69 research outputs found
First order quantum corrections to the classical reflection factor of the sinh-Gordon model
The sinh-Gordon model is restricted to a half-line by boundary conditions
maintaining integrability. A perturbative calculation of the reflection factor
is given to one loop order in the bulk coupling and to first order in the
difference of the two parameters introduced at the boundary, providing a
further verification of Ghoshal's formula. The calculation is consistent with a
conjecture for the general dependence of the reflection factor on the boundary
parameters and the bulk coupling.Comment: 16 pages, 1 figur
Modeling the burnout of solid polydisperse fuel under the conditions of external heat transfer
A self-similar burnout mode of solid polydisperse fuel is considered taking into consideration heat transfer between fuel particles, gases, and combustion chamber walls. A polydisperse composition of fuel is taken into account by introducing particle distribution functions by radiuses obtained for the kinetic and diffusion combustion modes. Equations for calculating the temperatures of particles and gases are presented, which are written for particles average with respect to their distribution functions by radiuses taking into account the fuel burnout ratio. The proposed equations take into consideration the influence of fuel composition, air excess factor, and gas recirculation ratio. Calculated graphs depicting the variation of particle and gas temperatures, and the fuel burnout ratio are presented for an anthracite-fired boiler. © 2013 Pleiades Publishing, Inc
Physicochemical and adsorption properties of some carbon materials in aqueous solutions
Water dispersions of carbon adsorbents-nanodiamonds of UD-DP and UD-HP-DP types, nanodiamond charge of UDB-A type, C-60 fullerene, nanotubes, and activated carbon-were studied. Some physicochemical properties of their surface (acidity and electrokinetic characteristics) were investigated, and the surface values of pK(a1) were calculated. The data on adsorption of iodine, malic acid, and cationic dyes onto these adsorbents from aqueous and 1 mol/L NaCl solutions were discussed and compared. The dyeadsorption data and the values of the zeta potential and suspension effect indicated a negatively charged surface of UDA-SP nanodiamond within a pH adsorption range from 5.5 to 8.0
Cobalt(II) and copper(II) complexes with carboxylic acids, imidazole, and 2-methylimidazole
The compositions of [MIm(MeIm)x]L complexes synthesized by the reaction of cobalt(II) and copper(II) fumarates ML · nH2O with imidazole (Im) and 2-methylimidazole (MeIm) were determined. The thermal decomposition of the salts was analyzed, and the pyridine nitrogen atom of imidazole and the oxygen atoms of carboxyl anions were shown to participate in complexation using electronic absorption spectra and IR spectra. The composition and stability of cobalt(II) and copper(II) imidazolatesuccinate complexes in an aqueous solution were determined photometrically and spectrophotometrically, and their higher stability in comparison with monoligand complexes was demonstrated
The XX-model with boundaries. Part III:Magnetization profiles and boundary bound states
We calculate the magnetization profiles of the and
operators for the XX-model with hermitian boundary terms. We study the profiles
on the finite chain and in the continuum limit. The results are discussed in
the context of conformal invariance. We also discuss boundary excitations and
their effect on the magnetization profiles.Comment: 30 pages, 3 figure
Self-Similar Potentials and the q-Oscillator Algebra at Roots of Unity
Properties of the simplest class of self-similar potentials are analyzed.
Wave functions of the corresponding Schr\"odinger equation provide bases of
representations of the -deformed Heisenberg-Weyl algebra. When the parameter
is a root of unity the functional form of the potentials can be found
explicitly. The general and the particular potentials are given
by the equianharmonic and (pseudo)lemniscatic Weierstrass functions
respectively.Comment: 15 pp, Latex, to appear in Lett.Math.Phy
Boundary bound states and boundary bootstrap in the sine-Gordon model with Dirichlet boundary conditions.
We present a complete study of boundary bound states and related boundary
S-matrices for the sine-Gordon model with Dirichlet boundary conditions. Our
approach is based partly on the bootstrap procedure, and partly on the explicit
solution of the inhomogeneous XXZ model with boundary magnetic field and of the
boundary Thirring model. We identify boundary bound states with new ``boundary
strings'' in the Bethe ansatz. The boundary energy is also computed.Comment: 25 pages, harvmac macros Report USC-95-001
The XX--model with boundaries. Part I: Diagonalization of the finite chain
This is the first of three papers dealing with the XX finite quantum chain
with arbitrary, not necessarily hermitian, boundary terms. This extends
previous work where the periodic or diagonal boundary terms were considered. In
order to find the spectrum and wave-functions an auxiliary quantum chain is
examined which is quadratic in fermionic creation and annihilation operators
and hence diagonalizable. The secular equation is in general complicated but
several cases were found when it can be solved analytically. For these cases
the ground-state energies are given. The appearance of boundary states is also
discussed and in view to the applications considered in the next papers, the
one and two-point functions are expressed in terms of Pfaffians.Comment: 56 pages, LaTeX, some minor correction
Magnetic susceptibility and low-temperature specific-heat of integrable 1-D Hubbard model under open-boundary conditions
The magnetic susceptibility and the low-temperature specific heat of the
1-dimensional Hubbard model under the integrable open-boundary conditions are
discussed through the Bethe ansatz with the string hypothesis. The
contributions of the boundary fields to both the susceptibility and the
specific heat are obtained, and their exact expressions are analytically
derived.Comment: 14 pages, Latex, No figures, to appear in J. Phys. A: Gen. & Mat
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