Relevant bibliographies by topics / XANES

Academic literature on the topic 'XANES'

Author: Grafiati
Published: 4 June 2021
Last updated: 7 September 2024

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Contents

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'XANES.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "XANES"

1

Natori, Sachika, Minako Kurisu, Naomi Kawamura, and Yoshio Takahashi. "High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy for the Speciation of Fe in Aerosol Samples." Minerals 12, no. 5 (April 26, 2022): 536. http://dx.doi.org/10.3390/min12050536.

Full text
Abstract:
In this study, we compared the high-energy resolution X-ray fluorescence X-ray absorption near-edge structure (HERFD-XANES) and normal XANES spectra of various iron (Fe) species and Fe in atmospheric aerosol samples to explore the advantages of Fe K-edge HERFD-XANES for Fe speciation in aerosols using the linear combination fitting (LCF) of XANES spectra. We also conducted Fe extraction experiments to validate the LCF-XANES. In the HERFD-XANES spectra, the pre-edge region showed specific structures absent in normal XANES. HERFD-XANES also produced more distinctive shoulders within each spectrum than normal XANES. HERFD-XANES was applied to an aerosol sample (MT21-S2) collected in Tokyo, Japan. Normal XANES identified ferrihydrite, biotite, and montmorillonite, whereas HERFD-XANES clearly detected goethite as a fourth component. Normal XANES did not distinguish between ferrihydrite and goethite in LCF because of their similar structures. A similar trend was observed in the pre-edge region, and the Fe extraction experiment result was consistent with the LCF result in the pre-edge region. Thus, LCF of HERFD-XANES, in particular for the pre-edge region, can be a powerful tool for Fe speciation in aerosols.
APA, Harvard, Vancouver, ISO, and other styles
2

Natori, Sachika, Minako Kurisu, Naomi Kawamura, and Yoshio Takahashi. "High-Energy Resolution Fluorescence Detected X-ray Absorption Spectroscopy for the Speciation of Fe in Aerosol Samples." Minerals 12, no. 5 (April 26, 2022): 536. http://dx.doi.org/10.3390/min12050536.

Full text
Abstract:
In this study, we compared the high-energy resolution X-ray fluorescence X-ray absorption near-edge structure (HERFD-XANES) and normal XANES spectra of various iron (Fe) species and Fe in atmospheric aerosol samples to explore the advantages of Fe K-edge HERFD-XANES for Fe speciation in aerosols using the linear combination fitting (LCF) of XANES spectra. We also conducted Fe extraction experiments to validate the LCF-XANES. In the HERFD-XANES spectra, the pre-edge region showed specific structures absent in normal XANES. HERFD-XANES also produced more distinctive shoulders within each spectrum than normal XANES. HERFD-XANES was applied to an aerosol sample (MT21-S2) collected in Tokyo, Japan. Normal XANES identified ferrihydrite, biotite, and montmorillonite, whereas HERFD-XANES clearly detected goethite as a fourth component. Normal XANES did not distinguish between ferrihydrite and goethite in LCF because of their similar structures. A similar trend was observed in the pre-edge region, and the Fe extraction experiment result was consistent with the LCF result in the pre-edge region. Thus, LCF of HERFD-XANES, in particular for the pre-edge region, can be a powerful tool for Fe speciation in aerosols.
APA, Harvard, Vancouver, ISO, and other styles
3

Nicholls, M., M. N. Najman, Z. Zhang, M. Kasrai, P. R. Norton, and P. U. P. A. Gilbert. "The contribution of XANES spectroscopy to tribology." Canadian Journal of Chemistry 85, no. 10 (October 1, 2007): 816–30. http://dx.doi.org/10.1139/v07-093.

Full text
Abstract:
X-ray absorption near edge structure spectroscopy (XANES) analysis has been routinely used to study the complex chemical interactions between additives in engine oil and metallic surfaces during high-temperature and pressure reciprocating wear conditions. XANES analysis provides detailed chemical and structural information on the resultant antiwear and tribo films formed on metallic surfaces. The following review will illustrate how XANES analysis on the macro scale can provide the information required to elucidate complex film formation mechanisms, then describes the use of emerging XANES spectromicroscopy to such systems, and concludes by showing the complementary nature of the macro and micro scale spatially resolved XANES analysis; Professor Bancroft has utilized the combination of these to stay at the forefront of XANES research in the field of tribology and in spectroscopy science in general.Key words: tribology, XANES, X-ray absorption near edge structure spectroscopy, metals, thiophosphates, spectromicroscopy, tribochemistry.
APA, Harvard, Vancouver, ISO, and other styles
4

Ge, Mingyuan, and Wah-Keat Lee. "PyXAS – an open-source package for 2D X-ray near-edge spectroscopy analysis." Journal of Synchrotron Radiation 27, no. 2 (February 20, 2020): 567–75. http://dx.doi.org/10.1107/s1600577520001071.

Full text
Abstract:
In the synchrotron X-ray community, X-ray absorption near-edge spectroscopy (XANES) is a widely used technique to probe the local coordination environment and the oxidation states of specific elements within a sample. Although this technique is usually applied to bulk samples, the advent of new synchrotron sources has enabled spatially resolved versions of this technique (2D XANES). This development has been extremely powerful for the study of heterogeneous systems, which is the case for nearly all real applications. However, associated with the development of 2D XANES comes the challenge of analyzing very large volumes of data. As an example, a single 2D XANES measurement at a synchrotron can easily produce ∼106 spatially resolved XANES spectra. Conventional manual analysis of an individual XANES spectrum is no longer feasible. Here, a software package is described that has been developed for high-throughput 2D XANES analysis. A detailed description of the software as well as example applications are provided.
APA, Harvard, Vancouver, ISO, and other styles
5

Kizler, P., P. Lamparter, and S. Steeb. "X -Ray Absorption Near Edge Structure (XANES) Calculations for the Amorphous Fe80B20- and Ni80B20-Alloys." Zeitschrift für Naturforschung A 44, no. 3 (March 1, 1989): 189–94. http://dx.doi.org/10.1515/zna-1989-0304.

Full text
Abstract:
Xanes spectra of the amorphous Fe80B20- and Ni80B20-alloys have been investigated using the electron multiple scattering theory of Durham et al. The calculations were based on several models for the structure of amorphous Fe80B20 and Ni80B20. Very good agreement between theoretical and experimental XANES curves was met. Opposite to former expectations for obtaining information on bond angles by XANES, this study shows that XANES points to more complex features of the structure than can be expressed in terms of bond angles.
APA, Harvard, Vancouver, ISO, and other styles
6

Park, Jae Yeon, Jitendra Pal Singh, Jun Lim, and Sangsul Lee. "Development of XANES nanoscopy on BL7C at PLS-II." Journal of Synchrotron Radiation 27, no. 2 (February 20, 2020): 545–50. http://dx.doi.org/10.1107/s160057752000082x.

