共查询到19条相似文献,搜索用时 93 毫秒
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同步辐射X射线光源已经成功地应用到高压科学研究的诸多领域. 文章简要回顾了同步辐射高压技术的发展历史,简要介绍了同步辐射X射线衍射技术在高压状态方程、强关联体系、地球内部物质以及早期生命起源等研究中的应用.介绍了同步辐射X射线光谱技术(包括晶格振动声子谱的测量)在高压研究中的应用,此外, 还介绍了时间分辨的同步辐射技术在冲击压缩研究中的应用,最后展望了未来先进光源应用于高压科学研究的前景. 相似文献
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同步辐射光源具有宽光谱、高亮度、高准直等优异性能,被广泛地用于高压科学研究。在依托同步辐射光源所发展的诸多高压研究手段中,X射线衍射是最基本的也是应用最多的实验技术之一。本文简单介绍了同步辐射光的独特性能和光源的基本构成,以及同步辐射光束线和实验站的基本概念。针对基于金刚石对顶砧(DAC)的高压X射线衍射技术,阐述了多种测试方法的原理和应用,包括粉末衍射、单晶衍射、多晶衍射、径向衍射、激光加温衍射以及快速加载衍射等。对北京同步辐射装置(BSRF)4W2高压衍射线站所提供的同步辐射光品质、X射线微聚焦能力、多种衍射方法以及新近发展的实验技术进行了较详细的描述,并展望了高能同步辐射光源(HEPS)的建设给高压科学研究带来的机遇。 相似文献
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上海光源X射线成像及其应用研究进展 总被引:2,自引:0,他引:2
作为具有国际先进水平的第三代同步辐射光源,上海光源的X射线亮度比普通X光管高12~16个量级,基于它的X射线成像具有高空间分辨、高衬度分辨和快时间分辨的特点,同步辐射X射线可对样品实现原位、无损、高分辨、三维和动态成像,而且可以实现相位衬度成像,从而将X射线成像的应用领域拓展到软组织、聚合物等低Z材料。自2009年正式向用户开放以来,上海光源已在生物医学、材料科学、古生物学、土壤学等领域取得了一大批重要研究成果。为更好地支持用户,上海光源X射线成像组在定量成像、CT成像、快速CT重构等成像方法学领域开展了较为全面、系统的研究,大幅提高了实验效率和对不同样品的适应性。本文简要介绍了上海光源X射线成像方法学发展及相关应用研究进展。 相似文献
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同步辐射X射线相衬显微CT在古生物学中的应用 总被引:3,自引:0,他引:3
X射线无损成像技术在古生物化石标本研究领域中应用十分广泛.近几年来,随着技术的不断革新,同步辐射X射线相衬显微断层成像技术(SRX-PC-μCT)也被引入到这一领域.由于同步辐射光源产生的硬X射线具有高亮度、高准直性和高空间相干性等优点,可以实现化石标本高分辨率(亚微米级)的无损三维显微成像,给古生物学的发展带来了新的机遇.文章简要回顾了用于古生物化石标本无损成像技术的发展历程,并在此基础L综述了同步辐射X射线断层显微成像技术在古生物学领域的应用现状和前景. 相似文献
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同步辐射光源是带电粒子在加速器储存环中以接近光速的速度运动时,沿轨道切线方向发射出的辐射,同步辐射X射线荧光分析(SR-XRF)是以同步辐射X射线作为激发光源的X荧光光谱分析技术.同步辐射X射线荧光分析包括了用于微区及微量元素分析的同步辐射XRF、用于表面及薄膜分析的同步辐射全反射X射线荧光(SR-TXRF)以及用于三... 相似文献
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随着第四代同步辐射光源的兴起,得益于X射线亮度和相干性的大幅度提升,同步辐射实验技术在谱学、散射和成像等方面取得了显著进步。这些技术能够探测复杂非均匀体系和动态变化过程中的物质结构、成分、化学价态、电子态和磁性等关键信息,在基础科学领域和应用基础研究中发挥关键作用。文章旨在介绍第四代同步辐射光源的线站技术优势,并结合具体例子探讨其在若干物理研究中的应用,同时也讨论了当前存在的工程技术挑战。希望人们能够了解第四代同步辐射光源的光束线站的特点和应用潜力,以促进其在各个科研领域的推广。 相似文献
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ABSTRACT We tested boron-doped diamond (BDD) synthesized by chemical vapor deposition (CVD) as a heating element in a multi-anvil apparatus. We succeeded in manufacturing BDD into a tubular shape by laser cutting and electric discharging machining. The BDD tube shaped by the electric discharging machining was contaminated by discharging electrode materials (Mo and W), which affected the heating performance. The laser-cut BDD tube has a clean surface and, therefore, had a good heating performance. We succeeded in generating temperature as high as 2670?K at a pressure around 30?GPa with laser-cut heater. Heating reproducibility was confirmed through repeated heating and cooling cycles. The recovered sample shows that a higher temperature generation above 2670?K was prevented by eutectic melting of ZrO2 thermal insulator and Al2O3 sample. Owing to the commercial availability with a reasonable price, CVD–BDD heaters are more practical than a high-pressure synthesized BDD heaters for wide applications. 相似文献
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A review is given on current high-pressure studies of magnetism employing the new method of nuclear forward scattering of synchrotron radiation as well as the conventional Mössbauer effect. Comparative studies of the magnetic properties of intermetallic RFe2 Laves phases and Eu(II)-chalcogenides are described. We present as examples the pressure induced changes in YFe2 and ScFe2 at pressures up to 100 GPa as well as studies of EuTe in the NaCl-type and the CsCl-type high-pressure phase. Future high-pressure applications of nuclear resonant scattering will be discussed. 相似文献
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Kristina E. Lipinska-Kalita Oliver A. Hemmers Patricia E. Kalita Steve Gramsh Thomas Hartmann 《Journal of Physics and Chemistry of Solids》2008,69(9):2268-2273
