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  • Polymer and Materials Science  (8)
  • Lupinus hirsutus  (2)
  • (+)-12α-hydroxylupanine  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Phytochemistry 29 (1990), S. 3923-3926 
    ISSN: 0031-9422
    Keywords: (-)-(cis-4'-α-l-rhamnosyloxycinnamoyl)epitupinine. ; (-)-(trans-4'-α-l-rhamnosyloxycinnamoyl)epilupinine ; Leguminosae, blue lupin ; Lupinus hirsutus ; glycoside ; quinolizidine alkaloid ; rhamnoside
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Phytochemistry 31 (1992), S. 3251-3253 
    ISSN: 0031-9422
    Keywords: (+)-12α-hydroxylupanine ; (+)-retamine ; (-)-lupanine, absolute configuration ; Leguminosae ; Lygos raetam ; alkaloid content. ; lupin alkaloid ; quinolizidine alkaloid
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Phytochemistry 37 (1994), S. 591-592 
    ISSN: 0031-9422
    Keywords: (-)-(3'-methoxy-4'-α-l-rhamnosyloxycinnamoyl)epilupinine. ; Leguminosae ; Lupinus hirsutus ; lupin alkaloid ; quinolizidine alkaloid ; rhamnoside
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology , Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: A matrix effect correction is required to improve the accuracy of quantitative AES analysis. The correction includes terms involving the atomic density (n), electron back-scattering factor (R) and electron escape depth (L). Many schemes have been proposed by various people for corrections of the R and L terms. However, up to now, there have been no systematic investigations of the correction accuracy of the proposed schemes. We have evaluated the correction accuracy, based on measured intensity data for Au—Cu alloys of different compositions. Comparison was made between the observed intensity ratio K (=Iunk/Istd) and the calculated intensity, ratio K′ (= C(nunk/nstd)(Runk/Rstd)(Lunk/Lstd)), where C and I represent the concentration and intensity, respectively. The superscripts ‘unk’ and ‘std’ denote that the parameters are for unknown and standard specimens, here the pure elements. If the correction works well, the error Er (= K′ — K)/(K) will become smaller. Evaluations were carried out on three schemes for the R correction and on seven schemes for the L correction using the Au 239 eV, Au 2024 eV and Cu 920 eV transitions. The root mean square (RMS) of the calculated errors showed several per cent for the best case and 20-30% for the worst case. The RMS error varied a few per cent between schemes for the R correction but it varied ∼30% for the L correction.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The Japanese VAMAS-SCA working group is composed of 19 institutes. Three kind of Au—Cu alloys (Au 75 at.-%-Cu 25 at.-%, Au 50 at.-%-Cu 50 at.-%, Au 25 at.-%-Cu 75 at.-%) were prepared, and these specimens, pure Au and pure Cu were distributed to the members of the VAMAS-SCA working group. The surface concentrations of these alloys were calculated from the Auger peak amplitudes in two ways. One method used the published relative sensitivity factors, and the other used pure Au and Pure Cu as the standard materials. The mean values of the surface concentrations calculated with the published relative sensitivity factors were almost the same as those calculated with the standard materials. This means that the published relative sensitivity factors are reliable to some extent. The error of the surface concentration calculated with pure Au and pure Cu as the standard materials lay between about 3% and 10%, and that with the relative sensitivity factors lay between about 7% and 20%. The calculated surface concentrations of Au were larger than the bulk concentrations of Au when the matrix effect was neglected.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The Japanese VAMAS-SCA working group is composed of 19 institutes. Three kinds of Au-Cu alloys (Au25 at%-Cu75 at%, Au50 at%-Cu50 at%, Au75 at%-Cu25 at%) were prepared, and these specimens were distributed to the members of Japanese VAMAS-SCA working group and Auger peak amplitude ratios were measured to clarify the correlation factor of different types of spectrometers. The comparison was carried out by using the relative sensitivity factor for Au and Cu. The relative sensitivity factor for lower energy varied from spectrometer to spectrometer, but that for higher energy did not vary so much. Therefore, to carry out the inter-laboratory comparison of the data, the transfer of the data of peak amplitude at higher energy should be recommended.
