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Efficient Numerical Scheme for Solving Large System of Nonlinear Equations

Computers, materials & Continua 2023年第3期74卷 5331-5347页

作者： Mudassir Shams Nasreen Kausar Shams Forruque Ahmed Irfan Anjum Badruddin Syed Javed Department of Mathematics and Statistics Riphah International UniversityI-14Islamabad44000Pakistan Department of Mathematics Yildiz Technical UniversityFaculty of Arts and ScienceEsenler34210IstanbulTurkey Science and Math Program Asian University for WomenChattogramBangladesh Mechanical Engineering Department College of EngineeringKing Khalid UniversityAbha61421Saudi Arabia

A fifth-order family of an iterative method for solving systems of nonlinear equations and highly nonlinear boundary value problems has been developed in this *** analysis demonstrates that the local order of convergence of the numerical method is *** computer algebra system CAS-Maple,Mathematica,or MATLAB was the primary tool for dealing with difficult problems since it allows for the handling and manipulation of complex mathematical equations and other mathematical *** numerical examples are provided to demonstrate the properties of the proposed rapidly convergent algorithms.A dynamic evaluation of the presented methods is also presented utilizing basins of attraction to analyze their convergence *** from visualizing iterative processes,this methodology provides useful information on iterations,such as the number of diverging-converging points and the average number of iterations as a function of initial *** numerous highly nonlinear boundary value problems and large nonlinear systems of equations of higher dimensions demonstrate the performance,efficiency,precision,and applicability of a newly presented technique.

关键词： Nonlinear equations convergence order boundary value problem computational time basins of attraction converging points

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The anelastic origin of mechanical cycling induced rejuvenation in the metallic glass

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science China(Physics,Mechanics & Astronomy) 2023年第8期66卷 93-100页

作者： Langting Zhang Yunjiang Wang Yong Yang Jichao Qiao School of Mechanics CivilEngineering and ArchitectureNorthwestern Polytechnical UniversityXi'an 70072China State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Department of Mechanical Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Department of Materials Science and Engineering College of EngineeringCity University of Hong KongHong Kong 999077China Innovation Center NPU-ChongqingChongqing 401135China

mechanical cycling is one of the effective methods to rejuvenate metallic glasses(MGs)and improve their mechanical *** anelastic origin of the rejuvenation by mechanical cycling in a La_(30)Ce_(30)Ni_(10)Al_(20)Co_(10) MG was investigated via differential scanning calorimetry(DSC)and dynamic mechanical analysis(DMA).We demonstrate that mechanical cycling promotes the activation of flow defects with short relaxation times,leading to anelastic strains and therefore considerable energy storage,which manifests itself as larger relaxation enthalpy on the DSC curves of ***,the MGs release the excess relaxation enthalpy caused by anelastic strain with time,thus suppressing atomic mobility and elevating β relaxation activation *** strategy of mechanical cycling at small strains,as demonstrated in the current work,can expand the energy states of MGs over a wide range of relaxation enthalpies.

关键词： metallic glass mechanical cycling rejuvenation anelastic strain structural heterogeneity

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Immiscibility in binary silicate liquids: Insight from ab initio molecular dynamics simulations

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Physical Review B 2024年第17期109卷 174215-174215页

作者： Xuan Ge Pingsheng Lai Caijuan Shi Tao Du Zhencai Li Wenquan Lu Jingyu Qin Fan Yang Yuanzheng Yue Morten M. Smedskjaer Jianguo Li Qiaodan Hu Shanghai Key Laboratory of Materials Laser Processing and Modification School of Materials Science and Engineering Department of Chemistry and Bioscience Beijing Synchrotron Radiation Facility School of Materials Science and Engineering School of Mechanical Engineering

