检索结果-南通市图书馆

Influence of B4c and ZrB2 reinforcements on microstructural,mechanical and wear behaviour of AA 2014 aluminium matrix hybrid composites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第10期40卷 242-254页

作者： ramesh Babu r rajendran c Saiyathibrahim A rajkumar Velu Department of Mechanical Engineering Karpagam Institute of TechnologyCoimbatore 641105India Department of Mechanical Engineering Sri Krishna College of Engineering and TechnologyCoimbatore 641008India Department of Mechanical Engineering Indian Institute of Technology JammuJammu and Kashmir 181221India

considering their affordability and high strength-to-weight ratio,lightweight aluminium alloys are the subject of intensive research aimed at improving their properties for use in the aerospace *** research effort aims to develop novel hybrid composites based on AA 2014 alloy through the use of liquid metallurgy stir casting to reinforce dual ceramic particles of Zirconium Diboride(ZrB_(2))and Boron carbide(B4c).The weight percentage(wt%)of ZrB_(2) was varied(0,5,10,and 15),while a constant 5 wt%of B4c was maintained during this *** as-cast samples have been assessed using an Optical Microscope(OM)and a Scanning Electron Microscope(SEM)with Energy Dispersive Spectroscopy(EDS).The properties such as hardness,tensile strength,and wear characteristics of stir cast specimens were assessed to examine the impact of varying weight percentages of reinforcements in AA 2014 *** particular,dry sliding wear behaviour was evaluated considering varied loads using a pin-on-disc *** the weight%of ZrB_(2) grew and B4c was incorporated,hybrid composites showed higher hardness,tensile strength,and wear ***,the incorporation of a cumulative reinforcement consisting of 15 wt%ZrB_(2) and 5 wt%B4c resulted in a significant 31.86%increase in hardness and a 44.1%increase in tensile strength compared to AA 2014 *** addition,it has been detected that wear resistance of hybrid composite pin(containing 20 wt%cumulative reinforcement)is higher than that of other stir cast wear test pins during the whole range of applied *** surfaces of tensile specimens showed ductile fracture in the AA 2014 matrix and mixed mode for hybrid *** surfaces obtained employing higher applied load indicated abrasive wear with little plastic deformation for hybrid composites and dominant adhesive wear for matrix ***,the superior mechanical and tribological performance of hybrid composites can be attributed to dual reinforcement pa

关键词： AA 2014 alloy Stir casting Hybrid composite Hardness Tensile strength Specific wear rate

Bile acid signaling in the regulation of whole body metabolic and immunological homeostasis

在线全文

学校读者我要写书评

暂无评论

Science china(life Sciences) 2024年第5期67卷 865-878页

作者： Wei Jia Yitao li Kenneth c.p.cheung Xiaojiao Zheng School of chinese Medicine Hong Kong Baptist UniversityHong KongChina center for Translational Medicine and Shanghai Key Laboratory of Diabetes Mellitus Shanghai Sixth People's Hospital Affiliated to Shanghai JiaoTong University School of MedicineShanghai 200233China

Bile acids(BAs)play a crucial role in nutrient absorption and act as key regulators of lipid and glucose metabolism and immune *** the enterohepatic circulation,BAs are synthesized,metabolized,and reabsorbed,with a portion entering the vascular circulation and distributing *** allows BAs to interact with receptors in all major organs,leading to organ-organ interactions that regulate both local and global metabolic processes,as well as the immune *** review focuses on the whole-body effects of BA-mediated metabolic and immunological regulation,including in the brain,heart,liver,intestine,eyes,skin,adipose tissue,and *** BA synthesis and receptor signaling is a promising strategy for the development of novel therapies for various diseases throughout the body.

关键词： bile acid whole body metabolism immunity

convergent plate boundary environments for formation of≥3800 Ma mafic-ultramafic assemblages(Isua area,Greenland):Implications for early global geodynamics

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2024年第3期15卷 119-136页

作者： Allen p.Nutman clark r.L.Friend Vickie c.Bennett School of Earth Atmospheric and Life SciencesUniversity of WollongongWollongongNSW 2522Australia Glendale TiddingtonOxon OX92LQUK research School of Earth Sciences Australian National UniversityCanberraACT 2601Australia

