A novel photocatalysis and gas sensing material was synthesized by decorating Au nanoparticles on tungsten trioxide nanorods. Tungsten trioxide nanorods were prepared through the ion-exchange method ...combined with hydrothermal treatment and further modified with Au nanoparticles (Au NPs). After Au NPs decorated on the surface of WO3 nanorods (WO3 NRs), the reducing gas (hydrogen, methanol, ethanol, etc.) sensing properties and the photocatalytic performance of rhodamine B (RhB) were all greatly improved. Au NP modified WO3 nanorods (Au NP@WO3 NRs) exhibit not only larger response (H2 50 ppm, recovery time lower than 10 s) and better selectivity (Ra/Rg = 6.6) for H2 gas detection than pure WO3 NRs but also high photocatalytic properties for the absolute degradation of RhB under simulated sunlight irradiation for 120 min.
We report the results of searches for solar axions and galactic dark matter axions or axionlike particles with the CDEX-1 experiment at the China Jinping Underground Laboratory, using 335.6 kg days ...of data from a p-type point-contact germanium detector. The data are compatible with the background model, and no excess signals are observed. Limits of solar axions on the model-independent coupling gAe<2.5×10−11 from Compton, bremsstrahlung, atomic-recombination, and deexcitation channels and gANeff×gAe<6.4×10−17 from a Fe57 M1 transition at 90% confidence level are derived. Within the framework of the Dine-Fischler-Srednicki-Zhitnitskiy and Kim-Shifman-Vainshtein-Zakharov models, our results exclude the axion mass heavier than 0.9 and 177 eV/c2, respectively. The derived constraints for dark matter axions below 1 keV improve over the previous results.
Abstract We report the phase-resolved spectral results of the first Galactic pulsating ultraluminous X-ray source (PULX) Swift J0243.6+6124, modeling its 2017–2018 outburst peak using data collected ...by the Hard X-ray Modulation Telescope (Insight-HXMT). The broad energy coverage of Insight-HXMT allows us to obtain a more accurate spectral continuum to reduce the coupling of broad iron line profiles with other components. We use three different continuum spectrum models but obtain similar iron line results. For the first time, we detect the pulse characteristics of the broad iron line in a PULX. The variation in the width and intensity of this iron line with σ ∼ 1.2–1.5 keV has a phase offset of about 0.25 from the pulse phase. We suggest that the uneven irradiation of the thick inner disk by the accretion column produces the modulated variation of the broad iron line. In addition, the nonpulsed narrow line is suggested to come from the outer disk region.
Abstract
Since the last IAEA Fusion Energy Conference in 2018, significant progress of the experimental program of HL-2A has been achieved on developing advanced plasma physics, edge localized mode ...(ELM) control physics and technology. Optimization of plasma confinement has been performed. In particular, high-
β
N
H-mode plasmas exhibiting an internal transport barrier have been obtained (normalized plasma pressure
β
N
reached up to 3). Injection of impurity improved the plasma confinement. ELM control using resonance magnetic perturbation or impurity injection has been achieved in a wide parameter regime, including types I and III. In addition, impurity seeding with supersonic molecular beam injection or laser blow-off techniques has been successfully applied to actively control the plasma confinement and instabilities, as well as plasma disruption with the aid of disruption prediction. Disruption prediction algorithms based on deep learning are developed. A prediction accuracy of 96.8% can be reached by assembling a convolutional neural network. Furthermore, transport resulting from a wide variety of phenomena such as energetic particles and magnetic islands has been investigated. In parallel with the HL-2A experiments, the HL-2M mega-ampere class tokamak was commissioned in 2020 with its first plasma. Key features and capabilities of HL-2M are briefly presented.
Increasing evidence has demonstrated a significant role of long non-coding RNAs (lncRNAs) in diverse biological processes. However, their functions in cerebral ischemia remain largely unknown. ...Through an lncRNA array analysis in a rat model of focal cerebral ischemia/reperfusion (I/R), we have identified CAMK2D-associated transcript 1 (C2dat1) as a novel I/R-induced lncRNA that regulated the expression of CaMKIIδ in murine models of focal cerebral ischemia. C2dat1 mRNA was upregulated in a time-dependent manner in mouse cortical penumbra after focal ischemic brain injury, which was accompanied by increased expression of CaMKIIδ at transcript and protein levels. The expression patterns of C2dat1 and CAMK2D were confirmed in mouse Neuro-2a cells in response to in vitro ischemia (oxygen-glucose deprivation/reoxygenation, OGD/R). Knockdown of C2dat1 resulted in a significant blockade of CaMKIIδ expression, and potentiated OGD/R-induced cell death. Mechanistically, reduced CaMKIIδ expression upon silencing C2dat1 inhibited OGD/R-induced activation of the NF-κB signaling pathway. Further analysis showed that the downregulation of IKKα and IKKβ expression and phosphorylation, and subsequent inhibition of IκBα degradation accounted for the inhibition of the NF-κB signaling activity caused by silencing C2dat1. In summary, we discovered a novel I/R-induced lncRNA C2dat1 that modulates the expression of CaMKIIδ to impact neuronal survival, and may be a potential target for therapeutic intervention of ischemic brain injury.
