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The low-latitude sodium layer:comparative data from lidar observations at Hainan,china and São Paulo,Brazil

Earth and Planetary Physics 2025年第1期9卷 39-53页

作者： Fang wu Jing Jiao GuoTao Yang LiFang Du zhengKuan Liu HaoRan zheng JiXin Guo ShaoHua Gong YaJun zhu State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China Hainan National Field Science Observation and Research Observatory for Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China University of chinese Academy of Sciences Beijing 100049China china-Brazil Joint Laboratory for Space Weather NSSC/INPESão Josédos Campos 12227-010Brazil School of Physics and Electronics Engineering Hainan Normal UniversityHaikou 571158China

Physical and chemical processes observed in the mesosphere and thermosphere above the Earth’s low latitudes are complex and highly interrelated to activity in the low-latitude *** sodium detected by lidar can yield clues to dynamic and chemical processes in these spatial layers above the Earth’s *** paper is based on sodium layer data collected at two low-latitude stations,one in the northern hemisphere and one in the *** low-latitude sodium layer exhibits conspicuous seasonal variations in shape,density,and altitude;these variations are similar between Earth’s hemispheres:sodium layer density at both stations reaches its seasonal maximum in autumn and minimum in ***,maximal Na density over Brazil is greater than that over *** variations of Na density above the two low-latitude stations are also similar;at both,maxima are observed before *** variations of the Na layer over Brazil that differ from those observed in the northern hemisphere may be related to the South Atlantic Magnetic Anomaly(SAMA)or fountain *** suggest that low-latitude Na layer data may provide useful additional evidence that could significantly improve the low-latitude part of the WAccM-Na model.

关键词： metallic sodium layer seasonal variation nocturnal variation lidar

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Probing the Bardeen-Kiselev black hole with the cosmological constant caused by Einstein equations coupled with nonlinear electrodynamics using quasinormal modes and greybody bounds

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communications in Theoretical Physics 2024年第6期76卷 102-119页

作者： S R wu B Q Wang z W Long college of Physics Guizhou UniversityGuiyang 550025China college Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this work,we investigate a static and spherically symmetric Bardeen-Kiselev black hole(BH)with the cosmological constant,which is a solution of the Einstein-non-linear Maxwell field *** compute the quasinormal frequencies for the Bardeen-Kiselev BH with the cosmological constant due to electromagnetic and gravitational *** varying the BH parameters,we discuss the behavior of both real and imaginary parts of the BH quasinormal frequencies and compare these frequencies with the Reissner-Nordström-de Sitter BH surrounded by quintessence(RN-dSQ).Interestingly,it is shown that the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ under electromagnetic perturbations are different when the charge parameter q,the state parameter w and the normalization factor c are varied;however,for the gravitational perturbations,the responses of the Bardeen-Kiselev BH with the cosmological constant and the RN-dSQ are different only when the charge parameter q is ***,compared with the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev BH with the cosmological constant damps faster and oscillates slowly;for the gravitational perturbations,the quasinormal mode decays slowly and oscillates *** also study the reflection and transmission coefficients along with the absorption cross section in the Bardeen-Kiselev BH with the cosmological constant;it is shown that the transmission coefficients will increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors Bardeen-Kiselev black hole with cosmological constant

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Preliminary performance analysis and optimization based on 1D neutronics model for Indian DEMO HccB blanket

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Plasma Science and Technology 2020年第8期22卷 184-191页

作者： D AGGARWAL c DANANI M z YOUSSEF Institute for Plasma Research GandhinagarGujarat 382428India Homi Bhabha National Institute(HBNI) AnushaktinagarMumbai 400094India University of california-Los Angeles Los AngelesCA 90095United States of America

India,under its breeding blanket R&D program for DEMO,is focusing on the development of two tritium breeding blanket concepts;namely the lead-lithium-cooled ceramic breeder and the helium-cooled ceramic breeder(HccB).The study presented in this paper focuses on the neutronic design analysis and optimization from the tritium breeding perspective of the HccB *** Indian concept has an edge-on configuration and is one of the variants of the helium-cooled solid breeder blanket concepts proposed by several partner countries in *** Indian HccB blanket having lithium titanate(Li2TiO3)as the tritium breeder and beryllium(Be)as the neutron multiplier with reduced-activation ferritic/martensitic steel structure aims at utilizing the low-energy neutrons at the rear part of the *** aim of the optimization study is to minimize the radial blanket thickness while ensuring tritium self-sufficiency and provide data for further neutronic design and thermal-hydraulic layout of the HccB *** is found that inboard and outboard blanket thicknesses of 40 cm and 60 cm,respectively,can give a tritium breeding ratio(TBR)>1.3,with 60%6Li enrichment,which is assumed to be sufficient to cover potential tritium losses and associated *** results also demonstrated that the Be packing fraction(PF)has a more profound impact on the TBR as compared to 6Li enrichment and the PF of Li2TiO3.