A review of our recent and ongoing extensive high-pressure synchrotron X-ray diffraction and high-pressure optical spectroscopy studies of nanocrystalline composites is presented. These heterophased, nano-architectured composites consist of amorphous matrices with dispersed nanocrystals or quantum dots. We show how besides compositional variations, additional tuning of these glass-derived nanocomposites can be done by exploiting elevated pressure. We examine stability and pressure-driven phase transitions occurring in nanocrystals as well as structural changes occurring in the glass matrix. Finally, we discuss the influence of the glass matrix of a composite on the structural transformations occurring in the embedded nanocrystals. 相似文献
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Abstract In the second phase construction of further insertion devices, beamlines and experimental stations at the Beijing Synchrotron Radiation Facility, a dedicated high-pressure x-ray diffraction station will be constructed. We outline the synchrotron radiation source, beamline optics and high-pressure x-ray diffraction apparatus. This facility is planned to operate for users in 1994. Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991 相似文献
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运用金刚石对顶砧(Diamond Anvil Cell,DAC)技术,以液氩作为传压介质,在最高压力为67 GPa的压力范围内对NiO进行了原位的同步辐射X射线衍射研究。在整个实验过程中,并未发现第一类结构相变,也没有发现T.Sasaki等预测的在60 GPa左右轴比c/a随压力的变化率而突然增大的现象,且此压力范围内NiO的结构畸变程度随压力的变化趋势相比以前的研究结果要平缓一些。用三阶的Brich-Murnaghan方程对实验数据进行拟合,得到的体弹模量及其对压力的一阶导数分别为B0=195(4) GPa和B0′=5.3(2)。 相似文献
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The high-pressure phase diagram of P is studied using density functional total energy, linear response lattice dynamics and model Debye-Grüneisen theories. The volume dependent electron-phonon coupling lambda approximately 0.7-0.9 is extracted for the bcc structure and found to increase with increasing volume. We propose that this phase might be realized in epitaxial thin films using templates such as V(100), Fe(100), or Cr(100) relevant to spintronics applications. 相似文献
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Kazumi Matsushige 《Phase Transitions》2013,86(3-4):247-262
Pressure effects of phase transition behaviour in two kinds of ferroelectric polymers of poly(vinylidene fluoride), PVDF, and copolymers of vinylidene fluoride and trifluoroethylene, (VDF/TrFE), are discussed. In the case of PVDF, several high-pressure treatments including a high-pressure annealing and a uniaxial compression were shown to induce a crystal transformation from a non-polar Form II crystal to a polar Form I crystal, which has ferroelectric characteristics and high piezoelectric activity. In addition, substantial pressure effects on ferroelectric phase transition points as well as crystal structures were observed for (VDF/TrFE) copolymers with different VDF contents. The most significant pressure effects were observed for copolymer samples with unstable ferroelectric structures at atmospheric pressure. From high-pressure X-ray and Raman scattering studies, these pressure effects were suggested to originate from the pressure-induced conformational transition from gauche to trans in the molecular chains. 相似文献
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V. E. Antonov O. I. Barkalov M. Calvo-Dahlborg U. Dahlborg V. F. Fedotov A. I. Harkunov 《高压研究》2013,33(3-6):261-272
Abstract Phase transformations occurring in initially amorphous Zn41 Sb59 semiconductor at pressures to 10 GPa and temperatures to 350C were studied using the measurement of electrical resistance, in situ energy dispersive X-ray diffraction and neutron diffraction on quenched high-pressure phases at ambient pressure. The studied T- P region involves the regions of reversible and irreversible crystallisation and phase transitions between the equilibrium crystalline low-pressure and high-pressure phases. 相似文献
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蓝光或紫外激光在光电子学和光储存方面有广阔的应用,一直是国际上关注的前沿领域.而金刚石是最好的半导体紫外发光材料.特别是用于高温、高压、高功率、强辐射和强腐蚀环境中更能显示其优越性.目前人们已在实验上用同质外延、异质外延的方法制备了金刚石紫外发光二极管,观察到了较强的紫外光发射.人们尝试用金刚石与其他半导体材料结合的方法,成功地研制出了金刚石紫外发光二极管,开拓了该研究领域最新研究方向.文章对这些金刚石紫外发光器件研究的最新进展进行了评述. 相似文献