Full text
Abstract:
X-ray absorption near-edge structure (XANES) imaging is a powerful tool to visualize the chemical state distribution of transition-metal-based materials at synchrotron radiation facilities. In recent years, the electrochemical working rechargeable battery has been the most studied material in XANES imaging owing to the large increase of portable electronics and electric vehicles. This work acknowledges the importance of battery analysis and has developed the XANES imaging system on BL7C at Pohang Light Source-II (PLS-II). BL7C employs an undulator taper configuration to obtain an energy band >130 eV near the K-absorption edge of the target element with a minimum energy interval >0.2 eV. While measuring energy-dependent images, the zone plate translation maintains the best focus, and then various data processes such as background correction, image registration and clustering allow single XANES spectrum extraction and chemical distribution mapping. Here, the XANES imaging process is described, the XANES spectrum quality is identified and the chemical states of the partially charged cathode material used in lithium-ion batteries as an application example are examined.
APA, Harvard, Vancouver, ISO, and other styles
7

Pongpiachan, Siwatt, Kanjana Thumanu, Charnwit Kositanont, Klaus Schwarzer, Jörg Prietzel, Phoosak Hirunyatrakul, and Itthipon Kittikoon. "Parameters Influencing Sulfur Speciation in Environmental Samples Using Sulfur K-Edge X-Ray Absorption Near-Edge Structure." Journal of Analytical Methods in Chemistry 2012 (2012): 1–12. http://dx.doi.org/10.1155/2012/659858.

Full text
Abstract:
This paper aims to enhance the credibility of applying the sulfur K-edge XANES spectroscopy as an innovative “fingerprint” for characterizing environmental samples. The sensitivities of sulfur K-edge XANES spectra of ten sulfur compound standards detected by two different detectors, namely, Lytle detector (LyD) and Germanium detector (GeD), were studied and compared. Further investigation on “self-absorption” effect revealed that the maximum sensitivities of sulfur K-edge XANES spectra were achieved when diluting sulfur compound standards with boron nitride (BN) at the mixing ratio of 0.1%. The “particle-size” effect on sulfur K-edge XANES spectrum sensitivities was examined by comparing signal-to-noise ratios of total suspended particles (TSP) and particulate matter of less than 10 millionths of a meter(PM10)collected at three major cities of Thailand. The analytical results have demonstrated that the signal-to-noise ratios of sulfur K-edge XANES spectra were positively correlated with sulfate content in aerosols and negatively connected with particle sizes. The combination of hierarchical cluster analysis (HCA) and principal component analysis (PCA) has proved that sulfur K-edge XANES spectrum can be used to characterize German terrestrial soils and Andaman coastal sediments. In addition, this study highlighted the capability of sulfur K-edge XANES spectra as an innovative “fingerprint” to distinguish tsunami backwash deposits (TBD) from typical marine sediments (TMS).
APA, Harvard, Vancouver, ISO, and other styles
8

Price, S. W. T., K. Ignatyev, K. Geraki, M. Basham, J. Filik, N. T. Vo, P. T. Witte, A. M. Beale, and J. F. W. Mosselmans. "Chemical imaging of single catalyst particles with scanning μ-XANES-CT and μ-XRF-CT." Physical Chemistry Chemical Physics 17, no. 1 (2015): 521–29. http://dx.doi.org/10.1039/c4cp04488f.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Leri, Alessandra C., and Bruce Ravel. "Sample thickness and quantitative concentration measurements in BrK-edge XANES spectroscopy of organic materials." Journal of Synchrotron Radiation 21, no. 3 (March 12, 2014): 623–26. http://dx.doi.org/10.1107/s1600577514001283.

Full text
Abstract:
While XANES spectroscopy is an established tool for quantitative information on chemical structure and speciation, elemental concentrations are generally quantified by other methods. The edge step in XANES spectra represents the absolute amount of the measured element in the sample, but matrix effects and sample thickness complicate the extraction of accurate concentrations from XANES measurements, particularly at hard X-ray energies where the X-ray beam penetrates deeply into the sample. The present study demonstrates a method of quantifying concentration with a detection limit approaching 1 mg kg−1using information routinely collected in the course of a hard X-ray XANES experiment. The XANES normalization procedure unambiguously separates the signal of the absorber from any source of background. The effects of sample thickness on edge steps at the bromineK-edge were assessed and an empirical correction factor for use with samples of variable mass developed.
APA, Harvard, Vancouver, ISO, and other styles
10

RANJAN, RAKESH KUMAR. "Derivation of Relation between a parameter of Inverse correlation and effective Charge of X-ray absorbing K-Edge of Copper atom in it’s different Compounds." Journal of Ultra Scientist of Physical Sciences Section B 32, no. 5 (October 31, 2020): 31–35. http://dx.doi.org/10.22147/jusps-b/320501.

Full text
Abstract:
The article gives an overview of the XANES technique contribution to the analysis of multi-component catalysts. The theoretical basis of the technique, the interpretation of the energy position and intensity of XANES features, and the numerical methods developed to interpret XANES data on catalytic systems are described and discussed. XANES in the K-edge of copper in the systems. CuO, Cu(NO3)2, La2CuO4, CuCl2, and CuBr have been investigated and transitions have been assigned to the observed structures. The measurements have been used for calculating the first coordination bond distance in the above systems. It is observed that the values so determined agree fairly well with crystallographic values
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "XANES"

1

Ferrand, Jessica. "Le phénomène de brunissement des vitraux médiévaux : critères d’identification et nature de la phase d’altération." Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1174/document.

Full text
Abstract:
Les vitraux du Moyen Âge, dont les pièces de verre contiennent du manganèse, sont fréquemment atteints d'une pathologie communément appelée «brunissement ». Ce phénomène, qui se traduit par la présence de taches brunes riches en manganèse en surface ou subsurface du verre limitant le passage de la lumière et gênant la lisibilité de l'œuvre, est peu documenté et son occurrence parmi les vitraux n'est pas précisément connue. Un des problèmes majeurs pour ce qui concerne la conservation/restauration des œuvres est l'absence de traitements efficaces et durables pour cette pathologie. En France actuellement, l'absence de traitement est donc préconisée, ce qui ne satisfait ni les architectes, ni les conservateurs, ni les restaurateurs. La connaissance approfondie des processus physico-chimiques à l'origine du phénomène de brunissement est donc nécessaire pour proposer des réponses aux questions et aux attentes des conservateurs/restaurateurs. Au cours de cette thèse un panel de 24 échantillons de verres de vitraux historiques et de 3 échantillons archéologiques ont été étudiés par des méthodes microscopiques et spectroscopiques afin i) d'établir des critères d'identification du phénomène de brunissement dû au manganèse et ii) d'obtenir des informations sur la nature des phases brunes et sur le degré d'oxydation du manganèse dans ces phases. Parallèlement à l'étude des échantillons anciens, des verres modèles de composition proche de celle des vitraux médiévaux ont été synthétisés avec deux objectifs : i) la compréhension de la réaction entre le manganèse et le fer et de l'influence des paramètres de fabrication sur la couleur des verres et ii) l'étude de l'influence que peuvent avoir les bactéries dans le développement du phénomène de brunissement
The medieval stained glass windows, which glass composition contain manganese, are often affected by an alteration commonly designated as "browning". This phenomenon results in the presence of Mn-rich brown spots at the surface or subsurface of the glass thus limiting the passage of light and hindering the interpretation of the artwork. Poorly documented, the occurrence of browning among stained glass windows is not precisely described. Currently, one of the major problems in terms of conservation and restoration is that long-term treatments are not available. In these conditions, the recommendations are not to treat the affected glasses, a solution that satisfies neither the architects nor the curators, nor the restorers. In order to answer the questions and expectations of curators and restorers the comprehension of this phenomenon is essential. In this work, a panel of 24 historical and 3 archaeological stained glass samples were studied by microscopic and spectroscopic methods in order to i) establish reliable criteria for identifying the browning phenomenon due to manganese and ii) obtain information on the nature of the dark phases and the oxidation state of manganese in these phases. In parallel with the study of ancient samples, synthetic glasses with medieval-like compositions were synthesized for: i) understanding the reaction between manganese and iron, as well as the influence of the process parameters on the color of glasses and ii) studying the influence of bacteria in the development of the browning phenomenon
APA, Harvard, Vancouver, ISO, and other styles
2

Gatuingt, Laure. "Etude des mécanismes de formation des patines manganésifères des grès du château de Lunéville." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1085/document.

