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Fabrication and analysis of TIG welding-brazing butt joints of in-situ TiB2/7050 composite and TA2

Defence Technology（防务技术） 2021年第3期17卷 1062-1070页

作者： Huan-huan Sun Yi-bo Ren Yang Feng Hao-qiang Ba Dong Chen chun-juan xia Hao-wei Wang School of Materials Science&Engineering Shenyang Ligong UniversityShenyangChina School of Materials Science&Engineering Shanghai Jiao Tong UniversityShanghaiChina

Lightweight hybrid structures of Al MMCs and titanium alloy dissimilar materials have great prospect in the defence industry application. So, it is necessary to join Al MMCs with Ti metal to achieve this structural design. In this work, in-situ Ti B_(2)/7050 composite and TA2 were firstly attempted to join by TIG welding-brazing technique. The result was that the intact welding-brazing butt joint was successfully fabricated. The joint presents dual characteristics, being a brazing on TA2 side and a welding on Ti B_(2)/7050 side. At brazing joint side, ER4043 filler metal effectively wets on TA2 under TIG heating condition,and a continuous interfacial reaction layer with 1 e3 mm is formed at welded metal/TA2 interface. The whole interfacial reaction layers are composed of Ti(Al Si)3 intermetallic compounds(IMCs), but their morphologies at the different regions present obvious distinguishes. The microhardness of the reaction layers is as much as 141 e190 HV. At welding joints side, the fusion zone appears the equixaed crystal structure, and the grain sizes are much smaller than those of welded metal, which is attributed to the effect of Ti B2 particulates from the melted Ti B_(2)/7050 on acceleration formation and inhibiting growth for the new crystal nucleus. The tensile test results show that average tensile strength of the optimal welding-brazing joint is able to achieve 138 MPa. The failure of the tensile joint occurs by quasi-cleavage pattern, and the cracks initiate from the IMCs layer at the groove surface of TA2 and propagate into the welded metal.

关键词： In-situ TiB2/7050 composite TA2 TIG welding-brazing Fabrication Analysis

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Efficient and Stable Photoassisted Lithium-Ion Battery Enabled by Photocathode with Synergistically Boosted Carriers Dynamics

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NANO-MICRO LETTERS 2025年第1期17卷 1-15页

作者： Ma, Zelin Wang, Shiyao Ma, Zhuangzhuang Li, juan Zhao, Luomeng Li, Zhihuan Wang, Shiyuan Shuang, Yazhou Wang, Jiulong Wang, Fang xia, Weiwei Jian, Jie He, Yibo Wang, Junjie Guo, Pengfei Wang, Hongqiang Northwestern Polytech Univ Ctr Nano Energy Mat State Key Lab Solidificat Proc Sch Mat Sci & Engn Xian 710072 Peoples R China NPU Shaanxi Joint Lab Graphene Xian 710072 Peoples R China Northwestern Polytech Univ Sch Mat Sci State Key Lab Solidificat Proc Xian 710072 Peoples R China Northwestern Polytech Univ Engn Dept Xian 710072 Peoples R China Northwestern Polytech Univ Ctr Adv Lubricat & Seal Mat Sch Mat Sci & Engn State Key Lab Solidificat Proc Xian 710072 Peoples R China Northwestern Polytech Univ Shenzhen Res & Dev Inst Shenzhen 518063 Peoples R China Shaanxi Normal Univ Key Lab Appl Surface & Colloid Chem Shaanxi Engn Lab Adv Energy Technol Shaanxi Key Lab Adv Energy DevicesSch Mat Sci & E Xian 710119 Peoples R China

