检索结果-南通市图书馆

Broadband angular spectrum analog processors based on all-dielectric metasurfaces

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 188-190页

作者： Lin Deng Yongmin Liu department of Electrical and Computer engineering Northeastern UniversityBoston 02115USA department of mechanical and industrial engineering Northeastern UniversityBoston 02115USA

Digital signal processors are extensively used to execute mathematical operations and advanced computational tasks on digital ***,they suffer from several inherent limitations,including low speed,high energy consumption,and large memory requirements,because of the hardware bottleneck and the imperative conversion between digital and analogue signals.

关键词： dielectric spectrum hardware

Breakdown of effective medium theory:A study of photonic spin Hall effect in deep-subwavelength all-dielectric multilayers

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 173-174页

作者： Yongmin Liu department of mechanical and industrial engineering Northeastern UniversityBoston 02115USA department of Electrical and Computer engineering Northeastern UniversityBoston 02115USA

Effective medium theory(EMT)has been widely applied in material science,electromagnetics and photonics to determine the effective material properties for inhomogeneous composites comprising subwavelength *** versatility of this foundational approach has been established through its application in classical Maxwell-Garnet models,which encompass relatively simple structures。

关键词： composites theory dielectric

Complex granular flows of sticky-wet material on flip-flow screens:Calibration of discrete element simulations

在线全文

学校读者我要写书评

暂无评论

Particuology 2024年第1期84卷 290-308页

作者： Ningning Xu Sen Tang Dongdong Lin Runhui Geng Xinwen Wang Xihui Liang School of Chemical and Environmental engineering China University of Mining and Technology(Beijing)Beijing100083China department of mechanical engineering University of ManitobaWinnipegManitobaR3T 5V6Canada

Discrete element method(DEM)is an effective approach for studying the screening process of flip-flow ***,there have been few studies focusing on the thick layer of sticky-wet particles on flip-flow *** achieve accurate simulations of the thick layer of sticky-wet particles on a flip-flow screen,firstly,the movement law of particle flow was studied,and a multi-regime combination cali-bration method based on characteristics of particle flow regimes was *** on the Plackett-Burman experiment,the curse of dimensionality caused by multi-state and multi-contact parameters was ***,the lifting cylinder,rotating drum,and trampoline tests were carried out to obtain macroscopic reference values under various granular flow *** calibration results were then determined using the response surface method and climbing ***,the calibration results were tested at both macroscopic and mesoscopic scales and compared with a commonly used calibration *** results demonstrate that the calibration method,which considers the multi-state characteristics,improves simulation accuracy by 2%-10%and reduces the simulation error to less than 10%,thus meeting the requirements for engineering optimization of flip-flow screens.

关键词： DEM Complex granular flow Parameter calibration Flip-flow screen Sticky-wet particles Thick layer

Cryogenic and conventional milling of AZ91 magnesium alloy

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 Magnesium and Alloys 2024年第6期12卷 2503-2519页

作者： Vikas Marakini Srinivasa Pai P Gururaj Bolar Bhaskara P Achar department of mechanical engineering Nitte(Deemed to be University)NMAM Institute of Technology(NMAMIT)Nitte 574110India department of mechanical and industrial engineering Manipal Institute of TechnologyManipal Academy of Higher EducationManipal 576104India

Use of magnesium is the need of the hour due to its low density as well as its high strength-to-weight and stiffness-to-weight ratio *** study focuses on the effectiveness of liquid nitrogen(LN_(2))assisted cryogenic machining on the surface integrity(SI)characteristics of AZ91 magnesium *** milling using uncoated carbide inserts have been performed under liquid nitrogen(LN_(2))assisted cryogenic condition and compared with conventional(dry)*** are performed using machining parameters in terms of cutting speeds of 325,475,625 m/min,feed rates of 0.05,0.1,0.15 mm/teeth and depth of cuts of 0.5,1,1.5 mm *** significant surface integrity characteristics such as surface roughness,microhardness,microstructure,and residual stresses have been *** of SI characteristics with respect to milling parameters have been identified using statistical technique such as ANOVA and signal-to-noise(S/N)ratio ***,the multi criteria decision making(MCDM)techniques such as additive ratio assessment method(ARAS)and complex proportional assessment(COPRAS)have been utilized to identify the optimal conditions for milling AZ91 magnesium alloy under both dry and cryogenic *** of LN_(2)during machining,resulted in reduction in machining temperature by upto 29%with a temperature drop from 251.2℃under dry condition to 178.5℃in cryogenic *** showed the advantage of performing cryogenic milling in improving the surface integrity to a significant *** machining considerably minimized the roughness by upto 28%and maximised the microhardness by upto 23%,when compared to dry *** speed has caused significant impact on surface roughness(95.33%-dry,92.92%-cryogenic)and surface microhardness(80.33%-dry,82.15%-cryogenic).Due to the reduction in machining temperature,cryogenic condition resulted in compressive residual stresses(maximumσ║=-113 MPa)on the alloy *** indicate no