Full text
Abstract:
La formation de patines noires riches en fer et/ou manganèse sur les édifices en grès est un phénomène observé pour une grande variété d’environnements mais qui n’est pas encore totalement compris. Le château de Lunéville, situé dans l’est de la France, est un cas d’étude intéressant puisqu'il présente des patines apparues pour différentes conditions : certaines semblent s’être formées naturellement alors que d’autres se sont développées sur des pierres ayant été exposées à un incendie. Ces dernières ont connu une élévation de leur température de surface, mais ont surtout été soumises à de grandes quantités d’eau lors de l’intervention des pompiers. Ce travail de thèse vise à mieux comprendre le phénomène de formation des patines en étudiant différents faciès de grès prélevés sur le château de Lunéville et en carrière. Afin d’appréhender l’influence des paramètres intrinsèques aux grès, des faciès patinés et non patinés ont été comparés d’un point de vue pétrophysique, chimique et minéralogique en s’appuyant sur des techniques d’analyse de laboratoire (microscopies optique et électronique avec sonde d’analyse dispersive en énergie, diffraction des rayons X, spectrométrie Raman, mesures de perméabilité, porosité et capillarité, ...), et sur de grands instruments (analyses par émission de rayons X induits par des particules (PIXE) sur l’accélérateur de proton AGLAE, analyses en micro-diffraction des rayons X et micro-spectrométrie d’absorption X (XANES) au synchrotron SOLEIL). En complément de cette caractérisation des blocs de pierre, les patines formées dans différents environnements ont également été comparées afin de dégager les paramètres extrinsèques dominants. Enfin, l’aspect dynamique de la libération du manganèse par les grès a été étudié, d’une part en menant des expériences de dissolution pour plusieurs pH, d’autre part en montrant qu’il était possible de recréer une patine de manganèse en laboratoire, par imbibition d’une éprouvette de grès. Les résultats obtenus permettent de proposer un modèle de formation des patines basé sur la dissolution des phases manganésifères initialement présentes dans les grès, puis la migration des ions libérés en solution dans le milieu poreux vers la surface des pierres
The formation of iron and/or manganese black patina on sandstone buildings is a phenomenon observed for various environments but which is not fully understood yet. The palace of Lunéville, in eastern France, is an interesting example because it has patinas that have developed in different conditions : some seem to have grown naturally while others have appeared on stones which were exposed to a fire. These stones experienced an increase of their surface temperature, but most of all, they were subjected to a substantial volume of water as part of attempts to extinguish the fire. The goal of this thesis is to understand the formation of the patinas by investigating different sandstone facies collected from the palace of Lunéville and from quarry. In order to understand the influence of the sandstones intrinsic parameters, the patinated and unpatinated facies were compared from petrophysical, chemical and mineralogical point of view, using laboratory techniques (optical and electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction, Raman spectrometry, permeability, porosity and capillarity measurements, ...) and large instruments (Particle Induced X-ray Emission (PIXE) on the AGLAE proton accelerator, X-ray micro-diffraction analysis and X-ray absorption micro spectroscopy (XANES) at the SOLEIL synchrotron). In addition to this characterization, patinas coming from different environments were also compared in order to extract the main extrinsic parameters. Finally, the dynamical aspect of the release of manganese from the sandstones was investigated by conducting dissolution experiments at various pH, and by demonstrating the possibility to recreate a Mn patina in laboratory, using sandstone imbibition techniques. The results allow to propose a model for the patina formation based on the dissolution of the Mn-phases initially present in the sandstones’ bulks, followed by the migration through the porous network towards the surface of the ions released in the solution
APA, Harvard, Vancouver, ISO, and other styles
3

Mizoguchi, Teruyasu. "Study of Local Atomic and Electronic Structures in Ceramic Materials by ELNES and XANES." 京都大学 (Kyoto University), 2002. http://hdl.handle.net/2433/149775.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Nemausat, Ruidy. "Etude expérimentale et théorique des fluctuations thermiques quantiques des noyaux par spectroscopies d'absorption X et RMN." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066158/document.

Full text
Abstract:
Le but de cette thèse est de décrire l'impact des fluctuations thermiques quantiques sur les spectres XANES et RMN du solide, à l'aide d'une étude conjointe expérimentale et théorique. Ce projet comporte deux volets. D'une part, il s'agit d'acquérir des données expérimentales de très bonne qualité, afin d'observer et comprendre l'influence des vibrations quantiques dans les oxydes d'éléments légers. D'autre part, un modèle théorique est mis en place afin de reproduire les effets observés expérimentalement et décrire leur origine d'un point de vue fondamental. L'approche théorique développée est fondée sur la théorie de la fonctionnelle de la densité. Dans le cadre de l'approximation de Born-Oppenheimer et de l'approximation quasi-harmonique, les fluctuations thermiques de nature quantiques sont modélisées en générant des configurations atomiques obéissant à la statistique quantique à température finie. Les spectres XANES et paramètres RMN sont, par la suite, calculés dans ces configurations et les résultats moyens sont comparés aux données spectroscopiques à température finie. Cette approche a été validée par une étude menée dans une série d'oxydes d'éléments légers, où les résultats se sont avérés être en excellent accord avec les données expérimentales originales que nous avons enregistrées. En outre, il est montré que les fluctuations quantiques des noyaux ne jouent pas le même rôle selon la symétrie locale du site atomique sondé
In this thesis the impact of quantum thermal fluctuations on XANES and solid-state NMR spectra is described using an experimental and theoretical joint study. This project has two components. First, high-quality experimental data are acquired in order to observe and understand the influence of quantum vibrations in light-elements oxides. Second, a theoretical model is set up to reproduce the effects observed experimentally and describe their origin from a fundamental point of view. The developed theoretical approach is based on the density-functional theory. Within the Born-Oppenheimer and quasiharmonic approximations, the quantum thermal fluctuations of nuclei are modeled by generating atomic configurations obeying quantum statistics at finite temperature. The XANES spectra and NMR parameters are subsequently calculated in these configurations and the average results are compared with spectroscopic data at finite temperature. This approach has been validated by a joint theoretical-experimental study conducted in a series of light-element oxides, where the results were found to be in excellent agreement with the original experimental data. In addition, it is shown that the impact of the quantum fluctuations of the nuclei is influenced by the local symmetry of the probed atomic site
APA, Harvard, Vancouver, ISO, and other styles
5

Marcaillou, Clément. "Serpentinisation et production d'hydrogène en contexte de dorsale lente : approche expérimentale et numérique." Phd thesis, Université de Grenoble, 2011. http://tel.archives-ouvertes.fr/tel-00676948.