Liquid-liquid phase separation (LLPS) is a prevalent phenomenon in silicate liquids. The ionic potential of the cations is widely recognized as a pivotal factor controlling the immiscibility extent of silicates; nonetheless, the intricate relationship between the two has yet to be fully understood. Here, using ab initio molecular dynamics simulations, we study the static and dynamic structural evolutions in a prototypical LLPS system (TiO2−SiO2), aiming to decode the structural origin of the nonmonotonic dependence of ionic potential on immiscibility extent. The simulations reproduce the initial stage of phase separation as represented by formation of microscale aggregative Ti-Ti clusters upon cooling. Such microphase separation primarily arises from the Coulombic repulsion between Ti4+ cations and adjacent Si4+ nodes, rather than the previously believed repulsion between poorly shielded Ti4+ cations. Analysis of dynamics reveals that the transport of Ti4+ cations across the Si-O-Si network is more sluggish than that of alkali (alkaline)-earth cations. Slow dynamics of Ti4+ cations are decoupled from their local coordination structure, but instead, it highly depends on the topological rigidity of these nearest-neighbor Ti–O bonds. As such, the high ionic potential of Ti4+ cations drives them away from nearby-network Si4+ nodes, promoting immiscibility. On the other hand, this same potential causes strong topological rigidity, and hence, suppresses immiscibility by hindering the Ti4+ migration. This dual effect of the ionic potential questions the classical structural model in LLPS and provides insights into the association between immiscibility extent and ionic potential.

关键词： Phase separation Liquid-liquid interfaces Ab initio molecular dynamics

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Achieving high carrier mobility and low lattice thermal conductivity in GeTe-based alloys by cationic/anionic co-doping

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Rare Metals 2024年第6期43卷 2784-2795页

作者： Xiao-Qiang Wang Xiao-Quan Hu Jun-Yan Lin Chu-Bin Li Xiao-Tong Yu Qi-Yong Chen Li-Li Xi Qi-Shuo Yang Han Li Ji-Ye Zhang Shuan-Kui Li Kai Guo School of Physics and Materials Science Guangzhou UniversityGuangzhou 510006China Research Center for Advanced Information Materials(CAIM) Huangpu Research&Graduate School of Guangzhou UniversitySino-Singapore Guangzhou Knowledge CityGuangzhou510555China School of Materials Science and Engineering Shanghai UniversityShanghai 200444China Materials Genome Institute Shanghai UniversityShanghai 200444China School of Mechanical and Mining Engineering University of QueenslandBrisbaneQLD 4072Australia Key Laboratory of Si-Based Information Materials&Devices and Integrated Circuits Design Department of Education of Guangdong ProvinceGuangzhou 510006China

TheⅣ-Ⅵcompound GeTe is considered as a promising alternative to the toxic PbTe for high-efficiency mid-temperature thermoelectric ***,pristine GeTe suffers from a high concentration of Ge vacancies,resulting in an excessively high hole concentration(>1×10^(21)cm^(-3)),which greatly limits its thermoelectric *** address this issue,CuBiTe_(2)alloying is introduced to increase the formation energy of Ge vacancies in GeTe,thereby inhibiting the high carrier *** carrier scattering caused by the electronegativity difference between different elements is suppressed due to the similar electronegativity of Cu and Ge atoms.A relatively high hole mobility is obtained,which ultimately leads to a high power ***,by introducing Se as an alloying element at the anionic site in GeTe,dense point defects with mass/strainfield fluctuations are *** contributes to the strengthening of phonon scattering,thereby reducing the lattice thermal conductivity from 1.44 W·m^(-1)·K^(-1)for pristine GeTe to 0.28 W·m^(-1)·K^(-1)for Ge_(0.95)Cu_(0.05)Bi_(0.05)Te_(0.9)Se_(0.15)compound at 623 K.

关键词： GeTe Carrier mobility CuBiTe_(2)alloying Lattice thermal conductivity Thermoelectric properties

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The Investigation of Microstructure and mechanical Property of Incorporation of Cerium Oxide to AA2219 Through Liquid Forging Technique

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Journal of The Institution of Engineers (India): Series D 2025年第1期106卷 9-17页

作者： Karthik, A. Karunanithi, R. Srinivasan, S.A. Kumareshbabu, S.P. Department of Mechanical Engineering B.S. Abdur Rahman Crescent Institute of Science and Technology Seethakathi Estate Vandalur Tamil Nadu Chennai600048 India Department of Aerospace Engineering B.S. Abdur Rahman Crescent Institute of Science and Technology Seethakathi Estate Vandalur Tamil Nadu Chennai600048 India Department of Metallurgical and Materials Engineering National Institute of Technology Tiruchirappalli Tanjore Main Road National Highway 67 Tamil Nadu Tiruchirappalli620015 India

