25,710 research outputs found
Phytohaemagglutinin on maternal and umbilical leukocytes
Almost all the umbilical lymphocytes showed more extensive blast cell formation
than that of their mother's lymphocytes with PHA. Pathological conditions of mother in pregnancy and labor such as anemia, gestational toxicosis,
difficult labor and asphyxia of babies, inhibited the normal response of both maternal and umbilical lymphocytes to PHA.</p
Quantum group symmetry of the Quantum Hall effect on the non-flat surfaces
After showing that the magnetic translation operators are not the symmetries
of the QHE on non-flat surfaces , we show that there exist another set of
operators which leads to the quantum group symmetries for some of these
surfaces . As a first example we show that the symmetry of the QHE on
sphere leads to algebra in the equator . We explain this result by a
contraction of . Secondly , with the help of the symmetry operators of
QHE on the Pioncare upper half plane , we will show that the ground state wave
functions form a representation of the algebra .Comment: 8 pages,latex,no figur
Laughlin states on the Poincare half-plane and its quantum group symmetry
We find the Laughlin states of the electrons on the Poincare half-plane in
different representations. In each case we show that there exist a quantum
group symmetry such that the Laughlin states are a representation of
it. We calculate the corresponding filling factor by using the plasma analogy
of the FQHE.Comment: 9 pages,Late
An Isomonodromy Cluster of Two Regular Singularities
We consider a linear matrix ODE with two coalescing regular
singularities. This coalescence is restricted with an isomonodromy condition
with respect to the distance between the merging singularities in a way
consistent with the ODE. In particular, a zero-distance limit for the ODE
exists. The monodromy group of the limiting ODE is calculated in terms of the
original one. This coalescing process generates a limit for the corresponding
nonlinear systems of isomonodromy deformations. In our main example the latter
limit reads as , where is the -th Painlev\'e equation. We
also discuss some general problems which arise while studying the
above-mentioned limits for the Painlev\'e equations.Comment: 44 pages, 8 figure
A Symmetric Generalization of Linear B\"acklund Transformation associated with the Hirota Bilinear Difference Equation
The Hirota bilinear difference equation is generalized to discrete space of
arbitrary dimension. Solutions to the nonlinear difference equations can be
obtained via B\"acklund transformation of the corresponding linear problems.Comment: Latex, 12 pages, 1 figur
Nonadiabatic generation of coherent phonons
The time-dependent density functional theory (TDDFT) is the leading
computationally feasible theory to treat excitations by strong electromagnetic
fields. Here the theory is applied to coherent optical phonon generation
produced by intense laser pulses. We examine the process in the crystalline
semimetal antimony (Sb), where nonadiabatic coupling is very important. This
material is of particular interest because it exhibits strong phonon coupling
and optical phonons of different symmetries can be observed. The TDDFT is able
to account for a number of qualitative features of the observed coherent
phonons, despite its unsatisfactory performance on reproducing the observed
dielectric functions of Sb. A simple dielectric model for nonadiabatic coherent
phonon generation is also examined and compared with the TDDFT calculations.Comment: 19 pages, 11 figures. This is prepared for a special issue of Journal
of Chemical Physics on the topic of nonadiabatic processe
Phase control of La2CuO4 in thin-film synthesis
The lanthanum copper oxide, La2CuO4, which is an end member of the prototype
high-Tc superconductors (La,Sr)2CuO4 and (La,Ba)2CuO4, crystallizes in the
"K2NiF4" structure in high-temperature bulk synthesis. The crystal chemistry,
however, predicts that La2CuO4 is at the borderline of the K2NiF4 stability and
that it can crystallize in the Nd2CuO4 structure at low synthesis temperatures.
In this article we demonstrate that low-temperature thin-film synthesis
actually crystallizes La2CuO4 in the Nd2CuO4 structure. We also show that the
phase control of "K2NiF4"-type La2CuO4 versus "Nd2CuO4"-type La2CuO4 can be
achieved by varying the synthesis temperature and using different substrates.Comment: 4 pages, 5 figures, submitted to PRB, revte
Multi-Instantons and Multi-Cuts
We discuss various aspects of multi-instanton configurations in generic
multi-cut matrix models. Explicit formulae are presented in the two-cut case
and, in particular, we obtain general formulae for multi-instanton amplitudes
in the one-cut matrix model case as a degeneration of the two-cut case. These
formulae show that the instanton gas is ultra-dilute, due to the repulsion
among the matrix model eigenvalues. We exemplify and test our general results
in the cubic matrix model, where multi-instanton amplitudes can be also
computed with orthogonal polynomials. As an application, we derive general
expressions for multi-instanton contributions in two-dimensional quantum
gravity, verifying them by computing the instanton corrections to the string
equation. The resulting amplitudes can be interpreted as regularized partition
functions for multiple ZZ-branes, which take into full account their
back-reaction on the target geometry. Finally, we also derive structural
properties of the trans-series solution to the Painleve I equation.Comment: 34 pages, 3 figures, JHEP3.cls; v2: added references, minor changes;
v3: added 1 reference, more minor changes, final version for JMP; v4: more
typos correcte
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