Full text
Abstract:
L'altération hydrothermale d'une péridotite océanique conduit à une profonde transformation minéralogique qui correspond au " processus de serpentinisation ". Durant ce processus, le Fe2+ initialement contenu dans les olivines et/ou les pyroxènes peut s'oxyder en Fe3+ en incorporant des phases nouvellement formées comme la serpentine et la magnétite. L'hydrolyse de l'eau associée à cette réaction entraine la production de grandes quantités d'hydrogène. Au niveau des dorsales océaniques, de fortes concentrations en hydrogène et hydrocarbures ont été récemment mises en évidence sur quelques sites hydrothermaux d'un genre nouveau, tous situés dans un contexte ultrabasique. Dans le but de comprendre les processus contrôlant l'altération hydrothermale des péridotites, et en particulier la production d'hydrogène dans ce type de contexte, nous avons couplé des expériences de serpentinisation insitu à des simulations thermodynamiques. Les produits de synthèse obtenus dans nos expériences ont été caractérisés à l'aide de différents outils spectroscopiques, principalement par absorption des rayons X en synchrotron. Nous avons ainsi développé plusieurs protocoles expérimentaux permettant d'une part de quantifier les proportions des phases minérales, mais aussi de déterminer la distribution et la spéciation du fer dans nos échantillons altérés. Nos expériences montrent que la cinétique de serpentinisation est fortement dépendante des conditions physicochimiques (température, rapport eau/roche, état structurel et composition chimique de protolithe) présentes dans le milieu naturel. Parallèlement, ces travaux indiquent que les rôles joués par la serpentine et la magnétite dans la production d'hydrogène évoluent suivant la température mais changent également fortement au cours de la réaction. Ces résultats, affinés par des modélisations numériques, ont été replacés dans un cadre naturel, dans le but de déterminer les différents processus se produisant le long d'un trajet P-T hydrothermal. Il apparait ainsi que l'essentiel de la réaction de serpentinisation s'effectue sur le trajet " prograde " avec une production maximale d'hydrogène située autour de 325°C. Enfin, et grâce aux gradients de température estimés dans ce type de contexte, nous avons pu estimer la taille et la géométrie probable d'un site hydrothermal comme celui de " Rainbow ".
APA, Harvard, Vancouver, ISO, and other styles
6

Piton, Marcelo Rizzo. "Síntese e caracterização do composto SrTi1-xMnxO3 nanoestruturado." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/18/18158/tde-29012015-215637/.

Full text
Abstract:
Amostras nanoestruturadas do sistema SrTi1-xMnxO3 (STM) com x = 0%, 0.5%, 1%, 2.5%, 5% e 10% na forma de pó foram sintetizadas através do método dos precursores poliméricos. As propriedades térmicas, estruturais e ópticas das amostras STM calcinadas em diferentes temperaturas foram analisadas a temperatura ambiente através de técnicas de análise térmica, difração de raios-x, espectroscopia de absorção de raios-x e fotoluminescência. Os resultados obtidos através das técnicas de analise térmica mostraram que o íon manganês causa um efeito retardante, aumentando a temperatura onde ocorre o início da cristalização. Os resultados de DRX mostraram que no limite de solubilidade estudado, o íon manganês foi incorporado em solução sólida no sítio B na rede do SrTiO3 (ST), assumindo estados de oxidação entre +3,4 e +3,7, indicando que ocorre a criação de defeitos para compensação de cargas, mantendo a neutralidade elétrica do material. A análise dos espectros de fotoluminescência das amostras STM amorfas mostrou que o aumento da quantidade de manganês até 1% leva a um aumento da intensidade fotoluminescência em relação a amostra SrTiO3. Entretanto, a adição de manganês acima desta quantidade leva a uma diminuição pronunciada da intensidade fotoluminescente. Nas amostras amorfas não foi observada uma variação significativa da ordem local ao redor dos átomos de titânio bem como no estado de oxidação dos átomos de manganês à medida que a quantidade de manganês aumenta. Desta forma, a variação da intensidade fotoluminescente não pôde ser atribuída a estes fatores. O aumento da temperatura de calcinação leva a uma diminuição significativa da intensidade fotoluminescente. Uma análise dos espectros XANES medidos na borda K do titânio destas amostras mostrou que ocorre uma maior ordenação dos átomos de Ti nos octaedros de oxigênio [TiO6] a medida que a temperatura de calcinação aumenta, ou seja, à medida que aumenta o grau de cristalinidade das amostras.
Nanostructured SrTi1-xMnxO3 (STM) powder samples with x = 0%, 0.5%, 1%, 2.5%, 5% and 10% were synthesized by the polymeric precursors method. The thermal, structural and optical properties of STM samples heat-treated at different temperatures were analyzed by thermal analysis, X-ray diffraction, X-ray absorption spectroscopy and photoluminescence techniques. The thermal analysis results have shown that manganese ion causes a retarding effect, increasing the onset of the crystallization temperature. The XRD results showed that manganese ion is incorporated in a solid solution in the B site of the SrTiO3 (ST) network for the range of solubility studied, with oxidation states between +3.4 and +3.7, indicating the creation of charge compensation defects, keeping the materials electrical neutrality. The analysis of the photoluminescence (PL) spectra of the STM amorphous samples showed that the PL intensity increases when the amount of manganese is up to 1%. However, higher manganese concentrations leads to a pronounced decrease of the photoluminescence intensity. The amorphous samples showed no significant change of the local order around the titanium atoms, observed as well as in the oxidation state of the manganese atoms as the amount of manganese increases. Thus, the variation of the photoluminescence intensity cannot be explained by these factors. Increasing the calcination temperature leads to a significant decrease of the photoluminescence intensity. An analysis of the XANES spectra measured at the titanium K edge of these samples showed that as the calcination temperature increases, i. e., as it increases the degree of crystallinity, the ordering of the Ti atoms in the oxygen octahedra TiO6 of the samples increases.
APA, Harvard, Vancouver, ISO, and other styles
7

Benali, Cherif Nourredine. "Etude structurale de complexes de cuivre par diffraction et spectroscopie d'absorption X (EXAFS et XANES)." Aix-Marseille 3, 1994. http://www.theses.fr/1994AIX30038.

Full text
Abstract:
La dopamine beta hydroxylase (dh) est une cuproenzyme liee a la biosynthese des catecholamines. Son site actif contient deux atomes de cuivre qui participent a des titres divers a l'hydroxylation de la dopamine en noradrenaline. Le but de ce travail est d'etudier une serie de complexes de cuivre, mimant le site actif de la dh, par diffraction x et spectroscopie d'absorption x. Devant les difficultes presentees par la cristallisation de ces complexes, une seule structure cristallographique originale ayant pu etre etablie au cours de ce travail, des mesures de spectroscopie d'absorption x ont ete effectuees a l'aide du rayonnement synchrotron et des installations du l. U. R. E. A orsay. Les spectres exafs et xanes ont ete interpretes, dans le cadre de la diffusion simple, en s'appuyant sur des modeles structuraux connus et sur des calculs de modelisation moleculaire. C'est ainsi qu'il a ete possible: de mettre en evidence des structures nouvelles dans lesquelles l'une des deux pyridines du ligand organique n'est pas impliquee dans la coordination de l'atome de cuivre; d'imaginer la structure de complexes bimetalliques inconnus; de suivre les changements structuraux accompagnant l'oxydation ou la reduction du metal, en particulier dans le cas ou un atome de soufre est lie a cu(i) ou cu(ii). Les resultats de ces travaux serviront de references pour l'etude exafs et xanes de la dh
APA, Harvard, Vancouver, ISO, and other styles
8

Gorczyca, Agnès. "Caractérisation de catalyseurs métalliques supportés par spectroscopie XANES, apports du calcul quantique dans l'interprétation des spectres expérimentaux." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENI062/document.

