共查询到20条相似文献，搜索用时 625 毫秒
1.
叶先贤 《矿物岩石地球化学通报》1988,(3)
在伦琴发现X射线的早些年代里,不同能量的X射线是根据它们的穿透物质的能力来区分的。布拉格利用晶体衍射把不同波长的X射线区分开。莫塞莱利用此种方法得到了许多X射线谱,此种方法至今仍用于X射线的测量及研究。无论使用何种方法对X射线进行测量,都需要一个合适的X射线探测器。最早的探测器为盖格计数管,后改用正比计数器及闭烁计数器。七十年代初期,固体探测器经过短时间的发展和完善,目前已广泛用于X射线测量。X射线能谱仪可应用于矿物学的研究。 相似文献
2.
介绍了在低真空模式下扫描电子显微镜配装X射线能量色散谱仪检测宝玉石的原理与方法。对比与评估了宝玉石样品的X射线能量色散谱仪的无标样定量分析数据与其标准数据,讨论了扫描电子显微镜配装X射线能量色散谱仪在宝玉石检测分析中存在的问题。通过与其它宝玉石检测分析仪器如X射线荧光分析仪、X射线粉末衍射仪、傅里叶变换红外光谱仪及激光拉曼光谱仪比较后认为,扫描电子显微镜配装X射线能量色散谱仪对宝玉石无损分析鉴定是最方便、有效的手段之一。 相似文献
3.
《岩矿测试》2008,27(2):126
为促进我国X射线光谱分析学术交流,展示国内在该领域研究和应用的最新进展,推动现代分析测试技术的发展,决定于2008年10月20—25日在海南三亚召开第七届全国X射线光谱学术报告会,会期5天。会议由中国地质学会、中国硅酸盐学会和中国光谱学会主办,国家地质实验测试中心承办。会议期间,特邀请国内外著名X射线荧光分析专家等作专题报告。热忱欢迎广大从事X射线光谱分析及相关领域工作的人员踊跃投稿和积极参加会议。征文主题:X射线光谱分析新理论、新技术、新方法、新仪器以及新应用。包括:(1)同步辐射X射线光谱分析;(2)聚束毛细管微束X射线光谱分析技术;(3)新型能量探测器技术的发展与应用;(4)X射线光谱分 相似文献
4.
现场X射线荧光分析技术 总被引：5，自引：5，他引：0
本文从携带式X射线荧光仪器、现场分析技术和技术应用三方面论述了现场X射线荧光分析技术的进展.从X射线激发源、X射线探测器和电子线路单元等角度,将携带式X射线荧光仪划分为四代,即以放射性同位源为激发源、以NaI(Tl)闪烁计数器为X射线探测器为技术特征的第一代仪器;以放射性同位素源和正比计数器为技术特征的第二代仪器;以放射性同位素、电制冷半导体探测器和以嵌入式微处理器为控制核心的多道脉冲幅度分析器为技术特征的第三代仪器;以低功率微型X射线发生器为激发源、电制冷半导体探测器和全数字化X射线能谱采集器为技术特征的第四代仪器.在现场分析技术方法方面,论述了X射线仪器谱解析技术、基体效应校正技术和现场原位分析中不平度效应、湿度效应、荧光颗粒不均匀效应校正技术进展.介绍了现场X射线荧光分析技术在地质矿产普查、环境污染调查、文物现场鉴定和合金分析等领域的应用进展.指出了目前国产携带式X射线荧光仪处于第三代和第四代仪器水平之间,低功率微型X射线发生器和电制冷半导体探测器还依赖于进口,全数字X射线能谱采集器还有待商品化;现场多元素分析的准确度和方法检出限都有待进一步改善;便携式仪器的应用领域有待拓宽. 相似文献
5.