In the gneiss terrane on the south side of the Eoarchean Isua supracrustal belt,ultramafic rocks with relict abyssal peridotite mineralogy(Bennett et al.,2002;Friend et al.,2002;Nutman et al.,2007;rollinson,2007;van de Löcht et al.,2020),layered gabbros with cumulate ultramafic rocks,basalts and associated siliceous sedimentary rocks were tectonically-imbricated,prior to and during intrusion of ca.3800 Ma *** with3800 Ma basalts in the Outer Arc Group of the nearby Isua supracrustal belt,the composition of all these mafic rocks(e.g.,Th-Hf-Nb systematics,high Th/Yb,Ba/Nb,Ba/Yb ratios and negative Nb and Ti anomalies)shows affinity with modern suprasubduction rocks whose genesis involved fluid fluxing of the upper ***,the majority of these samples have Ba/Nb and Ba/Yb values less than in modern island arc magmas,but similar to many backarc basin magmas(e.g.,pearce and Stern,2006).It is unknown whether these ca.3800 Ma mafic rocks are,(i)arc rocks where the Ba/Nb and Ba/Yb signatures reflect lower surficial Ba in Eoarchean oceanic settings,or(ii)in direct comparison with phanerozoic suites,these signatures reflect a back-arc setting with interplay between fluid fluxing and decompressional *** tectonic intercalation of upper mantle with lower and upper crustal rocks,combined with the fluid-fluxing influences seen in chemistry of all the mafic rocks is best accommodated in a compressional Eoarchean convergent plate boundary setting within a mobile-lid *** stagnant lid scenarios of crust formation,if operative,must have co-existed or alternated with mobile-lid regimes by 3800 Ma.

关键词： Eoarchean Fluid-fluxing plate tectonics Suprasubduction crustal evolution

Single atom cu-N-c catalysts for the electro-reduction of cO_(2) to cO assessed by rotating ring-disc electrode

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2024年第1期88卷 169-182,I0004页

作者： S.pérez-rodríguez M.Gutiérrez-roa c.Giménez-rubio D.ríos-ruiz p.Arévalo-cid M.V.Martínez-Huerta A.Zitolo M.J.Lázaro D.Sebastián Instituto de carboquímica(cSIc) Miguel Luesma Castán 450018 ZaragozaSpain Instituto de catálisis y petroleoquímica(cSIc) Marie Curie 228049 MadridSpain Synchrotron SOLEIL L’Orme des MerisiersDépartementale 12891190France

The electrochemical cO_(2) reduction reaction(cO_(2)rr) to controllable chemicals is considered as a promising pathway to store intermittent renewable energy. Herein, a set of catalysts based on copper-nitrogendoped carbon xerogel(cu-N-c) are successfully developed varying the copper amount and the nature of the copper precursor, for the efficient cO_(2)rr. The electrocatalytic performance of cu-N-c materials is assessed by a rotating ring-disc electrode(rrDE), technique still rarely explored for cO_(2)rr. For comparison, products are also characterized by online gas chromatography in a H-cell. The as-synthesized cu-Nc catalysts are found to be active and highly cO selective at low overpotentials(from -0.6 to -0.8 V ***) in 0.1 M KHcO_(3), while H_(2) from the competitive water reduction appears at larger overpotentials(-0.9 V vs. rHE). The optimum copper acetate-derived catalyst containing cu-N_(4) moieties exhibits a cO_(2)-to-cO turnover frequency of 997 h^(-1) at -0.9 V vs. rHE with a H_(2)/cO ratio of 1.8. These results demonstrate that rrDE configuration can be used as a feasible approach for identifying electrolysis products from cO_(2)rr.

关键词： cu-N-c carbon xerogel rotating ring disc electrode carbon dioxide reduction reaction carbon monoxide

Dynamic Event-Triggered consensus control for Input constrained Multi-Agent Systems With a Designable Minimum Inter-Event Time

在线全文

学校读者我要写书评

暂无评论

IEEE/cAA Journal of Automatica Sinica 2024年第3期11卷 649-660页

作者： Meilin li Yue Long Tieshan li Hongjing liang c.L.philip chen the School of Automation Engineering University of Electronic Science and Technology of ChinaChengdu 611731China IEEE the Yangtze Delta region Institute University of Electronic Science and Technology of ChinaHuzhou 313000 the Laboratory of Electromagnetic Space cognition and Intelligent control Beijing 100089China the School of computer Science and Engineering South China University of TechnologyGuangzhou 510006

This paper investigates the consensus control of multi-agent systems(MASs) with constrained input using the dynamic event-triggered mechanism(ETM).consider the MASs with small-scale networks where a centralized dynamic ETM with global information of the MASs is first ***,a distributed dynamic ETM which only uses local information is developed for the MASs with large-scale *** is shown that the semi-global consensus of the MASs can be achieved by the designed bounded control protocol where the Zeno phenomenon is eliminated by a designable minimum inter-event *** addition,it is easier to find a trade-off between the convergence rate and the minimum inter-event time by an adjustable ***,the results are extended to regional consensus of the MASs with the bounded control *** simulations show the effectiveness of the proposed approach.