Full text
Abstract:
L'étude des nanoagrégats métalliques supportés sur des oxydes est d'une importance primordiale autant au niveau fondamental que technologique, notamment dans le domaine de l'énergie. Les nanoparticules à base de platine supportées sur alumine Gamma sont largement utilisées comme catalyseurs hétérogènes ultradispersés, en particulier sous atmosphère réductrice d'hydrogène. Leur réactivité et leur sélectivité sont intimement liés à la géométrie locale et à la densité électronique des sites actifs. Ces dernières sont particulièrement ardues à définir, étant donnée la très faible taille des agrégats étudiés (environ 0.8 nm de diamètre). La spectroscopie XANES (X-Ray Absorption Near Edge Structure), nécessitant un rayonnement synchrotron, est un des outils les plus appropriés pour étudier ces systèmes, en particulier in situ, à l'échelle atomique. En effet les spectres XANES sont influencés par la géométrie locale et la symétrie de l'environnement des atomes (en particulier les angles entre les liaisons), le degré d'oxydation, les types de liaisons mis en jeu, et la structure électronique du système. Tous ces facteurs sont néanmoins difficiles à différencier et même à interpréter. Il est donc impossible de déduire de manière précise la structure des particules métalliques par la seule expérience, sans aucune comparaison avec des spectres simulés. La mise en place de modèles théoriques devient alors nécessaire. Nous mettons donc en oeuvre une approche associant expériences XANES haute résolution in situ et simulations quantiques, ces dernières visant à la proposition de modèles structuraux pertinents, à la quantification de la réactivité des agrégats et au calcul des caractéristiques spectrales pour comparaison à l'expérience. L'identification de la morphologie des particules, de l'interaction métal-support et du taux de couverture en H est ainsi rendue possible par l'association de l'expérience et du calcul. La bibliothèque de modèles existants de particules monométalliques de Pt supportées sur de l'alumine Gamma avec ou sans hydrogène adsorbé, est complétée par des modèles hydrogénés sur la face (110) et par des modèles de différentes tailles hydrogénés sur la face (100). Cette bibliothèque devenue assez complète a permis une étude de l'influence de la taille des particules, de leur morphologie, de leur structure électronique, des différentes face de l'alumine Gamma, ainsi que du taux de couverture en hydrogène sur la signature des spectres XANES. Cette première étude des catalyseurs monométalliques de platine, se conclue par la discrimination de certaines morphologies, mais surtout la quantification du taux de couverture en hydrogène des particules. Ensuite, des modèles de particules bimétalliques platine – étain supportés sur la face (100) de l'alumine Gamma sont élaborés avec adsorption d'hydrogène. Ces modèles permettent de mieux comprendre l'influence de l'étain sur la morphologie, les propriétés électroniques et l'interaction avec le support et l'hydrogène de ces agrégats. Différentes compositions ont été explorées, ce qui a apporté des informations sur la dilution du platine par l'étain. L'adsorption d'hydrogène a alors été étudiée sur des agrégats de Pt10Sn3 supportées sur la face (100) de l'alumine Gamma. Bien que de nombreux paramètres ne sont pas encore pris en compte dans ces modèles, la comparaison à l'expérience permet déjà d'avoir une première approximation sur la description de systèmes bimétalliques
The study of metallic nanoclusters supported on oxides is of paramount fundamental and technological importance, particularly in the field of energy. The nanoparticles based on platinum supported on gamma alumina are widely used as highly dispersed heterogeneous catalysts especially under reducing hydrogen atmosphere. Their reactivity and selectivity are intimately related to the local geometry and the electronic density of active sites. These are particularly difficult to define, given the very small size of the studied particles (about 0.8 nm in diameter). XANES (X-Ray Absorption Near Edge Structure) spectroscopy requiring synchrotron radiation, is one of the most appropriate tools to study these systems, especially in situ, at the atomic scale. Indeed the XANES spectra are influenced by the geometry and symmetry of the atoms local environment (especially angles between bonds), the degree of oxidation, the bond types involved, and the electronic structure of the system . All these factors are nevertheless difficult to differentiate and even to interpret. It is therefore impossible to infer accurately the structure of the metal particles by experience alone, without any comparison with simulated spectra. The establishment of theoretical models becomes necessary. We are implementing an approach that combines high-resolution XANES experiments in situ and quantum simulations, the latter aimed at proposing relevant structural models to quantify the reactivity of the particles and calculating spectral characteristics for comparison to experiment. The identification of the clusters morphologies, the metal-support interaction and the hydrogen coverage is made possible combining experiments and quantum calculations. The library of existing monometallic Pt particles models supported on Gamma alumina with or without adsorbed hydrogen, is refined. New models considering the two main surface of Gamma alumina, the particle size and hydrogen adsorption are developed. This extended library of models enabled a study of the effect of particle size, morphology, electronic structure, different alumina faces, and the hydrogen coverage on the signature of XANES spectra. This first study of monometallic platinum catalysts, concludes with the discrimination of the morphologies, but especially with the quantification of the hydrogen coverage of the particles for each temperature and hydrogen pressure experimental condition. Then, models of bimetallic Platinum-tin particles supported on the (100) Gamma alumina face are performed with hydrogen adsorption. These models provide insights into the effect of tin on the morphology, the electronic properties and the interaction with the support and hydrogen of these clusters. Different compositions were explored, which provided information on the dilution of platinum by tin. The adsorption of hydrogen was then studied on Pt10Sn3 clusters supported on the (100) face of alumina. Although many parameters are not yet included in these models, the comparison to the experience already provides a first approximation to the description of bimetallic systems
APA, Harvard, Vancouver, ISO, and other styles
9

Fernandes, Alessandro. "Síntese e caracterização do composto SrTi1-XNbXO3 nanoestruturado." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-15082012-125906/.

