ISSN:0005-9021    

DOI:10.1002/bbpc.19840880802

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

年代:1984

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880803

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

年代:1984

数据来源: WILEY

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880804

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

年代:1984

数据来源: WILEY

摘要:

AbstractAn equation of state, recently developed for high densities, is extended to the whole density range and is compared to tabulated values of the thermodynamic data of methane. The agreement is very satisfactory. At subcritical temperatures, the parameters can be derived from second virial coefficient, vapour pressure, orthobaric liquid volume, and isothermal compressibility. At supercritical temperatures, the number of necessaryp‐ν‐Tmeasurements can be considerably reduced in comparison to conventional equations of s

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880806

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

年代:1984

数据来源: WILEY

摘要:

AbstractWith the aid of the emf‐method the activity of oxygen in the total homogeneous region of copper‐lead alloys was determined at 1200°C. The logarithm of the activity coefficient of oxygen at constant alloy composition linearly depends on the oxygen concentration. The evaluation of the experimental data leads to the following values:. activity coefficients of oxygen (infinite dilute solution).For the solution reaction of oxygen in liquid lead and copper and their alloys the free energy of dissolution could be determined. For the pure metals the following values were obtained for 1200°C.A statistically derived solution model for gases in liquid binary metallic melts was applied to this system and is in full agreement with the experiments also at higher oxygen concentra

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880807

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe equation for the impedance of alloy electrodes was developed on the basis of a model for diffusion in polycrystalline alloys by using Fourier transformation and was included in the total cell impedance. In order to obtain experimental confirmation, the magnitude and the phase displacement of the impedance of cells containing electrodes made ofΓ(Fe,Zn) were measured with the aid of a special impedance spectrometer. The experimental results were very well represented by the theoretical equation in the frequency range from 0.3 Hz up to 7 kHz. The evaluation yielded the electrochemical parameters of the alloy electrode. Thus, the coefficientsD(25 °C) = 2 · 10−16cm2s−1of bulk andD'(25 °C = 5 · 10−8cm2s−1of grain boundary diffusion, as well as their activation energies wer

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880808

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

年代:1984

数据来源: WILEY

摘要:

AbstractDouble layer capacity of evaporated silver film electrodes was studied as a function of potential and of time in solutions containing different strongly adsorbable species. The potential regime of specific adsorption of chloride, cyanide, thiocyanate, and sulfide ions is determined. From the time dependence of the double layer capacitance as well as from electron micrographs, it can be deduced that surface migration takes place which leads to a flattening of the surface. In the case of sulfide and thiocyanate ions an additional process leads to a marked decrease in the capacity, which at the same time becomes nearly potential independent. This observation is attributed to the formation of an adsorbed layer of complexes.

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880809

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

年代:1984

数据来源: WILEY

摘要:

AbstractThe lithium bromide spinels Li2MnBr4and Li2CdBr4exhibit fast ionic conductivity in the solid state as the corresponding chloride spinels. The specific conductivities of the bromide spinels, however, are slightly smaller than those of the chlorides, e.g. for the cadmium compounds 0.11 and 0.26 Ω−1cm−1at 400°C, respectively. Even Li2MnCl4‐−4xBr4xsolid solutions do not show higher conductivity than pure Li2MnCl4. The activation energies for conduction decrease at higher temperatures, e.g. from 60 to 33 kJ mol−1for Li2MnBr4, caused by disorder of the cation sublattice at elevated temperatures. The non‐ideal dielectric behaviour of the lithium ion conducting compounds shown by a characteristic inclination of the spurs and skewness of the semicircles in the impedance diagrams can be correlated to both structure changes (disorder at elevated temperatures) and the different polarizability of th

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880810

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

年代:1984

数据来源: WILEY

摘要:

AbstractPseudo‐binary Nernst‐Planck equations have been employed to derive expressions for the ion retention in a neutral membrane as a function of the volume flux. The derivation requires an integration across the membrane. In case of a solution of two ion species this integration is exact. For solutions of three kinds of ions the desired result is only obtained along an approximative route and then still only in certain limiting cases.Nevertheless anomalies in the retention observed in systems containing three types of ions are predicted by the developed the

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880811

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

年代:1984

数据来源: WILEY

摘要:

AbstractIn extension of a previous study of liquid CH3CN, CH3I, CD3I, CH3Cl and CH3F, the density dependence of the degenerate methyl stretch Raman band of fluid CH3F at 50°C is investigated. The Raman bands are analyzed in the slow, intermediate and fast modulation limit of the Kubo model as well as in terms of theJ‐diffusion model both with and without Coriolis interaction. A modification of theJ‐diffusion model with decoupled collision frequency parameters for the reorientation of different spherical tensor components is also applied. Following theoretical arguments, the experimental correlation functions are decomposed into two partial correlation functionsg1(2)(t) andg2(2)(t). The partial correlation functionsg2(2)(t) are found to be systematically disturbed by non‐orientational, presumably collision‐induced effects. The behaviour of the partial correlation functionsg1(2)(t) is in reasonable agreement with nuclear magnetic relaxation results. TheJ‐diffusion model in its simple form, characterized by only one collision frequency, is found to be incapable to simultaneously describe the spinning and tumbling motion of the molecul

ISSN:0005-9021    

DOI:10.1002/bbpc.19840880812

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

年代:1984

数据来源: WILEY