原位微区X射线荧光光谱分析装置与技术研究进展 总被引：2，自引：1，他引：1
原位微区X射线荧光(Micro-XRF)光谱分析技术是X射线光谱学领域一重要分支。近年来X射线毛细管光学透镜聚焦技术不断进步,以实验室X光源为基础的原位微区X射线光谱分析装置与应用技术快速发展,已成功应用于多领域样品的原位、多维、动态和非破坏性微区分析。文章介绍了近年来X射线毛细管光学透镜技术发展和原位微区X射线光谱分析装置研制进展,对近年来micro-XRF光谱分析技术在大气气溶胶颗粒物分析与来源识别、考古样品产地和真伪鉴别、古气候古环境重建研究中沉积纹层样品元素分析,以及刑侦科学中指纹样品的鉴定等应用领域进行了系统介绍,阐述了micro-XRF光谱分析技术性能的影响因素(空间分辨率和强度增益)。micro-XRF光谱分析技术不仅可以获取样品表面的信息,还能够获取样品内部的信息,成为目前国际上一门迅速发展的竞争技术。我国在毛细管透镜制造技术与性能研究,以及micro-XRF应用领域取得了重要进展。由于X射线焦斑尺寸对能量的依赖性以及样品基质对X射线的吸收效应,在微区定量分析中易引入较大误差,利用X射线毛细管透镜获取更小光斑尺寸与高稳定性的X射线光束,提高micro-XRF分析技术的空间高分辨率性能和对基体效应进行校正实验将是今后一个重要的研究目标和分析研究难点。 相似文献
6.
介绍了微区X射线衍射仪发展的现状,给出了微区X射线衍射仪鉴定物相的研究实例,并讨论了微区X射线衍射法的优、缺点。通过配置有封闭3kWX射线光管、单毛细管透镜、Pixcel探测器和普通CCD视频的Panalytical X’Pert PRO MPDX射线衍射仪,对光片上的铍矿物进行了微区X射线衍射鉴定,结果确定该铍矿物为羟硅铍石。微区X射线衍射法具有微区、微量、原位和无损等优点,能够进行直径在100～300μm范围内的两种或两种以上矿物集合体的物相鉴定。与电子探针等微区手段相互结合、互相补充,鉴定结果更加可靠。 相似文献
7.
继光学显微镜、X射线分析方法之后,电子显微分析方法已成为一种重要的岩矿测试手段。这种方法主要包括:透射电子显微分析、扫描电子显微分析、电子探针X射线显微分析(简称电子探针分析)以及X射线能谱分析等。 相似文献
8.
9.
10.
1990年4月24日—27日由中国物理学会X射线衍射专业委员会、中国地质学会矿物X射线晶体学委员会、华北地区X射线联合会和北京市理化测试学会联合举行的全国X射线计算机软件交流会议在北京胜利召开。来自全国17个省、市的高等学校。研究院(所)以及工厂等部门的六十多位代表参加了会议。他们中间有著名的教授、副教授,研究员,副研究员。高级工程师以及具有丰富实践经验和一定理论水平的青年 相似文献
11.
Using the “Scenario Machine” (a computer code based on the Monte-Carlo method, developed to calculate the evolution of a large ensemble of binaries), we have carried out population-synthesis calculations for X-ray binaries for the purpose of modeling the X-ray luminosity functions in various type galaxies. These calculations were focused on the evolution of magnetized neutron stars. The X-ray luminosity function is not universal, and depends on the star formation rate in the galaxy. In theoretical models, it is very important to take into account the evolution of the binaries and their lifetimes in their X-ray stages. We calculated the cumulative and differential X-ray luminosity functions in galaxies with a constant star formation rate, the cumulative luminosity functions for various time intervals since the peak star formation, and curves describing the evolution of the X-ray luminosity after a star formation burst in the galaxy. 相似文献
12.
13.
A new mechanism for the generation of X-ray emission in binary Be/X stars is proposed. It is shown that the mass-transfer rate through the point L1 in a model in which the optical component of a Be/X star has an expanding envelope is sufficient to generate the observed X-ray luminosities of such stars. The results of computations indicate a dependence between the orbital periods and X-ray fluxes of these systems. The relationship between the orbital perod and the mass-transfer rate during flares obtained from modeling corresponds to the observed dependence of the maximum X-ray flux on the orbital period. 相似文献
14.
B. V. Komberg 《Astronomy Reports》2006,50(6):432-438
Based on the available observational data on the diffuse X-ray emission from hot gas in virialized systems (the central regions of clusters of galaxies or the coronas of spherical galaxies) and the masses of the central objects in these systems (the central galaxies in clusters or massive compact objects—supermassive black holes—in the galactic nuclei), we show that the X-ray luminosity is proportional to the square of the mass of the central object. This is consistent with the dependence obtained earlier between X-ray luminosities of systems and the square of their optical luminosities (i.e., the luminosity of stars in these systems). The existence of such dependences for virialized systems on various scales may provide evidence that they are all formed by a single mechanism, such as hierarchical gravitational clustering. Although the times to achieve hydrostatic equilibrium between the gaseous and stellar components in systems on various scales differ, the relation between certain internal parameters of these systems may remain the same. This enables us to estimate certain parameters of virialized systems in terms of others, in particular, to estimate the masses of their central objects based on the diffuse X-ray luminosity of their coronas. 相似文献
15.
