ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Physics  (9)
  • Computational Chemistry and Molecular Modeling  (3)
  • Wiley-Blackwell  (12)
  • National Academy of Sciences
  • 1
    Electronic Resource
    Electronic Resource
    Copolymerization of β-pinene with styrene oxide and N-vinylpyrrolidone (1982)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 1279-1285 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of β-pinene with styrene oxide (SO) and β-pinene with N-vinylpyrrolidone (VP) was investigated by using SnCl4 in dichloromethane diluent at low temperature. Monomer reactivity ratios were evaluated for both copolymers at -80°C; these are r1(SO) = 2.979 and r2(β-pinene) = 0.002 and r1(VP) = 0.096 and r2(β-pinene) = 0.294.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1982.170200511
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A quantal approximation to the study of the collisional resonances in the NA-N2 system (1989)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 36 (1989), S. 369-377 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Experimental works suggest the existence of an oscillating complex in the collisional quenching of Na with N2 molecules. Until now, however, few efforts have been dedicated to the study of these possible complexes. In this work, a diabatic and diabatic-configuration interaction method are proposed in order to investigate the existence of these quasibound levels. The results and their comparison with other available data are presented and discussed.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560360319
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Theoretical study of the interaction of Ga. Ga+, and Ga2+ with the hydrogen molecule (1992)
    New York, NY : Wiley-Blackwell
    International Journal of Quantum Chemistry 44 (1992), S. 781-791 
    Details
    ISSN: 0020-7608
    Keywords: Computational Chemistry and Molecular Modeling ; Atomic, Molecular and Optical Physics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The C2v, potential energy curves for the interaction of Ga, Ga+, and Ga2+ with the hydrogen molecule were calculated using the pseudopotential method of Durand et al. and triple-ζ gaussian basis sets. Electronic correlation has been taken into account by MRCI + MP2 calculations. We studied the 2B2(4p), 2A1(4p), 2A1(5s), and 2B2(5p) surfaces for the Ga + H2, the 1A1, 3B2, and 1B2 surfaces for Ga+ + H2 and the 2A1,(4s), 2B2, and 2A1(5s) surfaces for the Ga2+ + H2 reaction. We first analyzed the unrelaxed H2 approach to the metallic center, followed by the angle relaxation. The reactivity in all the interactions studied are analyzed with a model mechanism, previously proposed by us. © 1992 John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/qua.560440869
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Deformation, scattering, and birefringence of flexible polymer chains under external forces or electric fields (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 689-697 
    Details
    ISSN: 0887-6266
    Keywords: tensile force ; electric field ; chain conformation ; birefringence ; scattering ; Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of a tensile stress or an electric field on the conformation of a flexible polymer chain has been studied by combining theory with numerical simulation. In the presence of such external agents, the macromolecule experiences the action of two opposite forces at the chain ends. Two models are considered: the Gaussian bead-and-spring chain, and the freely jointed chain with segments of fixed length. From simulated Brownian trajectories we calculate steady-state properties of the polymer under the continuing action of the external forces. Thus, we compute the chain deformation and expansion, measured by the square radius of gyration, and analyze the influence of the external force on low-angle scattering of radiation. The effect of the link orientation in the optical anisotropy or birefringence is also analyzed. From existing theories, we predict very simple relationships between expansion, low-angle scattering, and birefringence, valid for Gaussian chains of any length, and for long freely jointed chains. The simulation results confirm those relationships. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys, 35: 689-697, 1997
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 5
    Electronic Resource
    Electronic Resource
    Chemical modification of poly(vinyl chloride): A conclusive study of the influence of tacticity (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 23 (1985), S. 1077-1087 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Three samples, A, B and C, of poly(vinyl chloride) (PVC) were prepared at 90, 60, and 0°C, respectively, to give them different isotactic content measured by 13C-NMR spectroscopy. A kinetic study of the nucleophilic substitution with sodium thiophenate, carried out for the three samples, showed that even at temperatures as high as 60°C a fraction of the units remain unreactive and that the extent of this fraction depends on the syndiotactic content of the polymer. This was also supported by a comparison of the behavior of samples B and C in substitution experiments at 5 and 60°C. In contrast the substitution experiments at -30°C demonstrated that, as suggested, a small fraction of extremely reactive units exists in PVC, the content of which is higher as the isotactic content of the polymer increases. In this connection, and even though a slight contribution of some defect structures cannot be ruled out, a 13C-NMR analysis of sample B after modification at 40°C to various degrees demonstrates that the reactivity of the isotactic triads is high in relation to the heterotactic. On the basis of the results obtained and the possible conformations in PVC the substitution mechanism is related to the occurrence of isotactic TT conformations. The results, as discussed in terms of the various ways in which isotactic TT conformations appear open new prospects in the field of PVC chemical modification and stabilization mechanisms.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.170230412
