400 research outputs found
Bosonic Weyl excitations induced by -orbital interactions in a cubic optical lattice
Weyl points exist in a fascinating topological state of matter with linear
band crossings analogous to magnetic monopoles. Tremendous efforts have been
devoted to investigate fermionic topological matters with Weyl points in the
single-particle band dispersion. It remains elusive for realizing
interaction-induced Weyl points, especially for bosons. Motivated by recent
experimental progress in ultracold atoms, we propose a scheme to create Weyl
points for Bogoliubov excitations of a bosonic superfluid in a
three-dimensional cubic optical lattice. The unique design of the lattice leads
to interaction-induced time-reversal symmetry breaking for a -orbital
superfluid, which in turn induces Weyl Bogoliubov excitations. Analogous to
Weyl semimetals of electronic systems, the superfluid also support
topologically protected edge modes due to the bulk-boundary correspondence
6-[(E)-2-Phenylvinyl]-1H-indole
The title compound, C16H13N, is essentially planar [maximum deviation from the least-squares plane = 0.081 (3) Å], with a dihedral angle of 1.65 (13)° between the planes of the indole and benzene rings. In the crystal, there are no significant intermolecular π–π interactions [minimum ring centroid–centroid separation = 4.217 (5) Å]
The effect of mud therapy on pain relief in patients with knee osteoarthritis: A meta-analysis of randomized controlled trials
Abstract Objectives: A meta-analysis was conducted to examine the effect of mud therapy on pain relief in patients with knee osteoarthritis (OA). Methods: A detailed search of PubMed Õ /MEDLINE Õ was undertaken to identify randomized controlled trials and prospective comparative studies published before 9 March 2013 that compared mud therapy with control group treatments in patients with knee OA. Results: A quantitative meta-analysis of seven studies (410 patients) was performed. There was a significant difference between the groups in the visual analogue scale pain score (standardized mean difference [SMD] À0.73) and Western Ontario and McMaster Universities Osteoarthritis Index pain score (SMD À0.30), with differences in favour of mud therapy. Conclusions: Mud therapy is a favourable option for pain relief in patients with knee OA. Additional high-quality randomized controlled trials need to be conducted to explore this issue further and to confirm this conclusion
Highly efficient and stable planar heterojunction solar cell based on sputtered and post-selenized Sb2Se3 thin film
Antimony selenide (Sb2Se3) is regarded as one of the key alternative absorber materials for conventional thin film solar cells due to its excellent optical and electrical properties. Here, we proposed a Sb2Se3 thin film solar cell fabricated using a two-step process magnetron sputtering followed by a post-selenization treatment, which enabled us to optimize the best quality of both the Sb2Se3 thin film and the Sb2Se3/CdS heterojunction interface. By tuning the selenization parameters, a Sb2Se3 thin film solar cell with high efficiency of 6.06% was achieved, the highest reported power conversion efficiency of sputtered Sb2Se3 planar heterojunction solar cells. Moreover, our device presented an outstanding open circuit voltage (VOC) of 494 mV which is superior to those reported Sb2Se3 solar cells. State and density of defects showed that proper selenization temperature could effectively passivate deep defects for the films and thus improve the device performance
Magnetic properties of Fe intercalation FexTaSe2
Intercalation of transition metal dichalcogenides with magnetic elements has been the subject of increasing research interest, aiming to explore novel magnetic materials with anisotropy and spin-orbit coupling. In this paper, two magnetic samples with varying Fe content have been prepared using different growth conditions via the chemical vapor transport method. A comprehensive investigation of the magnetic properties of the materials has been conducted using the Physical Property Measurement System (PPMS, EvercoolⅡ-9T, Quantum Design). The results reveal distinct features in the studied materials. Fe0.12TaSe2 exhibits significant ferromagnetism with a Curie transition temperature of 50 K. However, its in-plane magnetism is weak and no significant hysteresis loop is observed below the Curie temperature. On the other hand, Fe0.25TaSe2 exhibits antiferromagnetism without any hysteresis loop and has a Néel temperature up to 130 K. This finding is quite different from the intercalated iron in FexTaS2, where only an antiferromagnetic state occurs with x larger than 0.4. Our study thus provides updated insights into the magnetic properties of this new system and serves as a reference for future investigations of TaSe2 compounds with varying iron content
Role and mechanism of DNA methylation and its inhibitors in hepatic fibrosis
Liver fibrosis is a repair response to injury caused by various chronic stimuli that continually act on the liver. Among them, the activation of hepatic stellate cells (HSCs) and their transformation into a myofibroblast phenotype is a key event leading to liver fibrosis, however the mechanism has not yet been elucidated. The molecular basis of HSC activation involves changes in the regulation of gene expression without changes in the genome sequence, namely, via epigenetic regulation. DNA methylation is a key focus of epigenetic research, as it affects the expression of fibrosis-related, metabolism-related, and tumor suppressor genes. Increasing studies have shown that DNA methylation is closely related to several physiological and pathological processes including HSC activation and liver fibrosis. This review aimed to discuss the mechanism of DNA methylation in the pathogenesis of liver fibrosis, explore DNA methylation inhibitors as potential therapies for liver fibrosis, and provide new insights on the prevention and clinical treatment of liver fibrosis
Cobalt doped LaSrTiO3-delta as an anode catalyst: effect of Co nanoparticle precipitation on SOFCs operating on H2S-containing hydrogen
NSERC; National Nature Science Foundation of China [51072021]; China Scholarship CouncilThis article compares the effects of Co doping on phase structures and stability of lanthanum strontium titanate (LST) anodes and electrochemical measurements in solid oxide fuel cells (SOFCs) employing H2S-containing H-2 as fuel. The Co-doped LST (LSCT) with a perovskite structure was synthesized via a solid state approach, achieving excellent phase purity and refined particle size. The catalytic activity and electrochemical performance are significantly improved by introducing Co. A maximum power density of 300 mW cm(-2) was achieved at 900 degrees C with 5000 ppm H2S-H-2 in a fuel cell having a 300 mu m thick YSZ electrolyte. Trace amounts of metallic Co nanoparticles with sizes typically no larger than 10 nm in diameter were detected on the LSCT surface after reduction in H-2 at 900 degrees C. The nano-sized Co clusters could reduce the anode polarization resistance, as well as improve the cell performance, compared with undoped LST anodes. The LSCT anode catalyst was electrochemically stable in 5000 ppm H2S-H-2 during the test time at high operating temperature. The LSCT anode catalyst also had relatively high redox stability in reversible oxidation-reduction cycles
Design & Optimization of the HV divider for JUNO 20-inch PMT
The Jiangmen Underground Observatory (JUNO) is a 20-kton liquid scintillator
detector that employs 20,000 20-inch photomultiplier tubes (PMTs) as photon
sensors, with 5,000 dynode-PMTs from HAMAMATSU Photonics K.K. (HPK), and 15,000
MCP-PMTs from North Night Vision Technology (NNVT) installed in pure water.
JUNO aims to provide long-lasting and the best performance operation by
utilizing a high-transparency liquid scintillator, high detection efficiency
PMTs, and specially designed electronics including water-proof potting for the
high voltage (HV) dividers of PMTs. In this paper, we present a summary of the
design and optimization of HV dividers for both types of 20-inch PMTs, which
includes collection efficiency, charge resolution, HV divider current, pulse
shape, and maximum amplitude restriction. We have developed and finalized four
schemes of the HV divider for different scenarios, including the final version
selected by JUNO. All 20,000 20-inch PMTs have successfully undergone
production and burning tests.Comment: 14pages,28figure
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