Full text
Abstract:
Amostras nanoestrutradas do sistema \'SR\'TI IND.1-x\'NB IND.x\'O IND.3\' na forma de pó contendo até 10 mol % de nióbio foram preparadas através do método dos precursores poliméricos. As propriedades térmicas, estruturais e óticas destas amostras foram caracterizadas através de diferentes técnicas. Os resultados mostram que no limite de concentração de nióbio que foi incorporado a rede da matriz \'SR\'TI\'O IND.3\', ocorreu a formação da solução sólida \'SR\'TI IND.1-x\'NB IND.x\'O IND.3\' e que o aumento da quantidade de nióbio leva a uma maior aglomeração das partículas bem como a um aumento na temperatura de cristalização das amostras. Em bom acordo com dados da literatura, uma intensidade fotoluminescente significativa foi somente observada em amostras amorfas ou parcialmente cristalinas. Amostras na forma de filmes finos foram obtidas através da técnica de evaporação por feixe de elétrons. Os dados de difração de raios-X (DRX) mostram que em certas composições, além da fase \'SR\'TI\'O IND.3\', observou-se a presença da fase \'SR\'CO IND.3\'. Através das técnicas de DRX e Microscopia de força atômica (AFM) foi possível observar que, como no caso das amostras na forma de pó, o aumento da concentração de nióbio inibe o processo de cristalização da amostra. Medidas da resistência elétrica mostraram que todas as amostras, independente da concentração de nióbio, apresentam valores elevador de resistência, da ordem de \'10 POT.15\' \'ômega\' . Este valor, muito acima do esperado e do observado na literatura, inviabilizou a medidas de sensibilidade dos filmes a diferentes tipos de gases.
Nanostructured \'SR\'TI IND.1-x\'NB IND.x\'O IND.3\' samples in a powder form containing up to 10 mol% of niobium have been prepared by the polymeric precursor method. The thermal, structural and optical properties of these samples were characterized by different techniques. The results show that in the limit of concentration of niobium added to the samples, the dopant was incorporated into the \'SR\'TI\'O IND.3\' matrix lattice forming a \'SR\'TI IND.1-x\'NB IND.x\'O IND.3\' solid solution. The increasing on the amount of niobium leads to an increased agglomeration of the particles as well as an increase in the crystallization temperature of the samples. In good agreement with the literature data, a significant photoluminescence intensity was only observed in amorphous or partially crystalline samples. Samples in the form of thin films were obtained using the electron beam evaporation technique. X-ray diffraction (XRD) show that in certain compositions, beyond the \'SR\'TI\'O IND.3\' phase, it was also observed the presence of phase \'SR\'CO IND.3\' phase. Through the XRD and Atomic Force Microscope (AFM) results, it has been observed that, as in the case of the samples in powder form, the concentration of niobium inhibits the crystallization process of the sample. Electrical resistance measurements showed that all samples, independent of the concentration of niobium, present higher values of resistance of the order of \'10 POT.15\' \'ômega\' . This value is much higher than expected and reported in the literature and does not allowed to measure the sensibility of thin films to different species of gases.
APA, Harvard, Vancouver, ISO, and other styles
10

Santos, Sheila Renata. "Dinâmica do fósforo no solo em função da adição de ácidos orgânicos de baixa massa molar." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/11/11140/tde-10052016-131749/.

Full text
Abstract:
A baixa eficiência da adubação fosfatada em solos altamente intemperizados é devido, entre outros fatores, à adsorção do fósforo (P) à superfície das argilas silicatadas do tipo 1:1 e, principalmente, dos (hidr)óxidos de Fe e de Al. Manejos do solo que induzem a solubilização de formas de P indisponíveis para as plantas têm sido intensamente estudados nos últimos anos. Uma tentativa de aumentar a concentração de P disponível na solução do solo para sua absorção pelas plantas é a mobilização de P por ânions de ácidos orgânicos de baixa massa molar (AOBMM). Ânions derivados de AOBMM exsudados pelas raízes de plantas ou excretados por microrganismos são associados com algumas condições de rizosfera como deficiência de P e fitotoxidez de Al e interagem com o solo de forma a aumentar a biodisponibilidade de P. Dependendo dos atributos do solo, do grau de dissociação, das propriedades e do número de grupos carboxílicos dos ânions orgânicos, o P pode ser mobilizado do solo principalmente devido à dissolução complexométrica de minerais e à adsorção competitiva dos grupos funcionais carboxílicos e fosfato nos sítios de superfície coloidais. A capacidade dos ânions citrato, malato e oxalato em mobilizar P de amostras de um Neossolo Quartzarênico típico (RQ) e de um Latossolo Vermelho ácrico (LVwf) foi avaliada por meio de um estudo de lixiviação de ânions em colunas. Devido a não detecção de P nos efluentes das colunas com LVwf, foi realizado outro estudo em colunas, no qual somente citrato foi lixiviado, mas num volume maior, e as alterações das formas de P nas amostras desse solo induzidas pela lixiviação de citrato foram identificadas por espectroscopia de absorção de raios-X na borda K do fósforo (X-ray absorption near edge structure -XANES - spectroscopy). A capacidade dos ânions de AOBMM em solubilizar P foi mais dependente do teor de P disponível e de outros atributos do solo que do número de grupos funcionais carboxílicos dos ânions orgânicos. Somente o oxalato mobilizou P do RQ, enquanto todos os ânions de AOBMM foram capazes de mobilizar P do LVwf. Quando baixos volumes de solução contendo ânions de AOBMM foram lixiviados no solo, além do aumento do pH, a mobilização de P foi acompanhada pela mobilização de Al no RQ (pH água = 5), e pela mobilização de Ca no LVwf (pH água = 5.6), o que indica solubilização de P pela complexação de Al, Ca, ou Fe, de fosfatos insolúveis, ou pela inibição da precipitação de P com esses metais. Ao lixiviar um volume maior de citrato no LVwf, o P também não foi detectado nos efluentes das colunas, mas houve lixiviação intensa de Al e Fe, bem como mudanças nas proporções de formas de P no solo caracterizadas pelos espectros XANES. Embora tenhamos encontrado indícios da ação dos principais mecanismos de solubilização de P (dissolução complexométrica de minerais e troca de ligantes entre grupos funcionais carboxílicos e P adsorvido ao solo), os ânions de AOBMM mostraram pouco potencial de efetivamente aumentar a biodisponibilidade de P.
Phosphate fertilization of acidic, highly weathered soils is inefficient because of the adsorption of phosphorus (P) to 1:1 silicate clays and, especially, to Fe and Al oxides. Different soil management practices to induce solubilization of unavailable forms of P to plants nutrition have been intensively studied in recent years. The mobilization of P with anions of low molecular weight organic acids (LMWOA) increases the concentration of available P in the soil solution for plant uptake. Anions derived from LMWOA exudates from plants root or excreted by microbes are associated with some rhizosphere conditions, as deficiency of P and Al phytotoxicity, and they interact with the soil in order to increase P availability. Depending on the soil attributes, and degree of dissociation, properties, and number of carboxyl groups from organic anions, P can be mobilized from soil mainly because of complexometric dissolution of soil minerals and ligand exchange of functional carboxyl groups and P adsorbed in soil surface sites. The capacity of citrate, malate and oxalate anions to mobilize P from a Typic Quartzipsamment (RQ) and an Anionic Acrudox (LVwf) was evaluated in a column leaching study. Because no P was detectable in columns effluents from LVwf, another column leaching study was performed, but only citrate was leached with a greater volume of solution, and citrate-induced changes at P forms in the soil were identified by P K-edge X-ray absorption near edge structure - XANES - spectroscopy. The capacity of LMWOA anions to solubilize P was more dependent of P status and other soil attributes, than number of carboxyl groups of organic anions. Only oxalate mobilized P from RQ, and all LMWOA anions were able to mobilize P from LVwf. Increasing of P mobilization and soil pH were followed by increases of Al mobilization from RQ (pH water = 5), and Ca mobilization from LVwf (pH water = 5.6) at lower volumes of LMWOA anions leaching. Phosphorus was solubilized by complexation of Al, Ca or Fe from insoluble phosphate minerals, or by inhibition of Al, Ca or Fe phosphate precipitation. After leaching a greater volume of citrate through LVwf, P was still undetectable in effluents from columns, but there was an intensively leaching of Al and Fe, as well as changes in proportions of adsorbed P characterized in soil XANES spectra. Although we have found evidences about the action of main mechanisms of P solubilization (complexometric dissolution, and ligand exchange of carboxylic functional groups for adsorbed P on soil minerals) by LMWOA anions, they had a little potential to really increase P availability.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "XANES"

