58 research outputs found
A taxonomic review of the species of the genus Amara Bonelli (Coleoptera: Carabidae: Pterostichinae) from south-central Turkey
The twelve species and subspecies of the pterostichine genus Amara Bonelli living in the study area represent about 22% of the Turkish species of this genus. This study is based on material collected primarily in the province of Kahramanmara, but also in the surrounding provinces of Adana,Adýyaman, Gaziantep, Kayseri, and Malatya, situated in south-central Turkey, in the Taurus Mountains, and mostly within the Taurus refugium. The taxa are characterized by: keys; description of structural features; and photographs of habitus (male and female), and of male genitalia. For each species, thelocalities (many of them new), coordinates, altitudes of collection, its distribution in Turkey, and its chorotype were also given
Anomalous dynamics in two- and three- dimensional Heisenberg-Mattis spin glasses
We investigate the spectral and localization properties of unmagnetized
Heisenberg-Mattis spin glasses, in space dimensionalities and 3, at T=0.
We use numerical transfer-matrix methods combined with finite-size scaling to
calculate Lyapunov exponents, and eigenvalue-counting theorems, coupled with
Gaussian elimination algorithms, to evaluate densities of states. In we
find that all states are localized, with the localization length diverging as
, as energy . Logarithmic corrections to density of
states behave in accordance with theoretical predictions. In the
density-of-states dependence on energy is the same as for spin waves in pure
antiferromagnets, again in agreement with theoretical predictions, though the
corresponding amplitudes differ.Comment: RevTeX4, 9 pages, 9 .eps figure
Thermodynamic Properties of Weakly Anisotropic Disordered Magnetic Chains in the Large-S Limit
we investigate the thermodynamic properties of weakly anisotropic disordered
magnetic chains where the nearest-neighbor Heisenberg exchange coupling is the
dominant spin-spin interaction. In addition to the exchange interaction, there
is single-ion anisotropy with the direction of the easy axis being the same for
all spins. The analysis is carried out in the limit S >> 1, where S denotes the
ionic spin, and in the temperature range T << JaveS, where Jave is the average
magnitude of the exchange interaction. It is assumed that the independent boson
picture is appropriate so that the thermodynamic properties of the chain are
those of a gas of weakly interacting magnons whose frequencies are obtained
from linearized equations of motion for the spins. The =+/-J model is studied
in detail with both random and non-random anisotropy. Particular emphasis is
placed on the existenceComment: 15 pages, pdf forma
Analysis of an arbitrary-profile, cylindrical, impedance reflector surface illuminated by an E-polarized complex line source beam
Cataloged from PDF version of article.Electromagnetic scattering from a cylindrical reflector surface having an arbitrary
conic section profile is studied. We assumed an electrically thin layer antenna
illuminated by a complex line source in E-polarization mode. Our boundary value
formulation, without loss of generality, involves an integral equation approach
having impedance-type thin-layer boundary conditions. For simplicity, we also
considered both faces of the reflector of the same uniform impedance value. Our
computation employs the Method of Analytical Regularization (MAR) technique:
the integral equations are converted into the discrete Fourier transform domain
yielding two coupled dual series equations, which are then solved by the Fourier
inversion and Riemann Hilbert Problem techniques. We demonstrate the accuracy
and the convergence behaviors of our numerically solved MAR results that can
serve as an accurate benchmark for comparison with widely used results obtained
by approximate boundary conditions
Localized exciton states in pi-conjugated polymers with finite torsion
We investigate localized exciton states in pi-conjugated polymers with finite
torsion. The localized states are associated with a perturbed transfer integral
for which the magnitude of cosine of the torsion angle exceeds the magnitude of
the corresponding cosine of the unperturbed system. The localized state energy
is calculated as a function of the ratio of the perturbed to unperturbed
transfer integrals. Particular attention is paid to the optically active
symmetric localized states, and the effective oscillator strength, or square of
the absolute magnitude of the transition dipole moment, is calculated as a
function of the energy. The relation of the theory to recent optical studies of
poly(di-noctylfluorene)(PF8) is discussed.Comment: 11 pages pdf documen
Analysis of thin dielectric cylindrical reflector having an arbitrary conic section profile illuminated by complex line source: H-polarization case
Arbitrary conic section profile and thin dielectric reflector is analyzed by using the Method of Analytical Regularization (MAR) technique based on Riemann-Hilbert problem and Fourier inversion procedures. The reflector surface is assumed to be illuminated by an H-polarized complex line source type feed antenna. The convergence of the solution is verified and some changes in the radiation patterns are obtained especially for rather thicker cases. © 2014 IEEE
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