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  • Physics  (2)
  • Pisum  (1)
  • PIC
  • 1975-1979  (3)
  • 1979  (3)
Collection
Publisher
Years
  • 1975-1979  (3)
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Protoplasma 101 (1979), S. 73-80 
    ISSN: 1615-6102
    Keywords: Cotyledon culture ; Pisum ; Polytene chromosomes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The cotyledon cells ofPisum sativum have high DNA contents. By appropriate culture techniques, some of these cells can be triggered into division. Two types of dividing nuclei were seen. Firstly those that were polyploid with metaphases containing chromosome numbers ranging in value from 4 x to 32 x. Included among these were unexpected numbers equivalent to 12 x and 14 x. Secondly there were cells containing giant polytene chromosomes and these progressed from prophase to a metaphase where the polytene chromosomes separated into constituent single chromosomes.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 1411-1418 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The electroinitiated polymerizations of styrene, 2-vinylnaphthalene, and 9-vinylanthracene were compared in sulfolane and acetone solvents in the presence of ZnCl2. The relative orders of polymerization rates and polymerization efficiencies, in both solvents, were 9-vinylanthracene 〉 2-vinylnaphthalene 〉 styrene, with faster rates and higher efficiencies occurring in sulfolane. Data obtained from viscosity and gel permeation chromatography (GPC) studies indicate that the molecular weights of the polymers produced in these systems are extremely low, 〈5000. Chemical composition and infrared (IR) spectral data suggest that abnormal transfer reactions (possibly from solvent) may be occurring in the electroinitiated 9-vinylanthracene polymerizations. The polymerization mechanism appears to be cationic in these monomer-solvent systems with ZnCl2.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 17 (1979), S. 1153-1161 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: To elucidate mechanisms in electroinitiated polymerization reactions a comparison was conducted between ultraviolet (UV) photoinitiation and electroinitiation of N-vinyl phthalimide with zinc chloride as a catalyst. Both methods give low yields of a complex polymer product. A detailed analysis, infrared (IR), gel permeation chromatography (GPC), elemental, and molecular weight, conducted on the polymeric products, indicated that phthalimide ring opening was occurring and that complex mixtures of poly(N-vinyl phthalimide) derivatives were formed. Both initiation methods gave comparable results, which further indicated mechanistic similarity between photo-and electroinitiation in these donor-acceptor charge transfer polymerizations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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