ISSN:0005-9021    

DOI:10.1002/bbpc.19780820702

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractThe complex formation of aluminium sulphate and scandium sulphate is studied in aqueous solution using ultrasonic relaxation techniques in the frequency range 0.23 to 1500 MHz. Two and three chemical relaxation effects are observed for solutions of aluminium sulphate and scandium sulphate respectively, which are consistent with a three step association mechanism. For scandium sulphate rate and equilibrium constants as well as volumes of reaction are obtained for all three reaction steps by analysis of relaxation times and amplitudes.

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820703

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractFor the case of special molecular models representing the acetonitrile molecule the expansion coefficients of the molecular pair distribation function are calculated by use of perturbation theory. These results are used to get theoretical access to scattering intensities in the frame of several approximations. The first model describes the molecule by three hard spheres and uses a hard sphere liquid as a reference. In the second case the calculations are based on an anisotropic Lennard‐Jones potential by application of a model of overlapping ellipsoids and by use of a Lennard‐Jones liquid as a reference system. In the third model dipolar attractive forces are taken into account with an anisotropic hard‐sphere liquid as a reference. Finally all the calculations with different intermolecular potentials are compared with neutron scattering experi

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820704

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractComplex permittivities of aqueous solutions of ethylene‐glycols, HO‐(CH2‐CH2‐O)n‐H (n= 1, 2, 3, 4, 4.1, 8.7, or 13.2, and of ethylene‐glycol dimethylethers, H3C‐O‐(CH2‐CH2‐O)n,‐CH3(n = 1, 2, or 3), have been measured at 11 up to 13 frequencies in the range 2 to 40 GHz by an interferometric transmission method. A sum of relaxation functions has been fitted to the observed data to yield the hydration number and reorientation time of the hydration water. The values of these parameters are discussed and compared with those for poly (ethylene oxide) of different degree of polymerization and those for other series of organic solutes in order to get insight into the effect of various molecular parameters on the microdynamics of

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820705

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractMatrix‐elements of the elasticity modulus of a single crystal of 2.4‐hexadiine‐1.6‐diol‐bis(p‐toluene sulfonate) (PTS) and of the corresponding polymer single crystals were determined by Brillouin scattering. The solid‐state polymerization was achieved by annealing at 60°C and the variation of three selected elastic constants with conversion was determined. – The elastic constant in chain direction increases from 0.97·104N·mm−2to 4.38·104N · mm−1going from the monomer to the polymer. The magnitude of this constant changes smoothly with conversion. The dependence on conversion can be described by a model in which infinitely long linear macromolecules all extended alongbbut randomly distributed are embedded in the matrix of the residual monomer. – At low conversion there is some deviation from the predicted elastic behaviour due to the finite length of the macromolecules formed at

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820706

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractThe far‐infrared conductivity spectra of the fast ion conductor β‐CuBr (683 K), of the mixed crystal Ag0.85Cu0.15Br (573 K), and of AgBr (573 K) are experimentally determined from transmittance and reflectivity data. The very‐far‐infrared absorption band typical of structurally disordered solid electrolytes is observed in both β‐CuBr and Ag0.85Cu0.15Br. The band is interpreted in terms of a large‐amplitude irregular local motion of the cations. In the case of β‐CuBr, calculated frequency spectra are compared to the experimen

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820707

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractThe retarding effect of the tenside hexadecyl trimethyl ammonium bromide on the dismutation of Br2−radicals was investigated. Br2−radicals adsorbed singly at different micelles do not directly react with each other. The detachment of Br2−is required. A residence time of 1.5 ± 10−5s of Br2−on the micelles was derived from the kinetic data. Below the critical micelle concentration the tenside does not retard th

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820709

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractDie Reaktion von Wasserstoff‐Atomen mit Hydroperoxyl‐Radikalen wurde in der Gasphase in zwei isotermen Strömungssystemen bei Drücken um 5 ± 102[Pa] mit Helium als Trägergas bei 293 K untersucht. Die absoluten Konzentrationen von H, O und OH wurden mit der ESR gemessen. Als HO2‐Quelle diente die Reaktion:.Die Geschwindigkeitskonstante dieser Reaktion wird zu:k1(293 K) = (9,0 ± 1) 10−5[cm6/mol2sec] gemessen. – Aus der Messung der Konzentrationszeitprofile für kurze Reaktionszeiten wurden die spezifischen Geschwindigkeitskonstanten der Reaktionskanäle. bestimmt. Dabei wurde ausgenutzt, da13 durch NO eine homogene Katalyse der Rea

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820710

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractDer thermische Zerfall von C2F4wurde im Temperaturbereich von 1150 bis 1600 K und bei Drücken von 0,07 bis 46 bar in stark verdünnten Gemischen mit Argon als Trägergas hinter einfallenden und reflektierten Stoßwellen untersucht. C2F4zerfällt unter Bruch der C‐C‐Doppelbindung in zwei CF2‐Radikale. Die Reaktion folgt einem einfachen Dissoziations‐Rekombinations‐Mechanismus. Aus der Druckabhängigkeit der Geschwindigkeitskonstantek1.0.des Zerfalls erhält man unter Anwendung von Theorien unimolekularer Reaktionen für die Grenzbereiche sehr niedriger und sehr hoher Drücke die Arrhenius‐Ausdrücke.Eine Auswertung der chemischen Gleichgewichte ergibt in übereinstimmung mit dem Ergebnis der kinetischen Messungen eine Reaktionsenthalpie von δHR2980= (290,8 ± 5) kJ mol−1. Daraus wurde für die Bildungsenthalpie des CF2‐Radikals ein Wert von δHt298

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820711

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY

摘要:

AbstractGeneralized phenomenological equations of transport are derived for isothermal systems in which each neutral or ionic constituent or species exists as a mixture of several isotopes, except for the solvent. For this reason the following hypotheses is used: the entropy production is independent of isotopic composition. Relationships between generalized conductivity coefficients and the tracer diffusion coefficients are derived. The limiting behaviour of these coefficients is discussed.

ISSN:0005-9021    

DOI:10.1002/bbpc.19780820712

出版商:Wiley‐VCH Verlag GmbH&Co. KGaA    

年代:1978

数据来源: WILEY