes, its properties and its cost.

提供每个元素的基本信息、同位素、价值和历史。

Isotopes have the same atomic number but different mass numbers.

同一元素的同位素有相同的原子序数不同的质量数。

We summarize the study of geochemistry of the Co rich crust, and explain the diffusion of elements in the Co rich crust and the exchange with ambient seawater. Besides, we discuss the effect of phosphatization and substrate rocks on the composition of the Co rich crust. We also introduce the application of stable isotopes (including the stable isotopes of Pb, Nd, and Hf), radioactive...

概述了富钴结壳地球化学的研究成果阐述了富钴结壳中元素的扩散及与周围海水的交换，基岩和磷酸盐化事件对富钴结壳组成的影响分别介绍了稳定同位素(Pb、Nd和Hf的稳定同位素)、放射性同位素(Be、U和Th的放射性同位素)及元素(常量和微量元素、稀土元素)在富钴结壳古海洋学研究上的应用。

This paper discusses the research carried out on the Lake Sugan, in the northern margin of Chaidam Basin. The climate and environmental changes in Lake Sugan drainage area over the past 2670 years were studied using the varve dating of the well preserved lamination sediments in core SG03I taken from the center of Lake Sugan, the study of varve formation in modern lake system and modern process study of carbonate and oxygen isotopes of the water within the drainage area, and according to the main index of the stable isotopes of carbonate sediments synthesized other index analysis.

本文以柴达木盆地北缘苏干湖为研究对象，通过对湖泊中心位置SG03I孔保存完好的纹泥沉积物岩芯进行年代学研究，对湖泊现代沉积过程及碳酸盐、流域水体同位素进行现代过程研究，以沉积碳酸盐稳定同位素指标为主，结合其它代用指标的综合分析，探讨苏干湖流域近2670年来的气候与环境变化，综合区域其它记录对苏干湖流域晚全新世气候变化的驱动机制进行探讨，获得如下认识：1、柴达木盆地北缘苏干湖若干钻孔岩芯发现，水深大于3.0m的沉积物均具有裸眼可分辩的由深色层和浅色层组成的纹层层理。

More recently, other isotopes have been made at the paul scherrer institute in switzerland using neon atoms to bombard californium isotopes.

最近，其他同位素已在保罗scherrer研究所(35/12)在瑞士用氖原子轰击锎的同位素。

Based on the study of rock textures and structures, and stable isotopes of dolomite and S isotope of barite interlayers within the cap dolomite outcropped in the Miaohe area in the Three Gorge, it is testified that the stable isotopes show a strong negative excursion, and the isotopes of sulfur show a significant positive excursion, which is similar to the reported data of authigenic barites formed in a modern seafloor gas hydrate environment. Therefore, it can be concluded that the cap dolomite was most likely formed in a special environment under which a huge gas hydrate dissociated with the breakup of "Snow Earth" in later Neoproterozoic.

通过对湖北三峡庙河地区出露的&盖帽&白云岩的野外地质构造、碳－氧稳定同位素和重晶石夹层的硫稳定同位素特征的研究，发现除了明显的碳稳定同位素的负偏移之外，重晶石的硫同位素值表现出明显的正偏移，其数值可与现代海底甲烷喷气孔附近的自生重晶石矿物的同位素组成相对比，进而认为&盖帽&白云岩的成因是末元古代&雪球&事件之后天然气水合物的释放与全球环境突变背景下的沉积产物。

Most elements found in nature are mixtures of several isotopes; tin, for example, has 10 isotopes.

自然界里的大多数元素都是几种同位素的混合；例如锡，有十种同位素。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