同位素

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。

According to the principle of strontium isotope stratigraphy, we attempt to determine the age of the boundaries for Campanian/Santonian and Maastrichtian/Campanian by 87Sr/86Sr ratios for Gamba section in southern Tibet.

在与国际上同期海相地层锶同位素演化曲线对比的基础上，研究了晚白垩世海相碳酸盐锶同位素组成与主要地质事件的关系；在将本研究锶同位素数据融入到全球中新代海水锶同位素曲线的基础上，综合作出了中新生代海平面变化和锶同位素对照曲线，讨论了全球风化速率，造山事件，气候，海平面变化以及灾变性事件对中新生代海水锶同位素的控制作用；根据锶同位素地层学原理，本研究尝试将碳酸盐锶同位素组成用于海相地层定年上，利用已有的全球海水87Sr/86Sr值-年龄数据库和测试的藏南晚白垩海相碳酸盐的87Sr/86Sr值，确定了岗巴剖面Campanian/Santonian和Maastrichtian/Campanian阶界线，标定了广泛分布于白垩纪的厚壳蛤化石的年龄；本研究还将这些方法推广到了塔里木盆地井下奥陶纪地层的年龄标定，确定了中/上，中/下奥陶统界线，从锶同位素角度获得了古岩溶作用证据，显示锶同位素地层学在解决海相地层对比，年龄确定及在岩溶型油气储层研究中的潜在价值和良好应用前景。

Corbicula fluminea (Müller 1774) was bred in the laboratory and two shell samples (shell height, A=13 mm, B=9 mm) were selected to determine the carbon isotopic composition of the increment shells (aragonite, CaCO3) and the host water. The results indicate that the carbon isotopic compositions of the two shells increased as the δ^13 C values of the host water increased from -5.24‰ to 1.41‰, showing the influence of δ^13C values on the shell carbon isotopes.δ^13C value ranges from -4.76% to -2.09% and δ^13 C from -8.49% to -2.89%. The δ^13 C values of shells A and B are both more negative than the predicted equilibrium ones, indicating that the shell had used the metabolic CO2 rich in 12C during their growth process.

对双壳类河蚬进行了室内养殖，并选取两个壳体样品（壳高，A=13 mm， B=9 mm），测定其生长部分壳体和生长期间水体碳同位素，研究表明，随着水体碳同位素的升高（δ^13C由－5.24‰升至1.41‰），两壳体碳同位素也随之升高，表明水体对壳体碳同位素的影响；δ^13CA分布范围为－4.76‰~-2.09‰，δ^13CB为－8.49‰~-2.89‰，壳体A和B碳同位素均比预测平衡值偏负，表明壳体在形成过程中利用了新陈代谢产生的富集12C的CO2。

To address the issue, we analyze the correlation and similarity of the different radii sequence and the different combination sequence with the full- ring-sample sequences, based on 642 δ13C data of cellulose fixed in tree-ring at 8 different radii of two Cryptomeria fortunei tree disks from Mt. Tianmu, a subtropical mountain of China. It suggests that 2 to 4 radii mixture sample is the better and more efficient choice for the tree-ring δ13C analysis. It had better to take samples at obtuse angle with each other when to take samples at two or three radii.

研究利用来自天目山的两个柳杉树盘的多方位的和整轮的碳同位素测试数据（共计642个），通过不同方位和不同方位组合的平均碳同位素序列与整轮碳同位素序列的关系的多角度的考查、分析发现，并不是采样的方位数越多越好，选择2~4个方位采样合并分析树轮稳定碳同位素，既经济方便又能比较好的反映一棵树的δ13C变化过程与趋势。

This model indicates that the sulfur isotopes, whose values tend to be negative fractionate to a large scale because of the reductive process of dissimilating bacteria of sulfate.