Efficient and stable photocathodes with versatility are of significance in photoassisted lithium-ion batteries (PLIBs), while there is always a request on fast carrier transport in electrochemical active photocathodes. Present work proposes a general approach of creating bulk heterojunction to boost the carrier mobility of photocathodes by simply laser assisted embedding of plasmonic nanocrystals. When employed in PLIBs, it was found effective for synchronously enhanced photocharge separation and transport in light charging process. Additionally, experimental photon spectroscopy, finite difference time domain method simulation and theoretical analyses demonstrate that the improved carrier dynamics are driven by the plasmonic-induced hot electron injection from metal to TiO2, as well as the enhanced conductivity in TiO2 matrix due to the formation of oxygen vacancies after Schottky contact. Benefiting from these merits, several benchmark values in performance of TiO2-based photocathode applied in PLIBs are set, including the capacity of 276 mAh g(-1 ) at 0.2 A g(-1 )under illumination, photoconversion efficiency of 1.276% at 3 A g(-1 ), less capacity and Columbic efficiency loss even through 200 cycles. These results exemplify the potential of the bulk heterojunction strategy in developing highly efficient and stable photoassisted energy storage systems.

关键词： Photoassisted lithium-ion batteries Bulk heterojunction Carrier dynamics TiO2 nanofiber Plasmonic metal nanocrystals

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超声引导经胸穿刺活检周围型肺病变的影响因素及临床价值

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中国现代医学杂志 2020年第18期30卷 72-76页

作者：卜锐夏要友夏春娟陆健斐王燕李卓原赵鹤仙昆明医科大学第二附属医院超声医学科云南昆明650101 昆明医科大学第二附属医院病理科云南昆明650101

目的探讨超声引导经胸穿刺活检周围型肺病变的影响因素、穿刺技巧及安全性。方法回顾性分析177例可疑周围型肺病变患者行超声引导经胸穿刺活检的病理结果,分析患者年龄、性别、穿刺体位、穿刺部位、病灶大小、穿刺角度、穿刺针数及穿刺... 详细信息

目的探讨超声引导经胸穿刺活检周围型肺病变的影响因素、穿刺技巧及安全性。方法回顾性分析177例可疑周围型肺病变患者行超声引导经胸穿刺活检的病理结果,分析患者年龄、性别、穿刺体位、穿刺部位、病灶大小、穿刺角度、穿刺针数及穿刺针型号对穿刺有效率的影响。结果病理做出明确诊断患者153例,穿刺无效24例,穿刺有效率为86.44%。病灶大小>50mm及26~50mm的患者穿刺有效率高于病灶大小0.05)。177例患者穿刺术后并发症总发病率为5.65%(10/177),其中气胸3例(1.69%)、胸膜反应5例(2.82%)、咳血痰2例(1.13%)。结论病灶大小、穿刺时患者体位是影响超声引导经胸穿刺活检有效率的主要因素,应规范各项操作,为周围型肺病变的临床诊疗提供可靠的依据。

关键词：超声疗法穿刺术周围型肺病变

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Finiteness Conditions and Relative Singularity Categories

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Acta Mathematica Sinica,English Series 2022年第8期38卷 1436-1446页

作者： chun xia ZHANG School of Mathematical Sciences Chongqing Normal UniversityChongqing 401331P.R.China

We introduce the n-pure projective(resp.,injective)dimension of complexes in n-pure derived categories,and give some criteria for computing these dimensions in terms of the n-pure projective(resp.,injective)resolutions(resp.,coresolutions)and n-pure derived *** a consequence,we get some equivalent characterizations for the finiteness of n-pure global dimension of ***,we study Verdier quotient of bounded n-pure derived category modulo the bounded homotopy category of n-pure projective modules,which is called an n-pure singularity category since it can reflect the finiteness of n-pure global dimension of rings.

