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journal of Materials Science & Technology 2022年第5期100卷 150-160页

作者： Dongsen Geng Haiqing Li Ziliang Chen yu.x.xu Qimin Wang School of Electromechanical Engineering Guangdong University of TechnologyGuangzhou 510006China

Achieving high hardness and low friction at elevated temperatures for nitride-based hard coatings has substantial scientific interest and application *** this study,AlCrN/Cu coatings were deposited by a hybrid PVD technique combining arc evaporation from an Al_(60)Cr_(40) target and magnetron sputtering from a Cu target in a mixed Ar and N_(2) *** microstructure,oxidation behavior,and tribological properties of the coatings were ***/Cu coatings show a dual-phase structure of(Al,Cr)N solid solution and Cu metallic *** sputtering power of the Cu target induces the disintegration of interlayer interfaces of the nano-multilayered geometry,accompanied by a decline in hardness from above 30 GPa to 22.7 ***,the formation of fine CuO grains on the coating surface is conducive to reducing the friction coefficient of AlCrN/Cu when exposed to air at high *** AlCrN/Cu coating with a sputtering power of 0.5 kW obtains a friction coefficient of 0.39±0.05 after pre-oxidation at 800℃,distinctly lower than that of AlCrN,which exhibits a friction coefficient of~*** further transformation of CuO to cubic Cu(Al,Cr)_(2)O_(4),which stems from the solid-state reaction of CuO,Al_(2)O_(3),and Cr_(2)O_(3),would cause a rise in friction coefficient and wear *** mechanism of oxidation and tribological behavior of the AlCrN/Cu coatings related to the temperature and Cu content was discussed.

关键词： AlCrN/Cu coatings Microstructure Oxidation Friction

A transmission electron microscopy study of microscopic causes for localized-corrosion morphology variations in the AA7055 Al alloy

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journal of Materials Science & Technology 2018年第10期34卷 1719-1729页

作者： x.B. Yang j.H. Chen G.H. Zhang L.P. Huang T.W. Fan Y. Ding x.W. yu Center for High-Resolution Electron Microscopy College of Materials Sdence and Engineering Hunan University Changsha Hunan 410082 China Department of Applied Physics School of Physics and Electronics Hunan University Changsha Hunan 410082 China

By Using （scanning） transmission electron microscopy, localized-corrosion morphology variations of the AA7055 AIZn（Cu）Mg alloy with different thermal processes and their underlying microscopic causes were investigated systematically. Our study shows that the corrosion resistance of the nanoscale precipitates varies with their structure type and Cu-content. just like the Al-matrix, the early-stage precipitates are corrosion resistant, as compared with the ηp/η-precipitates without high Cu-content. With a high Cu-content, however, the η-precipitates become most corrosion resistant among all phases involved. Hence, tailoring the precipitate microstructure and chemistry though thermal processes may change the overall corrosion morphology and improve corrosion resistance property of the alloy.

关键词： Aluminum alloys Precipitates Corrosion Electron microscopy

Towards a unified nonlocal, peridynamics framework for the coarse-graining of molecular dynamics data with fractures

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Applied Mathematics and Mechanics(English Edition) 2023年第7期44卷 1125-1150页

作者： H.Q.YOU x.xU Y.yu S.SILLING M.D'ELIA j.FOSTER Department of Mathematics Lehigh UniversityBethlehemPA 18015U.S.A Department of Petroleum and Geosystems Engineering The University of Texas at AustinTX 78712-1139U.S.A. Center for Computing Research Sandia National LaboratoriesCA 94551-0969U.S.A.