关键词： Magnesium alloy Cryogenic machining Roughness Microhardness Microstructure Residual stress Multi criteria decision making

Chaotic Aquila Optimization Algorithm for Solving Phase Equilibrium Problems and Parameter Estimation of Semi-empirical Models

在线全文

学校读者我要写书评

暂无评论

Journal of Bionic engineering 2024年第1期21卷 486-526页

作者： Oguz Emrah Turgut Mert Sinan Turgut Erhan Kırtepe department of industrial engineering Faculty of Engineering and ArchitectureIzmir Bakircay UniversityMenemenizmirTurkey department of mechanical engineering Faculty of EngineeringEge UniversityBornovaizmirTurkey department of Motor Vehicles and Transportation Technologies Sirnak UniversitySirnakTurkey

This research study aims to enhance the optimization performance of a newly emerged Aquila Optimization algorithm by incorporating chaotic sequences rather than using uniformly generated Gaussian random *** work employs 25 different chaotic maps under the framework of Aquila *** considers the ten best chaotic variants for performance evaluation on multidimensional test functions composed of unimodal and multimodal problems,which have yet to be studied in past literature *** was found that Ikeda chaotic map enhanced Aquila Optimization algorithm yields the best predictions and becomes the leading method in most of the *** test the effectivity of this chaotic variant on real-world optimization problems,it is employed on two constrained engineering design problems,and its effectiveness has been ***,phase equilibrium and semi-empirical parameter estimation problems have been solved by the proposed method,and respective solutions have been compared with those obtained from state-of-art *** is observed that CH01 can successfully cope with the restrictive nonlinearities and nonconvexities of parameter estimation and phase equilibrium problems,showing the capabilities of yielding minimum prediction error values of no more than 0.05 compared to the remaining algorithms utilized in the performance benchmarking process.

关键词： Aquila optimization algorithm Chaotic maps Parameter estimation Phase equilibrium Unconstrained optimization

Heat transfer analysis in particle-laden flows using the immersed boundary method

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2024年第7期90卷 394-403页

作者： Ali Abbas Zaidi department of mechanical engineering University of Manitoba75A Chancellors CircleWinnipegR3T 5V6Canada

This paper investigates an efficient immersed boundary method(IBM)for multiple-core CPU machines with local grid refinement for the calculation of heat transfer between fluids and finite-sized *** fluid momentum equations are solved by using the fractional step method,while the energy equation is solved by employing the second-order Adams-Bashforth *** efficient load balancing between the CPU cores,the coupling between particles and fluid is obtained by applying the body force in the fluid equations,which depends on the solid volume fraction of particles contained in each grid cell,and then by linearly interpolating the particle temperature and velocity on the fluid grid cell(in place of the delta function commonly used in literature).Several test cases from the literature are studied,and good agreement is observed between the simulation results and the ***,a scaling study on multiple core machines is performed,demonstrating the proposed IBM's capabilities for a significant reduction in processing time.

关键词： Heat transfer Immersed boundary method Particle resolved direct numerical simulations Fluid solid interactions

Experimental and Finite Element Analysis of Corroded High-Pressure Pipeline Repaired by Laminated Composite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in engineering & Sciences 2024年第8期140卷 1783-1806页

作者： Seyed Mohammad Reza Abtahi Saeid Ansari Sadrabadi Gholam Hosein Rahimi Gaurav Singh Hamid Abyar Daniele Amato Luigi Federico Faculty of mechanical engineering Tarbiat Modares UniversityTehran***Iran A.Leon Linton department of mechanical Robotics and Industrial EngineeringLawrence Technological UniversitySouthfieldMI48075USA department of mechanical engineering Faculty of EngineeringMeybod UniversityYazd***Iran department of industrial engineering University of SalernoVia Giovanni PaoloⅡFiscianoItaly Italian Aerospace Research Center(C.I.R.A.) Via MaioriseCapuaCE81043Italy