关键词： n-pure projective dimension n-pure injective dimension n-pure global dimension n-pure derived category n-pure singularity category

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RiMOM-IM： A Novel Iterative Framework for Instance Matching

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Journal of Computer Science & Technology 2016年第1期31卷 185-197页

作者： Chao Shao Lin-Mei Hu juan-Zi Li Zhi-chun Wang Tonglee chung Jun-Bo xia Department of Computer Science and Technology Tsinghua University Beijing 100084 China College of Information Science and Technology Beijing Normal University Beijing 100875 China

Instance matching, which aims at discovering the correspondences of instances between knowledge bases, is a fundamental issue for the ontological data sharing and integration in Semantic Web. Although considerable instance matching approaches have already been proposed, how to ensure both high accuracy and efficiency is still a big challenge when dealing with large-scale knowledge bases. This paper proposes an iterative framework, RiMOM-IM （RiMOM-Instance Matching）. The key idea behind this framework is to fully utilize the distinctive and available matching information to improve the efficiency and control the error propagation. We participated in the 2013 and 2014 competition of Ontology Alignment Evaluation Initiative （OAEI）, and our system was ranked the first. Furthermore, the experiments on previous OAEI datasets also show that our system performs the best.

关键词： instance matching large-scale knowledge base blocking similarity aggregation

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Optimal timing of invasive intervention for high-risk non-ST-segment-elevation myocardial infarction patients

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Journal of Geriatric Cardiology 2024年第8期21卷 807-815页

作者： juan-juan ZHENG Yue-Qiao SI Tian-Yang xia Bing-Jun LU chun-Yu ZENG Wei-Eric WANG Department of Geriatrics Southwest HospitalThird Military Medical UniversityChongqingChina Department of Cardiology Daping HospitalThird Military Medical UniversityChongqingChina

OBJECTIVE To compare the immediate,early,and delayed percutaneous coronary intervention(PCI)strategies in non-ST-segment-elevation myocardial infarction(NSTEMI)patients with *** Medical records of patients treated at the Daping Hospital,Third Military Medical University,Chongqing,China between 2011 and 2021 were retrospectively *** patients with complete available information were *** patients assigned into three groups based on the timing of PCI including immediate(<2 h),early(2–24 h)and delayed(≥24 h)*** Cox hazards regression and simpler nonlinear models were *** A total of 657 patients were included in the *** median follow-up length was 3.29(interquartile range:1.45–4.85)*** PCI strategy improved the major adverse cardiac event(MACE)outcome compared to the immediate or delayed PCI *** PCI,diabetes mellitus,and left main or/and left anterior descending or/and left circumflex stenosis or/and right coronary artery≥99%were predictors for MACE *** optimal timing range for PCI to reduce MACE risk is 3–14 h *** high-risk NSTEMI patients,early PCI reduced primary clinical outcomes compared to immediate or delayed PCI,and the optimal timing range was 3–14 h *** PCI was superior for NSTEMI with chronic kidney *** Delayed invasive strategy was helpful to reduce the incidence of MACE for high-risk NSTEMI with chronic kidney *** immediate PCI strategy might increase the rate of MACE.

关键词： patients infarction Chongqing

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Feature analysis on US military aircraft engine advanced technology programs

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航空动力学报 2014年第7期29卷 1701-1709页

作者： LIANG chun-hua SUN Ming-xia LIU Hong-xia Shenyang Engine Design and Research Institute Aviation Industry Corporation of China

US military aircraft engine advanced technology programs were overviewed and analyzed from light weight gas generator(LWGG)program initiated in 1960 sthrough integrated high performance turbine engine technology(IHPTET)program started in 1980 s,then to versatile affordable advanced turbine engine(VAATE)*** features and trends were summarized and concluded by literature statistics method,such as teams based on closely corporation among government,industries and academics,goals oriented with national defence strategies and weapon system development requirements,engineering manufacture and development including all relative disciplines and areas,verification measured by technology readiness level,the application extending to military aircraft engine,civilian engine,gas turbine and space vehicle,*** experience and lessons obtained can provide reference and guide for technology research and engineering manufacture and development of military aircraft engines in the world.

