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A machine learning-based calibration method for strength simulation of self-piercing riveted joints

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Advances in Manufacturing 2024年第3期12卷 465-483页

作者： Yu-Xiang Ji Li Huang Qiu-Ren Chen Charles K.S.Moy Jing-Yi Zhang Xiao-Ya Hu Jian Wang Guo-Bi Tan Qing Liu Key Laboratory for Light-weight materials Nanjing Tech UniversityNanjing210009People’s Republic of China Design School Xi’an Jiaotong-Liverpool UniversitySuzhou215123JiangsuPeople’s Republic of China materials bigdata and applications division Materials Academy JitriSuzhou215131JiangsuPeople’s Republic of China School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing210094People’s Republic of China

This paper presents a new machine learning-based calibration framework for strength simulation models of self-piercing riveted(SPR)*** simulations were conducted through the integrated modeling of SPR joints from process to performance,while physical quasi-static tensile tests were performed on combinations of DP600 high-strength steel and 5754 aluminum alloy sheets under lap-shear loading conditions.A sensitivity study of the critical simulation parameters(e.g.,friction coefficient and scaling factor)was conducted using the controlled variables method and Sobol sensitivity analysis for feature ***,machine-learning-based surrogate models were used to train and accurately represent the mapping between the detailed joint profile and its load-displacement *** of the simulation model is defined as a dual-objective optimization task to minimize errors in key load displacement features between simulations and experiments.A multi-objective genetic algorithm(MOGA)was chosen for *** three combinations of SPR joints illustrated the effectiveness of the proposed framework,and good agreement was achieved between the calibrated models and experiments.

关键词： Machine learning Self-piercing riveting(SPR) Sensitivity analysis Multi-objective optimization

Effect of Firing Temperature on the Electromagnetic Properties of Electronic Transformer Cores Developed by Using Nanosized Mn–Zn Ferrite Powders

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Acta Metallurgica Sinica(English Letters) 2015年第2期28卷 159-163页

作者： Hassan Waqas Ammad Hussain Qureshi Muhammad Shahzad materials division Directorate of Technology PINSTECH

Current investigation deals with the effect of grain growth process as a function of sintering temperature on the electromagnetic properties （initial permeability, impedance, and gain） of Mn-Zn ferrite （MZF） cores （toroids）. By employing auto combustion process, nanosized [（20 ± 5） nm] MZF powders were synthesized and toroid shape cores were obtained after subsequent calcination and firing （sintering） process. It was observed that the submicron structure （0.5 μm） achieved in the ferrite core sintered at 1,000 ℃ was gradually transformed into micron size grains by increasing the firing temperature i.e., 1,100, 1,200, and 1,350 ℃. The results reveal that MZF core sintered at low temperature （1,000 ℃） showed high impedance, low initial permeability, and narrow working frequency range i.e., 3-15 MHz. However, the improvement in initial permeability, sintered density, and operational frequency range （100 kHz-17 MHz） was observed at high temperature （1,350 ℃） firing in the inert environment. This synthesized MZF core is more suitable for miniaturized switch mode power supply applications.

关键词： Mn-Zn ferrites Nanosized powders Impedance Sintering

Planar Channelling Criticalities of MeV Protons in Si Crystal： Simulations, Evaluation and applications

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Chinese Physics Letters 2008年第10期25卷 3724-3727页

作者： Mukhtar Ahmed Rana Methodology applications Initiative Physics Division PINSTECH Post Office Nilore Islamabad Pakistan

We reports a phase-space structure of MeV proton beam planar channelled along {110} planes in Si crystal using simulation results with the help of a computer code FLUX. The aim is to understand channelling conditions suitable for disorder measurement in crystals. Phase-space distribution of a planar channelled proton beam evolutes in a systematic fashion when it travels into the crystal. Planar channelled beam oscillates between phase-like and space-like conditions in which a part of the beam becomes under phase and space criticalities. These criticality conditions in planar channelling are analysed, explained and discussed with the perspective of defect measurement in crystals.

关键词： the power-law exponents precipitation durative abrupt precipitation change

Au and Ti induced charge redistributions on monolayer WS_2

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Chinese Physics B 2015年第7期24卷 429-434页

作者：朱会丽杨伟煌吴雅苹林伟康俊勇周昌杰 Department of Physics School of ScienceJimei University division of Physics and Applied Physics School of Physical and Mathematical ScienceNanyang Technological University Department of Physics Fujian Key Laboratory of Semiconductor Materials and ApplicationsXiamen University

By using the first-principles calculations, structural and electronic properties of Au and Ti adsorbed WS2 monolayers are studied systematically. For Au-adsorbed WS2, metallic interface states are induced in the middle of the band gap across the Fermi level. These interface states origin mainly from the Au-6s states. As to the Ti adsorbed WS2, some delocalized interface states appear and follow the bottom of conduction band. The Fermi level arises into the conduction band and leads to the n-type conducting behavior. The n-type interface states are found mainly come from the Ti-3d and W-5d states due to the strong Ti–S hybridization. The related partial charge densities between Ti and S atoms are much higher and increased by an order of magnitude as compared with that of Au-adsorbed WS2. Therefore, the electron transport across the Ti-adsorbed WS2 system is mainly by the resonant transport, which would further enhances the electronic transparency when monolayer WS2 contacts with metal Ti. These investigations are of significant importance in understanding the electronic properties of metal atom adsorption on monolayer WS2 and offer valuable references for the design and fabrication of 2D nanodevices.

