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International Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 908-914页

作者： Betül Kafkasl?o?lu Y?ld?z Hüseyin Y?lmaz Yahya Kemal Tür Department of Materials Science and Engineering Gebze Technical University

The aim of this work was to investigate the microstructure and mechanical properties of 1vol%-Ni-added yttria-stabilized zirconia (YSZ) toughened alumina composites. First, Ni powders were heterogeneously precipitated in an alumina–zirconia powder mixture suspended in water;the prepared specimens were then pressureless sintered at 1550°C/2 h in a 90vol%Ar/10vol% H2 atmosphere. The structure of phases and microstructure of the composites were characterized by X-ray diffraction and scanning electron microscopy, respectively. Mechanical characterization of the specimens was carried out through Vickers hardness, Vickers indentation toughness, and three-point flexural bending tests. The fine Ni particles were homogeneously dispersed throughout the alumina matrix because of the employed processing method. Furthermore, hardness and toughness values were found to increase by 8% and 50%, respectively, with Ni addition, whereas the relative densities and flexural strength values were found to remain unchanged.

关键词： alumina zirconia ceramic matrix microstructure hardness strength toughness

Hot Deformation Behavior and Processing Maps of a Medium Manganese TrIP Steel

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Acta Metallurgica Sinica(English Letters) 2019年第8期32卷 1021-1031页

作者： Ning Yan Hong-Shuang Di Hui-Qiang Huang r.D.K.Misra Yong-Gang Deng State Key Laboratory of rolling and Automation Northeastern UniversityShenyang 110819China Laboratory for Excellence in Advanced Steel research Department of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas El PasoEl PasoTX 7996&USA

The hot deformation behavior of a medium-Mn steel was studied in terms of hot compression flow curves in the temperature range of 850–1050 ℃ and strain rates of 0.05–10 *** thermo-mechanical analysis was carried out and suggested that the microstructure during deformation was completely austenite which had high tendency for dynamic recrystallization(DrX).The flow behavior was characterized by significant flow softening at deformation temperatures of 950–1050 ℃ and lower strain rates of 0.05–5 s-1, which was attributed to heating during deformation, DrX and flow instability.A step-by-step calculating procedure for constitutive equations is *** verification of the modified equations indicated that the developed constitutive models could accurately describe the flow softening behavior of studied ***, according to the processing maps and microstructure analysis, it suggested that hot working of medium Mn steel should be carried out at 1050 ℃, and the strain rate of 0.05–10 s-1 resulted in significantly recrystallized microstructures in the in *** flow localization is mainly flow instability mechanism for experimental steel.

关键词： Medium-Mn steel Hot deformation behavior Constitutive equations Flow instability mechanism recrystallized microstructure

Microstructural Development and Mechanical Properties of PM Ti-45Al-2Nb-2Mn-0.8 vol.%TiB_2 Processed by Field Assisted Hot Pressing

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Journal of Materials Science & Technology 2014年第11期30卷 1145-1154页

作者： r.Munoz-Moreno E.M.ruiz-Navas B.Srinivasarao J.M.Torralba Department of Materials Science and Engineering Universidad Carlos Ⅲ de MadridAvda.Universidad 3028911 LeganésMadridSpain IMDEA Materials Institute C/Eric Kandel 228906 GetafeMadridSpain

A γ-TiAI intermetallic alloy, Ti-45Al-2Nb-2Mn （at.%）-0.8 vol.%TiB2, has been processed from gas atomized praalloyed powder by field assisted hot pressing （FAHP）. An initial analysis of the prealloyed powder helped on the understanding of the intermetallic sintering behavior. Atomized powder consisted of α metastable phase that transformed into α2＋γ equilibrium phases by thermal treating. Different powder particle microstructures were found, which influence the microstructure development of the FAHP T-TiAI material depending on the sintering temperature. Duplex, nearly lamellar and fully lamellar microstructures were obtained at the sintaring temperatures above 1000 ℃. Lower consolidation temperatures, below 1000 ℃, led to the formation of an AI rich phase at powder particle boundaries, which is deleterious to the mechanical properties. High compressive yield strength of 1050 MPa was observed in samples with FAHP duplex microstructures at room temperature. Whereas nearly lamellar and fully lamellar microstructures showed yield strength values of 655 and 626 MPa at room temperature and 440 and 425 MPa at 750 ℃, respectively, which are superior in comparison to similar alloys processed by other techniques. These excellent properties can be explained due to the different volume fractions of the α2 and γ phases and the refinement of the PM microstructures.