Repairs of corroded high-pressure pipelines are essential for fluids transportation under high *** of the methods used in their repairs is the use of layered *** composite used must have the necessary ***,the experiments and analytical solutions presented in this paper are performed according to the relevant standards and codes,including ASME PCC-2,ASME B31.8S,ASME B31.4,ISO 24817 and ASME *** addition,the experimental tests are replicated numerically using the finite element *** the strain gauges at different distances from the defect location,can reduce the nonlinear effects,deformation,and fluctuations due to the high *** direct relationship between the depth of an axial defect and the stress concentration is observed at the inner side edges of the *** reparation reduces the non-linearities related to the sharp variation of the geometry and a more reliable numerical simulation could be performed.

关键词： High-pressure pipeline composite repair ASME PCC-2 ISO 24817

Sustainable Biocomposites Materials for Automotive Brake Pad Application:An Overview

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 Renewable Materials 2024年第3期12卷 485-511页

作者： Joseph O.Dirisu Imhade P.Okokpujie Olufunmilayo O.Joseph Sunday O.Oyedepo Oluwasegun Falodun Lagouge K.Tartibu Firdaussi D.Shehu department of mechanical engineering Covenant UniversityOtaOgunNigeria department of mechanical and Mechatronics engineering AFE Babalola UniversityAdoEkitiNigeria department of mechanical and industrial engineering Technology University of JohannesburgJohannesburg2028South Africa School of Chemical and Metallurgical engineering University of the WitwatersrandJohannesburgSouth Africa

Research into converting waste into viable eco-friendly products has gained global *** natural fibres and pulverized metallic waste becomes necessary to reduce noxious environmental emissions due to indiscriminately occupying the *** study reviews the literature in the broad area of green composites in search of materials that can be used in automotive brake *** made by biocomposite,rather than fossil fuels,will be favoured.A database containing the tribo-mechanical performance of numerous potential components for the future green composite was established using the technical details of bio-polymers and natural *** development of materials with diverse compositions and varying proportions is now conceivable,and these materials can be permanently connected in fully regulated *** explanation demonstrates that all of these variables affect friction coefficient,resistance to wear from friction and high temperatures,and the operating life of brake pads to varying *** this study,renewable materials for the matrix and reinforcement are screened to determine which have sufficient strength,coefficient of friction,wear resistance properties,and reasonable costs,making them a feasible option for a green *** most significant,intriguing,and unusual materials used in manufacturing brake pads are gathered in this review,which also analyzes how they affect the tribological characteristics of the pads.

关键词： Asbestos brake pad biocomposites green composite mechanical properties natural reinforcement waste

Generating synthetic as-built additive manufacturing surface topography using progressive growing generative adversarial networks

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Friction 2024年第6期12卷 1283-1298页

作者： Junhyeon SEO Prahalada RAO Bart RAEYMAEKERS department of mechanical engineering Virginia TechBlacksburgVA 24061USA Grado department of industrial and Systems engineering Virginia TechBlacksburgVA 24061USA

Numerically generating synthetic surface topography that closely resembles the features and characteristics of experimental surface topography measurements reduces the need to perform these intricate and costly ***,existing algorithms to numerically generated surface topography are not well-suited to create the specific characteristics and geometric features of as-built surfaces that result from laser powder bed fusion(LPBF),such as partially melted metal particles,porosity,laser scan lines,and ***,we present a method to generate synthetic as-built LPBF surface topography maps using a progressively growing generative adversarial *** qualitatively and quantitatively demonstrate good agreement between synthetic and experimental as-built LPBF surface topography maps using areal and deterministic surface topography parameters,radially averaged power spectral density,and material ratio *** ability to accurately generate synthetic as-built LPBF surface topography maps reduces the experimental burden of performing a large number of surface topography ***,it facilitates combining experimental measurements with synthetic surface topography maps to create large data-sets that facilitate,*** as-built surface topography to LPBF process parameters,or implementing digital surface twins to monitor complex end-use LPBF parts,amongst other applications.

关键词： additive manufacturing surface topography synthetic surface topography generative adversarial networks