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  • 1970-1974  (7)
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 38 (1973), S. 2817-2821 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 20 (1971), S. 216-226 
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die in der vorangehenden Arbeit dargestellte „II. Methode variabler Integrale“ benötigt zur Auswahl eines Parametersatzes zur Berechnung von Molekülspektren keine Abschätzungen oder willkürliche Parameteradjustierungen. Sie wird in der vorliegenden Arbeit auf eine Reihe von Stickstoff oder Sauerstoff enthaltenden Heterocyclen angewendet, um ihre Leistungsfähigkeit zu untersuchen. Die Ergebnisse sind mit denjenigen, die mit der ähnlichen „I. Methode variabler Integrale“ gewonnen wurden, vergleichbar. Zusätzlich werden mit der letzteren Methode einige Schwefel enthaltene Heterozyklen behandelt. Die Übereinstimmung von Theorie und Experiment ist zufriedenstellend.
    Notes: Abstract The variable integrals method II presented in the preceding paper, which needs no guess work in choosing a set of parameters to calculate the electronic spectra of molecules and contains no arbitrary adjusting parameters, is applied to various kinds of nitrogen- or oxygen-containing heteroatomic molecules in order to check the applicability of this method. At the same time the variable integrals method I, a simplified method of the variable integrals method II, is also applied to the same systems and some sulphur-containing molecules. The both methods give similar results and the agreement between theory and experiment is satisfactory.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Theoretical chemistry accounts 23 (1971), S. 67-74 
    ISSN: 1432-2234
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Der Ladungsübertragungs-Komplex zwischen Benzol und p-Benzochinon wird als ein einziges konjugiertes π-Elektronensystem behandelt. Seine π-Elektronenzustände werden nach der „Methode II der Variablen Integrale“ berechnet. Für drei Modelle des Komplexes werden die Potentialkurven, die Stabilisierungsenergien, die Diagramme der Orbitalenergien, die Elektronendichten, die Bindungsordnungen, die Dipolmomente sowie die elektronischen Übergangsenergien untersucht. Die Übereinstimmung mit dem Experiment ist für die Elektronenspektren zufriedenstellend.
    Abstract: Résumé Calcul des états électroniques π par la méthode des intégrales variables II pour le complexe de transfert de charge entre le benzène et la p-benzoquinone considéré comme un système conjugé unique. Discussion de trois modèles de complexe de transfert de charge: courbes d'énergie potentielle, énergies de stabilisation, diagrammes d'énergie orbitale, densités électroniques, moment dipolaire et énergies de transition électronique. L'accord entre théorie et expérience est satisfaisant tout au moins pour les spectres électroniques.
    Notes: Abstract The charge-transfer complex system between benzene and p-benzoquinone is treated as a single conjugated system of π-electrons and its π electron states are calculated by the Variable Integrals Method II. For three models of the charge-transfer complex, potential energy curves, stabilization energies, orbital energy diagrams, electron densities, bond orders, dipole moment and electronic transition energies are discussed. The agreement between theory and experiment is satisfactory as for as the electronic spectra are concerned.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 17 (1973), S. 1909-1917 
    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: Double-cantilever beam cleavage specimens are very useful in characterizing the fracture behavior of isotropic, homogeneous, brittle, and semibrittle polymers. However, until this time they have not been used for ductile materials such as rubber-modified polymers or polycarbonates because of excessive yielding or breakage of the specimen arms before crack propagation can occur. In order to make it possible to measure the fracture surface work of these materials, a new sandwich cleavage specimen was developed by bonding rigid reinforcement plates to both sides of the specimen sheet. With this sandwich-tapered double-cantilever beam cleavage specimen, one can create conditions under which controlled crack propagation through tough ductile materials and measurement of the fracture surface work-two previously unobtainable results-are readily determined. In this paper, the design and construction of the sandwich specimens, test procedure, and the data analysis will be discussed in detail.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 17 (1973), S. 2053-2066 
    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: With the use of a sandwich-tapered double-cantilever beam cleavage specimen (described in part I of this series), the fracture surface work of several commercial and experimental acrylic multipolymers has been measured as a function of crack velocity and rubber content. The plots of fracture surface work versus crack velocity clearly exhibit the effects of rate (crack velocity) and rubber concentration on fracture behavior. Specifically, the fracture surface work of specimens with seven different rubber contents has been determined over a crack velocity range from 10-5 meters/sec to approximately 10 meters/sec. For each material, distinct maxima occur in the curves of fracture surface work versus crack velocity. The significance of these observations is discussed.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 54 (1971), S. 1081-1083 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The unusual electronic spectrum of the title compound is shown to be due to the strong interaction between the π-orbitals of the double bonds and the Walsh-orbitals of the fourmembered ring.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bands with Iv 〈 13 eV in the photoelectron spectra of quinoline (IX), isoquinoline (X), cinnoline (XI), quinazoline (XII), and quinoxaline (XIII) have been reassigned in a way consistent with the assignment proposed for pyridine (II), the diazines (III, IV, V), s-triazine (VI), and 1,2,4,5-tetrazine (VII). The bands corresponding to the ejection of an electron from a π-orbital have been identified by a regression calculation based on a HMO perturbation treatment. It has been found that the combined through-space and through-bond interaction of the lone pairs in III, IV, V and in their corresponding benzologues XI, XII, XIII are the same within experimental error ( ±, 0.2 eV). Our assignment is also supported by an empirical correlation of the pKa, 1- values and the mean lone-pair ionization potentials of the azaderivatives I to XIII.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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