386 research outputs found
Efficient Synthesis of Angular Selective Surfaces Based on Accurate Equivalent Circuit Analysis
Rigid vortices in MgB2
Magnetic relaxation of high-pressure synthesized MgB bulks with different
thickness is investigated. It is found that the superconducting dia-magnetic
moment depends on time in a logarithmic way; the flux-creep activation energy
decreases linearly with the current density (as expected by Kim-Anderson
model); and the activation energy increases linearly with the thickness of
sample when it is thinner than about 1 mm. These features suggest that the
vortices in the MgB are rather rigid, and the pinning and creep can be well
described by Kim-Anderson model.Comment: Typo corrected & reference adde
Point-and-Shoot All-in-Focus Photo Synthesis from Smartphone Camera Pair
All-in-Focus (AIF) photography is expected to be a commercial selling point
for modern smartphones. Standard AIF synthesis requires manual, time-consuming
operations such as focal stack compositing, which is unfriendly to ordinary
people. To achieve point-and-shoot AIF photography with a smartphone, we expect
that an AIF photo can be generated from one shot of the scene, instead of from
multiple photos captured by the same camera. Benefiting from the multi-camera
module in modern smartphones, we introduce a new task of AIF synthesis from
main (wide) and ultra-wide cameras. The goal is to recover sharp details from
defocused regions in the main-camera photo with the help of the
ultra-wide-camera one. The camera setting poses new challenges such as
parallax-induced occlusions and inconsistent color between cameras. To overcome
the challenges, we introduce a predict-and-refine network to mitigate
occlusions and propose dynamic frequency-domain alignment for color correction.
To enable effective training and evaluation, we also build an AIF dataset with
2686 unique scenes. Each scene includes two photos captured by the main camera,
one photo captured by the ultrawide camera, and a synthesized AIF photo.
Results show that our solution, termed EasyAIF, can produce high-quality AIF
photos and outperforms strong baselines quantitatively and qualitatively. For
the first time, we demonstrate point-and-shoot AIF photo synthesis successfully
from main and ultra-wide cameras.Comment: Early Access by IEEE Transactions on Circuits and Systems for Video
Technology 202
Shadow of topologically charged rotating braneworld black hole
In this paper, we discuss optical properties of the topologically charged
rotating black hole. We study the horizon, the photon region, the shadow of the
black hole and other observables. The results show that in addition to the
black hole spin parameter , the other two parameters, tidal charge
and electric charge , are also found to affect the horizon, the photon
region and the black hole shadow. In a certain range, with the increase of the
three parameters, the horizon distance, shape of the photon region and the
black hole shadow will all shrink. Moreover, with the increase of these three
parameters, the distortion parameter gradually increases, while
the peak of the black hole energy emission rate decreases
A Robust Optimization of Capacity Allocation Policies in the Third-Party Warehouse
We study the capacity allocation policies of a third-party warehouse center, which supplies
several different level services on different prices with fixed capacity, on revenue management
perspective. For the single period situation, we use three different robust methods, absolute
robust, deviation robust, and relative robust method, to maximize the whole revenue. Then we give some
numerical examples to verify the practical applicability. For the multiperiod situation, as the
demand is uncertain, we propose a stochastic model for the multiperiod revenue management
problem of the warehouse. A novel robust optimization technique is applied in this model to
maximize the whole revenue. Then we give some numerical examples to verify the practical
applicability of our method
Observation of short-range Yu-Shiba-Rusinov states with threefold symmetry in layered superconductor 2H-NbSeâ‚‚
Yu-Shiba-Rusinov (YSR) states arise when magnetic impurities interact with superconductivity. The intricacy of coupling and the nature of the superconductivity determine the behavior of the YSR state, whose detailed correlations are not yet fully understood. Here, we study the YSR state of a single Fe adatom on the surface of 2H-NbSeâ‚‚ with combined low temperature scanning tunneling microscopy/spectroscopy, density functional theory calculations and tight-binding modeling. It is found that the Fe adatom occupies the hollow site of the Se surface layer. A prominent YSR state close to the Fermi level is observed. The YSR state exhibits a threefold symmetry along the diagonal direction of the Se lattice. The spatial decay of the YSR state follows a behavior in three-dimensional superconductivity. This behavior contrasts with a previous study of imbedded Fe impurities, whose YSR state shows a six-fold symmetry and a two-dimensional long-range decay. According to our theoretical modeling, the coupling configurations affect the adatom-substrate hopping and the interlayer coupling of the substrate. Both factors are crucial for the consequent behavior of the YSR state
Observation of short-range Yu-Shiba-Rusinov states with threefold symmetry in layered superconductor 2H-NbSeâ‚‚
Yu-Shiba-Rusinov (YSR) states arise when magnetic impurities interact with superconductivity. The intricacy of coupling and the nature of the superconductivity determine the behavior of the YSR state, whose detailed correlations are not yet fully understood. Here, we study the YSR state of a single Fe adatom on the surface of 2H-NbSeâ‚‚ with combined low temperature scanning tunneling microscopy/spectroscopy, density functional theory calculations and tight-binding modeling. It is found that the Fe adatom occupies the hollow site of the Se surface layer. A prominent YSR state close to the Fermi level is observed. The YSR state exhibits a threefold symmetry along the diagonal direction of the Se lattice. The spatial decay of the YSR state follows a behavior in three-dimensional superconductivity. This behavior contrasts with a previous study of imbedded Fe impurities, whose YSR state shows a six-fold symmetry and a two-dimensional long-range decay. According to our theoretical modeling, the coupling configurations affect the adatom-substrate hopping and the interlayer coupling of the substrate. Both factors are crucial for the consequent behavior of the YSR state
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