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Towards high-strength cold spray additive manufactured metals:Methods,mechanisms,and properties

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Journal of Materials Science & Technology 2024年第3期170卷 47-64页

作者： Shuo Yin Ningsong Fan Chunjie Huang Yingchun Xie Chao Zhang Rocco Lupoi Wenya Li Department of Mechanical Manufacturing&Biomedical EngineeringParsons BuildingTrinity College DublinThe University of DublinDublin 2Ireland Institute of Materials Technology Helmut-Schmidt-University/University of the Federal Armed Forces HamburgHamburg 22043Germany The Key Lab of Guangdong for Modern Surface Engineering Technology National Engineering Laboratory for Modern Materials Surface Engineering TechnologyInstitute of New MaterialsGuangdong Academy of SciencesGuangzhou 510651China College of Mechanical Engineering Yangzhou UniversityYangzhou 225127China State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Friction Welding TechnologiesNorthwestern Polytechnical UniversityXi’an 720072China

Cold spray,as a solid-state additive manufacturing process,has been attracting increasing attention from both scientific and industrial ***,cold-sprayed deposits generally have unfavorable mechanical properties in their as-fabricated state compared to conventionally manufactured and fusion-based additive-manufactured counterparts due to the inherent microstructural defects in the deposits(e.g.,porosity and incomplete interparticle bonding).This downside reduces its competitiveness and limits its wide applications as an additive manufacturing *** the past years,many strengthening technologies have been developed or introduced to adjust the microstructure and improve the mechanical properties of cold-sprayed *** term“strengthening”in this work specifically refers to improving the mechanical strength,particularly the tensile strength of the cold-sprayed bulk *** to the stage that the strengthening technologies are used in the cold spray process,they can be classified into three categories:pre-process(e.g.,powder heat treatment),in-process(e.g.,powder heating,in-situ micro-forging,laser-assisted cold spray),and post-process(e.g.,post heat treatment,hot isostatic pressing,hot rolling,friction stir processing).Therefore,a comprehensive review of these strengthening technolo-gies is conducted to illuminate the possible correlations between the strengthening mechanisms and the resultant deposit microstructures and mechanical *** review paper aims to help researchers and engineers well understand the different strengthening methods and provide guidance for the cold spray community to develop new strengthening strategies for future high-quality mass production.

关键词： Cold spray Additive manufacturing Strengthening Microstructure Ductility Tensile strength

Deformable microlaser force sensing

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Light(Science & Applications) 2024年第6期13卷 1196-1209页

作者： Eleni Dalaka Joseph SHill Jonathan H.H.Booth Anna Popczyk Stefan R.Pulver Malte C.Gather Marcel Schubert Centre of Biophotonics SUPASchool of Physics and AstronomyUniversity of St AndrewsNorth HaughSt AndrewsUK humboldt Centre for Nano-and Biophotonics Department of ChemistryUniversity of CologneKölnGermany School of Psychology and Neuroscience University of St AndrewsSt Mary’s QuadSouth StreetSt AndrewsUK Institute for Bioengineering of Catalonia BarcelonaSpain

Mechanical forces are key regulators of cellular behavior and function,affecting many fundamental biological processes such as cell migration,embryogenesis,immunological responses,and pathological *** force sensors and imaging techniques have been developed to quantify these otherwise invisible forces in single cells and in ***,current techniques rely heavily on high-resolution microscopy and do not allow interrogation of optically dense tissue,reducing their application to 2D cell cultures and highly transparent biological ***,we introduce DEFORM,deformable microlaser force sensing,a spectroscopic technique that detects sub-nanonewton forces with unprecedented spatio-temporal *** is based on the spectral analysis of laser emission from dye-doped oil microdroplets and uses the force-induced lifting of laser mode degeneracy in these droplets to detect nanometer *** validation by atomic force microscopy and development of a model that links changes in laser spectrum to applied force,DEFORM is used to measure forces in 3D and at depths of hundreds of microns within tumor spheroids and late-stage Drosophila *** furthermore show continuous force sensing with single-cell spatial and millisecond temporal resolution,thus paving the way for non-invasive studies of biomechanical forces in advanced stages of embryogenesis,tissue remodeling,and tumor invasion.

关键词： invasion otherwise hundreds

Photoinduced Radical-Ionic Transfer of Various Chlorofluorocarbons to Alkenes from Oxime-Based Surrogates

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CCS Chemistry 2024年第5期6卷 1222-1230页

作者： Jinghui Zhang Muliang Zhang Martin Oestreich Institut für Chemie Technische Universität Berlin10623 Berlin Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry University of Science and Technology of ChinaHefei 230026

Functional-group-transfer strategies that avoid the use of unsustainable chemicals are attractive for the development of green ***(CFCs)not only contribute to the depletion of the stratospheric ozone layer,but their gaseous nature also poses a serious threat in scientific ***,the design of effective and sustainable alternatives to CFCs is highly ***,a practical CFC transfer platform for the addition of both a fluoroalkyl group and a chlorine substituent across alkenes by a photomediated redox-neutral manifold using bench-stable and easy-to-handle oxime-based surrogates is *** distinct reactivity of these tunable reagents allows for their single-electron reduction to trigger fragmentation driven by benzonitrile formation and loss of carbon *** other fragments released in that step,namely an electrophilic fluoroalkyl radical and a nucleophilic chloride anion,are subsequently transferred onto alkenes by a radical-ionic mechanism to deliver the desired chlorofluorocarbon products.