Molecular dynamics(MD)has served as a powerful tool for designing materials with reduced reliance on laboratory ***,the use of MD directly to treat the deformation and failure of materials at the mesoscale is still largely beyond *** this work,we propose a learning framework to extract a peridynamics model as a mesoscale continuum surrogate from MD simulated material fracture data ***,we develop a novel coarse-graining method,to automatically handle the material fracture and its corresponding discontinuities in the MD displacement data *** by the weighted essentially non-oscillatory(WENO)scheme,the key idea lies at an adaptive procedure to automatically choose the locally smoothest stencil,then reconstruct the coarse-grained material displacement field as the piecewise smooth solutions containing ***,based on the coarse-grained MD data,a two-phase optimizationbased learning approach is proposed to infer the optimal peridynamics model with damage *** the first phase,we identify the optimal nonlocal kernel function from the data sets without material damage to capture the material stiffness ***,in the second phase,the material damage criterion is learnt as a smoothed step function from the data with *** a result,a peridynamics surrogate is *** a continuum model,our peridynamics surrogate model can be employed in further prediction tasks with different grid resolutions from training,and hence allows for substantial reductions in computational cost compared with *** illustrate the efficacy of the proposed approach with several numerical tests for the dynamic crack propagation problem in a single-layer *** tests show that the proposed data-driven model is robust and generalizable,in the sense that it is capable of modeling the initialization and growth of fractures under discretization and loading settings that are different from the ones used during training.

关键词： nonlocal model machine learning homogenization peridynamics material fracture

Annealing-induced Hardening in a Nanostructured Low-carbon Steel Prepared by Using Dynamic Plastic Deformation

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journal of Materials Science & Technology 2014年第8期30卷 731-735页

作者： L.x.Sun N.R.Tao M.Kuntz j.Q.yu K.Lu Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences Corporate Sector Research and Advance Engineering Production Technology 1 Materials and Process Engineering MetalsRobert Bosch GmbHP. O. Box 30 02 4070442 StuttgartGermany Research and Technology Center Asia Pacific Bosch(China) Investment Ltd.

Lamellar nanostructures were induced in a plain martensitic low-carbon steel by using dynamic plastic deformation at room *** nanostructured steel was hardened after annealing at 673 K for20 min,with a tensile strength increased from 1.2 GPa to 1.6 *** the remained nanostructures and annealing-induced precipitates in nano-scale play key roles in the hardening.

关键词： Nanostructure Annealing Precipitation hardening Low-carbon steel Dynamic plastic deformation

Chaos,Transport and Mesh Convergence for Fluid Mixing

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Acta Mathematicae Applicatae Sinica 2008年第3期24卷 355-368页

作者： H. Lim Y. yu j. Glimm x.L. Li D.H. Sharp Department of Applied Mathematics and Statistics Stony Brook University Stony Brook NY 11794-3600 USA Computational Science Center Brookhaven National Laboratory Upton N~ 11793-6000 USA Los Alamos National Laboratory Los Alamos NM USA

Chaotic mixing of distinct fluids produces a convoluted structure to the interface separating these fluids. For miscible fluids （as considered here）, this interface is defined as a 50% mass concentration isosurface. For shock wave induced （Richtmyer-Meshkov） instabilities, we find the interface to be increasingly complex as the computational mesh is refined. This interfacial chaos is cut off by viscosity, or by the computational mesh if the Kolmogorov scale is small relative to the mesh. In a regime of converged interface statistics, we then examine mixing, i.e. concentration statistics, regularized by mass diffusion. For Schmidt numbers significantly larger than unity, typical of a liquid or dense plasma, additional mesh refinement is normally needed to overcome numerical mass diffusion and to achieve a converged solution of the mixing problem. However, with the benefit of front tracking and with an algorithm that allows limited interface diffusion, we can assure convergence uniformly in the Schmidt number. We show that different solutions result from variation of the Schmidt number. We propose subgrid viscosity and mass diffusion parameterizations which might allow converged solutions at realistic grid levels.

关键词： Schmidt number mass diffusion turbulence multiphase flow

Analysis of mesoscale effects in high-shear granulation through a computational fluid dynamics-population balance coupled compartment model

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Particuology 2018年第1期16卷 1-12页

作者： P.j. Abrahamsson P. Kvist G. Reynolds x. yu I. Niklasson Bjorn M.j. Hounslow A. Rasmuson Department of Chemical and Biological Engineering Chalmers University of Technology SE-412 96 Gothenburg Sweden Pharmaceutical Development AstraZeneca Macclesfield SK10 2NA UK European Bioenergy Research Institute (EBRI) School of Engineering and Applied Science Aston University Birmingham B4 7ET UK AstraZeneca Pharmaceutical and Analytical R&D Molndal SE-431 83 Moldnal Sweden Department of Chemical and Biological Engineering University of Sheffield Sheffield SI 3JD UK

