ISSN:0049-8246    

DOI:10.1002/xrs.1300100102

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

年代:1981

数据来源: WILEY

摘要:

AbstractEs wird gezeigt, daß die in der Literatur beschriebenen einfachen Modellezur Korrektur des Korngrößeneinflusses für die quantitative Röntgenfluoreszenzanalyse von Elementen mit niedriger Ordnungszahl (⩽ 20) in gepreßten Pulverproben nicht ausreichen. Auf der Basis eines empirischen Korrekturvorschlages ist es jedoch möglich, ein mit einem Bindemittel verpreßtes Pulver ohne Kenntnis seiner mittleren Korngröße mit einer für die Praxis ausreichenden Genauigkeit zu analysieren. Es werden die zur Analysenberechnung notwendigen Voraussetzungen beschrieben und die verwendeten mathematischen Formeln am Beispiel eines Glaspulve

ISSN:0049-8246    

DOI:10.1002/xrs.1300100103

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

年代:1981

数据来源: WILEY

摘要:

AbstractA runaway criterion is proposed for X‐ray spectrometry which is based on the standard deviations obtained from the standard specimens with and without the analysis value to be tested. The standard deviations which are printed out on modern equipment are compared by means of theFtest. The procedure is explained by means of examples. The consequences for the analysis of unknown specimens are discusse

ISSN:0049-8246    

DOI:10.1002/xrs.1300100104

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

年代:1981

数据来源: WILEY

摘要:

AbstractWe have developed a highly versatile, energy‐dispersive system for X‐ray fluorescence (XRF) analysis. Excitation may be achieved both by a Ag anode tube and by isotopic sources of241Am or55Fe. Radiation from the former may be either filtered and collimated, or monochromatized by a pyrolytic graphite cylindrical monochromator with further filtration through Pd foils. The system is currently being used both for quantitative fundamental‐parameter (absolute) analysis and for standard‐based determinations. A variety of mounts allows quantitative work on solid thick or thin samples, liquids, and specimens evaporated on 6.2 μm thick Mylar. Aside from single‐sample operation, a 90 position sample changer allows multi‐sample analysis, with great gain in work efficiency. The latter is automatically controlled by a PDP 11/05 computer, which also calculates results from the raw data from a Tracor Northern NS 880 energy‐dispersive system. Accuracies for analyses of steels (percent level) are ∼5%, while trace Zr/Hf analysis can be performed with 10–15% error; sensitivity for the lat

ISSN:0049-8246    

DOI:10.1002/xrs.1300100105

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe design of an energy‐dispersive spectrometer equipped with a conventional X‐ray tube and a secondary target is described. The mechanical construction secures a well defined geometry and a high degree of flexibility. The geometry of the irradiation chamber has allowed the polarizing effect of scattering to be investigated. With emphasis on analysis of infinitely thick biological samples a close approximation to the fundamental parameter method for matrix correction has been stud

ISSN:0049-8246    

DOI:10.1002/xrs.1300100106

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

年代:1981

数据来源: WILEY

摘要:

AbstractThe X‐ray K absorption edges of cobalt in some complexes with nitrogen based ligands [α‐Co(py)2Cl2, Co(py)2Br2, Co(bipy)Br2and Co(phen)Br2] have been recorded using a 40 cm bent crystal spectrogrph. The absorption edge shift and edge width have been discussed in terms of effective nuclear charge, molecular symmetry and the nature of the ligand. The radii of the first coordination sphere have been calculated using Levy's method and a correlation sugge

ISSN:0049-8246    

DOI:10.1002/xrs.1300100107

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

年代:1981

数据来源: WILEY

摘要:

AbstractAn improved version of the LAMA program for the quantitative analysis of composition and mass thickness of thin film materials by X‐ray fluorescence (XRF) has been developed. The divergence and slow convergence problems occasionally experienced with the LAMA‐1 program have been eliminated by using the linear approximation method and the algorithm of simultaneous refinement of composition and thickness to greatly increase its capability and performance. A study of over a hundred simulated thin films showed that the LAMA‐2 program converged much faster than LAMA‐1 and gave better accuracy. The efficiency of the program has been improved to the point where it is feasible to operate on a minic

ISSN:0049-8246    

DOI:10.1002/xrs.1300100108

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

年代:1981

数据来源: WILEY

摘要:

AbstractTube‐excited energy‐dispersive X‐ray fluorescence with Mo K and Ti K secondary target radiation proves to be a rapid, precise and accurate method for the multielement analysis of phytoplankton collected on membrane filters. Using 150–750 ml water samples it is possible to determine the concentration of 11–16 elements among the 22 elements which can be systematically searched for in the spectra. The study area is an estuarine water body on the Gulf of Finland and an archipelago outside th

ISSN:0049-8246    

DOI:10.1002/xrs.1300100109

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

年代:1981

数据来源: WILEY

摘要:

AbstractFull spectra including both the continuous and characteristic lines from X‐ray tubes are evaluated in a simple way. The penetrating depth of an electron in the target of the X‐ray tube is determined and the Kramers' spectrum corrected for the effects of absorption. The characteristic lines are evaluated from a relation between direct electron excitation and indirect excitation by continuous X‐rays. The calculated spectra from W and Cu X‐ray tubes are given and their usefulness is confirmed by analysing some typical samples including Ag/Pd and Cu/Zn alloys and BaO/TiO2mixed

ISSN:0049-8246    

DOI:10.1002/xrs.1300100110

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

年代:1981

数据来源: WILEY

摘要:

AbstractA combination of deconvolution, spectra subtraction and elemental identification routimes has been made to alert the energy‐dispersive X‐ray spectrometrist to elements present in the sample but not included in the

ISSN:0049-8246    

DOI:10.1002/xrs.1300100111

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

年代:1981

数据来源: WILEY