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11.
Cyclic voltammetry, impedance and chronocoulometry have been employed for the quantitative study of 1-pentanol (n-PenOH) adsorption at the bismuth single-crystal plane | aqueous Na2SO4 solution interface. The adsorption isotherms, Gibbs energies of adsorption ΔG
A
∘, the limiting surface excess Γmax and other adsorption parameters, dependent on the crystallographic structure of the electrodes, have been determined. The
adsorption of n-PenOH on Bi single-crystal planes is mainly physical and is limited by the rate of diffusion of organic molecules to the
electrode surface. Comparison of the adsorption data for n-PenOH with 1-propanol (n-PrOH), 1-butanol (n-BuOH), cyclohexanol (CH) and 1-hexanol (n-HexOH) shows that the adsorption characteristics depend on the structure of the hydrocarbon group. The adsorption activity
of adsorbates at the bismuth | solution interface increases in the sequence n-PrOH < n-BuOH < CH ≤ n-PenOH < n-HA as the adsorption activity at the air | solution interface increases. For all the compounds studied, the adsorption activity
increases in the sequence of planes (111)<(001)<(011ˉ).
Received: 1 July 1998 / Accepted: 2 October 1998 相似文献
12.
Cyclic voltammetry, impedance and chronocoulometry have been employed for the quantitative study of 1-heptanol (1-HepOH)
adsorption on the bismuth single-crystal plane|aqueous Na2SO4 solution interface. The adsorption isotherms, Gibbs energies of adsorption,
, the limiting surface excess, Γmax, and other adsorption parameters have been determined. The adsorption of 1-HepOH on Bi single-crystal planes is mainly physical
and is limited by the rate of diffusion of organic molecules to the electrode surface. Comparison of the adsorption data for
1-HepOH with other alcohols shows that the adsorption characteristics depend on the structure of the hydrocarbon chain. The
adsorption activity of adsorbates at the bismuth|solution interface increases in the sequence 1-propanol<1-butanol<1-pentanol<1-hexanol<1-heptanol
as the adsorption activity at the air|solution interface increases. For all the compounds studied, the adsorption activity
increases in the sequence of planes as
. 相似文献
13.
Kundla E 《Solid state nuclear magnetic resonance》2007,31(2):91-99
The evolution of the magnetic polarization of an ensemble of paired spin(-1/2) nuclei in an MAS NMR (nuclear magnetic resonance) experiment and the induced spectrum are described theoretically by means of a Liouville-von Neumann equation representation in a wobbling rotating frame in combination with the averaged Hamiltonian theory. In this method, the effect of a high-intensity external static magnetic field and the effects of the leftover interaction components of the Hamiltonian that commute with the approximate Hamiltonian are taken into account simultaneously and equivalently. This method reproduces details that really exist in the recorded spectra, caused by secular terms in the Hamiltonian, which might otherwise be smoothed out owing to the approximate treatment of the effects of the secular terms. Complete analytical expressions, which describe the whole NMR spectrum including the rotational sideband sets, and which consider all the relevant intermolecular interactions, are obtained. 相似文献
14.
Eneli Härk Rutha Jäger Karmen Lust Heili Kasuk Enn Lust 《Journal of Solid State Electrochemistry》2012,16(3):921-926
Electroreduction of Eu(ClO4)3 and Eu2(SO4)3 has been studied at electrochemically polished
\textBi( 01[`1] ) {\text{Bi}}\left( {01\bar{1}} \right) single-crystal electrode in an acidic HClO4 or H2SO4 (pH ~3) aqueous solution with LiClO4 or Na2SO4 additions as a surface inactive electrolyte. The Eu3+ cations electroreduction rate depends on the electrode potential applied and the concentration of the supporting electrolyte
as well as the concentration of the Eu3+ ions. At the more negative electrode potentials than the zero charge potential (zcp), the diffusion current plateaus were
observed. The values of the rate constant for the heterogeneous reaction calculated at zcp are independent of the base electrolyte
concentration studied. Analysis of the kinetic data corrected for the electrical double-layer effect shows that the coincidence
of the corrected Tafel plots can be achieved, assuming that the effective charge of a reactant (+1.6) is significantly lower
than it would be expected (z
A = +3). 相似文献
15.
Kundla E 《Solid state nuclear magnetic resonance》2006,30(1):9-15
A novel way is proposed to describe the evolution of nuclear magnetic polarization and the induced NMR spectrum. In this method, the effect of a high-intensity external static magnetic field and the effects of proper Hamiltonian left over interaction components, which commute with the first, are taken into account simultaneously and equivalently. The method suits any concrete NMR problem. This brings forth the really existing details in the registered spectra, evoked by Hamiltonian secular terms, which may be otherwise smoothed due to approximate treatment of the effects of the secular terms. Complete analytical expressions are obtained describing the NMR spectra including the rotational sideband sets of single quadrupolar nuclei in rotating solids. 相似文献
16.
Enn Otsa Ludmila S. Kudrjawzewa Olaf G. Eisen 《Monatshefte für Chemie / Chemical Monthly》1980,111(1):37-42
Heats of mixing (H
E)ofn-octane with 1,2,3,4-isomers ofn-octyne,n-heptane withn-1-heptyne andn-nonane withn-1-nonyne at temperatures from 298.15 to 318.15 K were measured with aCalvet-type microcalorimeter. The results are presented in tables and correlated with theRedlich-Kister equation. 相似文献
17.
Arvet Pedas Enn Tamme 《Journal of Computational and Applied Mathematics》2011,236(2):167-176
Some regularity properties of the solution of linear multi-term fractional differential equations are derived. Based on these properties, the numerical solution of such equations by piecewise polynomial collocation methods is discussed. The results obtained in this paper extend the results of Pedas and Tamme (2011) [15] where we have assumed that in the fractional differential equation the order of the highest derivative of the unknown function is an integer. In the present paper, we study the attainable order of convergence of spline collocation methods for solving general linear fractional differential equations using Caputo form of the fractional derivatives and show how the convergence rate depends on the choice of the grid and collocation points. Theoretical results are verified by some numerical examples. 相似文献
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