关键词： Titanium aluminides Powder metallurgy Microstructure Mechanical properties Field assisted sintering

Can Quick release Experiments reveal the Muscle Structure？ A Bionic Approach

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Journal of Bionic Engineering 2012年第2期9卷 211-223页

作者： D. F. B. Haeufle M. Gunther r. Blickhan S. Schmitt Institute of Sports and Exercise-Science University of Stuttgart Allmandring 28 D-70569 Stuttgart Germany Stuttgart research Centre for Simulation Technology （SrC SimTech） University of Stuttgart Pfaffenwaldring 7a D-70569 Stuttgart Germany Institute of Motion Science Friedrich-Schiller-University Seidelstraβe 20 D-07749 Jena Germany

The goal of this study was to understand the macroscopic mechanical structure and function of biological muscle with respect to its dynamic role in the contraction. A recently published muscle model, deriving the hyperbolic force-velocity relation from first-order mechanical principles, predicts different force-velocity operating points for different load situations. With a new approach, this model could be simplified and thus, transferred into a numerical simulation and a hardware experiment. Two types of quick release experiments were performed in simulation and with the hardware setup, which represent two extreme cases of the contraction dynamics： against a constant force （isotonic） and against an inertial mass. Both experiments revealed hyperbolic or hyperbolic-like force-velocity relations. Interestingly, the analytical model not only predicts these extreme cases, but also additionally all contraction states in between. It was possible to validate these predictions with the numerical model and the hardware experiment. These results prove that the origin of the hyperbolic force-velocity relation can be mechanically explained on a macroscopic level by the dynamical interaction of three mechanical elements. The implications for the interpretation of biological muscle experiments and the realization of muscle-like bionic actuators are discussed.

关键词： force-velocity relation isotonic quick release proof of concept artificial muscle

A review:On path planning strategies for navigation of mobile robot

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Defence Technology（防务技术） 2019年第4期15卷 582-606页

作者： B.K. Patle Ganesh Babu L Anish Pandey D.r.K. Parhi A. Jagadeesh Department of Mechanical Engineering CVR College of Engineering Hyderabad India Department of Mechatronics Engineering Tishik International University Erbil Iraq Department of Mechanical Engineering KITS University Bhubaneshwar India Department of Mechanical Engineering NIT Rourkela India Department of Mechanical Engineering KL University Guntur India

This paper presents the rigorous study of mobile robot navigation techniques used so *** step by step investigations of classical and reactive approaches are made here to understand the development of path planning strategies in various environmental conditions and to identify research *** classical approaches such as cell decomposition(CD),roadmap approach(rA),artificial potential field(APF);reactive approaches such as genetic algorithm(GA),fuzzy logic(FL),neural network(NN),firefly algorithm(FA),particle swarm optimization(PSO),ant colony optimization(ACO),bacterial foraging optimization(BFO),artificial bee colony(ABC),cuckoo search(CS),shuffled frog leaping algorithm(SFLA)and other miscellaneous algorithms(OMA)are considered for *** navigation over static and dynamic condition is analyzed(for single and multiple robot systems)and it has been observed that the reactive approaches are more robust and perform well in all terrain when compared to classical *** is also observed that the reactive approaches are used to improve the performance of the classical approaches as a hybrid ***,reactive approaches are more popular and widely used for path planning of mobile *** paper concludes with tabular data and charts comparing the frequency of individual navigational strategies which can be used for specific application in robotics.

关键词： Mobile robot navigation Path planning Classical approaches reactive approaches Artificial intelligence

Influence of cryogenic treatment on the wear characteristics of 100Cr6 bearing steel

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 46-51页

作者： r.Sri Siva D.Mohan Lal P.Kesavan Nair M.Arockia Jaswin Department of Mechanical Engineering College of Engineering GuindyAnna University Department of Metallurgical and Material Engineering Indian Institute of Technology Madras Department of Mechanical Engineering Aksheyaa College of Engineering

A series of reciprocating wear tests were performed on the deep cryogenically treated and conventionally heat-treated samples of 100Cr6 bearing steel to study the wear resistance. The worn surfaces as well as the wear debris were analyzed by scanning electron microscopy. The improvement in wear resistance of the deep cryogenically treated samples ranges from 49% to 52%. This significant improvement in wear resistance can be attributed to finer carbide precipitation in the tempered martensitie matrix and the transformation of retained aus- tenite into martensite. X-ray diffraction analysis shows that the volume fraction of retained austenite in the conventionally heat-treated samples is 14% and that of the deep cryogenically treated samples is only 3%.

关键词： bearing steel cryogenic treatment wear resistance carbides martensite

Utility of Preoperative Positron Emission Tomography (PET) in Localizing Perforator Vessels of Anterolateral Thigh Free Flap

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Modeling Methane Emission from rice Paddy Soils:Ⅰ.Model Development

International Journal of Otolaryngology and Head & Neck Surgery（耳鼻喉） 2024年第4期 275页

作者： Alexandra McMillan Sameer A. Alvi Zaid Al-Qurayshi Zachary Fleishacker Nitin A. Pagedar Marisa r. Buchakjian

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Pedosphere 1999年第1期9卷 1-10页

作者： HUANGYAO r．L．SASS 等 CollegeofresourcesandEnvirontnentalSciences NanjingAgriculturalUniversityNanjing210095China Departm

With an understanding of the processes of methane production, oxidation and emission, a semi-empirical model, focused on the contributions of rice plants to the processes and also the influence of environmental factors, was developed to predict methane emission from rice paddy soils. In the present model, the amount of methane transported from the soil to the atmosphere was determined by the rates of CH4 production and an emitted fraction. The rates of CH4 production in irrigated rice soils were computed from the availability of methanogenic substrates that are primarily derived from rice plaaes and added organic matter and the influence of soil texture, soil redox potential and temperature. The fraction of methane emitted was assumed to be modulated by the rice plants and declines with rice growth and development. TO make it applicable to a wider area with limited data sets, a simplified version of the model was also derived to predict methane emission in a more practical manner.

