377 research outputs found
Magnetothermoelectric DC conductivities from holography models with hyperscaling factor in Lifshitz spacetime
We investigate an Einstein-Maxwell-Dilaton-Axion holographic model and obtain
two branches of a charged black hole solution with a dynamic exponent and a
hyperscaling violation factor when a magnetic field presents. The
magnetothermoelectric DC conductivities are then calculated in terms of horizon
data by means of holographic principle. We find that linear temperature
dependence resistivity and quadratic temperature dependence inverse Hall angle
can be achieved in our model. The well-known anomalous temperature scaling of
the Nernst signal and the Seebeck coefficient of cuprate strange metals are
also discussed.Comment: 1+23 pages, 4 figures, references adde
Research of growth mechanism of ceramic coatings fabricated by micro-arc oxidation on magnesium alloys at high current mode
AbstractMicro-arc oxidation (MAO) coatings of ZK60 magnesium alloys were formed in a self-developed dual electrolyte composed of sodium silicate and phosphate at the high constant current of 1.8 A (15 A/dm2). The MAO process and growth mechanism were investigated by scanning electron microscopy (SEM) coupled with an energy dispersive spectrometer (EDS), confocal laser scanning microscopy and X-ray diffraction (XRD). The results indicate that the growth process of MAO coating mainly goes through “forming → puncturing → rapid growth of micro-arc oxidation →large arc discharge → self-repairing”. The coating grows inward and outward at the same time in the initial stage, but outward growth of the coating is dominant later. Mg, Mg2SiO4 and MgO are the main phases of ceramic coating
Uncertainty-aware Unsupervised Multi-Object Tracking
Without manually annotated identities, unsupervised multi-object trackers are
inferior to learning reliable feature embeddings. It causes the
similarity-based inter-frame association stage also be error-prone, where an
uncertainty problem arises. The frame-by-frame accumulated uncertainty prevents
trackers from learning the consistent feature embedding against time variation.
To avoid this uncertainty problem, recent self-supervised techniques are
adopted, whereas they failed to capture temporal relations. The interframe
uncertainty still exists. In fact, this paper argues that though the
uncertainty problem is inevitable, it is possible to leverage the uncertainty
itself to improve the learned consistency in turn. Specifically, an
uncertainty-based metric is developed to verify and rectify the risky
associations. The resulting accurate pseudo-tracklets boost learning the
feature consistency. And accurate tracklets can incorporate temporal
information into spatial transformation. This paper proposes a tracklet-guided
augmentation strategy to simulate tracklets' motion, which adopts a
hierarchical uncertainty-based sampling mechanism for hard sample mining. The
ultimate unsupervised MOT framework, namely U2MOT, is proven effective on
MOT-Challenges and VisDrone-MOT benchmark. U2MOT achieves a SOTA performance
among the published supervised and unsupervised trackers.Comment: Accepted by International Conference on Computer Vision (ICCV) 202
Three-dimensional potential energy surface for fission of U within covariant density functional theory
We have calculated the three-dimensional potential energy surface (PES) for
the fission of compound nucleus U using the covariant density
functional theory with constraints on the axial quadrupole and octupole
deformations as well as the nucleon number in the neck
. By considering the additonal degree of freedom , coexistence of the
elongated and compact fission modes is predicted for . Remarkably, the PES becomes very shallow across a large range of
quadrupole and octupole deformations for small , and consequently, the
scission line in plane will extend to a shallow band,
which leads to a fluctuation for the estimated total kinetic energies by
several to ten MeV and for the fragment masses by several to about ten
nucleons
Mixing of X and Y states from QCD Sum Rules analysis
We study and states as mixed states in
QCD sum rules. By calculating the two-point correlation functions of pure
states of their corresponding currents, we review the mass and coupling
constant predictions of , , states. By
calculating the two-point mixed correlation functions of and
currents, and we estimate the mass and coupling constants of
the corresponding `"physical state" that couples to both and
currents. Our results suggest that states are more
likely mixing from and components, while
for and states, there is less mixing between
and . Our results suggest the series
of states have more complicated components.Comment: 14 pages,3 figs, 7 table
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