放射性同位素

Various dating methods have been proposed such as radiochemical dating by 10Be and U-Th series, biostratigraphy, magnetostratigraphy, Sr stable isotope method, estimates from the age of substrate, and determinates by regressive formulas.

常用的生长速率测定方法有：10Be和U-Th系放射性同位素测年法、生物地层法、磁性地层法、稳定同位素法、基岩年龄推定法，以及经验公式计算法等。

The decay of ~(99m)Tc source was used to verify experimentally that in the measurement of the number of atoms of a radioactive isotope in a sample at time t_0, the error introduced through the inaccuracy of its decay constant can be reduced to a much smaller value by the careful selection of the time of measurement or measurements of its radioactivity at around one life time (1/λ) after t_0 and doing the calculation.

本文用~(99m)Tc源的衰变实验证明了：在测量一个样品中在t_0时的一种放射性同位素的原子数时只需精心选择一次或多次测量其放射性的时刻在t_0后约该同位素的一个寿期(1/λ)，并进行计算，则由它的衰变常数或其半衰期(T1/2)的不准确性而引进的误差可以被降低到较小值。

When the distribution of important fission products is calculated, emphasis is placed on the noble gas radionuclides and upon radioisotope of iodine because of their great contribution to accident dose.

在对重要裂变产物分布的仿真计算中，重点放在了惰性气体核素和碘的放射性同位素上，因为它们是事故中放射性剂量的重要来源。

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。

When O and radiogenic isotopic measurements are employed as tracers to evaluate magma-country rock interaction it is essential to provide evidence that open system processes have not perturbed the isotopic systematics.

用氧同位素和放射性同位素示踪岩浆和围岩相互作用时，必须在开放体系没有扰动同位素系统情况下进行。

Low-temperature hydrothermal processes can mask evidence of high-temperature processes in the oxygen isotope system, and in radiogenic systems such as Re/Os and Pb where involved elements may be mobile under hydrothermal conditions, or host phases may close to exchange and uptake at different temperatures.

在氧同位素体系和放射性同位素体系(如Re/Os、Pb同位素体系)中，元素在热液条件下活动性强或主相没有发生同位素交换与吸收，都会导致低温热液过程掩盖高温过程。

After being shot by neutron,~(74)Se isotope can be changed to be short decayed period to radioisotope.

经中子照射后~(74)Se同位素可变成短衰期放射性同位素~(75)Se，而90%以上高浓度的~(75)Se同位素做成的放射源在农业与核医学等方面有重要的应用价值。

Radioisotope renography/methods ; urologic diseases/diagnosis ; atropine/diagnostic use ;~（131）I--orthoiodohippuric acid/diagnostic use ; iodine radioisotopes/diagnostic use ; case report

放射性同位素肾成象/方法；泌尿系疾病/诊断；阿托品/诊断应用；碘马尿；酸/诊断应用；碘放射性同位素/诊断应用；病例报告

Result: in substantial stage, thirty-four patients showed intrapelvic radioactive concentration imaging out of the baldder, in which sixteen were in the left side and eighteen were in the right. in delayed stage, radioactive concentration still existed, with the positive rate of 56.7%.

结果：34例在实质期内可见膀胱外盆腔大小不等的同位素浓聚显像，其中偏左侧16例，右侧18例，延迟期放射性同位素浓聚仍持续存在，阳性率56.7%。26例未见明显持续性同位素浓聚。

Specifically, the invention relates to vasoactive intestinal receptor binding peptides, derivatives and analogues of vasoactive intestinal peptide, and embodiments of such peptides radiolabeled with a radioisotope, as well as methods and kits for making, radiolabeling and using such peptides for radiodiagnostic and radiotherapeutic purposes.

具体地，本发明涉及到具血管活性肠受体结合特性的肽，血管活性肠肽的衍生物和类似物，和用放射性同位素标记这类肽的实施方案，以及生产、放射性标记与使用这类肽的方法和药盒进行放射性诊断和放射性治疗。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。