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61.
62.
Martin Schmidtke 《Zeitschrift für Physik A Hadrons and Nuclei》1965,188(2):165-166
Gold foils of 0.25 mg/cm2 were irradiated with the protons of a Van de Graaff accelerator at 77 °K. The increase of electrical resistivity is measured as a function of proton energy between 80keV and 1.4 MeV. Comparison with theory shows, that the calculated resistivity change is too large by a factor of 2.9 but gives the correct energy dependence. 相似文献
63.
We have measured the spin polarization of Xe (4p)(-1) photoelectrons after ionization with circularly polarized light at photon energies close to the ionization threshold where a resonant enhancement of quadrupole transitions has recently been predicted. At a reaction angle of 90 degrees a nonvanishing longitudinal spin polarization component of about 4% clearly indicates a quadrupole contribution to the photoexcitation. This is the first experimental evidence for the influence of nondipole transitions on the photoionization process at excitation energies much below 1 keV in an observable other than the intensity angular distribution. 相似文献
64.
H. -H. Schmidtke 《Czechoslovak Journal of Physics》1970,20(5):536-557
In the introduction the methods used by the study of complexes in melts and solutions are mentioned, e.g. optical spectroscopy, ESR and nuclear resonance, Cotton and Faraday effect and electron microscopy. Then the classification of electronic transitions in complexes is given on the basis of crystal field and M.O. theory with regard to the transitive elements and rare earths. The problems connected with the charge transfer transitions are mentioned, too. Finally, the spectroscopy of melts and the production of complexes are discussed. 相似文献
65.
66.
The 10 K emission spectrum of Cs2TeBr6 was measured by recording the fluctuating photon flux. Since this fluctuation, according to the theory, is due to the dynamic coupling of the molecular system to the environment controlling the dissipation of energy, it should depend on the frequency of the emitted photons. By this, the vibrational structure of the transition has been resolved which could not be obtained by usual emission spectroscopy.Dedicated to Professor Dr. H. Hartmann, Frankfurt am Main, on the occasion of his seventieth birthday 相似文献
67.
Hans-Herbert Schmidtke 《Theoretical chemistry accounts》1971,20(2):92-104
Zusammenfassung Eine kurze Ableitung des Angular Overlap-Modells wird gegeben. Das Modell wird auf zweikernige Übergangsmetallkomplexe vom Typ L5M-O-ML5 angewandt. Die Parametrisierung vond-Orbitalwechselwirkungen liefert fürD
4h-Symmetrie die Orbitalreihenfolgee
g<b
2g=b
1u<e
u
*
<a
1g
*
<b
1g=b
2u<a
2u
*
. Aus dem Orbitalschema lassen sich die magnetischen (intramolekularer Antiferromagnetismus) und die optischen Eigenschaften (Elektronenspektren) erklären, die sich von den gewinkelten Molekülen wesentlich unterscheiden. Der im linearen Cr-Komplex neu auftretende Bandentyp wird einem Übergang einesd-Elektrons in ein Molekülorbital zugeordnet, das über die Cr-O-Cr-Bindungsregion delokalisiert ist.
Dem Andenken von Herrn Professor Hans-Ludwig Schläfer gewidmet.
Herrn Prof. Dr. Hans-Ludwig Schläfer, der das Thema dieser Arbeit anregte, danke ich an dieser Stelle nochmals herzlich für viele wertvolle Diskussionen. Der Deutschen Forschungsgemeinschaft, Bad Godesberg, sei für die Bereitstellung finanzieller Mittel gedankt. 相似文献
Angular overlap treatment of low symmetry complexesII. Binuclear complexes with a linear oxygen bridge
A short derivation of the Angular Overlap model is presented. It is applied on binuclear transition metal complexes of the type L5M-O-ML5. A parametrization ofd-orbital interactions forD 4h symmetry yields the energy ordere g<b 2g=b 1u<e u * <a 1g * <b 1g=b 2u<a 2u * . From the orbital scheme the magnetic (intra molecular antiferromagnetism) and optical properties (electron spectra) are explained, which are different from corresponding molecules with angled structure. The new type of bands found in the spectrum of the linear Cr complex is assigned to a transition of ad electron into a molecular orbital which is delocalized over the Cr-O-Cr bond moiety.