In this study, an attempt is made to prepare aluminum metal matrix composites of AA2219 with varying reinforcement of weight percentages of cerium oxide (X = 0.5%, 1%, 1.5%, and 2%) by liquid metallurgy technique involving liquid forging operation. The incorporation of rare earth oxide to AA2219 through liquid forging technique offers excellent solubility of the solute atom along with near-net shape capability, higher materials property, and reduced porosity level when compared with conventional casting route. The reinforcement of cerium oxide improves mobility, casting microstructure, reduces shrinkage and hot tearing tendency of AA2219. The AA2219 composites sample were casted at the following process parameter such as the applied pressure load 350 MPa, the heating die temperature 200 °C, melt temperature 750 °C, and 60 s dwell time. The main objective was to determine the effect of CeO2 particles on the microstructure and mechanical properties of AA2219 composites through liquid forging technique. X-ray diffraction studies revealed the presence of intermetallic phase present in the composites and the presence of CeO2 confirmed by EDS analysis. Scanning electron microscopy images showed a homogeneous distribution of CeO2 particles within the matrix and the grain boundaries. The reinforcement of CeO2 increase hardness of the composites with a maximum hardness of 123 VHN observed for 2 wt% CeO2 with AA2219. The tensile test indicated the significant effect of the CeO2 particles with an ultimate tensile strength of 232 MPa and 87 MPa yield strength when compared to the unreinforced material was around 130 Mpa and 75 MPa, respectively. Fractography showed ductile fracture mode failure and the increase in CeO2 decrease the level of strain rate. © The Institution of Engineers (India) 2020.

关键词： Microstructure

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Analyses of Full-load, Modal, and Fatigue Life of Electric Motorcycle Frame Using Finite Element Software ANSYS

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Sensors and materials 2023年第8期35卷 2817-2829页

作者： Dai, Hong-Mei Chen, Bo-Hao Hsu, Chao-Ming Lin, Chiang-Lung Yang, Cheng-Fu College of Art Zhongqiao Vocational and Technical University Shanghai201514 China Department of Mechanical Engineering National Kaohsiung University of Science and Technology Kaohsiung807 Taiwan Department of Chemical and Materials Engineering National University of Kaohsiung Kaohsiung811 Taiwan Department of Aeronautical Engineering Chaoyang University of Technology Taichung413 Taiwan

There are two methods of analyzing the effects of various loads on the full-load, modal, and fatigue life of an electric motorcycle frame. The first method involves attaching stress sensors to the frame, and the second method utilizes finite element method (FEM) software for simulation. In this study, the simulation method was employed, and this paper details the creation of an analysis system for an electric motorcycle frame using FEM software tools such as Visual Basic and ANSYS parametric design languages. By inputting geometric models and parameters, the system generated LOG files to create FEM models of the motorcycle frame. These LOG files were then imported into ANSYS for structural analysis, which included full-load analysis, modal analysis, and fatigue life analysis. By utilizing the aforementioned models, users were able to easily perform full-load, modal, and fatigue life analyses of the electric motorcycle frame by inputting the necessary parameters into function tables. During the full-load analysis, various forces were applied at different positions to determine the maximum stress, deformation, and strain values. The modal analysis of the electric motorcycle frame involved determining the first through sixth orders of the natural vibration frequencies and modes (mode shape), as well as the vibration frequencies and modes under full load. In the fatigue life analysis, a fatigue tool was used to apply forces ranging from 50 to 200% of the full-load boundary condition. Additionally, the relationship between the number of cycles to failure (N) and the applied stress amplitude was examined. © MYU K.K.

关键词： Modal analysis

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Ultrasonic Welding of Glass Fiber Reinforced Vitrimer Composites 38

Ultrasonic Welding of Glass Fiber Reinforced Vitrimer Compos...

