ISSN:0049-8246    

DOI:10.1002/xrs.1300010302

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

年代:1972

数据来源: WILEY

摘要:

AbstractNous avons appliqué la méthode de double concentration, dont nous rappelons brièvement le principe, à la détermination précise des constituants majeurs et mineurs, soit Fe2O3MnO, TiO2, CaO, K2O, P2O5, SiO2, Al2,O3, MgO et Na2O, dans les roches silicatées ou apparentdées. Dans ce cas, la technique de la double mesure permet de corriger pour l'effet interélément avec une précision relative théorique de l'ordre de quelques dixièmes de pour cent et nous avons pu grâce des précautions particuliéres en ce qui concerne la préparation des “perles” vitri‐ fiées et la mesure des intensités nettes, porter la precision pratique à un niveau comparable. Une étude exploratoire alors menée sur quatorze roches étalons (dont sept du Centre de Recherches Pétrographiques et Géochimiques de Nancy et sept de l'U.S. Geological Survey à Washington) nous a conduits à des résultats très satisfaisants, en ce sens qu'ils concordent généralement avec les valeurs “recommandées” dans la limite de ±1 pour cent, voire mieux, en valeur relative. Un petit nombre de valeurs recommandées ou proposées, dans le domaine des très faibles concentrations, peuvent même être contestées ou améliorées.Cette méthode simple et directe qui nous dispense d'avoir recours à toute espèce de coefficients d'influence ou de para‐ mètres fondamentaux, ainsi qu'aux machines, est quasi‐absolue. On peut I'employer avec avantage non seulement pour l'analyse des roches et des composés similaires, mais aussi et même avec une pr

ISSN:0049-8246    

DOI:10.1002/xrs.1300010303

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

年代:1972

数据来源: WILEY

摘要:

AbstractRapidly recorded X‐ray diffraction powder patterns from some metals and from rock salt have been obtained by using the energy sensitive Si (Li) semiconductor detector with the multichannel pulse height analyser. The measured energy resolution of the detector system was about 210 eV for Cu Kα radiation. A good agreement was obtained between observed and calculated positions and relative intensities of the diffraction lin

ISSN:0049-8246    

DOI:10.1002/xrs.1300010304

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe use of non‐dispersive X‐ray fluorescenceanalysis as a general tool in chemical laboratories has developed rather slowly until recently. Most analysers have used radioactive isotopes as the means of excitation and these have been widely used in portable instruments and in on‐line control applications. For general use wide element coverage is necessary, especially the ability to cover elements of lower atomic numbers. For the determination of these light elements a compact source—sample—detector geometry is essential. Early experiments in developing an on‐line system showed the possibilities of one such compact arrangement and resulted in an instrument specifically designed for use in the chemical laboratory. Solid, liquid and powder samples can be examined for silicon and all heavier elements. Basically, sample excitation is by radioactive sources but the instrument was designed to accept also a miniature X‐ray tube which provides higher sensitivity and precision. The measuring head with radioactive isotope or X‐ray tube can be removed and mounted for remote use either for on‐line applications or in an automatic

ISSN:0049-8246    

DOI:10.1002/xrs.1300010305

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

年代:1972

数据来源: WILEY

摘要:

AbstractNew equations have been derived to describe the dependence of characteristic X‐ray intensity on particle size in heterogeneous specimens. The formulae include the effects of continuous size distributions, a problem not covered in earlier theoretical wor

ISSN:0049-8246    

DOI:10.1002/xrs.1300010306

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

年代:1972

数据来源: WILEY

摘要:

AbstractThe Berry—Furuta—Rhodes model is used to derive formulae for the characteristic X‐ray intensity in specimens of ‘non‐infinite’ thickness, as a function of particle size both for discrete values and for continuous distributions, including the Junge distribution for aerosols. Significant simplifications in otherwise complex for mulae are obtained for a number of cases of practical importance, namely, thin specimens, monolayers and low or high packing fractions. The simplified working formulae consist of the equation for a thin, homogeneous specimen, multiplied by a grain size dependent factor. This factor is a function of fluorescent grain size only, so eliminating most inter‐element effects. Practical applications of these cussed, with special reference to energy dispersive X‐ray fluorescence analysis of thin briquetted specimens and of aerosols colle

ISSN:0049-8246    

DOI:10.1002/xrs.1300010307

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

年代:1972

数据来源: WILEY

摘要:

AbstractEnergy dispersive analysis of X‐rays is a relatively new but rapidly growing technique for X‐ray fluorescence spectrometry offering simultaneous analyses of many elements with sensitivities to a few p.p.m. The digitally recorded spectra lend themselves to processing to remove background and interfering peaks. The net counts for each element can be converted to concentration using any of a variety of mathematical models for interelement effects. When proper specimen preparation is used, final accuracies of better than 1 per cent can be realised over much of the analytical ra

ISSN:0049-8246    

DOI:10.1002/xrs.1300010308

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

年代:1972

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300010311

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

年代:1972

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300010312

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

年代:1972

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300010301

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

年代:1972

数据来源: WILEY