2,569 research outputs found
Suppression and enhancement of the critical current in multiterminal S/N/S mesoscopic structures
We analyse the measured critical current in a mesoscopic
4-terminal S/N/S structure. The current through the S/N interface is shown to
consist not only of the Josephson component but also a
phase-coherent part of the subgap current. The current
is determined by the both components and and depends
in a nonmonotonic way on the voltage between superconductors and normal
reservoirs reaching a maximum at . The obtained theoretical
resultas are in qualitative agreement with recent experimental data.Comment: 4 page, 3 figures. To be puplished in PRB Rapid co
Trees with Given Stability Number and Minimum Number of Stable Sets
We study the structure of trees minimizing their number of stable sets for
given order and stability number . Our main result is that the
edges of a non-trivial extremal tree can be partitioned into stars,
each of size or , so that every vertex is included in at most two
distinct stars, and the centers of these stars form a stable set of the tree.Comment: v2: Referees' comments incorporate
Bandgap properties of two-dimensional low-index photonic crystals
We study the bandgap properties of two-dimensional photonic crystals created
by a lattice of rods or holes conformed in a symmetric or asymmetric triangular
structure. Using the plane-wave analysis, we calculate a minimum value of the
refractive index contrast for opening both partial and full two-dimensional
spectral gaps for both TM and TE polarized waves. We also analyze the effect of
ellipticity of rods and holes and their orientation on the threshold value and
the relative size of the bandgap.Comment: 5 pages, 6 figures, App. Phys. B. styl
Final state interaction and decays in perturbative QCD
We predict branching ratios and CP asymmetries of the decays using
perturbative QCD factorization theorem, in which tree, penguin, and
annihilation contributions, including both factorizable and nonfactorizable
ones, are expressed as convolutions of hard six-quark amplitudes with universal
meson wave functions. The unitarity angle and the and
meson wave functions extracted from experimental data of the and
decays are employed. Since the decays are sensitive to
final-state-interaction effects, the comparision of our predictions with future
data can test the neglect of these effects in the above formalism. The CP
asymmetry in the modes and the
branching ratios depend on annihilation and nonfactorizable amplitudes. The
data can also verify the evaluation of these contributions.Comment: 13 pages in latex file, 7 figures in ps file
Finite size effects with variable range exchange coupling in thin-film Pd/Fe/Pd trilayers
The magnetic properties of thin-film Pd/Fe/Pd trilayers in which an embedded
~1.5 A-thick ultrathin layer of Fe induces ferromagnetism in the surrounding Pd
have been investigated. The thickness of the ferromagnetic trilayer is
controlled by varying the thickness of the top Pd layer over a range from 8 A
to 56 A. As the thickness of the top Pd layer decreases, or equivalently as the
embedded Fe layer moves closer to the top surface, the saturated magnetization
normalized to area and the Curie temperature decrease whereas the coercivity
increases. These thickness-dependent observations for proximity-polarized
thin-film Pd are qualitatively consistent with finite size effects that are
well known for regular thin-film ferromagnets. The critical exponent of
the order parameter (magnetization) is found to approach the mean field value
of 0.5 as the thickness of the top Pd layer increases. The functional forms for
the thickness dependences, which are strongly modified by the nonuniform
exchange interaction in the polarized Pd, provide important new insights to
understanding nanomagnetism in two-dimensions.Comment: 14 pages, 5 figures, submitted to JMM
Magnetic dipole probes of the sd and pf shell crossing in the A=36,38 argon isotopes
We have calculated the M1 strength distributions in the A=36,38 argon
isotopes within large-scale shell model studies which consider valence nucleons
in the sd and pf shells. While the M1 strength in 36Ar is well reproduced
within the sd shell, the experimentally observed strong fragmentation of the M1
strength in 38Ar requires configuration mixing between the sd and the pf shells
adding to our understanding of correlations across the N=20 shell gap.Comment: 14 pages, 8 figure
Separated magnet yoke for permanent magnet linear generator for marine wave energy converters
In this paper the performance of a longitudinal flux permanent magnet linear generator (PMLG) for wave energy converters (WEC) is investigated. The influence of the number of slots per pole, phase q and the number of stator's winding sections are analysed. The power output and the cogging forces in the PMLG are calculated and reviewed with respect to the above design parameters. In addition, an optimised PMLG model is designed and simulated. Three-dimensional Finite Element Method (FEM) is used for solving the combined field and circuit equations of the generator.The PRIMaRE project
Comparing levonorgestrel intrauterine system versus hysteroscopic resection in patients with postmenstrual spotting related to a niche in the caesarean scar (MIHYS NICHE trial) : Protocol of a randomised controlled trial
Funding This work was supported by National Key Research and Development Programme (2018YFC1002102), Research Project of Shanghai Health and Fitness Commission (201940012,20184Y0344)),Shanghai Municipal Key Clinical Specialty (shslczdzk01802), Medical Engineering Cross Funds from Shanghai Jiao Tong University (YG2017QN38, ZH2018QNA36, YG2021ZD31), Medical innovation research project of the 2020 'Science and Technology Innovation Action Plan' of Shanghai Science and Technology Commission (20Y11907700), and Clinical Science and Technology Innovation Project of Shanghai Hospital Development Center(SHDC22020216).Peer reviewedPublisher PD
Velocity autocorrelation function of a Brownian particle
In this article, we present molecular dynamics study of the velocity
autocorrelation function (VACF) of a Brownian particle. We compare the results
of the simulation with the exact analytic predictions for a compressible fluid
from [6] and an approximate result combining the predictions from hydrodynamics
at short and long times. The physical quantities which determine the decay were
determined from separate bulk simulations of the Lennard-Jones fluid at the
same thermodynamic state point.We observe that the long-time regime of the VACF
compares well the predictions from the macroscopic hydrodynamics, but the
intermediate decay is sensitive to the viscoelastic nature of the solvent.Comment: 7 pages, 6 figure
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