Library

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
  • 1985-1989  (40)
  • 1890-1899
  • 1989  (17)
  • 1986  (23)
  • Chemistry  (40)
  • 1
    Electronic Resource
    Electronic Resource
    Elektrochemische Darstellung von Cyclopolyphosphanen - Elektrochemische Untersuchung von Phenyldichlorphosphan, o-, m-, p-Bromphenyl-dichlorphosphan sowie tert.-Butyldichlorphosphan (1986)
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 542 (1986), S. 167-174 
    Details
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis of Different Cyclopolyphosphanes by Cathodic Reduction, Electrochemical Investigation of Phenyldichlorophosphane, o-, m-, p-Bromophenyldichlorophosphane and tert.-ButyldichlorophosphaneThe electrochemical properties of selected dichlorophosphanes R-PCl2 (R = C6H5, o-BrC6H4, m-BrC6H4, p-BrC6H4, t-Bu) have been investigated by the Differential-Pulse-Polarography (DPP) and by cyclic voltammetry. On the basis of the obtained results an electrolysis (cathodic reduction) has been carried out with these substances in a 1,2-dichlorethane/0.1 M tetrabutyl-ammonium tetrafluoroborate solution with a mercury pool. The following cyclopolyphosphanes have been prepared, isolated, and characterized: (C6H5P)5,(4); (o-BrC6H4P)4; (m-BrC6H4P)5,(4,6); (p-BrC6H4P)5,(4); (t-BuP)4.
    Notes: Mit Hilfe von Differential-Puls-Polarographie (DPP) und Cyclovoltammetrie wurde das elektrochemische Verhalten ausgewählter Dichlorphosphan-Verbindungen R-PCl2 (R = C6H5, o-BrC6H4, m-BrC6H4, p-BrC6H4, t-Bu) untersucht. Auf der Grundlage der erhaltenen Werte wurden diese Substanzen in einer 1,2-Dichlorethan/0,1 M Tetrabutylammonium-tetrafluoroborat-Lösung kathodisch an einem Quecksilbersee elektrolysiert. Folgende Cyclopolyphosphane wurden dabei hergestellt, isoliert und charakterisiert: (C6H5P)5,(4); (o-BrC6H4P)4; (m-BrC6H4P)5,(4,6); (p-BrC6H4P)5,(4); (t-BuP)4.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/zaac.19865421122
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Influence of different tripeptides on the stability of the collagen triple helix. II. An experimental approach with appropriate variations of a trimer model oligotripeptide (1986)
    New York : Wiley-Blackwell
    Biopolymers 25 (1986), S. 1081-1086 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A collagen model peptide comprising three covalently cross-linked chains (Ala-Gly-Pro)8 with a stable triple-helix conformation was utilized as the constant part of elongated model peptides of different composition. The tripeptides Gly-Pro-Hyp, Gly-Pro-Ala, Gly-Pro-Pro, Gly-Pro-Ser, Gly-Ala-Hyp, Gly-Phe-Hyp, Gly-Glu-Hyp, Gly-Ala-Lys, and Gly-Pro-Phe were coupled at the N-terminal to the cross-linked peptide. The transition temperatures determined by CD measurements are higher for the peptides containing the Gly-X-Hyp sequences followed by those with the Gly-Pro-Y sequences. In experiments with combinations of two different tripeptides coupled to the constant part of the cross-linked model peptides higher transition temperatures were observed if the sequence of helix-promoting tripeptides was not interrupted.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360250608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Protein complexation with DNA phosphates as a cause for DNA duplex destabilization: A thermodynamic model (1989)
    New York : Wiley-Blackwell
    Biopolymers 28 (1989), S. 1653-1665 
    Details
    ISSN: 0006-3525
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Complexation of positively charged sites in a protein with the negative DNA phosphate groups shields the phosphate charges. This diminishes interstrand electrostatic repulsions, which stabilizes the duplex. When phosphate shidlding is present in one DNA strand only, the conformation of this strand changes due to a decrease of intrastrand phosphate-phosphate repulsions. This destabilizes the duplex since then the strands differ in conformation. A thermodynamic model is formulated to describe this stabilization/destabilization effect in terms of changed enthalpies and entropies of hybridization. It is found that protein complexation with one DNA strand can indeed lower the TM value of a duplex. The model is applied to the action of helicases (replication), RNA polymerases (transcription), and restriction endonucleases. Mechanisms with unilateral charge shielding are proposed for their duplex-destabilizing properties.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bip.360281002
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Thermal degradation of cellulose-containing composites during processing (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 233-240 