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38th Technical Conference of the American Society for Composites, ASC 2023

作者： Biswal, Agni K. Nandi, Ankush Wang, Hung Vashisth, Aniruddh Mechanical Engineering Department University of Washington Seattle98195 United States Materials Science and Engineering University of Washington Seattle98195 United States

ISBN: (纸本)9781605956916

The welding of composites has become a crucial step in the production of complex composite parts. Typically, various welding and joining techniques are used to manufacture composite assemblies. However, ultrasonic welding is one of the most popular methods for welding thermoplastic composites and cannot be used for composites with a thermosetting matrix. This study employed ultrasonic welding process for fiber-reinforced polymer composites with a dynamic covalent adaptive network (CAN). We used a thermosetting polymeric network with an associative dynamic CAN, commonly known as vitrimers;the dynamic nature of these polymers makes them reprocessable, recyclable, and reusable. These polymers can be crosslinked like thermosets but flow as thermoplastics at elevated temperatures. Thin composites were fabricated by reinforcing glass fibers into the vitrimer polymeric matrix and then welded together using ultrasonic welding. This work represents the first demonstration of welding vitrimer glass fiber-reinforced composites (vGFRC). The vGFRC matrix employed transesterification molecular exchange reactions to initiate chain mobility, leading to interlocking and rearrangement reactions on the bondline during the welding process. We evaluated the mechanical, chemical, and morphological properties of welded lap joints before and after mechanical testing. Shear strengths of 10 MPa were observed for vGFRC, indicating good weldability properties of vitrimer surfaces. The reprocessable nature of these composites was evaluated by repeated testing of lap shear strength followed by ultrasonic welding over five cycles. Additionally, we evaluated the surface functionality and atomic percentage on the fractured surface using FTIR and XPS, respectively. This exciting discovery shows that high frequency and pressure can be used to weld and reprocess polymers with dynamic molecular networks by exploiting molecular fusion and rearrangement reactions at the bondline. © 2023 by DEStech Public

关键词： Dynamics

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Multi-scale defects in powder-based additively manufactured metals and alloys

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Journal of materials science & Technology 2022年第27期122卷 165-199页

作者： J.Fu H.Li X.Song M.W.Fu Department of Mechanical Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Department of Mechanical and Automation Engineering Chinese University of Hong KongShatinHong KongChina

Defect formation is a critical challenge for powder-based metal additive manufacturing(AM).Current understanding on the three important issues including formation mechanism,influence and control method of metal AM defects should be *** this review paper,multi-scale defects in AMed metals and alloys are identified and for the first time classified into three categories,including geometry related,surface integrity related and microstructural *** particular,the microstructural defects are further divided into internal cracks and pores,textured columnar grains,compositional defects and dislocation *** root causes of the multi-scale defects are *** key factors that affect the defect formation are identified and *** detection methods and modeling of the multi-scale defects are briefly *** effects of the multi-scale defects on the mechanical properties especially for tensile properties and fatigue performance of AMed metallic components are *** control and mitigation methods for the corresponding defects,include process parameter control,post processing,alloy design and hybrid AM techniques,are summarized and *** research aspect,current research gaps and future prospects from three important aspects of the multi-scale AM defects are identified and delineated.

关键词： Metal additive manufacturing Multi-scale defects Detection and modeling mechanical properties Defect control and mitigation

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Reuse of sodium–doped iridium oxide nanoparticles as a bio–stimulating electrode by a chemical and electrochemical recovery process

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Ceramics International 2024年第4期50卷 6220-6228页

作者： Tso, Kuang-Chih Chen, Chieh-Hsuan Chen, Po-Chun Li, Shao-Sian Chen, Jeng-Lung Ohta, Jun Wu, Pu-Wei Division of Materials Science Graduate School of Science and Technology Nara Institute of Science and Technology Nara630-0192 Japan Graduate Degree Program of Science and Technology of Accelerator Light Source National Yang Ming Chiao Tung University Hsinchu300 Taiwan Department of Materials Science and Engineering National Yang Ming Chiao Tung University Hsinchu300 Taiwan Institute of Materials Science and Engineering National Taipei University of Technology Taipei106 Taiwan National Synchrotron Radiation Research Center Hsinchu300 Taiwan