1

F, Hepp Aloysius, and United States. National Aeronautics and Space Administration., eds. XANES and EXAFS study of Au-substituted YBBa₂Cu₃O₇-[delta]. Washington, DC: National Aeronautics and Space Administration, 1990.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

C, Koningsberger D., and Prins Roelof, eds. X-ray absorption: Principles, applications, techniques of EXAFS, SEXAFS, and XANES. New York: Wiley, 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Kizler, Peter. Untersuchung der dreidimensionalen Struktur der amorphen Legierung Fe80B20 [Fe-B] anhand von Strukturmodellen mit Hilfe der XANES-Spektroskopie. [s.l.]: [s.n.], 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

Javaxišvili, Giorgi. Adrepʻeodaluri xanis kʻartʻuli stelebi. Tʻbilisi: Tʻbilisis universitetis gamomcʻemloba, 1998.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

Tʻbilisis saxelmcipʻo universiteti. Sakʻartʻvelos istoriis instituti, ed. Pʻeodaluri xanis Sakʻartʻvelos ekonomikuri istoria. Tʻbilisi: Gamomcʻemloba "Kolori", 2020.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Cerasuolo, Omar. Xanaes: Poesía, canciones y otros relatos. Bs. As. [i.e. Buenos Aires]: Corregidor, 1991.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

Margiašvili, S. Antikur xanis mdidruli samarxebi Algetʻis xeobidan. Tʻbilisi: Mecʻniereba, 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Nioraże, Medea. Żveli kʻvis xanis mġvime-namosaxlarebi Cqalcitʻelas xeobaši. Tʻbilisi: "Mecʻniereba", 1992.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Berżnišvili, Mamisa. Pʻeodaluri xanis Sakʻartʻvelos istoriis cerilobitʻi cqaroebi: Cqarotʻmcʻodneobitʻi gamokvlevebi. Tʻbilisi: Mecnʻiereba, 1989.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Vašakiże, V. Elinisturi xanis Kʻartʻlis samepʻos socʻialuri istoriidan: Istoriul-cqarotʻmcʻodneobitʻi gamokvleva. Tʻbilisi: Mecʻniereba, 1991.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "XANES"

1

Cleaves, Henderson James. "XANES." In Encyclopedia of Astrobiology, 1781. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. http://dx.doi.org/10.1007/978-3-642-11274-4_1693.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Cleaves, Henderson James. "XANES." In Encyclopedia of Astrobiology, 2657. Berlin, Heidelberg: Springer Berlin Heidelberg, 2015. http://dx.doi.org/10.1007/978-3-662-44185-5_1693.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Cleaves, Henderson James. "XANES." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-27833-4_1693-4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Cleaves, Henderson James. "XANES." In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2022. http://dx.doi.org/10.1007/978-3-642-27833-4_1693-5.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Cleaves, Henderson James. "XANES." In Encyclopedia of Astrobiology, 3255. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_1693.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Cramer, Stephen P. "XANES and XMCD." In X-Ray Spectroscopy with Synchrotron Radiation, 165–90. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-28551-7_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Bauch, Jürgen, and Rüdiger Rosenkranz. "EXAFS / XANES - Röntgenabsorptionsspektroskopie." In Physikalische Werkstoffdiagnostik, 70–71. Berlin, Heidelberg: Springer Berlin Heidelberg, 2017. http://dx.doi.org/10.1007/978-3-662-53952-1_35.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

García Ruiz, Joaquín. "Local Geometry by XANES and RXS." In Springer Proceedings in Physics, 345–50. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-73811-6_22.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Shimomura, Osamu, and Takaaki Kawamura. "EXAFS and XANES study under pressure." In High‐Pressure Research in Mineral Physics: A Volume in Honor of Syun‐iti Akimoto, 187–93. Washington, D. C.: American Geophysical Union, 1987. http://dx.doi.org/10.1029/gm039p0187.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Hasnain, S. Samar. "EXAFS and XANES Studies of Copper Proteins." In Biophysics and Synchrotron Radiation, 147–58. Berlin, Heidelberg: Springer Berlin Heidelberg, 1987. http://dx.doi.org/10.1007/978-3-642-71490-0_18.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "XANES"

1

Metzler, Rebecca A., Ronke M. Olabisi, Mike Abrecht, Daniel Ariosa, Christopher J. Johnson, Benjamin Gilbert, Bradley H. Frazer, Susan N. Coppersmith, and P. U. P. A. Gilbert. "XANES in Nanobiology." In X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference. AIP, 2007. http://dx.doi.org/10.1063/1.2644429.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Biegert, Jens. "Attosecond water-window XANES." In Ultrafast Phenomena and Nanophotonics XXV, edited by Markus Betz and Abdulhakem Y. Elezzabi. SPIE, 2021. http://dx.doi.org/10.1117/12.2577019.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Rau, Christoph, Andrea Somogyi, A. Bytchkov, and Alexandre S. Simionovici. "XANES micro-imaging and tomography." In International Symposium on Optical Science and Technology, edited by Ulrich Bonse. SPIE, 2002. http://dx.doi.org/10.1117/12.452851.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Miller, Nicholas A., and Roseanne J. Sension. "Polarized XANES Elucidate Femtosecond Bond Elongation." In Laser Science. Washington, D.C.: OSA, 2017. http://dx.doi.org/10.1364/ls.2017.lm2f.2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Zhang, Z., E. S. Yamaguchi, M. Kasrai, G. M. Bancroft, X. Liu, and M. E. Fleet. "Tribofilms Generated From ZDDP and DDP on Steel Surfaces: Part 2 — Chemistry." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-63251.

Full text
Abstract:
The chemical constitution of tribofilms, generated from zinc dialkyldithiophosphate (ZDDP) and ashless dialkyldithiophosphate (DDP), has been examined by X-ray Absorption Near Edge Structure (XANES) spectroscopy. The identification of spectral features and interpretation of the results for P, O, Fe, and S species are given, allowing an overall mechanism to be deduced. The role of Fe in these films was investigated in some detail using P L-edge, O K-edge and Fe L-edge XANES spectra.
APA, Harvard, Vancouver, ISO, and other styles
6

Harris, William M., George J. Nelson, John R. Izzo, Kyle N. Grew, Wilson K. S. Chiu, Yong S. Chu, Jaemock Yi, Joy Andrews, Yijin Liu, and Piero Pianetta. "Full Field Imaging of Nickel Oxidation States in Solid Oxide Fuel Cell Anode Materials by Xanes Nanotomography." In ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology collocated with ASME 2011 5th International Conference on Energy Sustainability. ASMEDC, 2011. http://dx.doi.org/10.1115/fuelcell2011-54947.