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Direct search methods for the molecular conformation problem (1994)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Computational Chemistry 15 (1994), S. 627-632 
    Details
    ISSN: 0192-8651
    Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Computer Science
    Notes: An important area of research in computational biochemistry is the design of molecules for specific applications. The design of these molecules, which depends on the accurate determination of their three-dimensional structure, can be formulated as a global optimization problem. In this article, we present results from the application of a new conformation searching method based on direct search methods. We compare these results to some earlier results using genetic algorithms and simulated annealing. © 1994 by John Wiley & Sons, Inc.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jcc.540150606
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Cationic copolymerization of β-pinene and epichlorohydrin (1981)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 19 (1981), S. 1533-1538 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: β-Pinene and epichlorohydrin (ECH) have been copolymerized cationically using BF3(C2H5)2O and SnCl4 as catalysts. Polymerizations were carried out at -80°C in methylenechloride. Monomer reactivity ratios were determined in both catalysts which were r1(ECH) = 1.06 ± 0.15 and r2 (β-pinene) = 0.32 ± 0.08 in BF3(C2H5)2O and r1(ECH) = 0.33 ± 0.11 and r2(β-pinene) = 2.03 ± 0.44 in SnCl4. Copolymers of different composition were soluble in acetone and insoluble in methanol. This characteristic was taken to indicate that the polymeric products were real copolymers and not a mixture of two homopolymers of epichlorohydrin and β-pinene.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1981.170190624
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Cationic polymerization of β-pinene (1984)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 673-677 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: β-Pinene was polymerized with cationic initiators in reactions that were carried out to study the solvent, temperature, initiator, and monomer-to-solvent ratio. Polymers obtained under different conditions were characterized by intrinsic viscosity, softening point, and gel permeation chromatography.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1984.170220317
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    A new look at the crystallization of polyethylene. II. Crystallization from the melt at low supercoolings (1982)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 20 (1982), S. 1717-1732 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This article is part of the general project laid out in Part I (ref. 9) and is concerned with obtaining information on primary (unthickened) crystals of polyethylene formed at low supercoolings. For this, a technique had to be devised by which crystallization could be speeded up so as to eliminate or at least reduce lamellar thickening. Indeed we were able to increase the rate of crystallization by an order of magnitude using a technique which we have called enhanced self-nucleation. Using this technique we find that when viewed under an optical microscope, spherulites crystallize uniformly over the field of view, and not, as is usual, by a radial growth process. Isothermal crystallization in bulk linear polyethylene has been studied by means of the enhanced self-nucleation technique as a function of crystallization time by using Raman LAM and melting points to assess variations of fold length Data have been obtained at very much shorter times than before. At short times, we find a constant fold length; at longer times the crystals thicken linearly with the logarithm of time. Values of the initial fold length for crystallization temperatures between 118 and 130°C are presented. Associated with the thickening at short times we find an induction time which increases with temperature.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1982.180200921
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Studies on polyethylene crystallized at unusually high supercoolings: Fold length, habit, growth rate, epitaxy (1984)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 22 (1984), S. 1085-1096 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The newly arisen possibility of crystallizing polyethylene at supercoolings much higher than were achievable previously has enabled the study of crystallization to be extended in several directions. Thus, fold length can be followed down to previously inaccessibly low crystallization temperatures, in the present case with sharp fractions, demonstrating the essential independence of the fold length of molecular weight. In this context the thinnest isolated crystal reported so far was obtained (ca. 6 nm). The faceted nature of crystals grown at such low temperatures and high rates has been noted, and is in line with new conceptions of polymer crystal growth. A previous observation of exceptionally high crystal growth rate (ca. 2 m/s) has been supplemented by measurements over a range of crystallization temperatures and the results found to be in good agreement with the predicated regime III behavior in the least theory of Hoffman. Observations of epitaxy on mica, while broadly in line with those by Lovinger, were revealing in several respects. Among these the observation that the substrate can influence the fold length when the chains are parallel to the substrate plane remains unexplained and puzzling.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1984.180220611
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...