关键词： CH_4 emission global warming greenhouse gases modeling rice paddy soils

A comprehensive review of pre-lithiation/sodiation additives for Li-ion and Na-ion batteries

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Journal of Energy Chemistry 2023年第1期76卷 479-494,I0012页

作者： Pranav Kulkarni Hyunyoung Jung Debasis Ghosh Mohammed Jalalah Mabkhoot Alsaiari Farid A.Harraz r.Geetha Balakrishna Centre for Nano and Material Sciences Jain Global CampusJain UniversityKanakapuraBangalore 562112KarnatakaIndia Department of Energy Engineering Gyeongsang National UniversityJinju-siCyeongnam 52725South Korea Promising Centre for Sensors and Electronic Devices(PCSED) Advanced Materials and Nano-Research CentreNajran UniversityNajran 11001Saudi Arabia Department of Electrical Engineering College of EngineeringNajran UniversityNajran 11001Saudi Arabia Empty Quarter Unit Department of ChemistryFaculty of Science and Arts at SharurahNajran UniversityNajran 11001Saudi Arabia Nanomaterials and Nanotechnology Department Central Metallurgical Research and Development Institute(CMRDI)HelwanCairo 11421Egypt

Lithium/Sodium-ion batteries(LIB/SIB)have attracted enormous attention as a promising electrochemical energy storage system due to their high energy density and long cycle *** of the major hurdles is the initial irreversible capacity loss during the first few cycles owing to forming the solid electrolyte interphase layer(SEI).This process consumes a profusion of lithium/sodium,which reduces the overall energy density and cycle ***,a suitable approach to compensate for the irreversible capacity loss must be developed to improve the energy density and cycle ***-lithiation/sodiation is a widely accepted process to compensate for the irreversible capacity loss during the initial *** strategies such as physical,chemical,and electrochemical pre-lithiation/sodiation have been explored;however,these approaches add an extra step to the current manufacturing *** to these strategies,pre-lithiation/sodiation additives have attracted enormous attention due to their easy adaptability and compatibility with the current battery manufacturing *** this review,we consolidate recent developments and emphasize the importance of using pre-lithiation/sodiation additives(anode and cathode)to overcome the irreversible capacity loss during the initial cycles in lithium/sodium-ion *** review also addresses the technical and scientific challenges of using pre-lithiation/sodiation additives and offers the insights to boost the energy density and cycle life with their possible commercial *** most important prerequisites for designing effective pre-lithiation/sodiation additives have been explored and the future directions have been discussed.

关键词： Pre-lithiation/sodiation additives Solid electrolyte interphase Anode pre-lithiation/sodiation additives Cathode pre-lithiation/sodiation additives Coulombic efficiency

A comparative assessment of empirical and lattice Boltzmann method-based drag models for simulation of gas-solid flow hydrodynamics in a bubbling fluidized bed

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Particuology 2017年第4期15卷 129-137页

作者： Carlos M. romero Luna Luis r. Carrocci Gretta L.A.F. Arce Ivonete Avila UNESP - Sflo Paulo State University School of Engineering Department of Energy Laboratory of Combustion and Carbon Capture (LC3) CEP 12.516-410 Guaratinguetd SP Brazil INPE - Brazilian Space research Institute Combustion and Propulsion Associated I.aboratory CEP 12.630-000 Cachoeira Paulista SP Brazil UNJFSC -Jose Faustino Sanchez Carrion National University Faculty of Chemical and Metallurgical Engineering Advanced Materials and Nanotechnology Research Group Huacho Lima Peru

In simulations of fluidized beds using computational fluid dynamics （CFD）, the description of gas-solid flow hydrodynamics relies on a drag model to account for the momentum transfer between gas and solid phases. Although several studies of drag models have been published, there have been few investigations of the application of lattice Boltzmann method （LBM）-based drag models to bubbling fluidized bed simu- lations. In the present study, a comprehensive comparison of empirical and LBM-based drag models was carried out to assess the performance of these models during simulations of gas-solid flow hydrodynam- ics in a bubbling fluidized bed. A CFD model using the MFIX code based on the Eulerian-Eulerian approach and the kinetic theory of granular flow was used to simulate a 2D bubbling fluidized bed with Geldart B particles. The simulation results were validated by comparison with experimental data. Statistical anal- ysis of the results shows that LBM-based drag models can reliably model gas-solid flow hydrodynamics in a bubbling fluidized bed.

关键词： CFD Drag model Gas-solid flow hydrodynamics Bubbling fluidized bed