The impact of impurity ions on a pedestal has been investigated in the HL-2A Tokamak, at the Southwestern Institute of Physics, Chengdu, China. Experimental results have clearly shown that during the ...H-mode phase, an electromagnetic turbulence was excited in the edge plasma region, where the impurity ions exhibited a peaked profile. It has been found that double impurity critical gradients are responsible for triggering the turbulence. Strong stiffness of the impurity profile has been observed during cyclic transitions between the I-phase and H-mode regime. The results suggest that the underlying physics of the self-regulated edge impurity profile offers the possibility for an active control of the pedestal dynamics via pedestal turbulence.
To date, attempts to regenerate functional periodontal tissues (including cementum) are largely unsuccessful due to a lack of full understanding about the cellular origin (epithelial or mesenchymal ...cells) essential for root cementum growth. To address this issue, we first identified a rapid cementum growth window from the ages of postnatal day 28 (P28) to P56. Next, we showed that expression patterns of Axin2 and β-catenin within cementum-forming periodontal ligament (PDL) cells are negatively associated with rapid cementum growth. Furthermore, cell lineage tracing studies revealed that the Axin2+-mesenchymal PDL cells and their progeny rapidly expand and directly contribute to postnatal acellular and cellular cementum growth. In contrast, the number of K14+ epithelial cells, which were initially active at early stages of development, was reduced during rapid cementum formation from P28 to P56. The in vivo cell ablation of these Axin2+ cells using Axin2CreERT2/+; R26RDTA/+ mice led to severe cementum hypoplasia, whereas constitutive activation of β-catenin in the Axin2+ cells resulted in an acceleration in cellular cementogenesis plus a transition from acellular cementum to cellular cementum. Thus, we conclude that Axin2+-mesenchymal PDL cells, instead of K14+ epithelial cells, significantly contribute to rapid cementum growth.
In candidate gene era, dozens of single-nucleotide polymorphisms (SNPs) within renin-angiotensin-aldosterone system (RAAS) have been reported to be significantly associated with hypertension. ...However, the unbiased genome-wide association studies (GWAS) rarely identified the SNPs within RAAS were associated with hypertension or blood pressure (BP) traits. In order to figure out whether genetic polymorphisms of RAAS are really associated with hypertension, we systemically searched the GWAS Catalogue and identified all the known RAAS genes and relevant diseases/traits. After data processing, we found that polymorphisms within REN, AGT, ACE2, CYP11B2, ATP6AP2 and HSD11B2 were not associated with any disease or trait. SNPs within ACE, AGTR1, AGTR2, MAS1, RENBP and NR3C2 were associated with other diseases or traits, but showed no direct connection with hypertension. The only SNP associated with a BP trait, systolic BP was rs17367504. However, it is located in the intronic region of MTHFR near many plausible candidate genes, including CLCN6, NPPA, NPPB and AGTRAP. Therefore, the effect of RAAS polymorphisms may have been overestimated during the 'candidate gene era'. In the time of 'precision medicine', the power of RAAS variants needs to be reconsidered when evaluating one's susceptibility of hypertension.
The ultrasonic vibration-assisted grinding method has been widely used as a cost-effective machining method for hard and brittle materials. It is generally known that the ultrasonic vibration during ...grinding procedure causes the micro-fracture of the workpiece, which can improve grinding efficiency and provide better surface integrity. On the other hand, the ultrasonic vibration also acts on the diamond wheel surface, affecting its wear during the grinding process. In this study, the alumina ceramic was ground with and without the ultrasonic vibration-assisted grinding ceramic to investigate the wear characteristics of the diamond wheel. The changes of the diamond wheel surface topography were captured and the grinding forces were measured during the grinding process. Based on the analysis of the experimental data, it was found that the ultrasonic vibration caused great wear but at the same time improved the self-sharpening property of the diamond wheel. One can also found that as the ultrasonic vibration on the diamond grits produce micro cutting edge the diamond wheel work surface was steady kept sharpness during ultrasonic vibration-assisted grinding, and the grinding force and force ratio did not increase with the increasing of cumulative material removal volume.
Abstract
In view of the wide application of vortex tube (VOTU) in the market, and in order to enhance the capability of VOTU in the higher inlet pressure, three-dimensional numerical simulations were ...performed with existing experimental data and models to analyse the flow fields of VOTUs at different pressures. With the increase of pressure, the maximum temperature of the VOTU rises rapidly and the minimum temperature decreases smoothly. Meanwhile, when the VOTU works under high pressure, the wall thickness and sealing degree of the VOTU design should be increased accordingly, while the inner wall of the VOTU should be made of wear-resistant material to avoid the wear of the VOTU caused by the long-term scouring of the high-speed airflow.
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