There is a need for mesoscale resolution and coupling between flow-field information and the evolution of particle properties in high-shear granulation. We have developed a modelling framework that com- partmentalizes the high-shear granulation process based on relevant process parameters in time and space. The model comprises a coupled-flow-field and population-balance solver and is used to resolve and analyze the effects of mesoscales on the evolution of particle properties. A Diosna high-shear mixer was modelled with microcrystalline cellulose powder as the granulation material. An analysis of the flow-field solution and compartmentalization allows for a resolution of the stress and collision peak at the impeller blades. Different compartmentalizations showed the importance of resolving the impeller region, for aggregating systems and systems with breakage. An independent study investigated the time evolution of the flow field by changing the particle properties in three discrete steps that represent pow- der mixing, the initial granulation stage mixing and the late stage granular mixing. The results of the temporal resolution study show clear changes in collision behavior, especially from powder to granular mixing, which indicates the importance of resolving mesoscale phenomena in time and space.

关键词： High-shear wet granulation Population-balance model Compartment model Computational fluid dynamics

THE REINFORCING MECHANISM OF TiB2 IN TiB2/A357 COMPOSITE

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Acta Metallurgica Sinica(English Letters) 2003年第5期16卷 375-378页

作者： B.yu Y.j.Zhang Z.x.Zhao~ F.x.Zhao: Q.K.Cai C.S.Liu ShenyangResearchInstituteofFoundry TheChineseAcademyofMachinerySciencesShenyang110022China EastChinaUniversityofScienceandTechnology Shanghai200237China SchoolofMaterials&Metallurgy NortheasternUniversityShenyang110004China

Mechanical properties were tested for in situ TiB2/A357 composite fabricated by LSM (mixed salts reaction) method. Micro structures of as cast and plastic deformed TiB2/A357 were investigated. The results show that there is a low misfit between (200) Al and (101)TiB2 with [011]//Al [101]TiB2. There is a change from fully dendritic structure of the α-Al of A357 to a rosette-type structure of TiB2/A357. Significant increases in proof stress and Young's modulus can be obtained at low TiB2 additions. There exist dislocation loops around neighboring TiB2 particles with about 0.1μm in diameter and dislocation multiplication near TiB2 particles.

关键词： TiB2/Al in situ composite reinforcing mechanism

A self-adaptive inorganic in-situ separator by particle crosslinking for nonflammable lithium-ion batteries

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journal of Energy Chemistry 2025年第1期100卷 469-480页

作者： jiarui Yang jiuzhou Liu Wenrui Cai Ziyu Zhao Shan Wang Lu He Shanshan Lv Zhiwei Zhu Zhongfeng ji Guojiang Wen Hua Li yuanming Zhai xuewei Fu Wei Yang yu Wang College of Polymer Science and Engineering State Key Laboratory of Polymer Materials Engineering Sichuan University

All-safe liquid-state lithium-ion batteries(ASLS-LIBs) is of great interest as they can potentially combine the safety of all-solid-state batteries with the high performance and low manufacturing cost of traditional liquid-state LIBs. However, the practical success of ASLS-LIBs is bottlenecked by the lack of advanced separator technology that can simultaneously realize high performances in puncturing-tolerability,fire-resistance, and importantly, wetting-capability with non-flammable liquid-electrolytes. Here, we propose a concept of inorganic in-situ separator(IISS) by hybrid-sol physical crosslinking directly onto the electrode surface to address the above challenges. Particularly, the hybrid-sol is designed with silica nanoparticles as the building block and poly(vinylidene difluoride) nanoparticles as the crosslinking agent. The critical factors for controlling the IISS microstructures and properties have been systematically investigated. The advantages of the IISS have been confirmed by its fast wetting with various fireresistant liquid-electrolytes, customizable thickness and porous structures, robust interface with planar or three-dimensional(3D)-structured electrodes, and importantly, unexpected self-adaptability against puncturing. Enabled by the above merits, a fire-resistant ASLS-LIB is successfully assembled and demonstrated with stable electrochemical performance. This sol-crosslinked IISS may open an avenue for the studies on the next-generation separator technology, cell assembling, solid electrolyte processing as well as non-flammable secondary batteries.