关键词： constrained input designable minimum inter-event time directed communication topology dynamic event-triggered mechanism MASs consensus control

LpcS Ni-Zn-Al_(2)O_(3) Intermediate Layer Enhanced SpS Nicr-cr_(3)c_(2) coating with Higher corrosion and Wear resistances

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 188-195页

作者：白杨 li Yan XING Lukuo li Xiangbo WANG Zhenhua State Key Laboratory of Marine coatings Marine Chemical Research Institute Co.Ltd.Qingdao 266071China college of Mechanical and Electrical Engineering University of China Petroleum(East China)Qingdao 266580China Science and Technology on Marine corrosion and protection Laboratory Luoyang Ship Materials Research InstituteQingdao 266101China

The double-layer Nicr-cr_(3)c_(2)/Ni-Zn-Al_(2)O_(3) coatings with sufficient corrosion and wear resistance were prepared on low carbon steel *** intermediate layers Ni-Zn-Al_(2)O_(3) were fabricated by using low-pressure cold spray (LpcS) method to improve the salt fog corrosion resistance properties of the supersonic plasma spray (SpS) Nicr-cr_(3)c_(2) *** friction and wear performance for the double-layer and single-layer Nicr-cr_(3)c_(2) coatings were carried out by line-contact reciprocating sliding,*** with the coating surface analysis techniques,the effect of the salt fog corrosion on the tribological properties of the double-layer coatings was *** results showed that the double-layer coatings exhibited better wear resistance than that of the single-layer coatings,due to the better corrosion resistance of the intermediate layer;the wear mass losses of the double-layer coatings was reduced by 70%than that of the single layer coatings and the wear mechanism of coatings after salt fog corrosion conditions is mainly corrosion wear.

关键词： low-pressure cold spray Nicr-cr_(3)c_(2)coating wear behavior salt fog corrosion

Industrial Fusion cascade Detection of Solder Joint

在线全文

学校读者我要写书评

暂无评论

computers, Materials and continua 2024年第1期81卷 1197-1214页

作者： li c. Zhang p. Wang S. liu L. Shi M. chongqing School University of Chinese Academy of Sciences Chongqing University Chongqing 400044 China Automatic reasoning and cognition research center Chongqing Institute ofGreen and Intelligent Technology Chinese Academy of Sciences Chongqing 400714 China college of Artificial Intelligence Chongqing School University of Chinese Academy of Sciences Chongqing 400714 China Design Department Liuzhou Fuzhen Bodywork Industrial Co. Ltd. Liuzhou 545006 China

With the remarkable advancements in machine vision research and its ever-expanding applications, scholars have increasingly focused on harnessing various vision methodologieswithin the industrial realm. Specifically, detecting vehicle floor welding points poses unique challenges, including high operational costs and limited portability in practical settings. To address these challenges, this paper innovatively integrates template matching and the Faster rcNN algorithm, presenting an industrial fusion cascaded solder joint detection algorithm that seamlessly blends template matching with deep learning techniques. This algorithm meticulously weights and fuses the optimized features of both methodologies, enhancing the overall detection capabilities. Furthermore, it introduces an optimized multi-scale and multi-template matching approach, leveraging a diverse array of templates and image pyramid algorithms to bolster the accuracy and resilience of object detection. By integrating deep learning algorithms with this multi-scale and multi-template matching strategy, the cascaded target matching algorithm effectively accurately identifies solder joint types and positions. A comprehensive welding point dataset, labeled by experts specifically for vehicle detection, was constructed based on images from authentic industrial environments to validate the algorithm's performance. Experiments demonstrate the algorithm's compelling performance in industrial scenarios, outperforming the single-template matching algorithm by 21.3%, the multi-scale and multitemplate matching algorithm by 3.4%, the Faster rcNN algorithm by 19.7%, and the YOLOv9 algorithm by 17.3% in terms of solder joint detection accuracy. This optimized algorithm exhibits remarkable robustness and portability, ideally suited for detecting solder joints across diverse vehicle workpieces. Notably, this study's dataset and feature fusion approach can be a valuable resource for other algorithms seeking to enhance their