关键词： aircraft engine military aircraft engine advanced technology program technology corporation multi-discipline development technology verification

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Analysis on capabilities of density-based solvers within OpenFOAM to distinguish aerothermal variables in difusion boundary layer

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Chinese Journal of Aeronautics 2013年第6期26卷 1370-1379页

作者： Shen chun Sun Fengxian xia Xinlin School of Energy Science and Engineering Harbin Institute of Technology School of Power and Energy Science Harbin Engineering University

Open source feld operation and manipulation（OpenFOAM）is one of the most prevalent open source computational fluid dynamics（CFD）*** is very convenient for researchers to develop their own codes based on the class library toolbox within *** recent years,several density-based solvers within OpenFOAM for supersonic/hypersonic compressible flow are coming *** the capabilities of these solvers to capture shock wave have already been verifed by some researchers,these solvers still need to be validated comprehensively as commercial CFD *** boundary layer where diffusion is the dominant transportation manner,the convective discrete schemes＇capability to capture aerothermal variables,such as temperature and heat flux,is different from each other due to their own numerical dissipative characteristics and from viewpoint of this capability,these compressible solvers within OpenFOAM can be validated *** this paper,frstly,the organizational architecture of density-based solvers within OpenFOAM is ***,from the viewpoint of the capability to capture aerothermal variables,the numerical results of several typical geometrical felds predicted by these solvers are compared with both the outcome obtained from the commercial software Fastran and the experimental *** the computing process,the Roe,AUSM＋（Advection Upstream Splitting Method）,and HLLC（Harten-Lax-van Leer-Contact）convective discrete schemes of which the spatial accuracy is 1st and 2nd order are utilized,*** compared results show that the aerothermal variables are in agreement with results generated by Fastran and the experimental data even if the1st order spatial precision is ***,the accuracy of these density-based solvers can meet the requirement of engineering and scientifc problems to capture aerothermal variables in diffusion boundary layer.

关键词： Aerothermal variables Boundary layer Computational fluid dynamics(CFD) Heat flux Open source Supersonic

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Improved RIP-based performance guarantees for multipath matching pursuit

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Science China(Information Sciences) 2018年第10期61卷 173-186页

作者： juan ZHAO xia BAI Ran TAO School of Information and Electronics Beijing Institute of Technology Beijing Key Laboratory of Fractional Signals and Systems Beijing Institute of Technology

The multipath matching pursuit(MMP) is a generalization of the orthogonal matching pursuit(OMP), which generates multiple child paths for every candidate in each iteration and selects the candidate having the minimal residual as the final support set when iteration ends. In this paper we analyze its performance in both noiseless and noisy cases. The restricted isometry property(RIP)-based condition of MMP that ensures accurate recovery of sparse signals in the noiseless case is derived by using a simple technique. The performance guarantees of the MMP for support recovery in noisy cases are also *** is shown that under certain conditions on the RIP and minimum magnitude of nonzero components of the sparse signal, the MMP will exactly recover the true support of the sparse signal in cases of bounded noises and recover the true support with a high probability in the case of Gaussian noise. Our bounds on the RIP improve the existing results.

关键词： compressed sensing(CS) sparse signal reconstruction multipath matching pursuit(MMP) support recovery restricted isometry property(RIP)

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Multiplicity of Solutions for Quasilinear Elliptic Systems with Singularity

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Acta Mathematicae Applicatae Sinica 2015年第1期31卷 277-286页

作者： juan LI Yu-xia TONG Department of Mathematics Ningbo University College of Science Heibei United University

In this paper, we study the existence of multiple solutions for the following quasilinear ellipticsystem：-△pu-μ1︳u︳p-1u/︳x︳=α1up（t）-2/︳x︳t＋β1︳v︳β2︳u︳β1-2u,x∈Ω,-△qu-μ2︳v︳q-2v/︳x︳q=α2 vq（s）-2/︳x︳sv＋β2︳u︳β1︳v︳β2-2v,x∈Ω u（x）=v（x）=0 x∈Ω Multiplicity of solutions for the quasilinear problem is obtained via variational method.

关键词： quasilinear elliptic system singularity critical growth

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