We consider various physical processes that affect the thermal balance of an X-ray jet. We focus on the rapid cooling of dense
jets via bremsstrahlung, and all processes are considered from the viewpoint of their contributions to the jet thermal balance.
Jet heating by Compton scattering of hard X-ray photons from the hot corona, the effect of shocks in the jet on heating of
the jet, and the transformation of jet kinetic energy into heat via Coulomb collisions between protons of the jet and corona
are considered. Numerical values have been obtained for the Galactic microquasar SS 433 based on previous results for modeling
the X-ray spectrum of this source. Collisions of the jet particles with the ambient gas turns out to be the most important
jet heating mechanism for this source. 相似文献
16.
Ruarri J. Day-Stirrat Robert G. Loucks Kitty L. Milliken Stephen Hillier Ben A. van der Pluijm 《Sedimentary Geology》2008,208(1-2):27-35
Calcite-cemented zones in the prolific gas-producing Barnett Shale (Ft. Worth Basin, Texas) preserve very early compactional fabrics that contrast markedly with fabrics in the enclosing host-rocks. The compactional state of these zones, based upon alignments of phyllosilicates as determined by High-resolution X-ray goniometry (HRXTG), complemented by X-ray powder diffraction (XRPD), back-scattered electron imaging, and elemental X-ray mapping, points to a prelithification, near-syndepositional timing of initial authigenic calcite emplacement. Thus, these carbonate-cemented zones are of particular interest for the information they provide on the character of grain assemblages and sediment types at the time of deposition and also on the early post-depositional environmental chemistry of the Barnett Shale strata. 相似文献
17.
V. I. Silaev G. A. Karpov L. P. Anikin V. N. Filippov V. A. Petrovsky A. E. Sukharev Yu. S. Simakova 《Doklady Earth Sciences》2017,476(1):1048-1053
The results of X-ray structural, electron-microscopic, and X-ray spectral microprobe studies of Al-based metal solid solutions that underwent nuclear disintegration and that were discovered in nature for the first time are presented. Based on the similarity to technical counterparts, it is suggested to recognize the previously unknown alloys as natural duralumin. 相似文献
18.
19.
以往千枚岩是依据显微镜下观察岩石结构构造及矿物成分进行分类定名.实际上千枚岩中鳞片状绿泥石和黑云母以及微粒石英、钾长石和斜长石在岩石薄片中区分十分困难.为了准确鉴定千枚岩中鳞片状和微粒状造岩矿物种类及其相对含量,利用X射线粉晶衍射半定量技术对19件千枚岩岩石进行分析测试.研究结果显示：利用云母、绿泥石、石英、钾长石和斜长石等造岩矿物X射线衍射峰的明显差异,结合X射线衍射全谱拟合半定量分析测试技术,能快速检测云母、绿泥石、石英、钾长石和斜长石等造岩矿物种类与含量.实践证明,将千枚岩岩石野外观察、岩石薄片鉴定和X射线粉晶衍射技术紧密结合起来,才能准确定出千枚岩岩石的名称. 相似文献
20.
The structural state of diaplectic labradorite glass (≈An58) from the Manicouagan impact crater and of its fusion-formed glass analog have been investigated by X-ray diffraction studies. The experimental X-ray intensity distribution patterns indicate that the diaplectic and fusion-formed glasses are structurally rather similar, the former being apparently slightly less disordered. Theoretical X-ray distribution curves have been calculated using the structure of high albite as a quasi-crystalline model of the glass structure. The experimental and theoretical curves show fair similarity when the calculations are based on the complete unit cell. It is inferred therefore, that the structures of both kinds of glasses possess an average short range order comparable to that in high albite and extending to about the dimensions of the unit cell. In addition, the experimental X-ray scattering pattern and X-ray Debye-Scherrer transmission photographs of the diaplectic glass reveal the presence of relics up to about 8 nm in size of the previous crystalline lattice of the primary labradorite. The present results support Grady's shear band model according to which diaplectic glass may represent the quench product of a shock-generated high-density melt frozen in prior to total pressure release. 相似文献