ISSN:0049-8246    

DOI:10.1002/xrs.1300040202

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

年代:1975

数据来源: WILEY

摘要:

AbstractThis paper deals with the quantitative analysis of neodymium, erbium and ytterbium oxides in borate, silicate and tellurite glasses by means of energy dispersive X‐ray analysis in a scanning electron microscope. The problem of the deconvolution of overlapping intensity peaks is discussed and calibration curves for rare earth oxides in the different base glasses are establishe

ISSN:0049-8246    

DOI:10.1002/xrs.1300040203

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

年代:1975

数据来源: WILEY

摘要:

AbstractA fast, efficient calibration procedure is proposed based on the accurate analysis of multicomponent systems by means of the influence coefficient method. It relies on a series of well designed additions made to a suitable standard composition, the latter also being used as a reference sample. We show that, for annelement composition, using the hypothesis ofconstantcoefficients, (n+ 1) preparations – allowingn(n+ 1) intensity measurements – are in principle sufficient to calculate then2calibration parameters [i.e.n(n− 1) influence coefficients andnreferenc relative intensities] which are necessary for a complete analysis. Actual analyses are carried out by measuring the fluorescent intensities using the ratio (i.e. unknown/standard) method, and then calculating the concentrations from the usual relationships through an iterative calculation, preferably executed by a computer program. A detailed description of a typical application is given, which involved the study of fused specimens (borax fusion) of bauxite and resulted in the very accurate analysis of calcined samples, as well as the direct analysis of raw bauxites following an adequate treatment of the ignition loss problem. While the method is immediately applicable to every system studied in either solid or liquid solution, it clearly extends tocompactsystems over a suitable compositional range, provided that carefully controlled additions can be achieved and that all prepared samples are homoge

ISSN:0049-8246    

DOI:10.1002/xrs.1300040204

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

年代:1975

数据来源: WILEY

摘要:

AbstractOne way carrying out quantitative X‐ray fluorescence analysis with fundamental parameters is the method of variable take‐off angle. At angles nearly parallel to the sample surface, the equations can be solved more easily and no knowledge of the white spectrum and μ(λ) is needed. For practical application, in order to get a well defined geometry, we used a diffraction goniometer, an X‐ray tube with Mo target and an energy dispersive detector, followed by a multichannel analyser. After calibrating the system, all information essential for a quantitative analysis was obtained from a single measurement. The validity of the final equations was verified by experiments with different alloys, consisting of two, three and four com

ISSN:0049-8246    

DOI:10.1002/xrs.1300040205

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

年代:1975

数据来源: WILEY

摘要:

AbstractA technique is outlined which use the electron microprobe to obtain X‐ray absorption spectra, by photon absorption, in the long wavelength region. Spectra are presented for SiO, SiO2, rectorite, talc, vermiculite, V2O5, Cr2O3, Fe2O3, maghemite, Mylar and collodion. For all compounds the main absorption edge is near to 536 eV, which is significantly higher than core binding measured in ESCA studies. The transition metal oxides and organic films show a sharp absorption line near 531 eV in addition to the above edge. This absorption line is very close in energy to the anomalous peak observed in the oxygen K emission spectra when using KAP or other acid phthalate crystals and it seems likely that the two phenomena are associate

ISSN:0049-8246    

DOI:10.1002/xrs.1300040206

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

年代:1975

数据来源: WILEY

摘要:

AbstractDirect X‐ray fluorescence analysis of pieces of cloth cut from clothing on which there is a suspected paint smear has been found to be a useful forensic technique for comparing a reference paint sample with the smeared substance. Even though the X‐ray method does not compare all the constituents of the paint, it may often be sufficient to distinguish rapidly between two suspect paint sources, and can therefore be a valuable method in paint transfer cases such as hit and run accidents. A feature of the method is that elements present in the cloth, such as sulphur in wool and titanium in some synthetic fibres, can be used as internal standa

ISSN:0049-8246    

DOI:10.1002/xrs.1300040207

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

年代:1975

数据来源: WILEY

摘要:

AbstractA single crystal of indium antimonide (zinc blende type InSb) was evaluated as an X‐ray monochromator. The long 2dspacing of 7.481 Å makes it possible to diffract Si K α in an ordinary X‐ray emission spectrometer. The indium antimonide data were compared with crystals of EDDT, Ge and LiF. Indium antimonide shows seven times higher Si Kα intensity than EDDT. It also has very low second order reflection. A low coefficient of thermal expansion (4.9 × 10−6°C−1), together with its very stable chemical nature will facilitate high precision measurement ranging from14Si to46Pd(Kα),38Sr to92U(Lα) an

ISSN:0049-8246    

DOI:10.1002/xrs.1300040208

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe use of Nickel‐59 as an excitation source for the X‐ray fluorescence analysis of carbon and low alloy steels has been investigated. Nickel‐59 has a half life of 80 000 y and is essentially a pure source of cobalt K X‐rays. It is ideal as an X‐ray source for field systems because the encapsulated source is small, rugged and requires no external power or maintenance. The prototype system require ∼2½ minutes to obtain a manganese analysis, and 15 minutes to determine vanadium, chromium and manganese concentrations. These times could be shortened about a factor of 40 with a more intense excitation source and a larger area detector. The feasibility of portable field systems

ISSN:0049-8246    

DOI:10.1002/xrs.1300040209

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

年代:1975

数据来源: WILEY

摘要:

AbstractThe zinc concentration in an epitaxial layer of InSb was measured by proton excited X‐rays. For the determination of zinc concentration, the X‐ray yield was compared to that from known zinc concentrations. As layer thickness, stopping power and X‐ray absorption must be taken into account, a general mathematical evaluation was developed. In an appendix, the derived equations are shown to allow a layer thickness determination. The calculated values agree quite well with the experimental re

ISSN:0049-8246    

DOI:10.1002/xrs.1300040210

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

年代:1975

数据来源: WILEY

摘要:

AbstractA table is presented summarizing recently available data of experimentally determined K shell X‐ray fluorescence yield

ISSN:0049-8246    

DOI:10.1002/xrs.1300040211

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

年代:1975

数据来源: WILEY