A sequential chlorination and electrochemical reduction process is demonstrated to convert Na–doped iridium oxide nanoparticles into useful IrIIICl63−(aq) serving as the precursor for the fabrication of bio–stimulating electrode. The Na–doped iridium oxide nanoparticles are treated in 35 wt% hydrochloric acid at 70 °C for 18 h to form IrIVCl62−(aq) with pH of 0.3, so the latter could be readily reduced to IrIIICl63−(aq) at a potentiostatic mode of 0.6 V (vs. SCE). The oxidation state and the nature of complexing ligands for the regenerated IrIIICl63− and IrIVCl62−, as well as commercially available IrIIICl63− are validated by X–ray Absorption Spectroscopy. UV–Vis profiles of regenerated IrIVCl62−(aq) are recorded and the absorbance at 487 nm signal is benchmarked against that of standard IrIVCl62−(aq) to obtain the effective regeneration ratio of 68.6%. X–ray diffraction patterns of Na–doped iridium oxide nanoparticles before and after the annealing treatment indicate the amorphous structure facilitates the chlorination step. The regenerated IrIIICl63− is reused to synthesize Na–doped iridium oxide thin film serving as a bio–stimulating electrode for implantable bio–electronics. The regenerated Na–doped iridium oxide thin film reveals a charge-storage capacity of 0.32 mC/cm2-nm and impressive stability that are comparable to those of fresh Na–doped iridium oxide thin film derived from commercially available IrIIICl63−. © 2023 Elsevier Ltd and Techna Group S.r.l.

关键词： Transition metal oxides

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Recent Progress and New Horizons in Emerging Novel MXene-Based materials for Energy Storage Applications for Current Environmental Remediation and Energy Crises

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Electrochemical Energy Reviews 2024年第1期7卷 700-786页

作者： Karim Khan Ayesha Khan Tareen Muhammad Iqbal Ye Zhang Asif Mahmood Nasir mahmood Zhe Shi Chunyang Ma J.R.Rosin Han Zhang Additive Manufacturing Institute Shenzhen UniversityShenzhen 518060GuangdongChina School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808GuangdongChina Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology of Ministry of EducationInstitute of Microscale OptoelectronicsEngineeringShenzhen UniversityShenzhen 518060GuangdongChina Department of Bio‑Chemistry Quaid-I-Azam UniversityIslamabad 45320Pakistan School of Chemistry and Chemical Engineering University of South ChinaHengyang 421001HunanChina School of Chemical and Biomolecular Engineering The University of SydneySydneyNSW 2006Australia School of Science The Royal Melbourne Institute of Technology UniversityMelbourneVIC 3000Australia Department of Mechanical Engineering City University of Hong Kong83 Tat Chee AvenueKowloonHong KongChina

Unsustainable fossil fuel energy usage and its environmental impacts are the most significant scientific challenges in the scientific ***-dimensional(2D)materials have received a lot of attention recently because of their great potential for application in addressing some of society’s most enduring issues with renewable *** metal-based nitrides,carbides,or carbonitrides,known as“MXenes”,are a relatively new and large family of 2D *** the discovery of the first MXene,Ti_(3)C_(2) in 2011 has become one of the fastest-expanding families of 2D materials with unique physiochemical *** surface terminations with hydroxyl,oxygen,fluorine,etc.,are invariably present in the so far reported materials,imparting hydrophilicity to their *** current finding of multi-transition metal-layered MXenes with controlled surface termination capacity opens the door to fabricating unique structures for producing renewable *** NMs-based flexible chemistry allows them to be tuned for energy-producing/storage,electromagnetic interference shielding,gas/biosensors,water distillation,nanocomposite reinforcement,lubrication,and photo/electro/chemical *** review will first discuss the advancement of MXenes synthesis methods,their properties/stability,and renewable energy ***,we will highlight the constraints and challenges that impede the scientific community from synthesizing functional MXene with controlled composition and *** will further reveal the high-tech implementations for renewable energy storage applications along with future challenges and their solutions.

关键词： Recent development in synthesis Structures Properties of MXenes nanomaterials Propose approaches of diverse MXene-based nanoplatforms MXenes for renewable energy applications Optimization strategies and mechanisms to enhance MXenes compatibility Current challenges and probable progress for MXenes in renewable energy applications

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