检索结果-南通市图书馆

A Model of Tangential Contact Damping Considering Asperity Interaction and Lateral Contact

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2018年第6期31卷 758-774页

作者： w.P.Fu Z.Q.Gao w.wang J.B.wu School of Mechanical and Precision Instrument Engineering Xi'an University of TechnologyXi'an 710048 China

A precise tangential contact damping model is proposed,which includes the lateral contact of the upper-lower asperities and the interaction of adjacent *** effects of the normal static preload,frequency,and amplitude of tangential displacement on the tangential contact damping were analyzed by simulation,***,the results of simulation are verified by *** tangential contact damping of considering the interaction and lateral contact of asperity is very close to the experimental results.

关键词： Asperity Lateral contact Interaction Tangential contact damping

Microstructure and Mechanical Properties of Fe-based Amorphous Composite Coatings Reinforced by Stainless Steel Powders

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 Materials Science & Technology 2015年第1期31卷 43-47页

作者： H.Zhou C.Zhang w.wang M.Yasir L.Liu School of Materials Science and Engineering State Key Lab for Materials Processing and Die &Mould TechnologyHuazhong University of Science and Technology Huazhong University of Science and Technology Research Institute in Shenzhen

In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) *** microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous *** strength of coatings to the substrate was determined by 'pull-off' tensile *** results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous *** addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.

关键词： Thermal spraying Fe-based amorphous coating Stainl

High-efficiency,large-area,topologyoptimized metasurfaces

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2019年第1期8卷 749-757页

作者： Thaibao Phan David Sell Evan w.wang Sage Doshay Kofi Edee Jianji Yang Jonathan A.Fan Department of Electrical Engineering Stanford UniversityStanfordCA 94305USA Department of Applied Physics Stanford UniversityStanfordCA 94305USA Universite Clermont Auvergne Institut PascalBP 10448F-63000 Clermont-FerrandFrance CNRS UMR 6602Institut PascalF-63177 AubiereFrance

Metasurfaces are ultrathin optical elements that are highly promising for constructing lightweight and compact optical *** their practical implementation,it is imperative to maximize the metasurface *** optimization provides a pathway for pushing the limits of metasurface efficiency;however,topology optimization methods have been limited to the design of microscale devices due to the extensive computational resources that are *** introduce a new strategy for optimizing large-area metasurfaces in a computationally efficient *** stitching together individually optimized sections of the metasurface,we can reduce the computational complexity of the optimization from high-polynomial to *** a proof of concept,we design and experimentally demonstrate large-area,high-numerical-aperture silicon metasurface lenses with focusing efficiencies exceeding 90%.These concepts can be generalized to the design of multifunctional,broadband diffractive optical devices and will enable the implementation of large-area,high-performance metasurfaces in practical optical systems.

关键词： topology optimization surface

Snapshot Mueller spectropolarimeter imager

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microsystems & Nanoengineering 2023年第5期9卷 271-279页

作者： Tianxiang Dai Thaibao Phan Evan w.wang Soonyang Kwon Jaehyeon Son Myungjun Lee Jonathan A.Fan Department of Electrical Engineering Stanford UniversityStanfordCA 94305USA Equipment R&D Team 4 Mechatronics ResearchSamsung Electronics Co.LtdGyeonggi-do 18848Republic of Korea

we introduce an imaging system that can simultaneously record complete Mueller polarization responses for a set of wavelength channels in a single image *** division-of-focal-plane concept combines a multiplexed illumination scheme based on Fourier optics together with an integrated telescopic light-field imaging ***-resolved imaging is achieved using broadband nanostructured plasmonic polarizers as functional pinhole *** recording of polarization and wavelength information on the image sensor is highly *** also develop a calibration approach based on a customized neural network architecture that can produce calibrated measurements in *** a proof-of-concept demonstration,we use our calibrated system to accurately reconstruct a thin film thickness map from a four-inch *** anticipate that our concept will have utility in metrology,machine vision,computational imaging,and optical computing platforms.

关键词： polarization image Snapshot

Cu-assisted austenite reversion and enhanced TRIP effect in maraging stainless steels

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 Materials Science & Technology 2022年第9期104卷 52-58页

作者： M.C.Niu K.Yang J.H.Luan w.wang Z.B.Jiao School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation Center for Advance Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHong KongChina Department of Materials Science and Engineering City University of Hong KongHong KongChina The Hong Kong Polytechnic University Shenzhen Research Institute ShenzhenGuangdongChina

Control of the formation and stability of reverted austenite is critical in achieving a favorable combination of strength,ductility,and toughness in high-strength *** this work,the effects of Cu precipitation on the austenite reversion and mechanical properties of maraging stainless steels were investigated by atom probe tomography,transmission electron microscopy,and mechanical *** results indicate that Cu accelerates the austenite reversion kinetics in two manners:first,Cu,as an austenite stabilizer,increases the equilibrium austenite fraction and hence enhances the chemical driving force for the austenite formation,and second,Cu-rich nanoprecipitates promote the austenite reversion by serving as heterogeneous nucleation sites and providing Ni-enriched chemical conditions through interfacial *** addition,the Cu precipitation hardening compensates the strength drop induced by the formation of soft reverted *** tensile deformation,the metastable reverted austenite transforms to martensite,which substantially improves the ductility and toughness through a transformation-induced plasticity(TRIP)*** Cu-added maraging stainless steel exhibits a superior combination of a yield strength of~1.3 GPa,an elongation of~15%,and an impact toughness of~58 J.

