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1.
The correlation between Al metabolism and senile dementia in animal has been studied by AMS(accelerator mass spectrometry).Three groups of laboratory rats were fed with normal food.food with high Al content,and with enriched Ca and Mg together with high Al,respectively for six to eight months.Mapping test was made to recored th degree of wisdom degeneration.Half of the rats were sacrificed and Al contents in various organs were measured by atomic absorption spectroscopy.The rest were injected with ^26Al,killed after 5,10,15,25,and 35d and ^26Al contents measured by AMS.The distribution of Al as well as the correlation among the accumulation of ^26Al,and the existed Al content and dementia was studied.  相似文献   

2.
报道了用于加速器质谱计2 6 Al分析的Al2 O3的制备流程及2 6 Al的测量过程。制备的空白样品2 6 Al/ 2 7Al比值 <10 - 13,显示出同量异位素2 6 Mg干扰小。制备流程是成功的。  相似文献   

3.
Some interferences are often encountered in accelerator mass spectrometry (AMS) measurements, especially for medium-heavy nuclide measurement, It is difficult for online discrimination of the nuclide of interest from the interfering ones. In order to solve this problem, we developed a method to simulate the experimental spectra of medium-heavy nuclides in AMS measurements. The results obtained from this method are in good agreement with experimental values.  相似文献   

4.
许丽红  夏晔  杜慧芳  周祖铭 《核技术》2001,24(9):779-782
介绍了无铅汽油添加剂甲基叔丁基醚、甲基叔戊基醚及甲基环戊二烯三羰基锰的应用现状和毒理学研究进展,提出用加速器质谱法研究所新的汽油添加剂甲基叔戊基基因毒性的研究方向。  相似文献   

5.
236U is a long-lived radioactive isotope which is produced principally by thermal neutron capture on 235U. 236U may be potentially applied in geological research and nuclear safeguards. Accelerator mass spectrometry is presently the most sensitive technique for the measurement of 236U and a measurement method for long-lived heavy ion 236U has been developed. The set-up uses a dedicated injector and the newly proposed 208Pb16 molecular ions for the simulation of 236U ion transport. A sensitivity of lower than 10−10 has been achieved for the isotopic ratio 236U/238U in present work.  相似文献   

6.
The concentration of the natural ultra-trace radionuclides CI and U in the uranium depended on the neutron flux.In this article,a method for measuring 36C1 and 236U in the same uranium mineral with accelerator mass spectrometry was developed in China Institute of Atomic Energy,providing a protocol of the potential application of 236U in uranium mining,environmental,and geological research.The two samples were from Guangxi and Shanxi province,China,and their ratios 36Cl/C1 and 236U/238U were measured.More experimental data conduced to understand the natural nuclides in the uranium mineral.We plan to conduct more efforts on the research.  相似文献   

7.
《核技术(英文版)》2016,(3):152-157
Aluminum is concerned as a possible cause of many diseases.To investigate the long-term A1 biokinetics and bioavailability in various kinds of Al-contained medicine and food,an accelerator mass spectrometry(AMS)based on the HI-13 tandem has been established for biological analysis with ~(26)A1(T_(1/2) = 716,000 years) as the tracer.In this paper,the animal tracing,sample preparation procedure and ~(26)A1-AMS measurement are presented.The sample preparation procedure has been simplified.A high sensitivity of 5×10~(-15) for ~(26)A1/~(27)A1 has been achieved.Two phases were found before and after a break time(t_b)for the ~(26)A1 retained in blood and brain,with t_b≈8 and12 h after the ~(26)Al tracer injection,respectively.  相似文献   

8.
本文介绍加速器质谱计用于测定天然物质中超微量同位素~(10)Be及其在地球科学中的应用。环绕样品~(10)Be的测定可用于研究大气和海洋中发生的各种传输作用过程;大陆沉积物~(10)Be分布及迁移直接与黄土(或土壤)的堆积和侵蚀有关。~(10)Be是一种反映各种地球化学作用过程的理想的示踪剂。  相似文献   

9.
姜山  黄麒 《核技术》1993,16(12):720-725
描述了中国原子能科学研究院的基于HI-13串列加速器建立的加速器质谱计装置和测定^36Cl的实验方法。利用这台加速器质谱计测定^36Cl/Cl同位素原子比值的灵敏度已好于3×10×-15,对地下水,盐湖和铀矿石样品中的^31Cl进行了测定,这些样品的^36Cl/Cl同位素比为1.2×10×-12-2.2×10^-14。  相似文献   

10.
加速器质谱(AMS)测量中的粒子鉴别探测器   总被引:1,自引:0,他引:1  
描述了中国原子能科学研究院AMS测量中使用的飞行时间探测器、多阳极电离室、Bragg探测器、入射离子X射线探测器以及充气飞行时间探测器。通过它们可以获得粒子的飞行时间、部分能量和总能量,从而达到粒子鉴别的目的。介绍了采用这些探测器在HI—13串列AMS系统上做的相关工作以及取得成果。  相似文献   