根据内蒙古乌达矿区高硫煤9煤层（有机硫同位素值 d 34 S=－12.3‰~5.8‰，黄铁矿硫同位素值 d 34 S=－18.7‰~1.1‰）和低硫煤13煤层（有机硫同位素值 d 34 S 为8.9‰~ 11.5‰，黄铁矿硫同位素值 d 34 S 为8.3‰~ 9.7‰）剖面上有机硫和黄铁矿硫同位素的组成，结合煤岩学特征的综合分析以及黄铁矿化菌落和蓝藻胶壳的发现，提出了高硫煤中硫的演化模式，认为高硫煤中硫的同位素由于硫酸盐的异化细菌还原作用导致硫同位素大规模分馏，使之趋于负值。

The objective of this study is to introduce briefly the basic concept and expression of isotope and the theory of isotopic hydrograph separation,to review the advantages and disadvantages of various hydrograph separation methods which are applied all over the world and to introduce two-component and three-component isotopic hydrograph separation models in details.

简要介绍了同位素的基本概念、表示方法以及同位素示踪流量过程线分割的基本原理。综述了国内外关于流量过程线分割各种方法的优缺点，并对二水源同位素过程线分割模型和三水源同位素过程线分割模型进行了详细介绍和推导。

Using the sign if icance of these characters in the aspect of sediment environment, th is paper analyzed C and O iso tope ofQ ian jiang Saline lake and educed conclu sion s: there are good relat ivity betw een the change of clim ate and sedim ent\r\nenvironm en t and the con tent's change of C and O iso tope from high to low; it is aobturated saline lake of\r\ninnerland tow ard Q ian jiang saline lake, and the con ten t of C and O iso tope was primarily decided that Ciso tope is - 5‰ and O isotope is - 2‰.

主要介绍了碳和氧同位素的地球化学特征，利用这些特征在沉积环境方面的指示意义分析了潜江盐湖的碳、氧同位素并得出了以下认识：碳、氧同位素值的高低变化与气候的变化和沉积环境的变化具有很好的相关性；潜江盐湖是一个封闭的内陆盐湖，就该湖而言，其碳同位素值可初步确定为- 5‰，其氧同位素值为- 2‰。

Three main methods with lacustrine carbonates have been used to reconstruct the lake water palaeo-temperature at present. First, the technique of isotopic geological thermometer, since being put forward to reconstruct sea-water paleo-temperature, was subsequently introduced into lacustrine carbonate sediments for constructing lake-water based upon the function relationship between lake-water temperature and the oxygen isotopic compositions of lacustrine carbonate and lake-water. Second, paleo-temperature of the lake-water can be reconstructed by determining Mg/Ca values of the lacustrine ostracode shells. And third, paleo-temperature of the lake-water can be reconstructed based upon the statistic model between the oxygen isotopic composition of lacustrine carbonate and the Lake-water temperature by testing the modem hydrogeological parameters and some relevant isotopic data of the lake basin.

目前利用湖泊碳酸盐对湖泊古水温进行重建主要有三种方式，一是运用同位素地质温度计原理，利用水温与湖泊碳酸盐氧同位素值和湖水氧同位素值三者之间的函数关系，对湖泊古水温做定量研究；二是通过测定介壳[Mg(上标 2+)]/[Ca(上标 2+)]进而重建古水温；三是通过测定湖泊流域范围内现代水文气象参数及一些相关的同位素资料直接建立起湖泊自生碳酸盐氧同位素值与温度间的统计模型。

Excitation functions of neutron, proton and α particle emission prior to scission measured in the reactions 28 Si+ 164,167,170 Er→ 192,195,198 Pb are studied using an extensive fission diffusion model and it is found that the model can well describe the trend of particle multiplicities of Pb isotopes measured experimentally as a function of the bombarding energy,which indicates the existence of isotope effects in prescission particle emission.

用推广的裂变扩散模型研究了2 8Si+16 4，16 7，170 Er→192 ，195，198Pb反应中测量的断前中子、质子和α粒子多重性的激发函数。发现扩散模型能很好地拟合这些轻粒子多重性随裂变系统激发能和Pb同位素的变化趋势。表明断前粒子发射存在一个同位素效应。进而在一个考虑了裂变过程中摩擦效应的统计模型的框架内，在In和Er这两个元素的同位素链中，考察了同位素效应与裂变碎片质量不对称性和裂变系统尺度的关系。计算结果表明：同位素效应的存在不依赖于裂变系统的大小和不对称性。此外，当裂变系统具有高的中质比时，轻带电粒子发射将不再敏感于裂变延迟时间的长短，而中子发射则非常敏感。

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。

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