    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 strength properties of composites made of untreated cellulose fibers and linear low density polyethylene were investigated as a function of processing parameters. Studies have shown that the strength properties of composites increase with processing time and temperature. The increase in strength is accompanied by the appearance of new infrared absorption bands at 1718 and 1735 cm-1. A linear relationship between the absorbance and yield strength of composites indicates that oxidation, possibly directly at interfaces, takes place and enhances adhesion between the cellulose and polyethylene.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070370118
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Solvent effects in on-column injection of large sample volumes (1986)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 9 (1986), S. 405-407 
    Details
    ISSN: 0935-6304
    Keywords: Capillary GC ; Solvent effects ; Solvent trapping ; Phase soaking ; Large sample volumes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240090708
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Extending the scope of enantiomer separation on diluted methylated β-cyclodextrin derivatives by high-resolution gas chromatography (1989)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 12 (1989), S. 383-393 
    Details
    ISSN: 0935-6304
    Keywords: Enantioselective gas chromatography ; Enantiomer separation of underivatized volatiles ; Cyclodextrin derivatives ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: High-resolution open-tubular columns coated with solutions of heptakis(2,3,6-tri-O-methyl)-β-cyclodextrin (Phase I) or heptakis(2,6-di-O-methyl-3-O-trifluoroacetyl)-β-cyclodextrin (Phase II) in moderately polar polysiloxanes such as OV-1701 (5% cyanopropyl/7% phenyl/88% methylpolysiloxane) and OV-225 (25% cyanopropyl/50% phenyl/25% methylpolysiloxane) are used for the gas chromatographic enantiomer separation of volatiles belonging to different classes of compounds. No derivatization procedures are necessary for most of the resolved chiral molecules. The chiral stationary phases can be operated between 25 and 190°C for extended periods of time. The enantiomer separation of saturated, unfunctionalized hydrocarbons clearly demonstrates the importance of molecular inclusion in chiral recognition using cyclodextrins for this class of compounds. The different, and in some cases complementary, selectivity of the Phases I and II is demonstrated.
    Additional Material: 20 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240120608
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Gas chromatographic enantiomer separation on per-n-pentylated amylose (1989)
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 12 (1989), S. 549-551 
    Details
    ISSN: 0935-6304
    Keywords: Enantioselective gas chromatography ; Carbohydrate chiral stationary phase ; Per-n-pentylated amylose ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jhrc.1240120815
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Einflüsse von HCl und N2 auf die Hochtemperaturkorrosion in Atmosphären mit niedrigem Sauerstoffdruck (1989)
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 40 (1989), S. 642-650 
    Details
    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: Influence of HCl and N2 on high temperature corrosion in atmospheres with low oxygen pressuresThe effects of HCl and N2 on the high temperature corrosion in atmospheres with low oxygen pressures were investigated.Investigations of the alloy Fe-20Cr in He-H2-H2-O-HCl atmospheres at 1173 K under conditions, where no condensed chlorides could be formed, show the simultaneous growth of Cr2O3 and evaporation of CrCl2. The kinetics of the reactions can be described by growth of Cr2O3 according to the parabolic rate law and transport of CrCl2 in the gas flow following a linear rate law.During heating of the samples in He-H2-H2O-HCl condensed chlorides are formed which decrease the adherence of the oxide layers and cause oxide spallation during cooling. This can be avoided either by preoxidation in H2-H2O or heating in dry hydrogen. The porosity of Cr2O3 layers is not enhanced when HCl is added to the gas atmosphere.The oxidation and evaporation is enhanced in N2-H2-H2O-HCl atmospheres compared to He-H2-H2O-HCl atmospheres. The Cr2O3 scales are coarse grained and poros. The enhanced porosity is caused by the nucleation and growth of chromium nitrides in the transient state of oxidation.
