2,222 research outputs found
Blue Phosphorene Oxide: Strain-tunable Quantum Phase Transitions and Novel 2D Emergent Fermions
Tunable quantum phase transitions and novel emergent fermions in solid state
materials are fascinating subjects of research. Here, we propose a new stable
two-dimensional (2D) material, the blue phosphorene oxide (BPO), which exhibits
both. Based on first-principles calculations, we show that its equilibrium
state is a narrow-bandgap semiconductor with three bands at low energy.
Remarkably, a moderate strain can drive a semiconductor-to-semimetal quantum
phase transition in BPO. At the critical transition point, the three bands
cross at a single point at Fermi level, around which the quasiparticles are a
novel type of 2D pseudospin-1 fermions. Going beyond the transition, the system
becomes a symmetry-protected semimetal, for which the conduction and valence
bands touch quadratically at a single Fermi point that is protected by
symmetry, and the low-energy quasiparticles become another novel type of 2D
double Weyl fermions. We construct effective models characterizing the phase
transition and these novel emergent fermions, and we point out several exotic
effects, including super Klein tunneling, supercollimation, and universal
optical absorbance. Our result reveals BPO as an intriguing platform for the
exploration of fundamental properties of quantum phase transitions and novel
emergent fermions, and also suggests its great potential in nanoscale device
applications.Comment: 23 pages, 5 figure
Study Majorana Neutrino Contribution to B-meson Semi-leptonic Rare Decays
B meson semi-leptonic rare decays are sensitive to new physics beyond
standard model. We study the process and
investigate the Majorana neutrino contribution to its decay width. The
constraints on the Majorana neutrino mass and mixing parameter are obtained
from this decay channel with the latest LHCb data. Utilizing the best fit for
the parameters, we study the lepton number violating decay , and find its branching ratio is about
, which is consistent with the LHCb data reported recently.Comment: 10 pages, 3 figure
Memory augment is All You Need for image restoration
Image restoration is a low-level vision task, most CNN methods are designed
as a black box, lacking transparency and internal aesthetics. Although some
methods combining traditional optimization algorithms with DNNs have been
proposed, they all have some limitations. In this paper, we propose a
three-granularity memory layer and contrast learning named MemoryNet,
specifically, dividing the samples into positive, negative, and actual three
samples for contrastive learning, where the memory layer is able to preserve
the deep features of the image and the contrastive learning converges the
learned features to balance. Experiments on Derain/Deshadow/Deblur task
demonstrate that these methods are effective in improving restoration
performance. In addition, this paper's model obtains significant PSNR, SSIM
gain on three datasets with different degradation types, which is a strong
proof that the recovered images are perceptually realistic. The source code of
MemoryNet can be obtained from https://github.com/zhangbaijin/MemoryNe
NeAI: A Pre-convoluted Representation for Plug-and-Play Neural Ambient Illumination
Recent advances in implicit neural representation have demonstrated the
ability to recover detailed geometry and material from multi-view images.
However, the use of simplified lighting models such as environment maps to
represent non-distant illumination, or using a network to fit indirect light
modeling without a solid basis, can lead to an undesirable decomposition
between lighting and material. To address this, we propose a fully
differentiable framework named neural ambient illumination (NeAI) that uses
Neural Radiance Fields (NeRF) as a lighting model to handle complex lighting in
a physically based way. Together with integral lobe encoding for
roughness-adaptive specular lobe and leveraging the pre-convoluted background
for accurate decomposition, the proposed method represents a significant step
towards integrating physically based rendering into the NeRF representation.
The experiments demonstrate the superior performance of novel-view rendering
compared to previous works, and the capability to re-render objects under
arbitrary NeRF-style environments opens up exciting possibilities for bridging
the gap between virtual and real-world scenes. The project and supplementary
materials are available at https://yiyuzhuang.github.io/NeAI/.Comment: Project page: <a class="link-external link-https"
href="https://yiyuzhuang.github.io/NeAI/" rel="external noopener
nofollow">https://yiyuzhuang.github.io/NeAI/</a
Genes related to the very early stage of ConA-induced fulminant hepatitis: a gene-chip-based study in a mouse model
<p>Abstract</p> <p>Background</p> <p>Due to the high morbidity and mortality of fulminant hepatitis, early diagnosis followed by early effective treatment is the key for prognosis improvement. So far, little is known about the gene expression changes in the early stage of this serious illness. Identification of the genes related to the very early stage of fulminant hepatitis development may provide precise clues for early diagnosis.</p> <p>Results</p> <p>Balb/C mice were used for ConA injection to induce fulminant hepatitis that was confirmed by pathological and biochemical examination. After a gene chip-based screening, the data of gene expression in the liver, was further dissected by ANOVA analysis, gene expression profiles, gene network construction and real-time RT-PCR.</p> <p>At the very early stage of ConA-triggered fulminant hepatitis, totally 1,473 genes with different expression variations were identified. Among these, 26 genes were finally selected for further investigation. The data from gene network analysis demonstrate that two genes, MPDZ and Acsl1, localized in the core of the network.</p> <p>Conclusions</p> <p>At the early stages of fulminant hepatitis, expression of twenty-six genes involved in protein transport, transcription regulation and cell metabolism altered significantly. These genes form a network and have shown strong correlation with fulminant hepatitis development. Our study provides several potential targets for the early diagnosis of fulminant hepatitis.</p
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