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  • 1965-1969  (5)
  • 1960-1964
  • 1950-1954
  • 1968  (5)
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  • 1965-1969  (5)
  • 1960-1964
  • 1950-1954
Year
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  • 1
    Electronic Resource
    Electronic Resource
    Control of Growth of Axenic Cultures of Mammalian Cells by Serum Lipids (1968)
    [s.l.] : Nature Publishing Group
    Nature 219 (1968), S. 300-300 
    Details
    ISSN: 1476-4687
    Source: Nature Archives 1869 - 2009
    Topics: Biology , Chemistry and Pharmacology , Medicine , Natural Sciences in General , Physics
    Notes: [Auszug] This procedure was applied to calf serum which was then tested for residual lipid content. Charcoal-treated calf serum (2 ml.) and 2 ml. of native calf serum were extracted three times with 2 ml. of ether. Evaporation of the ether and drying over P2O5 in a vacuum gave 0.10 and 0.50 mg of residues ...
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1038/219300a0
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Some comments on the parameter choices for S.C.M.O. calculations on five membered heteroatomic π-electron systems (1968)
    Springer
    Theoretical chemistry accounts 10 (1968), S. 1-12 
    Details
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Bei den üblichen semiempirischen SCMO-Rechnungen an Heteroaromaten ergeben sich unerwartete Abhängigkeiten der Ladungsverteilung von den β Rumpf-Termen [1]. Die gebräuchlichste Parameterwahl führt zu chemisch unverständlichen Ladungsverteilungen bei Furan und Pyrrol [2]. Es wird gezeigt, daß der erste Effekt mit der relativen Größe der Diagonalelemente der Fockmatrix zusammenhängt; der zweite Effekt hängt sehr stark von den Nichtnachbarelementen ab: Bei Einschluß von Nichtnachbar-β Rumpf-Termen und entsprechender Parameterwahl erhält man befriedigende Ladungsverteilungen.
    Abstract: Résumé Il a été indiqué [1] que le traitement semi-empirique S.C.M.O. habituel des systèmes d'électrons π dans les hétérocycles comporte des relations in attendues entre la distribution de charge et les termes β coeur impliquant les hétéroatomes. D'autres chercheurs [2] ont affirmé que les choix les plus communs de paramètres fournissent des densités de charge dans le furane et le pyrrole déraisonnables sur le plan chimique. On montre ici que le premier effet est lié aux grandeurs relatives des éléments diagonaux de la matrice de Fock et que le second effet dépend fortement des éléments non immédiatement voisins de cette matrice, mais peut être annulé avec certains choix de paramètres par introduction des termes non voisins β coeur dans les calculs.
    Notes: Abstract It has been reported [1] that the usual semi-empirical S.C.M.O. treatments of heteroatomic π-electron systems yield unexpected dependencies of charge distribution on the β core terms involving the heteroatoms. Other workers [2] have claimed that the most usual choices of parameters yield chemically unreasonable charge densities in furan and pyrrole. It is shown here that the first effect is related to the relative magnitudes of the diagonal elements of the Fock matrix and that the second depends very strongly on the nonnearest neighbor F matrix elements but can be overcome with certain parameter choices by the inclusion of non-nearest neighbor β core terms in the calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00529038
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    On the dynamic mechanical behaviour of drawn poly(ethylene terephthalate) fibers (1968)
    Springer
    Colloid & polymer science 228 (1968), S. 54-58 
    Details
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Zusammenfassung Der Einfluß von Verstreckung und Temperaturbehandlung auf den α-Übergang in Poly(äthylenterephthalat), PET, Garn wurde untersucht unter Anwendung von Röntgen- und dynamisch-mechanischen Methoden. Es wurde gefunden, daß für hohe Vergütungstemperaturen verstreckte, kristalline PET-Garne eine Verschiebung des α-Überganges zu niedrigeren Temperaturen aufweisen, ähnlich wie für nicht verstrecktes, kristallines PET. Der Hauptunterschied zwischen verstreckten und nicht verstreckten Garnen ist die Lage des α-Überganges auf der Temperaturskala; der α-Übergang liegt für höhere Verstreckung bei höheren Temperaturen. Die Verlagerung des α-Überganges durch Temperaturbehandlung wird auf die Anzahl der Kristallite zurückgeführt, während seine Verschiebung durch Verstreckung erklärt wird durch die Orientierung in den amorphen Bezirken.
    Notes: Abstract The effect of drawing and annealing treatments on the α transition in poly(ethylene terephthalate), PET, yarns has been studied using a combination of X-ray and dynamic mechanical techniques. It was found that drawn, crystalline PET yarns exhibit a shift in the position of the α transition to lower temperatures for high annealing temperatures; this effect has been observed for unoriented, crystalline PET. The main difference between the results for the drawn and unoriented yarns lies in the position of the α transition on the temperature scale; the α transition occurs at higher temperatures the higher the draw ratio. The shift in the position of the α transition with anealing is interpreted in terms of the number of crystals whilst the change in position of the α transition brought about by drawing is explained by orientation in the amorphous regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02125764
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Multiple melting in nylon 66 (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 6 (1968), S. 1773-1781 
    Details
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Either of the two endothermic melting peaks found by differential thermal analysis of nylon 66 may be converted to the other by appropriate choice of annealing conditions. The two peaks are considered due to the melting of two morphological species, forms I and II. Form I is relatively fixed in melting temperature, while the form II melting temperature varies with annealing conditions and can be either above or below form I. The two forms can be distinguished by whether or not the conversion I → II takes place; if the sample is in form II no change in the thermogram is observed under suitable conversion conditions. The conversion of form I to form II also takes place during cold drawing. It has been previously shown that form I results from rapid cooling from the melt, and form II results from slow cooling. Form I appears to be kinetically favored, while form II is thermodynamically preferred. The variability in the form II melting point is attributed to variable crystal size and/or perfection.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.160061007
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    Paper (German National Licenses)
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  • 5
    Electronic Resource
    Electronic Resource
    The effect of structural changes on dye diffusion in poly(ethylene terephthalate) (1968)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 12 (1968), S. 2491-2508 
    Details
    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: The diffusion of a disperse dye, 1-amino-4-hydroxyanthraquinone (C.I. Disperse Red 15) into poly(ethylene terephthalate) fibers has been studied as a function of heatsetting temperature and draw ratio. It was found that the dynamic loss modulus E″, measured under the dyeing conditions, was related to the dye diffusivity D. This indicates that the diffusion is controlled by the mobility of the polymer chain segments. Both the diffusivity and dye saturation values do not vary monotonically with heatsetting temperature but exhibit a minimum at a heat-setting temperature near 175°C. X-ray diffraction measurements were used to show that this behavior is attributable to crystallinity and crystal size changes resulting from heat-setting.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1968.070121109
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    Paper (German National Licenses)
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