11.
151Sm is an interesting nuclide in many research fields. Measurement methods of the long-lived 151Sm with accelerator mass spectrometry have been developed at China Institute of Atomic Energy. The chemical form of samples was Sm2O3 and the extracted ion was SmO. To date, the sensitivity, that is, the isotopic ratio, of 151Sm measured using accelerator mass spectrometry is about 10−8. This method was also used to measure the concentration of tracer 151Sm in biological samples for clarifying whether the rare earth elements can enter into the brain. It is not possible at present to determine whether the tracer has penetrated the blood-brain barrier into the brain.  相似文献   

12.
ABSTRACT

Strontium-90 is one of the most important fission products due to the potential health risks of its uptake and retention in the human body. Conventional analysis techniques involve β counting, which requires ingrowth of 90Y over a period of two weeks. Accelerator mass spectrometry (AMS) has the potential to shorten the analysis time while offering a lower limit of detection than β counting. Here, Sr in samples was recovered as SrF2 to provide sufficient negative ions in the caesium-sputtering ion source. In the sample preparation step, 95–98% of Sr was recovered and 99–100% of Zr removed by ion-exchange separation. Sr recovery was ~30% in the precipitation process, and this can be improved. A maximum 500 nA beam current of SrF3 ions was obtained from SrF2 samples mixed with PbF2. A five-anode gas ionization detector was used to avoid isobaric interference from 90Zr. The 90Sr/Sr atomic ratio background of ~6 × 10–13 (~3 mBq 90Sr) was comparable with that achieved at other AMS facilities. Good linearity in 90Sr/Sr atomic ratios was obtained from 1.75 × 10–10 to 3.38 × 10–9. Suitable techniques for sample preparation and measurement were thus achieved for 90Sr analysis by AMS.  相似文献   

13.
In 2007 we published [1] the design of a novel accelerator mass spectrometry (AMS) system capable of analyzing gaseous samples injected continuously into a microwave plasma gas ion source. Obvious advantages of such a system are drastically reduced processing times and avoidance of potentially contaminating chemical preparation steps. Another paper in these proceedings will present the progress with the development of the microwave gas ion source that has since been built and tested at the National Ocean Sciences AMS Facility in Woods Hole [2]. In this paper we will review the original design and present updates, reflecting our recent encouraging experience with the system. A simple summary: large acceptance ion beam optics design is beneficial to accelerator mass spectrometry in general, but essential to AMS with plasma gas ion sources.  相似文献   

14.
周善铸  潘浩昌 《核技术》1993,16(3):169-173
在利用回旋加速器质谱技术进行氚断代的测量中,工作气体是电解水样品时收集到的含氚氢气,并混入少许一定量的空气。空气中的微量~3He和样品中的~3H同时加速并被用作参考标准以监督加速器的束流变化。描述了利用金硅面垒探测器望远镜和铝吸收箔的组合来探测和鉴别~3H和~3He的实验方法和结果。  相似文献   

15.
卢相顺  陈茂柏 《核技术》1996,19(4):204-207
理论分析和实验结果表明,超灵敏小型回旋加速器质谱计分析的放射性核素主要有^14C、^3H、^26Al^40K、^44Ti等。在采取一定的技术措施后,可以分析的放射笥核素还可更多。  相似文献   

16.
本工作描述基于2.5MV静电加速器建立的加速器质谱计的基本原理、实验装置以及重水样品中氚浓度(T/D)的测定。为了比较,还用放射性法进行了测量。实验结果表明,基于一台能量约1—2MeV加速器测定氚的灵敏度已达到10~(-14),而潜在灵敏度还可能高2—3个量级。本文还讨论了这种技术的前景和问题。  相似文献   

17.
The performance of the compact ETH-TANDY system for accelerator mass spectrometry measurements of 236U is presented. Despite the low ion energies of around 1.2 MeV we can demonstrate a background level that is comparable to larger facilities. The careful ion-optical design of the high-energy spectrometer leads to a high suppression of neighboring isotopes sufficient to measure samples with isotopic ratios of 236U/238U > 10-11 the ion chamber only, as demonstrated by systematic investigations with different slit settings and time-of-flight measurements. Additionally, a high overall efficiency is achieved due to a high transmission through the accelerator.  相似文献   

18.
建立了痕量锂同位素的高精度热电离质谱测量技术。通过双带测量、加入磷酸发射剂及采用预烧处理方法等途径,抑制了分馏效应,提高了痕量锂质谱分析的精度。采用浓缩锂同位素标准样品考察了测量效果,对于100ng锂样品,测量相对标准偏差好于0.086%;对于10ng锂样品,相对标准偏差好于0.90%。  相似文献   

19.
A sequential data correction method using several experimental parameters of pulsed resonance ionization mass spectrometry was developed to reduce mass discrimination effects for isotope ratio analysis as well as fluctuations in the ion count rate. This correction method was applied to isotope ratio determination of stable titanium isotopes using a two-step, single color ionization scheme. A significant improvement of the precision of the measured isotopic ratio of stable titanium isotopes was demonstrated after correction with a parameter set consisting of laser power, atmospheric pressure, and laser frequency.  相似文献   

20.
王兆荣  彭子成 《核技术》1998,21(12):714-717
介绍用MAT-262质谱仪对国内石笋标样(GBW04412),(GBW04413)和国际珊瑚标样(RKM-4)进行的测试,取得了与标准一至的结果。  相似文献   

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