1,140 research outputs found
Spin-orbit coupling and intrinsic spin mixing in quantum dots
Spin-orbit coupling effects are studied in quantum dots in InSb, a narrow-gap
material. Competition between different Rashba and Dresselhaus terms is shown
to produce wholesale changes in the spectrum. The large (and negative)
-factor and the Rashba field produce states where spin is no longer a good
quantum number and intrinsic flips occur at moderate magnetic fields. For dots
with two electrons, a singlet-triplet mixing occurs in the ground state, with
observable signatures in intraband FIR absorption, and possible importance in
quantum computation.Comment: REVTEX4 text with 3 figures (high resolution figs available by
request). Submitted to PR
Development of Lab-to-Fab Production Equipment Across Several Length Scales for Printed Energy Technologies, Including Solar Cells
Sources of saturated fatty acids in Belgian adolescents' diet: implications for the development of food-based dietary guidelines
Identifying a few foot-and-mouth disease virus signature nucleotide strings for computational genotyping
<p>Abstract</p> <p>Background</p> <p>Serotypes of the Foot-and-Mouth disease viruses (FMDVs) were generally determined by biological experiments. The computational genotyping is not well studied even with the availability of whole viral genomes, due to uneven evolution among genes as well as frequent genetic recombination. Naively using sequence comparison for genotyping is only able to achieve a limited extent of success.</p> <p>Results</p> <p>We used 129 FMDV strains with known serotype as training strains to select as many as 140 most serotype-specific nucleotide strings. We then constructed a linear-kernel Support Vector Machine classifier using these 140 strings. Under the leave-one-out cross validation scheme, this classifier was able to assign correct serotype to 127 of these 129 strains, achieving 98.45% accuracy. It also assigned serotype correctly to an independent test set of 83 other FMDV strains downloaded separately from NCBI GenBank.</p> <p>Conclusion</p> <p>Computational genotyping is much faster and much cheaper than the wet-lab based biological experiments, upon the availability of the detailed molecular sequences. The high accuracy of our proposed method suggests the potential of utilizing a few signature nucleotide strings instead of whole genomes to determine the serotypes of novel FMDV strains.</p
Biomechanics-informed Neural Networks for Myocardial Motion Tracking in MRI
Image registration is an ill-posed inverse problem which often requires
regularisation on the solution space. In contrast to most of the current
approaches which impose explicit regularisation terms such as smoothness, in
this paper we propose a novel method that can implicitly learn
biomechanics-informed regularisation. Such an approach can incorporate
application-specific prior knowledge into deep learning based registration.
Particularly, the proposed biomechanics-informed regularisation leverages a
variational autoencoder (VAE) to learn a manifold for biomechanically plausible
deformations and to implicitly capture their underlying properties via
reconstructing biomechanical simulations. The learnt VAE regulariser then can
be coupled with any deep learning based registration network to regularise the
solution space to be biomechanically plausible. The proposed method is
validated in the context of myocardial motion tracking on 2D stacks of cardiac
MRI data from two different datasets. The results show that it can achieve
better performance against other competing methods in terms of motion tracking
accuracy and has the ability to learn biomechanical properties such as
incompressibility and strains. The method has also been shown to have better
generalisability to unseen domains compared with commonly used L2
regularisation schemes.Comment: The paper is early accepted by MICCAI 202
Spin dynamics in semiconductors
This article reviews the current status of spin dynamics in semiconductors
which has achieved a lot of progress in the past years due to the fast growing
field of semiconductor spintronics. The primary focus is the theoretical and
experimental developments of spin relaxation and dephasing in both spin
precession in time domain and spin diffusion and transport in spacial domain. A
fully microscopic many-body investigation on spin dynamics based on the kinetic
spin Bloch equation approach is reviewed comprehensively.Comment: a review article with 193 pages and 1103 references. To be published
in Physics Reports
Effects of salt compensation on the climate model response in simulations of large changes of the Atlantic meridional overturning circulation
© 2007 American Meteorological Society (https://www.ametsoc.org/ams/index.cfm/publications/ethical-guidelines-and-ams-policies/ams-copyright-policy/
Development of Lab-to-Fab Production Equipment Across Several Length Scales for Printed Energy Technologies, Including Solar Cells
Feasibility studies of time-like proton electromagnetic form factors at PANDA at FAIR
Simulation results for future measurements of electromagnetic proton form
factors at \PANDA (FAIR) within the PandaRoot software framework are reported.
The statistical precision with which the proton form factors can be determined
is estimated. The signal channel is studied on the basis
of two different but consistent procedures. The suppression of the main
background channel, , is studied.
Furthermore, the background versus signal efficiency, statistical and
systematical uncertainties on the extracted proton form factors are evaluated
using two different procedures. The results are consistent with those of a
previous simulation study using an older, simplified framework. However, a
slightly better precision is achieved in the PandaRoot study in a large range
of momentum transfer, assuming the nominal beam conditions and detector
performance
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