关键词： Silica nanoparticles

Formation of High-quality Advanced High-k Oxide Layers at Low Temperature by Excimer UV Lamp-assisted Photo-CVD and Sol-gel Processing

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Chemical Research in Chinese Universities 2004年第4期20卷 396-402页

作者： yu j. j. Electronic & Electrical Engineering University College London

We have successfully demonstrated that high quality and high dielectric constant layers can be fabricated by low temperature photo-induced or -assisted processing. Ta_2O_5 and ZrO_2 have been deposited at txcimer lamps. The UV annealing of as-grown layers was found to significantly improve their electrical properties. Low leakage current densities on the order of 10 -8 A/cm 2 at 1 MV/cm for deposited ultrathin Ta_2O_5 films and ca.10 -6 A/cm 2 for the photo-CVD ZrO_2 layers and photo-irradiated sol-gel HfO_2 layers have been readily achieved. The improvement in the leakage properties of these layers is attributed to the UV-generated active oxygen species O( 1D) which strongly oxidize any suboxides to form more stoichiometric oxides on removing certain defects, oxygen vacancies and impurities present in the as-prepared layers. The photo-CVD Ta_2O_5 films deposited across 10.16-cm Si wafers exhibit a high thickness uniformity with a variation of less than \{±2.0%\} being obtained for ultrathin ca.10 nm thick films. The lamp technology can in principle be extended to larger area wafers, providing a promising low temperature route to the fabrication of a range of high quality thin films for future ULSI technology.

关键词： Excimer lamp High-kdielectrics Thin film Chemical vapour deposition(CVD) Sol-gel processing

Dietary carbohydrate intake and risk of type 2 diabetes:a 16-year prospective cohort study

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Science China Life Sciences 2025年

作者： Lu Gan Yi Yang Bin Zhao Kai yu Kehua Guo Fang Fang Zhiguang Zhou Demetrius Albanes jiaqi Huang Key Laboratory of Diabetes Immunology Ministry of Education and Department of Metabolism and Endocrinology The Second Xiangya Hospital of Central South University CSU-Sinocare Research Center for Nutrition and Metabolic Health Xiangya School of Public Health Central South UniversityFurong Laboratory Division of Cancer Epidemiology and Genetics National Cancer Institute NIH Department of Health and Human Services School of Computer Science and Engineering Central South University Institute of Environmental Medicine Karolinska Institute National Clinical Research Center for Metabolic Diseases Key Laboratory of Diabetes Immunology Ministry of Education and Department of Metabolism and Endocrinology The Second Xiangya Hospital of Central South University

Despite considerable research underscoring the importance of carbohydrate intake in relation to the risk of type 2 diabetes(T2D), a comprehensive assessment of this relationship is currently lacking. We aimed to examine the associations of various types and food sources of dietary carbohydrate intake with the risk of T2D, to evaluate potential effect modification by other factors, including genetic susceptibility,and to explore the potential mediators for such associations. The present study included 161,872 participants of the UK Biobank who were free of prevalent cancer, cardiovascular disease, or diabetes, and had at least one validated 24-h dietary recall assessment. Multivariableadjusted age-stratified Cox proportional hazard regression models were applied to estimate hazard ratios(HRs) and 95% confidence intervals(CI) for the associations of various types and food sources of dietary carbohydrate intake with risk of T2D. During a median follow-up of13.6 years, 4,176 incident cases of T2D were identified. In the multivariable-adjusted models, a greater intake of fiber, carbohydrates from whole grains, and carbohydrates from non-starchy vegetables was significantly associated with a lower risk of T2D(highest vs. lowest quantile, HR [95% CI]=0.70 [0.62–0.79], 0.74 [0.67–0.82], and 0.83 [0.75–0.92], respectively, all P for trend <0.005). In contrast, a higher intake of starch and carbohydrate from starchy vegetables was associated with an increased risk of T2D(highest vs. lowest quantile, HR [95%CI]=1.31 [1.16–1.48] and 1.19 [1.09–1.31], respectively, both P for trend <0.005). Replacing one serving of refined grains or starchy vegetables with an equal amount of whole grains or non-starchy vegetables was associated with 4% to 10% lower risk of T2D(all P values <0.001).The observed associations were generally similar across population subgroups, including individuals with different genetic susceptibility to T2D. Mediation analyses of the inverse association between T

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