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  • 79.60  (5)
  • Polymer and Materials Science  (5)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 97 (1995), S. 25-34 
    ISSN: 1434-6036
    Keywords: 79.60 ; 71.28
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The electronic structure of the layered compounds LaI2 and CeI2 was investigated by photoemission and electron energy loss spectroscopy. From the experimental results we are able to confirm the metallic nature of these compounds, and by using photon energy dependent measurements of the valence band we can identify the orbital character of the conduction band as essentially 5d1-like. A detailed analysis of the Ce 3d and 4f spectra yields a remarkably small 4f-5d hybridization strength, almost completely decoupling the f-electron from the conduction band, which makes CeI2 a somewhat unusual system compared to other metallic Ce compounds. Band structure calculations by Jepsen and Andersen [1] confirm these experimental results.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 97 (1995), S. 83-93 
    ISSN: 1434-6036
    Keywords: 79.60 ; 71.20 ; 71.28
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have investigated hole doped (by lithium) and electron-doped (by nickel metal) NiO with photoemission (PES), inverse photoemission (IPES) and low and high energy electron energy loss spectroscopy (EELS). Both types of doping create empty states approximately in the middle of the charge transfer gap of undoped NiO.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1434-6036
    Keywords: 79.60 ; 71.20 ; 71.28
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract From photoemission and electron-energy-loss data the following picture of KMnO4, with MnVII (with a formal charge state Mn7+ (3d 0)) tetrahedrally surrounded by four O2−-ions, is deduced: strong covalent bonding between MnVII and O2− leads to a considerable occupation of the Mn-3 d shell. The ground state of the (MnO4)−1 molecule is an orbital and spin singlet as seen by the absence of any multiplet splitting in the Mn core levels. The valence band shows a four peak structure extending form 4 eV to 8 eV below the Fermi energy. The first peak at 4.2 eV has mainly O-2p character. The remaining peaks are of strongly mixed Mn-3d/O-2p character due to the covalent bonding. This mixing decreases with increasing binding energy. The electron energy loss data show a variety of structures between 2 eV and 10 eV independent of the primary electron energy which defines them as dipole allowed charge-transfer transitions. An additional excitation at 1.8 eV decreases quickly in intensity with increasing electron energy which classifies it as a dipole or spin forbidden transition in the compound. This energy is close to the value of 1.6 eV reported for the activation energy observed in electrical transport data. The results are compared to quantum chemical molecular orbital calculations of the (MnO4)−1 molecule.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 44 (1987), S. 75-79 
    ISSN: 1432-0630
    Keywords: 74.00 ; 74.10 ; 74.70 ; 79.60
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract XPS and UPS photoemission results on the new high-T c oxide superconductors La2−xMexCuO4 (Me=Sr, Ba) with a maximumT c≈40 K show the following: 1) the electronic density of states atE F is small (smaller than in pure Cu); the work function is metallic like with a value around 4.2 eV. 2) The Cu-2p spectra show hardly a possible small tendency to a mixed valent Cu3+/Cu2+state with increasing Me content, but smaller than expected from the Me2+ concentration suggesting that oxygen defects are responsible for the charge compensation. 3) The core level spectra of La, Me, and O show satellites which are at least partially related to O2− defects and which change in intensity with increasing surface sensitivity of the experiments. First core-level spectra on y1.2Ba0.8CuO4 with aT c ≈ K indicate a complicated composition of these new compounds.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 35 (1984), S. 7-15 
    ISSN: 0947-5117
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: ESCA Untersuchungen an Stählen, gebeizt in HCl mit und ohne InhibitorzusatzEs wird berichtet über ESCA Untersuchungen (Electron Spectroscopy for Chemical Analysis) an kalt gewalzten ST 13 Stahlproben, gebeizt in HCl-Lösung mit und ohne Inhibitor-Zusatz (Dibutylthioharnstoff, DBTU). Die Ergebnisse zeigen, daß das DBTU-Molekül dissoziativ an der Metalloberfläche chemisorbiert wird. Das häufig benutzte Inhibitionsmodell, daß die Metalloberfläche durch die Inhibitormoleküle vollständig bedeckt wird und damit das Metall vor dem Angriff durch die Säure geschützt wird, kann für den Inhibitor DBTU durch unsere ESCA-Experimente nicht bestätigt werden. Die Ergebnisse sind in Übereinstimmung mit anderen Beobachtungen über die Chemisorption schwefelhaltiger Moleküle an Eisen-Oberflächen.
    Notes: ESCA experiments (Electron Spectroscopy for Chemical Analysis) on cold rolled ST 13 steel samples, etched in HCl solutions without and with inhibitor additives (dibutylthiourea, DBTU) are reported.These data showed, that DBTU is dissociatively chemisorbed at the metal surface. The frequently used assumption that the metal surface is covered by the inhibitor molecules preventing the direct attack of the acid cannot be confirmed by our ESCA results, at least for the inhibitor DBTU. The results are in agreement with previous findings on the chemisorption of sulphurous molecules on iron surfaces.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 20 (1991), S. 377-379 
    ISSN: 1434-6079
    Keywords: 79.60 ; 71.20 ; 36.40
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We measured XPS and UPS spectra of gold clusters with 55 atoms, embedded in an electrically isolating phosphine matrix, and of gold-phosphine, from which the clusters were chemically derived. Compared to the spectra of bulk gold the valence band spectrum and the core level spectra of the clusters showed shifts of the peaks and the fermi level to higher binding energies. The shift of the peaks could qualitatively be interpreted by a final state effect. We succeeded in a separation of bulk and surface contributions to the core level spectra and in a reasonable quantitative analysis of the valence band spectrum of the clusters. The Au 4f core level spectrum of gold-phosphine showed two peaks at 1.5 eV higher binding energies than the corresponding peaks of the clusters.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Chemie Ingenieur Technik - CIT 65 (1993), S. 1132-1133 
    ISSN: 0009-286X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 19 (1975), S. 215-225 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Acetylation of phenol-formaldehyde (PF) wood adhesives afforded derivatives which could be characterized by proton magnetic resonance (PMR) spectroscopy. Through use of the chemical shift and integral parameters, relative comparisons were made for the degree of polymerization of resins prepared with different molar ratios. Additionally, PMR studies of these acetylated derivatives provided a means of determining methylol content and number of aromatic protons remaining, and to some extent gave an estimate of molar formaldehyde-to-phenol ratio. Experiments conducted with Ca(OH)2 and NaOH as catalysts showed the latter to be the more effective catalyst for PF systems.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 1973-1985 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Comparisons were made of differential scanning-calorimetric (DSC) thermograms of both liquid and powdered commercial phenol-formaldehyde resins. By a combination of the results from analyses under a variety of conditions, such as ambient pressure, high pressure, using freeze-dried samples, and also by direct observation of the resin-curing process in wood-veneer assemblies, the curing reactions of phenol-formaldehyde resins were found to differ for resol and novolac systems. At a heating rate of 10°C/min, the resol resin showed endothermic curing reactions at temperatures of about 150°C, while the novolac-type resin showed an exothermic peak maximum at about 160°C. Results are presented to show how DSC can be used to differentiate between a resol and novolac system.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 0142-2421
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Type of Medium: Electronic Resource
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