ISSN:0049-8246    

DOI:10.1002/xrs.1300090402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA procedure is presented for constructing calibration curves of X‐ray fluorescence activity versus analyte concentration for finite multicomponent media. The composition must be known for all components other than the low‐concentration analyte. If these compositions are not known, the system's mass absorption coefficient must be measured. The analyte must be present in low enough concentration so that it does not contribute significantly to the total mass absorption coefficient. The calibration curve for a multicomponent system is constructed numerically from data on analyte activity versus secondary component composition in binary systems (analyte plus one secondary component). Thus calibration curves for any system containing the analyte and n secondary components are constructed from data on the n corresponding binary systems. The method is found to reproduce measured activities of uranium solutions with an accuracy of 5

ISSN:0049-8246    

DOI:10.1002/xrs.1300090403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe emission intensities of K X‐rays from a number of activation products have been calculated from the known absolute γ intensities, K capture data and internal conversion coefficients of the radionuclides and the fluorescence yields of the daughter products. The calculated X‐ray intensities of a few isotopes are compared with those experimentally reported. The X‐ray spectrometry of activation products could usefully supplement the γ‐ray spectrometry in the instrumental neutron activation analysis and in such cases the data presented here will be

ISSN:0049-8246    

DOI:10.1002/xrs.1300090404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe qualitative and quantitative composition of technical aluminium phosphide was studied employing X‐ray electron spectrometry, X‐ray fluorescence analysis and X‐ray diffractometry as well as gravimetric and gas volumetric methods. In addition to aluminium phosphide, AIN (8%), Al(1%) and Al(OH)3(10%) were found. Al(OH)3is produced by the reaction of AlP with H2O. Models describing this reaction in humid air and allowing for quantitative analysis are pres

ISSN:0049-8246    

DOI:10.1002/xrs.1300090405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractDas Konzept der hybriden Röntgenfluoreszenzanalytk ermöglicht die quantitative Bestimmlung einer Probenzusammensetzung mit Hilfe einzigen Standardpprobe und der Kenntnis von theoretischen Zusammenhängen im Sinne der fundamentalen Parameterrechnung. Die gesuchten Konzentrationen werden aus einem Differentialausdruck berechnet, der die Zählratenänderungen als Funktion von Konzentrationsänderungen beschreibt. Im Fall des Linermodells wird diese Funktion liner approximiert, im quadratischen Modell durch eine Funktion zweiter Ordnung. Die vorliegende Arbeit geht von dem Linearmodell aus, das von Kramer, Ebel und Tschismarov vorgestellt wurde und ergänzt es zur verbesserten Bestimmbarkeit kleiner Konzentrationen. Die Ergebnisse der Theoretischen Gegenöberstellung von linerarem und quadratischem Modell werden mit experimentellen Ergebnissen

ISSN:0049-8246    

DOI:10.1002/xrs.1300090406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractUsing the effective wavelength concept, it is derived theoretically that the reciprocal of the analyte‐line intensity is linearly correlated with the reciprocal of the weight fraction of the analyte. This linear relationship is substantiated experimentally in some liquid and fusion product samples. Two ways of application of the relationship in X‐ray fluorescence analysis and their advantages are also described. It is emphasized that if the relationship is used the construction of calibration curves is not requi

ISSN:0049-8246    

DOI:10.1002/xrs.1300090407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe paper reviews recent developments in energy‐dispersive X‐ray detectors and attempts to assess their relevance to industrial process control requireme

ISSN:0049-8246    

DOI:10.1002/xrs.1300090408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractSpace resolved X‐ray spectroscopy with a curved crystal X‐ray spectrometer for an extended source such as the Tokamak is discussed. Limits of resolution caused by instrumental broadening are shown, using various entrance apertures. Ion density distribution may be obtained by measurement of intensity variation along spectral lines. In order to obtain ion temperature distribution about the central plasma line in the Tokamak, a novel method is proposed. In this method reflection in the curved crystal takes place through the double reflection process. This is possible as practically no instrumental broadening is caused when using this method, while it reflects the radiation in a strictly space resolved m

ISSN:0049-8246    

DOI:10.1002/xrs.1300090409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractA first approximation indicates that fundamental alpha coefficients for a given analyte vary as a function of the ratio of their respective atomic number raised to a power. This simple rule applies mainly at the limits (i.e., when the weight fraction of analytei, wi is of the order of 0.0 or 1.0) in cases of absorption and weak enhancement. The relation thus provides a means of generating coefficients for the system i‐k from experimental data obtained on system i‐j and a means of verifying experimental alphas, since arrays of coefficients must show a high degree of concorda

ISSN:0049-8246    

DOI:10.1002/xrs.1300090410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY

摘要:

AbstractThe use of an automated, software‐controlled X‐ray fluorescence spectrometer (Phillips AXS System)for analysis of geologic materials gives rapid, precise results. Fluorescence intensities are corrected for background and peak overlap and for mass absorption, and ratioed to a standard rock analyzed at frequent intervals. Major element determinations show precision and accuracy in the 0.5–3% range and are based on calibration with a wide variety of international reference rocks. Determinations for major elements are done on specially fused rock powders. Precision and accuracy for trace elements are generally in the 1–5% range. Calibration is also by use of reference rocks but the determinations are done directly on pressed rock

ISSN:0049-8246    

DOI:10.1002/xrs.1300090411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1980

数据来源: WILEY