Résumé Une brève représentation du modèle Angular Overlap est donnée. Le modèle est appliqué aux composés binucléaires de groupes de transition du type L5M-O-ML5. La parametrization des interactions des orbitalesd pour la symétrieD 4h donne les énergies d'orbitalese g<b 2g=b 1u<e u * <a 1g * <b 1g=b 2u<a 2u * . Cette série peux expliquer les propriétés magnétiques (antiferromagnétisme intramoléculaire) et optiques, qui sont différent de molécules avec structure angulaire. Le nouveau type des bandes trouvé dans le spectre du complex linéaire Cr est assigné à la transition d'un électrond dans une orbitale moléculaire qui est délocalisée sur la région de liaison Cr-O-Cr.
Dem Andenken von Herrn Professor Hans-Ludwig Schläfer gewidmet.
Herrn Prof. Dr. Hans-Ludwig Schläfer, der das Thema dieser Arbeit anregte, danke ich an dieser Stelle nochmals herzlich für viele wertvolle Diskussionen. Der Deutschen Forschungsgemeinschaft, Bad Godesberg, sei für die Bereitstellung finanzieller Mittel gedankt. 相似文献
68.
Gerhard Schmidtke Wolfgang Julius Riedel Manfred Knothe Helmut Wolf Ulrich Klocke Horst Maximilian Preier Roland Grisar Werner Fischer 《Fresenius' Journal of Analytical Chemistry》1984,317(3-4):347-349
Summary An IR laser diode spectrometer of modular design with micro-processor control is presented. It consists of laser source (vibration decoupled refrigerator with temperature control unit and laser power supply), mode filter, open-path and detector modules, and electronics for the data evaluation. For quantitative gas analysis the diode is tuned by periodic current pulses over the frequency range of a selected spectral line. The determination of the gas concentration is based on the measurement of the extinction of the signal integrated over the absorption line profile (integrative spectroscopy). As an example the measurement of the atmospheric minor constituent carbon monoxide is described for an open path of 50 m.
Dedicated to Prof. Dr. W. Fresenius on the occasion of his 70th birthday 相似文献
Gasanalyse mit IR-Diodenlaser-Spektrometern
Zusammenfassung Ein modular aufgebautes, mikroprozessor-gesteuertes IR-Diodenlaser-Spektrometer wird vorgestellt. Es besteht aus dem Laser-Modul (vibrationsentkoppelter Kühler mit Temperaturregler und Laserstromversorgung), dem Modenfilter, der Meßstrecke und dem Detektor-Modul und der Auswerteelektronik. Für die quantitative Gasanalyse wird die Laserdiode mit periodischen Stromimpulsen derart durchgestimmt, daß der Frequenzbereich der jeweils ausgewählten Spektrallinie während des Impulses durchlaufen wird. Die Bestimmung der Gaskonzentration beruht auf der Messung der Extinktion, integriert über das Profil der betreffenden Absorptionslinie (Integrativspektroskopie). Als Anwendungsbeispiel wird die Messung des atmosphärischen Spurengases Kohlenmonoxid auf einer 50m langen Fernmeßstrecke beschrieben.
Dedicated to Prof. Dr. W. Fresenius on the occasion of his 70th birthday 相似文献
69.
J. Schmidtke 《Fresenius' Journal of Analytical Chemistry》1986,324(3-4):212-213
70.
Bridgette G. Logan David L. Hopkins Leigh M. Schmidtke Stephanie M. Fowler 《Journal of Raman spectroscopy : JRS》2020,51(11):2338-2346
The diet of cattle has been shown to alter both subcutaneous fat and muscle fatty acid composition, and these differences cause a change in the Raman spectra of the fat due to the different chemical bonds associated with these biochemical changes. Because biochemical changes only lead to subtle changes in the Raman spectra, statistical methods based upon chemometric modelling are necessary to extract indicative information on the type of feed consumed. This investigation undertook a feasibility study using a limited sample set derived from two producers in one location to ascertain the potential for Raman spectroscopy to accurately discriminate grain-fed cattle from grass-fed cattle and investigated the usefulness of principal component analysis (PCA) and partial least squares discriminate analysis (PLS-DA) to best discriminate between feeding groups using the information from the Raman spectra. The first two principal components accounted for 83% of the variation in the spectra and demonstrated discrimination of samples by feed type. PLS-DA resulted in a model that was able to accurately predict grain- and grass-fed carcases with a misclassification rate of 3.5%. Changes in beef cattle diets lead to subtle changes in subcutaneous fat; using Raman spectroscopy with chemometric modelling, these changes can be identified and used to identify the production system of beef products. This study successfully uses Raman spectroscopy as an automated, nondestructive and rapid technique in the range of 600–2000 cm−1 in combination with pattern recognition of unsupervised (PCA) and supervised (PLS-DA) techniques to classify the production system of cattle between grain and grass fed. 相似文献