关键词： alkenes chlorofluorocarbons functionalgroup transfer radical-ionic crossover photoredox catalysis

Porphyrinic Acceptors forFullerene-Free MolecularPhotovoltaics

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CCS Chemistry 2024年第2期6卷 276-296页

作者： Jorge Labella Juan Laforga-Martin Tomás Torres Department of Organic Chemistry Universidad Aut´onoma de Madrid28049 Madrid Institute for Advanced Research in Chemical Sciences Universidad Aut´onoma de MadridMadrid IMDEA—Nanociencia 28049 Madrid

Over the past few years,the development of nonfullerene acceptors(NFAs)has become a prominent focus in both organic and perovskite solar cell(OSCs and PSCs,respectively)research *** this context,porphyrinoids,compounds structurally related to porphyrins,have emerged as promising solar cell *** contrast to the widely used fullerene acceptors,porphyrinoids exhibit strong,broad absorption properties across the UV–vis/NIR spectrum,which can be easily tuned through chemical ***,they can be prepared and derivatized using cost-effective and straightforward methodologies,allowing for convenient adjustments in thin-film morphology,processability,supramolecular organization,and energy ***,these compounds offer higher thermal and photochemical stability,resulting in longer device lifetimes compared to their fullerene-based *** this review,we outline the utilization of porphyrinoids as NFAs in OSCs and PSCs,discussing essential aspects such as design guidelines,molecular properties,and device *** goal is to inspire and further promote the development of n-type porphyrinoids,which have not yet fully unleashed their potential.

关键词： fullerene-free molecular photovoltaics nonfullerene acceptors porphyrinic acceptors n-type porphyrinoids organic and perovskite solar cells

Benefits Realization Management of Computer Vision in Construction:A Missed,Yet Not Lost,Opportunity

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Engineering 2023年第8期27卷 11-13页

作者： Peter E.D.Love Jane Matthews Weili Fang Hanbin Luo School of Civil and Mechanical Engineering Curtin UniversityPerthWA 6845Australia b School of Architecture and Built Environment Deakin University Geelong Waterfront CampusGeelongVIC 3220Australia Department of Civil and Building Systems Technische Universität BerlinBerlin 13156Germany National Center of Technology Innovation for Digital Construction Huazhong University of Science and TechnologyWuhan 430074China School of Civil Engineering and Mechanics Huazhong University of Science and TechnologyWuhan 430074China

*** While the applications of computer visions are varied in construction,research has tended to focus on measuring the accuracy of object detectors such as faster region-based-convolution neural networks(Faster R-CNN)and single shot detector algorithms(SDD)[1].Limited,if any,attention has focused on determining the benefits of such technology in construction beyond the claims that it can help detect problems quickly and *** this point are the numerous review papers that have frequented the literature[2,3].

关键词： faster Management benefits

Applications of object detection networks in high-power laser systems and experiments

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High Power Laser Science and Engineering 2023年第1期11卷 52-60页

作者： Jinpu Lin Florian Haberstroh Stefan Karsch Andreas Döpp Ludwig-Maximilians-Universität München GarchingGermany

The recent advent of deep artificial neural networks has resulted in a dramatic increase in performance for object classification and *** pre-trained with everyday objects,we find that a state-of-the-art object detection architecture can very efficiently be fine-tuned to work on a variety of object detection tasks in a high-power laser *** this paper,three exemplary applications are *** show that the plasma waves in a laser±plasma accelerator can be detected and located on the optical *** plasma wavelength and plasma density are estimated ***,we present the detection of all the peaks in an electron energy spectrum of the accelerated electron beam,and the beam charge of each peak is estimated ***,we demonstrate the detection of optical damage in a high-power laser *** reliability of the object detector is demonstrated over1000 laser shots in each *** study shows that deep object detection networks are suitable to assist online and offline experimental analysis,even with small training *** believe that the presented methodology is adaptable yet robust,and we encourage further applications in Hz-level or kHz-level high-power laser facilities regarding the control and diagnostic tools,especially for those involving image data.

关键词： high repetition rate laser±plasma accelerators machine learning object detection optical diagnostics

Electrochemical Kinetic Modulators in Lithium–Sulfur Batteries:From Defect-Rich Catalysts to Single Atomic Catalysts

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Energy & Environmental Materials 2022年第3期5卷 731-750页

作者： Jing Zhang Caiyin You Hongzhen Lin Jian Wang School of Materials Science and Engineering Xi’an University of TechnologyXi’an 710048China i-Lab Suzhou Institute of Nano-tech and Nano-bionicsChinese Academy of SciencesSuzhou 215123China Helmholtz Institute Ulm(HIU) Ulm D89081Germany