关键词： DEMO helium-cooled ceramic breeder blanket neutronic optimization study tritium breeding ratio

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Novel Agents in the Management of Hepatic Encephalopathy:A Review

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Journal of clinical and Translational Hepatology 2021年第5期9卷 749-759页

作者： Leen z.Hasan George Y.wu Department of Medicine Division of Gastroenterology-HepatologyUniversity of Connecticut Health CenterFarmingtonCTUSA

Hepatic encephalopathy is an often devastating complication of chronic liver disease,associated with high mortality and increased burden on patients and healthcare *** agents(such as nonabsorbable disaccharides and oral antibiotics)are often only partially effective and associated with unpleasant side *** our improved understanding of the pathophysiology of hepatic encephalopathy,multiple treatment modalities have emerged with promising results when used alone or as an adjunct to standard *** mechanisms of these agents vary greatly,and include the manipulation of gut microbial composition,reduction of oxidative stress,inhibition of inflammatory mediators,protection of endothelial integrity,modulation of neurotransmitter release and function,and other novel methods to reduce blood ammonia and *** their promising results,the studies assessing these treatment modalities are often limited by study design,sample size,outcome assessment heterogeneity,and paucity of data regarding their safety *** this article,we discuss these novel agents in depth and provide the best evidence supporting their use,along with a critical look at their limitations and future directions.

关键词： Hepatic encephalopathy Liver cirrhosis Ammonia

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Ultrahigh strength Mg-Y-Ni alloys obtained by regulating second phases

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Journal of Materials Science & Technology 2020年第10期42卷 117-124页

作者： S.z.wu X.G.Qiao M.Y.zheng School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

Mg-Y-Ni alloys with different second phases were designed by changing Y/Ni atomic ratio from 1.5 to *** microstructure and mechanical properties of as-cast and as-extruded alloys were *** as-cast Mg-Y-Ni alloy with Y/Ni ratio of 1.5 is composed ofα-Mg and long period stacking ordered(LPSO)*** Y/Ni ratio is equal to 1,nanoscale lamellarγ’phase and eutectic Mg2Ni phase are formed in addition to LPSO *** Y/Ni ratio decreases further,the amount of eutectic Mg2Ni phase increases,while the amount of LPSO phase *** extrusion,the LPSO andγ’phases are distributed along the extrusion direction,while eutectic Mg2Ni phase is broken and dispersed in the as-extruded *** phase and Mg2Ni phase in the alloys promote dynamic recrystallization(DRX)during extrusion,whileγ’phase inhibits ***,the Mg96Y2Ni2(at.%)alloy with LPSO phase andγ’phase as the main second phases shows the strongest basal texture after *** tensile yield strength of the as-extruded Mg-Y-Ni alloys increases first and then decreases with decreasing Y/Ni *** as-extruded Mg96Y2Ni2(at.%)alloy with Y/Ni=1 exhibits excellent mechanical properties with tensile yield strength of 465 MPa,ultimate tensile strength of 510 MPa and elongation to failure of 7.2%,which is attributed to the synergistic effect of bulk LPSO phase and nanoscaleγ’phase.

关键词： Mg-Y-Ni alloys LPSO γ’Phase Mg2Ni Mechanical properties

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Effect of Silver content on Microstructure and Properties of Brass/steel Induction Brazing Joint Using Ag-cu-zn-Sn Filler Metal

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Journal of Materials Science & Technology 2011年第4期27卷 377-381页

作者： J. cao L.X. zhang H.Q. Wang L.z. wu J.c. Feng State KeyLab of Advanced Welding Production Technology Harbin Instituteof Technology Harbin 150001 China center for composite Materials and Structures Harbin Institute of Technology Harbin 150001 China

The induction brazing of brass to steel using Ag-cu-zn-Sn filler metal was investigated in this study. The influence of A8 content on the microstructure and properties were analyzed by means of optical microscopy, scanning electron microscopy and electron probe microanalysis. Defect free joint was achieved using Ag- cu-zn-Sn filler metal. The microstructure of the joint was mainly composed of Ag-based solid solution and cu-based solid solution. The increase of A8 content and the cooling rate both led to the increase of the needle like eutectic structure. The tensile strength decreased with the increase of Ag content. The tensile strength at room temperature using Ag25cuznSn filler metal reached 445 MPa. All fractures using Ag-cu-zn-Sn filler metal presented ductile characteristic.

关键词： Induction brazing Brass Steel Microstructure Tensile strength

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A new model for the expansion tube considering the stress coupling:Theory,experiments and simulations

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Defence Technology（防务技术） 2022年第7期18卷 1190-1204页

作者： M.z.wu X.W.zhang Q.M.zhang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyHaidian DistrictBeijing10081China

Based on the two-arc profile assumption,the expansion deformation and energy absorption of circular tubes compressed by conical-cylindrical dies were ***,the deformation of the two arcs was analyzed independently and an improved model denoted as Model-I was ***,by further involving the coupling between the bending moment and membrane forces,a more elaborate model,i.e.,Model-II was ***,experiments and simulations were conducted to verify the models,which show that,compared with previous theoretical models,Model-II could not only capture the prominent features of the deformation,but also improve the prediction accuracy of the steady driving force *** means of this model,it was found that the critical semi-conical angle,which makes the driving force minimum,increases with the increase of the friction coefficient,expansion ratio as well as the radius/thickness ratio of the ***,the energy dissipation due to stretching is always greater than that of bending,while the friction dissipation can account for the largest proportion at small semi-conical angle or large friction *** a certain friction and die conditions,the specific energy absorption of expanded tubes can be much higher than that under progressive collapse mode.

