1,153 research outputs found
Phonon-assisted tunneling in asymmetric resonant tunneling structures
Based on the dielectric continuum model, we calculated the phonon assisted
tunneling (PAT) current of general double barrier resonant tunneling structures
(DBRTSs) including both symmetric and antisymmetric ones. The results indicate
that the four higher frequency interface phonon modes (especially the one which
peaks at either interface of the emitter barrier) dominate the PAT processes,
which increase the valley current and decrease the PVR of the DBRTSs. We show
that an asymmetric structure can lead to improved performance.Comment: 1 paper and 5 figure
Quantum and classical correlations in the one-dimensional XY model with Dzyaloshinskii-Moriya interaction
We study the effect of Dzyaloshinskii-Moriya (DM) interaction on pairwise
quantum discord, entanglement, and classical correlation in the anisotropic XY
spin-half chain. Analytical expressions for both quantum and classical
correlations are obtained from the spin-spin correlation functions. We show
that these pairwise quantities exhibit various behaviors in relation to the
relative strengths of the DM interaction, the anisotropy and the magnetic
intensity. We observe non-analyticities of the derivatives of both quantum and
classical correlations with respect to the magnetic intensity at the critical
point, with consideration of the DM interaction.Comment: 18pages, 6figure
Centrality dependence of spectra for identified hadrons in Au+Au and Cu+Cu collisions at GeV
The centrality dependence of transverse momentum spectra for identified
hadrons at midrapidity in Au+Au collisions at GeV is
systematically studied in a quark combination model. The
spectra of , , and in
different centrality bins and the nuclear modification factors () for
these hadrons are calculated. The centrality dependence of the average
collective transverse velocity for the hot and dense quark matter
is obtained in Au+Au collisions, and it is applied to a relative smaller Cu+Cu
collision system. The centrality dependence of spectra and
the for , and in Cu+Cu collisions at
GeV are well described. The results show that is only a function of the number of participants and it is
independent of the collision system.Comment: 7 pages, 6 figure
Twofold Structured Features-Based Siamese Network for Infrared Target Tracking
Nowadays, infrared target tracking has been a critical technology in the
field of computer vision and has many applications, such as motion analysis,
pedestrian surveillance, intelligent detection, and so forth. Unfortunately,
due to the lack of color, texture and other detailed information, tracking
drift often occurs when the tracker encounters infrared targets that vary in
size or shape. To address this issue, we present a twofold structured
features-based Siamese network for infrared target tracking. First of all, in
order to improve the discriminative capacity for infrared targets, a novel
feature fusion network is proposed to fuse both shallow spatial information and
deep semantic information into the extracted features in a comprehensive
manner. Then, a multi-template update module based on template update mechanism
is designed to effectively deal with interferences from target appearance
changes which are prone to cause early tracking failures. Finally, both
qualitative and quantitative experiments are carried out on VOT-TIR 2016
dataset, which demonstrates that our method achieves the balance of promising
tracking performance and real-time tracking speed against other out-of-the-art
trackers.Comment: 13 pages,9 figures,references adde
The LAMOST Complete Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap I. The Spectroscopic Redshift Catalog
We present a spectroscopic redshift catalog from the LAMOST Complete
Spectroscopic Survey of Pointing Area (LaCoSSPAr) in the Southern Galactic Cap
(SGC), which is designed to observe all sources (Galactic and extra-galactic)
by using repeating observations with a limiting magnitude of in
two fields. The project is mainly focusing on the completeness of
LAMOST ExtraGAlactic Surveys (LEGAS) in the SGC, the deficiencies of source
selection methods and the basic performance parameters of LAMOST telescope. In
both fields, more than 95% of galaxies have been observed. A post-processing
has been applied to LAMOST 1D spectrum to remove the majority of remaining sky
background residuals. More than 10,000 spectra have been visually inspected to
measure the redshift by using combinations of different emission/absorption
features with uncertainty of . In total, there are 1528
redshifts (623 absorption and 905 emission line galaxies) in Field A and 1570
redshifts (569 absorption and 1001 emission line galaxies) in Field B have been
measured. The results show that it is possible to derive redshift from low SNR
galaxies with our post-processing and visual inspection. Our analysis also
indicates that up to 1/4 of the input targets for a typical extra-galactic
spectroscopic survey might be unreliable. The multi-wavelength data analysis
shows that the majority of mid-infrared-detected absorption (91.3%) and
emission line galaxies (93.3%) can be well separated by an empirical criterion
of . Meanwhile, a fainter sequence paralleled to the main population
of galaxies has been witnessed both in / and /
diagrams, which could be the population of luminous dwarf galaxies but
contaminated by the edge-on/highly inclined galaxies ().Comment: 19 pages, 14 figures, 2 MRT, accepted by ApJ
Recommended from our members
Dysregulated protocadherin-pathway activity as an intrinsic defect in induced pluripotent stem cell-derived cortical interneurons from subjects with schizophrenia.
We generated cortical interneurons (cINs) from induced pluripotent stem cells derived from 14 healthy controls and 14 subjects with schizophrenia. Both healthy control cINs and schizophrenia cINs were authentic, fired spontaneously, received functional excitatory inputs from host neurons, and induced GABA-mediated inhibition in host neurons in vivo. However, schizophrenia cINs had dysregulated expression of protocadherin genes, which lie within documented schizophrenia loci. Mice lacking protocadherin-α showed defective arborization and synaptic density of prefrontal cortex cINs and behavioral abnormalities. Schizophrenia cINs similarly showed defects in synaptic density and arborization that were reversed by inhibitors of protein kinase C, a downstream kinase in the protocadherin pathway. These findings reveal an intrinsic abnormality in schizophrenia cINs in the absence of any circuit-driven pathology. They also demonstrate the utility of homogenous and functional populations of a relevant neuronal subtype for probing pathogenesis mechanisms during development
Prostate deformation from inflatable rectal probe cover and dosimetric effects in prostate seed implant brachytherapy: Deformation on prostate permanent brachytherapy dosimetry
Prostate brachytherapy is an important treatment technique for patients with localized prostate cancer. An inflatable rectal ultrasound probe cover is frequently utilized during the procedure to adjust for unfavorable prostate position relative to the implant grid. However, the inflated cover causes prostate deformation, which is not accounted for during dosimetric planning. Most of the therapeutic dose is delivered after the procedure when the prostate and surrounding organs-at-risk are less deformed. The aim of this study is to quantify the potential dosimetry changes between the initial plan (prostate deformed) and the more realistic dosimetry when the prostate is less deformed without the cover
- …