摘要:

Density, viscosity, electric permittivity and refractive indices for mixtures of water with four isomeric butanediols were measured over the whole composition range at 298.15K. From these data the excess molar volumes, apparent and partial molar volumes of butanediols and water, the excess electric permittivity and Kirkwood's correlation factor for investigated mixtures were calulated.

ISSN:0031-9104    

DOI:10.1080/00319109508030666

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

We have measured the thermal conductivity in both solid and liquid states for amorphous sample of selenium doped with three different concentrations (10,1000,50000 ppm) of zinc. The measurements were taken in the temperature range from 323 to 713 K, and were carried out using the concentric cylinder method. It was found that thermal conductivity of the samples is of the phonon type. Its temperature dependence follows the relationkph∝T−1, and can be explained by the influence of thermal effects on the atomic structure.

ISSN:0031-9104    

DOI:10.1080/00319109508030667

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The conductance of ter-BuEt3NI, sec-BuEt3NI, iso-BuEt3NI,n-BuEt3NI and Bu4NI in toluene acetonitrile mixtures has been measured. The range of dielectric constant of the solvent mixtures covered from 9,4 to 35,9. The densities and viscosities of the solvent mixtures were also determined. The phoreograms of the ter-BuEt3NI and sec-BuEt3NI in the mixtures having molar fractions of toluene of 0,4, 0,5 and 0,6 and those of the iso-BuEt3NI and Bu4NI in the molar fractions 0,3, 0,4 and 0,5 show similar shape. The phoreograms lie below the Onsager limit line. The conductance data for the salts having asymmetric cations were analyzed using the Fuoss Onsager equation for unassociated 1–1 electrolytes. The data for the saltn-BuEt3NI in mixtures of mole fraction 0,1, 0,2 and 0,4 of toluene were fitted to the equation. All other systems studied did not fit. This investigation suggests that the geometry of the hydrocarbons chains has an effect on the conductance behaviour of ammonium salts.

ISSN:0031-9104    

DOI:10.1080/00319109508030668

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Isobaric VLE data were measured for the binary systems of anisole with benzonitrile and nitrobenzene over the entire composition range by an indirect method using a Swietoslawski-type ebulliometer at three pressures. The experimentalt-xdata were found to be well represented by Wilson and NRTL models.

ISSN:0031-9104    

DOI:10.1080/00319109508030669

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The existence of pre-transitional surface ordering and disordering at the liquid crystal-isotropic liquid interface has been established from the surface tension measurements. A spinning-drop technique has been used for this study. Measurements were carried out in the smecticA(SA), nematic (N) and isotropic (I) phases of the liquid crystals and reproducible results were obtained. The results suggest that the equilibrium value of γ changes discontinuously in theNandSAphases. The slopedγ/dTis positive for both the isotropic phase just aboveTNIas well as for the nematic phase just below it. Similar positive slope has been obtained in the vicinity ofTAN. A positive value of dγ/dt implies excess surface order than that of the bulk interior. From the density measurements it has been observed that there is a correlation between the anomalies in the temperature dependence of surface tension and density in the isotropic phase.

ISSN:0031-9104    

DOI:10.1080/00319109508030670

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

The1H-NMR spectra of butane-1,2-diol (BD-1,2)-water mixtures as function of concentration were recorded at 298 K and the spectral parameters, Δ δ (BD-1,2-H2O) were evaluated. The surface tensions (σ12) were measured at 298.15 K. From literature values of density (d12) viscosity (η12), dielectric permittivity (ε12) and the measured surface tensions the molar volumes (V12) and their deviations from “ideality”, at 298.15 K, were calculated. Further on the temperature coefficients of dielectric permittivity, α12' were evaluated. These structural parameters as functions of concentration suggest the formation of the “complexes” (sub-units) of the BD-1,2 · 2H2O, BD-1,2 · 4H2O and 2BD-1,2 · H2O types.

ISSN:0031-9104    

DOI:10.1080/00319109508030671

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

Earlier estimations of the critical temperature of tungsten supply two groups of values different from one another by a factor of about 2. By calculating the critical values from a van der Waals-like equation of state modified for metals using Coulomb interaction in the attractive part, the lower temperature (about 12,000 K) has been supported. Besides the other critical parameters, the number of free electrona per atom has been obtained (zc= 3.14). A scaling of the critical temperature with the plasmon energy also fits numerically, although there is a different dependence upon the electron density.

ISSN:0031-9104    

DOI:10.1080/00319109508030672

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

In liquids of spherical molecules (Ar, Kr, Xe, CH4) the mobility of thermal electrons passes through a maximum at a density near 1 × 1028molecule/m3. The ratioRmaxμnof the maximum mobility to the mobility in the gas phase, normalized for density, correlates strongly with the isotropic molecular polarizability α. The value ofRmaxμndecreases with decreasing sphericity of the molecules.

ISSN:0031-9104    

DOI:10.1080/00319109508030673

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0031-9104    

DOI:10.1080/00319109508030665

出版商:Taylor & Francis Group    

年代:1995

数据来源: Taylor