6,751 research outputs found
Improper ferroelectricity in ultrathin hexagonal ferrites films
Suppression of ferroelectricity in ultrathin films of improper ferroelectric hexagonal ferrites or manganites has been attributed to the effect of interfacial clamping; however, the quantitative understanding and related phenomenological model are still lacking. In this work, we report on the paraelectric-to-ferroelectric phase transition of epitaxial h-ScFeO3 films with different thicknesses through in situ reflection highenergy electron diffraction. Based on the interfacial clamping model and the Landau theory, we show that the thickness-dependence of the ferroelectric Curie temperature can be understood in terms of the characteristic length of an interfacial clamping layer and the bulk Curie temperature. Furthermore, we found that the critical thickness of improper ferroelectricity is proportional to the characteristic length of the interfacial clamping layer. These results reveal the essential role of mechanical clamping from interface on the improper ferroelectricity of hexagonal ferrites or manganites and could serve as the guidance to achieve robust improper ferroelectricity in ultrathin films
Systematic study of elliptic flow parameter in the relativistic nuclear collisions at RHIC and LHC energies
We employed the new issue of a parton and hadron cascade model PACIAE 2.1 to
systematically investigate the charged particle elliptic flow parameter
in the relativistic nuclear collisions at RHIC and LHC energies. With randomly
sampling the transverse momentum and components of the particles
generated in string fragmentation on the circumference of an ellipse instead of
circle originally, the calculated charged particle and
fairly reproduce the corresponding experimental data in the Au+Au/Pb+Pb
collisions at =0.2/2.76 TeV. In addition, the charged particle
and in the p+p collisions at =7 TeV as well as
in the p+Au/p+Pb collisions at =0.2/5.02 TeV are predicted.Comment: 7 pages, 5 figure
MiniSeg: An Extremely Minimum Network for Efficient COVID-19 Segmentation
The rapid spread of the new pandemic, i.e., COVID-19, has severely threatened
global health. Deep-learning-based computer-aided screening, e.g., COVID-19
infected CT area segmentation, has attracted much attention. However, the
publicly available COVID-19 training data are limited, easily causing
overfitting for traditional deep learning methods that are usually data-hungry
with millions of parameters. On the other hand, fast training/testing and low
computational cost are also necessary for quick deployment and development of
COVID-19 screening systems, but traditional deep learning methods are usually
computationally intensive. To address the above problems, we propose MiniSeg, a
lightweight deep learning model for efficient COVID-19 segmentation. Compared
with traditional segmentation methods, MiniSeg has several significant
strengths: i) it only has 83K parameters and is thus not easy to overfit; ii)
it has high computational efficiency and is thus convenient for practical
deployment; iii) it can be fast retrained by other users using their private
COVID-19 data for further improving performance. In addition, we build a
comprehensive COVID-19 segmentation benchmark for comparing MiniSeg to
traditional methods
A pilot study of aortic hemodynamics before and after thoracic endovascular repair with a double-branched endograft
This work was partially supported by Bolton Medical, Sunrise, Florida, US. The authors declare that although Bolton Medical supported this study, the funding company had no control, input or influence on the study design, data analysis or publications.Peer reviewedPublisher PD
Higher moment singularities explored by the net proton non-statistical fluctuations
We use the non-statistical fluctuation instead of the full one to explore the
higher moment singularities of net proton event distributions in the
relativistic Au+Au collisions at from 11.5 to 200 GeV
calculated by the parton and hadron cascade model PACIAE. The PACIAE results of
mean (), variance (), skewness (), and kurtosis () are
consistent with the corresponding STAR data. Non-statistical moments are
calculated as the difference between the moments derived from real events and
the ones from mixed events, which are constructed by combining particles
randomly selected from different real events. An evidence of singularity at
60 GeV is first seen in the energy dependent
non-statistical and .Comment: 5 pages,5 figure
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