关键词： cascade object detection deep learning feature fusion multi-scale and multi-template matching solder joint dataset

constructing long-cycling crystalline c_(3)N_(4)-based carbonaceous anodes for sodium-ion battery via N configuration control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

carbon Energy 2024年第1期6卷 159-171页

作者： Ying Wang Hongguan li Shuanlong Di Boyin Zhai ping Niu Antonios Kelarakis Shulan Wang li li School of Metallurgy Northeastern UniversityShenyangLiaoningChina State Key Laboratory of rolling and Automation Northeastern UniversityShenyangLiaoningChina Department of chemistry College of ScienceNortheastern UniversityShenyangLiaoningChina School of Natural Sciences UCLan Research Centre for Smart MaterialsUniversity of Central LancashirePrestonUK Foshan Graduate School of Innovation Northeastern UniversityFoshanGuangdongChina

carbon nitrides with two-dimensional layered structures and high theoretical capacities are attractive as anode materials for sodium-ion batteries while their low crystallinity and insufficient structural stability strongly restrict their practical *** carbon nitrides with conductive carbon may relieve these ***,little is known about the influence of nitrogen(N)configurations on the interactions between carbon and c_(3)N_(4),which is fundamentally critical for guiding the precise design of advanced c_(3)N_(4)-related ***,highly crystalline c_(3)N_(4)(poly(triazine imide),pTI)based all-carbon composites were developed by molten salt *** importantly,the vital role of pyrrolic-N for enhancing charge transfer and boosting Na+storage of c_(3)N_(4)-based composites,which was confirmed by both theoretical and experimental evidence,was spot-highlighted for the first *** elaborately controlling the salt composition,the composite with high pyrrolic-N and minimized graphitic-N content was *** from the formation of highly crystalline pTI and electrochemically favorable pyrrolic-N configurations,the composite delivered an unusual reverse growth and record-level cycling stability even after 5000 cycles along with high reversible capacity and outstanding full-cell capacity *** work broadens the energy storage applications of c_(3)N_(4) and provides new prospects for the design of advanced all-carbon electrodes.

关键词： anode highly crystalline c_(3)N_(4) N configuration sodium-ion batteries ultra-long cyclic stability

Built-in electric field induced S-scheme g-c_(3)N_(4)homojunction for efficient photocatalytic hydrogen evolution:Interfacial engineering and morphology control

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano research 2024年第6期17卷 4961-4970页

作者： Yongpan Gu Yike li Haoqiang Feng Yanan Han Zhongjun li college of chemistry Zhengzhou UniversityZhengzhou 450001China

S-scheme possesses superior redox capabilities compared with the II-scheme,providing an effective method to solve the innate defects of g-c_(3)N_(4)(cN).In this study,S-doped g-c_(3)N_(4)/g-c_(3)N_(4)(ScN-tm/cN)S-scheme homojunction was constructed by rationally integrating morphology control with interfacial engineering to enhance the photocatalytic hydrogen evolution ***-situ Kelvin probe force microscopy(KpFM)confirms the transport of photo-generated electrons from cN to *** functional theory(DFT)calculations reveal that the generation of a built-in electric field between ScN and cN enables the carrier separation to be more efficient and *** transient absorption spectrum(fs-TAS)indicates prolonged lifetimes of ScN-tm/cN_(3)(τ1:9.7,τ2:110,andτ3:1343.5 ps)in comparison to those of cN(τ1:4.86,τ2:55.2,andτ3:927 ps),signifying that the construction of homojunction promotes the separation and transport of electron hole pairs,thus favoring the photocatalytic *** visible light irradiation,the optimized ScN-tm/cN_(3)exhibits excellent photocatalytic activity with the hydrogen evolution rate of 5407.3μmol·g^(−1)·h^(−1),which is 20.4 times higher than that of cN(265.7μmol·g^(−1)·h^(−1)).Moreover,the homojunction also displays an apparent quantum efficiency of 26.8%at 435 nm as well as ultra-long and ultra-stable cycle *** work offers a new strategy to construct highly efficient photocatalysts based on the metal-free conjugated polymeric cN for realizing solar energy conversion.

关键词： homojunction built-in electric field morphology control interfacial engineering carrier separation