Full text
Abstract:
A greater understanding of nickel reduction-oxidation cycling (redox) mechanisms at the microstructural level can enhance SOFC performance and reliability. Transmission x-ray microscopy (TXM) provides several techniques for exploring oxidation states within SOFC electrode microstructure. X-ray nanotomography and full field x-ray absorption near edge structure (XANES) spectroscopy are new TXM techniques that have been applied in tandem to study samples of varying nickel (Ni) and nickel oxide (NiO) compositions. The imaged samples are treated as mock SOFC anodes containing distinct Ni and NiO regions. XANES spectra for the individual materials provide a basis for the processing and analysis of these mixed samples. Images of composite samples obtained using x-ray nanotomography are treated using numerical image processing steps including: scaling, tomographic reconstruction, and image alignment and subtraction. The distinct nickel and nickel oxide phases have been uniquely identified using full field XANES nanotomography. Applications to SOFC anodes are discussed.
APA, Harvard, Vancouver, ISO, and other styles
7

Lobacheva, O., L. V. Goncharova, M. Chavarha, and T. K. Sham. "XANES study of Fe-implanted strontium titanate." In ELECTRONIC, PHOTONIC, PLASMONIC, PHONONIC AND MAGNETIC PROPERTIES OF NANOMATERIALS. AIP Publishing LLC, 2014. http://dx.doi.org/10.1063/1.4870200.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Arcovito, Alessandro, Maurizio Benfatto, Paola D’Angelo, and Stefano Della Longa. "Hemeproteins: Recent Advances in Quantitative XANES Analysis." In X-RAY ABSORPTION FINE STRUCTURE - XAFS13: 13th International Conference. AIP, 2007. http://dx.doi.org/10.1063/1.2644508.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Philippon, D., M. I. De Barros, Th Le Mogne, J. M. Martin, and M. Kasrai. "Friction-Induced Change of Boron Hybridization in Lubricant Additives." In World Tribology Congress III. ASMEDC, 2005. http://dx.doi.org/10.1115/wtc2005-64188.

Full text
Abstract:
Tribochemical interactions between antiwear zinc dithiophosphate (Zndtp), friction modifier molybdenum dithiocarbamate (Modtc) and overbased detergent calcium borate (OCB) lubricant additives have been investigated. A Cameron-Plint friction machine was used to generate large tribofilm areas in mild tribological conditions. Two analytical techniques, X-ray photoelectron spectroscopy (XPS) and X-ray absorption near edge structure spectroscopy (XANES), have been employed to characterize the chemical species in tribofilms. XANES spectroscopy at the P K and L-edges, S K-edge, Mo L and M-edges and B K-edge was carried out in order to investigate phosphate, sulfide and borate species in tribofilms. The XANES spectra were recorded in both the total electron yield (TEY), surface sensitive and fluorescent yield (FY), bulk sensitive mode. This was completed with XPS analyses in the same location in the tribofilm. The ternary system Zndtp + Modtc + OCB provides a low wear rate comparable to the binary system Modtc + OCB. XANES analyses have shown that adding OCB to the binary system Zndtp + Modtc increases the formation of MoS2 and reduce the formation of ZnS. It has been seen that few quantity of boron is consumed during the tests, meaning that boron does not react with other additives, we only observe a formation of calcium phosphate. A special attention has been paid on the hybridization of boron (trigonal sp2 and tetrahedral sp3). All tribofilms show a higher proportion of trigonal borate than the additives alone. However, this proportion is the highest in the case of tribofilms produce with the ternary mixture OCB + Zndtp + Modtc. Borate has a planar conformation and could be friction-oriented in the sliding interface. The oriented borate planar molecule might be at the origin of the MoS2 sheets orientation in the ternary system.
APA, Harvard, Vancouver, ISO, and other styles
10

Pattammattel, Ajith, Ryan Tappero, Mingyuan Ge, Yong Chu, Xiaojing Huang, Yuan Gao, and Hanfei Yan. "Nano-XANES: Chemical Mapping with Hard X-Rays." In Goldschmidt2020. Geochemical Society, 2020. http://dx.doi.org/10.46427/gold2020.2044.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "XANES"

1

Myneni, S. C. B., and R. C. C. Perera. Ca and S K-edge XANES studies of calcite-acid mine water interactions. Office of Scientific and Technical Information (OSTI), April 1997. http://dx.doi.org/10.2172/603631.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Robblee, John Henry. XANES, EXAFS and Kbeta spectroscopic studies of the oxygen-evolving complex in Photosystem II. Office of Scientific and Technical Information (OSTI), December 2000. http://dx.doi.org/10.2172/773946.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Brown, J. R., M. Kasrai, G. M. Bancroft, C. M. White, and K H Tan. Fingerprinting sulfur forms in coal and coal macerals using sulfur l-edge XANES validation of classical methodology. Natural Resources Canada/ESS/Scientific and Technical Publishing Services, 1992. http://dx.doi.org/10.4095/304540.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Palmer, S. R., and G. P. Huffman. Analyzing organic sulfur in coal/char: Integrated mild gasification/XANES methods. Technical report, 1 March--31 May 1994. Office of Scientific and Technical Information (OSTI), September 1994. http://dx.doi.org/10.2172/10183105.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Del Grande, N. L shell XANES (x-ray absorption near edge structure) for solid metals: Ti, V, Cr, Fe, Ni, Cu. Office of Scientific and Technical Information (OSTI), January 1990. http://dx.doi.org/10.2172/7253344.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Schmuki, P., S. Virtanen, H. Boehni, H. S. Isaacs, M. P. Ryan, and L. J. Oblonsky. In situ XANES study of the cathodic reduction behavior of the passive film on iron and artificial passive films. Office of Scientific and Technical Information (OSTI), October 1997. http://dx.doi.org/10.2172/537262.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Palmer, S. R., and G. P. Huffman. Analyzing organic sulfur in coal/char: Integrated mild degradation/XANES methods. [Quarterly] technical report, September 1--November 30, 1993. Office of Scientific and Technical Information (OSTI), December 1993. http://dx.doi.org/10.2172/10133861.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

O'Day, P., S. A. Carroll, and S. Bajt. Comparison of Synchrotron X-Ray Fluorescence Mapping and Micro-XANES to Bulk X-Ray Absorption Spectra in Metal-Contaminated Sediments. Office of Scientific and Technical Information (OSTI), January 2003. http://dx.doi.org/10.2172/15007217.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Palmer, S. R., and G. P. Huffman. Analyzing organic sulfur in coal/char: Integrated mild degradation/XANES methods. [Quarterly] technical report, December 1, 1993--February 28, 1994. Office of Scientific and Technical Information (OSTI), June 1994. http://dx.doi.org/10.2172/10154276.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Chaturvedi, S., J. A. Rodriguez, J. C. Hanson, A. Albornoz, and J. L. Brito. Properties of pure and sulfided NiMoO{sub 4} and CoMoO{sub 4} catalysts: TPR, XANES and time-resolved XRD studies. Office of Scientific and Technical Information (OSTI), December 1998. http://dx.doi.org/10.2172/555287.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'XANES' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography