ISSN:0049-8246    

DOI:10.1002/xrs.1300130102

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe performance of an energy‐dispersive x‐ray fluorescence (ED‐XRF) system for the analysis of silicate rocks was investigated in detail. Data are presented to demonstrate the selection of optimum excitation conditions for the major elements (Na‐Fe), analysed on glass beads, and the trace elements (particularly the Rb‐Nb group) analysed on powder pellets. Limitations in spectrum analysis due to overlap interferences are discussed and have largely been overcome using x‐ray profile fitting software. The results show that when operated under optimum excitation conditions, ED‐XRF spectrometry can routinely achieve a high degree of accuracy and precision in the analysis of a wide range of major and trace elements in silicate rocks. For many elements, 2s standard deviations are better than 2% relative. Limits of determination for many trace elements are in the r

ISSN:0049-8246    

DOI:10.1002/xrs.1300130103

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn connection with progress in the creation of differential and so‐called differential methods of concentration correction, work has been carried out on the ordering of equations. It has been shown that it is possible to create three principal, complete systems of so‐called differential concentration correction equations by (1) using the Claisse method, (2) using the method of function expansion in a Taylor series and (3) using a special method discussed in this paper. These equations can be used instead of the classical concentration correction methods. Moreover, it has been proved that the respective procedures can be used in the creation of expressions which are the analogues of classical intensity correction equati

ISSN:0049-8246    

DOI:10.1002/xrs.1300130104

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe problem of a simplified expression for the enhancement term of correction equations in XRF analysis was treated using the example of binaries. Attention was paid to up‐to‐date propositions of a solution to that problem and new cases of solutions were considered. Some common elements of these solutions were found and on the basis of a fundamental expression of enhancement effects a more general equation is gi

ISSN:0049-8246    

DOI:10.1002/xrs.1300130105

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe methodology of direct hair analysis by energy‐dispersive x‐ray fluorescence was studied. The effect on the XRF result of having a non‐homogeneous radial distribution of the analyte in a single hair strand and the macroscopic effects in a bundle of hairs were calculated to evaluate possible systematic errors. The detection limits were mapped as a function of the target thickness and surface fraction. It appeared that a 10 mg cm−2sample thickness, i. e. a target with about four layers of hair strands, is recommended. The standard deviation of this simple direct analytical method is 6–19% for some important elements. Discrepancies with neutron activation analysis had a mean value of around 15%. About twelve elements can be determined simultaneously on a rout

ISSN:0049-8246    

DOI:10.1002/xrs.1300130106

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe use of peak‐to‐background ratios has been suggested for the analysis of particles or rough surfaces as the peak‐to‐background ratio is assumed to be independent of geometry. The validity of this assumption is examined for flat specimens. It is shown that the peak‐to‐background ratio does not vary much with sample orientation but does vary with voltage, tending to a limit at high voltages. Methods of analysis using the peak‐to‐background ratio are proposed and the effects of fluorescenc

ISSN:0049-8246    

DOI:10.1002/xrs.1300130107

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

年代:1984

数据来源: WILEY

摘要:

AbstractA probability method is used to describe the processes of characteristic x‐ray fluorescence excitation and absorption in a heterogeneous monolayer of particles. Based on this the analytical dependence of the characteristic x‐ray peak intensity on the sizes and shape of particles, and the distribution of elements among the particles is inferred, for two kinds of spectrum excitation. Theoretical evaluations for applying boundaries of the ‘thin’ homogeneous layer model to a heterogeneous monolayer are given. The elements to be determined in unknown compositions are S, Fe

ISSN:0049-8246    

DOI:10.1002/xrs.1300130108

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe dead time of a Philips PW 1410 x‐ray fluorescence spectrometer with a photon detector has been calculated employing intensities of first‐ and second‐order reflections. The spread of the values obtained can be considered very satisfactory in the light of the experimental difficulties inherent in this m

ISSN:0049-8246    

DOI:10.1002/xrs.1300130109

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

年代:1984

数据来源: WILEY

摘要:

AbstractReflexion Curves from gypsum and beryl crystals have been calculated using the dynamic theory of x‐ray diffraction, assuming that the crystal is perfect, and taking into account the photoabsorption of incident photons by the crystal. The calculations were performed for two values of photon energy: 851 eV (Ni Lα emission) and 1098 eV (Ga Lα emission). The results are discussed comparativ

ISSN:0049-8246    

DOI:10.1002/xrs.1300130110

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

年代:1984

数据来源: WILEY

ISSN:0049-8246    

DOI:10.1002/xrs.1300130111

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

年代:1984

数据来源: WILEY