Lithium–sulfur batteries exhibit unparalleled merits in theoretical energy density(2600 W h kg^(-1))among next-generation storage ***,the sluggish electrochemical kinetics of sulfur reduction reactions,sulfide oxidation reactions in the sulfur cathode,and the lithium dendrite growth resulted from uncontrollable lithium behaviors in lithium anode have inhibited high-rate conversions and uniform deposition to achieve high *** to the“adsorption-catalysis”synergetic effects,the reaction kinetics of sulfur reduction reactions/sulfide oxidation reactions composed of the delithiation of Li_(2)S and the interconversions of sulfur species are propelled by lowering the delithiation/diffusion energy barriers,inhibiting polysulfide ***,the anodic plating kinetic behaviors modulated by the catalysts tend to uniformize without dendrite *** this review,the various active catalysts in modulating lithium behaviors are summarized,especially for the defect-rich catalysts and single atomic *** working mechanisms of these highly active catalysts revealed from theoretical simulation to in situ/operando characterizations are also ***,the opportunities of future higher performance enhancement to realize practical applications of lithium–sulfur batteries are prospected,shedding light on the future practical development.

关键词： defect-rich catalyst electrochemical kinetic modulation in situ/operando characterization lithium–sulfur battery single atomic catalyst

Fabrication of monodispersed B,N co-doped hierarchical porous carbon nanocages through confined etching to boost electrocatalytic oxygen reduction

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Nano Research 2023年第1期16卷 290-298页

作者： Xuefei Wang Chao Han Haitao Li Panpan Su Na Ta Yanfu Ma Zhenguo Huang Jian Liu School of Civil&Environmental Engineering University of Technology SydneySydneyNSW2007Australia State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China DICP-Surrey Joint Centre for Future Materials University of Surrey GuildfordSurreyGU27XHUK

Dual heteroatom-doped carbons have attracted widespread research attention as catalysts in the field of energy storage and conversion due to their unique electronic structures and chemical *** particular,boron and nitrogen co-doped carbon(B,N@C)has shown great potential for photo/electrocatalytic ***,more needs to be done for rational designing and regulating the structure of these materials to improve their catalytic ***,monodispersed hierarchical porous B,N@C nanocages were fabricated by pyrolyzing zeolite imidazole framework(ZIF)which was treated with ammonia borane or boric acid via an integrated double-solvent impregnation and nanocofined-etching *** treated ZIF-8 provided an essential structural template to achieve B,N co-doped hierarchical structures with micro/meso/macro multimodal pore size *** resultant B,N@C nanocages displayed high catalytic activities for electrochemical oxygen reduction reaction(ORR)in alkaline media,outperforming most carbon-based catalysts,particularly from the perspective of the half-wave *** high catalytic performance is due to the enhanced activity by the coexistence of B and N and the mass transfer promoted by the unique hierarchical porous structure.

关键词： heteroatom doping hierarchical porous carbon host-guest chemistry confined etching electrocatalysis mass transfer

Thermal cycling creep properties of a directionally solidified superalloy DZ125

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Journal of Materials Science & Technology 2022年第9期104卷 269-284页

作者： Wenrui An Satoshi Utada Xiaotong Guo Stoichko Antonov Weiwei Zheng Jonathan Cormier Qiang Feng Beijing Advanced Innovation Center for Materials Genome Engineering State Key Laboratory for Advanced Metals and MaterialsUniversity of Science and Technology BeijingBeijing 100083China Institut Pprime UPR CNRS 3346Department of Physics and Mechanics of MaterialsISAE-ENSMABP4010986961 Futuroscope Chasseneuil CedexFrance China Electronic Product Reliability and Environmental Testing Research Institute Guangzhou 510610China Department of Microstructure Physics and Alloy Design Max-Planck-Institut für Eisenforschung GmbHDüsseldorf 40237Germany

Aero-engine turbine blades may suffer overheating during service,which can result in severe microstructural and mechanical degradation within tens of *** this study,the thermal cycling creep under(950℃/15 min+1100℃/1 min)-100 MPa was performed on a directionally solidified superalloy,*** effects of overheating and thermal cycling on the creep properties were evaluated in terms of creep behavior and microstructural evolution against isothermally crept specimens under 950℃/100 MPa,950℃/270 MPa,and 1100℃/100 *** results indicated that the thermal cycling creep life was reduced dramatically compared to the isothermal creep under 950℃/100 *** plastic creep deformation mainly occurred during the overheating stage during the thermal cycling *** thermal cycling creep curve exhibited three stages,similar to the 1100℃isothermal creep,but its minimum creep rate occurred at a lower creep *** overheating events caused severe microstructural degradation,such as substantial dissolution ofγ'phase,earlier formation of raftedγ'microstructure,widening of theγchannels,and instability of the interfacial dislocation *** microstructural degradation was the main reason for the dramatic decrease in thermal cycling creep life,as the thermal cycling promoted more dislocations to cut intoγ'phase and more cracks to initiate at grain boundaries,carbides,and residual eutectic *** study underlines the importance of evaluating the thermal cycling creep properties of superalloys to be used as turbine blades and provides insights into the effect of thermal cycling on directionally solidified superalloys for component design.

关键词： Directional solidified superalloy Thermal cycling creep Overheating Creep properties Microstructural degradation