    Additional Material: 5 Ill.
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  • 7
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: In Auger electron spectroscopy, the relative sensitivities of elements, which are widely used in quantitative analysis, are primarily obtained by measurement. Nevertheless, it is very tedious to collect all relative elemental sensitivity factors for different primary electron beam energies. In view of this, we have examined methods of deriving the relative sensitivity factor for an arbitrary electron beam energy from one experimental value determined at a set energy. For this calculation, we have to consider the contributions of the ionization cross-section and the electron backscattering factor. Several formulas for the ionization cross-section and the backscattering correction factor have been reported. We have performed experiments to examine their correction accuracy. It was found that when Gryziński's formula is used as the ionization cross-section and Love-Scott's formula as the backscattering correction factor, the difference between calculated sensitivity values and measured values was found to be 〈15% for excitation energies of 〈20 keV.
    Additional Material: 8 Ill.
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  • 8
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 7 (1985), S. 289-294 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The ‘filter-fit’ method, which was originally developed for the analysis of energy dispersive x-ray data, has been applied to the quantitative analysis of Auger spectra for the first time. It is a digital peak deconvolution technique in the presence of the continuum background using least-squares fitting calculations, including the prefiltering of spectra. To evaluate this method, composite-known spectra digitally composed of Cr, O and Ni standard spectra were prepared. For the deconvolution of Cr and O peaks under the influence of the Ni peak tail, the present method showed remarkable advantage over the conventional least-squares fitting without prefiltering. As a digital filter for prefiltering, derivative filters of different orders and ‘top-hat’ filter were examined. In derivative filters, it was found that there is an optimum order in the balance of advantage of suppressing the background and disadvantage of losing peak intensity. The ‘top-hat’ filter is a very practical filter in both background suppression and noise attenuation.
    Additional Material: 6 Ill.
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  • 9
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 21 (1994), S. 606-614 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The analyser transmission function T of a concentric hemispherical analyser (CHA) with an input lens system has been studied, and the behaviour of T under suitable operation conditions for a point source has been determined by means of numerical calculations. One of the significant factors controlling T was found to be the aberrations of the input lens, which have a strong dependence on the retardation ration γ and the angular magnification Mα of the lens. The Mα also determines the entering angles of electrons to the CHA, and thus this should be kept sufficiently small as far as the aberrations in the CHA are concerned. The calculated results showed, however, that for each γ there exists an optimum Mα, which corresponds to a compromise point between the aberrations of the input lens and those of the CHA. If Mα is kept constant, T varies according to the increase or decrease in the lens aberrations as functions of γ. Lineshapes calculated for a monochromatic point source were also shown. These were found to be asymmetrical and have tailings on the low-energy side due to the aberrations of the CHA.
    Additional Material: 8 Ill.
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester [u.a.] : Wiley-Blackwell
    Surface and Interface Analysis 11 (1988), S. 94-102 
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: The possibility of quantitative AES analysis using the whole EN(E) spectrum was examined for Au—Cu alloy samples. The EN(E) spectrum was measured under ϕ = 0° (normal) incidence of 10 keV electrons for the Au-44 at% Cu sample, and under ϕ = 0°, 30°, and 45° incidence of 10 keV primary electrons for the Au-20 at% Cu sample. Those spectra were compared with spectra which were obtained by linear combination of pure Au and Cu spectra measured under the same experimental conditions.Both measured and synthesized spectra coincided very well in the energy region lower than 1000 eV, except the region of slow secondary electrons. The results indicate that energy distribution of backscattered electrons of the Au—Cu alloy can be estimated well by linear combinations of pure sample spectra. They also indicate that, by comparison of the shape of the measured EN(E) spectrum with the synthesized one, the surface composition of the Au—Cu alloy sample can be estimated with reasonable accuracy (several % error).
    Additional Material: 8 Ill.
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