关键词： Maraging stainless steel TRIP effect Austenite reversion Cu-rich nanoprecipitate

Analyzing the Effects of Key Design Factors of a Negative-Differential-Resistance(NDR)Microfluidic Oscillator–an Equivalent-Circuit-Model Approach

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2022年第6期14卷 1381-1399页

作者： J.w.wu H.M.Xia Z.P.wang w.wang H.J.Du School of Mechanical Engineering Nanjing University of Science and TechnologyNanjingJiangsu 210094China Singapore Institute of Manufacturing Technology 73 Nanyang DriveSingapore 637662Singapore School of Mechanical and Aerospace Engineering Nanyang Technological University50 Nanyang AvenueSingapore 639798Singapore

Numerical study on dynamic hydroelastic problems is usually rather complex due to the coupling of fluid and solid ***,we demonstrate that the performance of a hydroelastic microfluidic oscillator can be analyzed using a simple equivalent circuit *** studies reveal that its transition from the steady state to the oscillation state follows the negative-differential-resistance(NDR)*** performance is mainly determined by a bias fluidic resistor,and a pressurevariant resistor which further relates to the bending stiffness of the elastic diaphragm and the depth of the oscillation *** this work,a numerical study is conducted to examine the effects of key design factors on the device robustness,the applicable fluid viscosity,the flow rate,and the transition *** underlying physics is interpreted,providing a new perspective on hydroelastic oscillation *** findings also provide design guidelines of the NDR fluidic oscillator.

关键词： Microfluidic oscillator hydroelastics equivalent circuit model negative differential resistance

Effect of water injection on the cavitation control:experiments on a NACA66(MOD)hydrofoil

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2020年第5期36卷 999-1017,I0001页

作者： w.wang T.Tang Q.D.Zhang X.F.wang Z.Y.An T.H.Tong Z.J.Li School of Energy and Power Engineering Dalian University of TechnologyDalian 116024China Key Laboratory of Ocean Energy Utilization and Energy Conservation of Ministry of EducationDalian University of TechnologyDalian 116024China

The objective of this work is to investigate experimentally controlling cavitating flow over NACA66(MOD)hydrofoils by means of an active water injection along its suction *** continuous water vertically jets out of the chamber inside the hydrofoil through evenly distributed surface *** were carried out in cavitation water *** high-speed visualization technology and the particle image velocimetry(PIV)system to study the sheetlcloud cavity *** studied the effects of this active control on cavity evolution with four kinds of jet flow at two different jet *** analyzed the effect of water injection on the mechanism of the cavitating flow *** results were all compared with that for the original hydrofoil without jet and show that the active jet can effectively suppress the sheet/cloud cavitation characterized by shrinking the attached cavity size and breaking the large-scaled cloud sheding vortex cavity into small-scaled *** optimum effectiveness of cavitation suppression is affected by the jet flow rates and jet *** water injection at flow rate coefficient 0.0245 with the jet position of 0.45C reduces the maximum sheet cavity length by 79.4%and the cavity shedding is diminished completely,which gives the most superior effect of sheet cavitation *** jet blocks the re-entrant jet moving upstream and weakens the power of re-entrant jet and thus restrains the cavitation development effectively and stabilizes the flow field.

关键词： Cavitation active control Sheet/cloud cavitation.water injection Re-entrant jet

Enhanced oxidation resistance of Ce by addition of Ga and nanocrystallization

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 Materials Science & Technology 2023年第16期147卷 26-36页

作者： T.S.Liang Y.F.Jiang H.Y.Li w.wang Q.Zhang B.Zhang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China The 404 Company Limited China National Nuclear CorporationLanzhou 732850China State Key Laboratory of Material Processing and Die&Mould Technology School of Material Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

Ce is prone to catastrophic oxidation at room temperature and its oxidation resistance is difficult to be improved by ***,we found that the oxidation resistance of active metal Ce can be significantly improved by the addition of 20 at.%*** ion beam lift-out technique and scanning transmission electron microscopy analysis disclosed that a discontinuous Ga-rich layer was generated beneath the oxide layer in the coarse-grained Ce-Ga *** Ga-rich layer formed by selective oxidation of Ce acts as a diffusion barrier for Ce outward diffusion and ceases the O/M interfacial reaction when a critical concentration of Ga(75 at.%)is *** nanocrystallization,uniform distribution of Ga was *** oxidation,a relatively continuous Ga-rich layer was formed which further enhanced the oxidation *** introduction of noble elements combining with nanocrystallization may provide a novel strategy for the protection of metals with high activity and poor oxidation resistance.

关键词： Ce-Ga alloy Oxidation resistance Diffusion barrier Nanocrystallization

Characterising Mechanical Properties of Flowing Microcapsules Using a Deep Convolutional Neural Network

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2022年第1期14卷 79-100页

作者： T.Lin Z.wang R.X.Lu w.wang Y.Sui School of Engineering and Materials Science Queen Mary University of LondonLondon E14NSUnited Kingdom Department of Mechanical Engineering University College LondonLondon WC1E 6BTUnited Kingdom

Deformable microcapsules are widely used in industries and also serve as a mechanical model of living biological *** this study,we develop a novel method,by integrating a deep convolutional neural network(DCNN)with high-fidelity mechanistic capsule modelling,to identify the membrane constitutive law and estimate associated parameters of a microcapsule from its steady deformed profile in a capillary *** with conventional inverse methods,the present approach is more accurate and can increase the prediction throughput rate by a few orders of *** can process capsules with large deformation in inertial ***,the method can predict the capsule membrane shear elasticity,area dilatation modulus and initial inflation from a single steady capsule *** explore the mechanism that the DCNN makes decisions by considering its feature maps,and discuss their potential implication on the development of inverse *** present method provides a promising tool which may enable high-throughput mechanical characterisation of microcapsules and biological cells in microfluidic flows.

关键词： Microcapsules flow cytometry deep convolutional neural network high throughput mechanical characterisation