    Notes: Der Einfluß von gasförmigem HCl und Stickstoff auf die Hochtemperatur-Korrosion in Atmosphären mit niedrigem Sauerstoffpartialdruck wurde untersucht.Untersuchungen mit der Legierung Fe-20Cr in He-H2-H2O-HCl-Atmosphären bei 1173 K unter Bedingungen, bei denen keine kondensierten Chloride gebildet werden, zeigten, daß gleichzeitig Wachstum von Cr2O3 und Abdampfen von CrCl2 erfolgt. Die Kinetik der Gesamtreaktion läßt sich durch Überlagerung eines parabolischen Zeitgesetzes für das Oxidwachstum mit einem linearen Zeitgesetz für die Abdiffusion des Chlorides in den Gasstrom beschreiben.Beim Aufheizen der Proben in He-H2-H2O-HCl bilden sich kondensierte Chloride, die die Haftung der Oxidschichten beeinträchtigen und Abplatzen beim Abkühlen verursachen. Voroxidation in H2-H2O oder Aufheizen in getrocknetem Wasserstoff verhindern dies. Die Porosität von Cr2O3-Schichten wird durch den Zusatz von HCl zur Gasatmosphäre nicht erhöht.In N2-H2-H2O-HCl-Atmosphären ist die Oxidation und das Abdampfen beschleunigt gegenüber He-H2-H2O-HCl-Atmosphären. Die gebildeten Cr2O3-Schichten sind grobkörnig und porös. Ursache der erhöhten Porosität ist die Keimbildung und das Wachstum von Chromnitriden im Anfangsstadium der Oxidation.
    Additional Material: 16 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/maco.19890401104
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Das Korrosionsverhalten von pulvermetallurgischem ChromVortrag gehalten anläßlich der Dechema-Jahrestagung 1989, Frankfurt, 1. und 2. 6. 1989. (1989)
    Weinheim [u.a.] : Wiley-Blackwell
    Materials and Corrosion/Werkstoffe und Korrosion 40 (1989), S. 715-719 
    Details
    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: Corrosion behaviour of powder metallurgically produced chromiumPowder metallurgically produced chromium of purity 99.96 percent can be processed into semifinished and finished parts of up to now restricted sizes. It is highly resistant to certain hot solutions of salts, hot carbonic acids, oxidizing anorganic acids, bases and gases (hot gases especially in combination with ashes and slags). It is shown in which fields and for what kind of functional parts pure chromium eventually could be used.
    Notes: Pulvermetallurgisch hergestelltes Chrom der Reinheit 99,96 kann zu Halbfertig- und Fertigprodukten von bisher allerdings nur begrenzter Größe geformt werden. Das Material ist hochbeständig gegen verschiedene heiße Salzlösungen, heiße Carbonsäuren, oxidierende anorganische Säuren, Basen und Gase (gegen Heiß- gase speziell in Verbindung mit Aschen und Schlacken). Es wird gezeigt, in welchen Gebieten und für welche Funktionsteile reines Chrom eventuell verwendet werden könnte.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/maco.19890401204
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    The cell-plasma membranes as composite system of two-dimensional liquid crystal and macromolecular network and how to mimick its physical propertiesPaper presented at the meeting of the GDCh-Fachgruppe “Makromolekulare Chemie” on “Polymers and Biological Functions” in Bad Nauheim (West-Germany) on April 18/19. 1988. (1989)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 166 (1989), S. 1-19 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The evolution of the cell has become possible after nature had invented the composite membrane by combining two states of matter: the two-dimensional liquid crystalline lipid/protein bilayer and the macromolecular network.In the first part we introduce the essential structural features of the cell plasma membrane (case of erythrocyte) and describe their extraordinary mechanical properties. These are unmatched by the technical materials and allow migrating cells to squeeze through narrow gaps of the tissue or of the extracellular protein networks without loss of material or lysis. As an example, how nature manages to alter the structure and function of biomenbranes drastically by minor biochemical signals we consider chemically induced shape changes of cells.In the second part we describe some efforts to mimick mechanical properties of cell membranes with composite membranes of monomeric and polymeric amphiphiles. These model systems exhibit promising new material properties for future applications in chemistry and biotechnology.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1989.051660101
    Library Location Call Number Volume/Issue/Year 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...