关键词： Expansion circular tube Stress coupling Strain hardening Energy absorption

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Numerical investigation on the flowfield of “swallowtail” cavity for supersonic mixing enhancement

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Acta Mechanica Sinica 2009年第1期25卷 37-44页

作者： c. Wang z. Jiang z. Hu J. Lu Institute or Mechanics. chinese Academy of Sciences 100190 Beijing China RecAPT Gyeongsang National University JinjuKyeongnam 660-701 South Korea

A ＂swallowtail＂ cavity for the supersonic combustor was proposed to serve as an efficient flame holder for scramjets by enhancing the mass exchange between the cavity and the main flow. A numerical study on the ＂swallow- tail＂ cavity was conducted by solving the three-dimensional Reynolds-averaged Navier-Stokes equations implemented with a k-e turbulence model in a multi-block mesh. Turbu- lence model and numerical algorithms were validated first, and then test cases were calculated to investigate into the mechanism of cavity flows. Numerical results demonstrated that the certain mass in the supersonic main flow was sucked into the cavity and moved spirally toward the combustor walls. After that, the flow went out of the cavity at its lateral end, and finally was efficiently mixed with the main flow. The comparison between the ＂swallowtail＂ cavity and the conventional one showed that the mass exchanged between the cavity and the main flow was enhanced by the lateral flow that was induced due to the pressure gradient inside the cavity and was driven by the three-dimensional vortex ring generated from the ＂swallowtail＂ cavity structure.

关键词： Supersonic mixing - Flame holder "Swallowtail" cavity - combustion ignition Numerical simulation

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Advances in centrifugal Separators for Particulate Matter control from Stationary Sources

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Journal of Thermal Science 2002年第3期11卷 283-288页

作者： z.c.Tan University of Illinois Urbana USA

This paper summarized recent developments in centrifugal separators for particulate matter (PM) emission control. Airborne particulate matter, which is responsible for many health and environmental problems, is generated mostly from combustion processes in stationary sources such as house burners and power plants and other production facilities, except field dust. Reverse flow cyclones are centrifugal separators having been widely used for industrial particulate matter removal. Typical pressure drops of these cyclones for air cleaning are 500 Pa or higher, and were believed to be only able to separate particles larger than 10 μm. An aerodynamic deduster that could separate particles as small as 1μm at a pressure drop of 200 Pa was recently developed. Field evaluation showed that the deduster can be effectively used in reducing particulate matter emission from stationary sources.

关键词： particulate matter emission control centrifugal separator cyclones aerodynamic deduster particle cut size.

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基于机器学习筛选猪活体肌内脂肪含量间接选育和构建预测模型的关键性状

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南京农业大学学报 2025年第1期48卷 161-170页

作者：吴建杨文孟孜查成万吴望军南京农业大学动物科技学院江苏南京210095

[目的]本研究旨在探究猪断奶重、屠宰前活体重、背膘厚等性状因素对猪肌内脂肪(intramuscular fat,IMF)含量的影响,确定影响猪IMF含量的关键性状因素。[方法]以805头皮特兰×[杜洛克×(长白×大白)]四元商品猪群为试验对象,记录性别,测... 详细信息

[目的]本研究旨在探究猪断奶重、屠宰前活体重、背膘厚等性状因素对猪肌内脂肪(intramuscular fat,IMF)含量的影响,确定影响猪IMF含量的关键性状因素。[方法]以805头皮特兰×[杜洛克×(长白×大白)]四元商品猪群为试验对象,记录性别,测定初生重、断奶重、屠宰前活体重和IMF含量等14个性状,然后通过相关性分析从14个性状中初步筛选出影响IMF含量的性状因素,再通过随机森林模型评估各性状因素对IMF含量影响的重要性,进一步通过LASSO回归和逐步回归筛选出影响IMF含量的关键性状因素;在此基础上,利用广义线性模型(generalized linear model,GLM)分析关键性状因素不同水平对IMF含量的影响。[结果]相关性分析结果显示,猪IMF含量与断奶重(r=0.13, Pc*值也呈显著相关(P0.05)。胸腰椎结合处背膘厚大于26 mm组的平均IMF含量(2.73%)显著高于其他背膘厚组(P0.05)。[结论]本研究通过机器学习确定了性别、断奶重、屠宰前活体重和胸腰椎结合处背膘厚4个与IMF含量显著相关的活体可测定性状,并发现平均IMF含量随着屠宰前活体重和胸腰椎结合处背膘厚的增加呈明显的上升趋势。

关键词：猪肌内脂肪间接选择模型构建机器学习活体可测定性状

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