关键词： WS2 transition metal dichalcogenides two-dimensional materials first-principles calculations

A cellulose-based lithium-ion battery separator with regulated ionic transport and high thermal stability for extreme environments

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Nano Research 2025年第1期18卷 315-322页

作者： Kun-Peng Yang Song Xie Zi-Meng Han Hao-Cheng Liu Chong-Han Yin Wen-Bin Sun Zhang-Chi Ling Huai-Bin Yang De-Han Li Qing-Fang Guan Shu-Hong Yu Department of Chemistry New Cornerstone Science LaboratoryInstitute of Biomimetic Materials&ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsDivision of Nanomaterials&ChemistryHefei National Research Center for Physical Sciences at the MicroscaleUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

Separators play a critical role in lithium-ion ***,the restrictions of thermal stability and inferior electrical performance in commercial polyolefin separators significantly limit their applications under harsh ***,we report a cellulose-assisted self-assembly strategy to construct a cellulose-based separator massively and *** an ultrahigh ionic conductivity in electrolytes of 3.7 mS·cm^(-1) and the ability to regulate ion transport,the obtained separator is a promising alternative for high-performance lithium-ion *** addition,integrated with high thermal stability,the cellulose-based separator endows batteries with high safety at high temperatures,greatly expanding the application scenarios of energy storage devices in extreme environments.

关键词： lithium-ion batteries bio-inspired materials battery separators cellulose nanofiber ultrahigh ionic conductivity high safety

Stepwise magnetization reversal of geometrically tuned in diameter Ni and FeCo bi-segmented nanowire arrays

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Nano Research 2019年第7期12卷 1547-1553页

作者： Ester M. Palmero Miguel Mendez Silvia Gonzalez Cristina Bran Victor Vega Manuel Vazquez Victor M. Prida Institute of materials Science of Madrid (ICMM-CSIC) Madrid 28049Spain Department of Physics University of OviedoFederico Garda Lorca 18Oviedo 33007Spain division of Permanent Magnets and applications IMDEA NanoscienceMadrid 28049Spain

Magnetization reversal processes of hexagonal dense arrays of bi-segmented Ni and Fe50Co50 nanowires consisting of two well defined diameters (45 and 80 nm) have been *** nanowires were grown inside of tailored pores of anodic alumina templates by combined anodization,atomic layer deposition (ALD) and electrodeposition *** experiments have allowed to identify their two-step magnetization reversal process ascribed to the respective segments of different *** is concluded from the differential susceptibility observed in the hysteresis loops,contrary to those for nanowires with homogeneous *** results are also confirmed by the first-order reversal curve (FORC) distribution diagrams,where an elongation parallel to the interaction axis around two coercive field values is obtained,which is correlated to the difference in diameter of the two *** well-defined two-step magnetization reversal process through the nanowire diameter design is thought to be very useful for the advanced control of the remagnetization in arrays of magnetic multidomain systems.

关键词： Bi-segmented nanowires nickel iron cobalt alloy stepwise magnetization reversal first-order reversal curve (FORC)

Recent Advances in Rare-Earth Polypnictides

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Chinese Journal of Chemistry 2020年第3期38卷 295-304页

作者： Lei Qiao Chao Zhang Xiang Wen Zhang Zi-Chuan Wang Haolin Yin Zhong Ming Sun School of materials Science and Engineering Tianjin Key Laboratory for Rare Earth Materials and ApplicationsState Key Laboratory of Element-Organic ChemistryNankai UniversityTianjin 300350China division of Chemistry and Chemical Engineering California Institute of TechnologyPasadenaCA 91125United Stotes

The polypnictide complexes of rare earth cations have drawn the attention of the scientific community for their uncommon bonding modes and potential ***,we present a systematic and comprehensive summary on recent advances in the field of rare earth polypnictides,focusing on their synthesis,structures,and *** structural stbilizing effects imposed by the electropositive rare earth cations as well as the reducing capability of rare earth precursors in the synthesis of these polypnictide complexes are described in this *** also disscuss in detail the bonding interactions and coordination modes between rare earth cations and polypnictide clusters as well as the similarities and the peculiarity of some structures.

关键词： rare bonding complexes

Structure and magnetic properties of bulk nanocrystalline Nd-Fe-B permanent magnets prepared by hot pressing and hot deformation

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Journal of Rare Earths 2013年第7期31卷 674-678页

作者：宋杰岳明左建华张子瑞刘卫强张东涛张久兴郭朝晖李卫 College of materials Science and Engineering Beijing University of Technology division of Functional materials Central Iron and Steel Research Institute

Structure and magnetic properties were studied for bulk nanocrystalline Nd-Fe-B permanent magnets that were prepared at 650 ℃ for 3 min under 300 MPa using the SPS-3.20-MK-V sintering machine and the hot pressed magnets were then submitted to hot deformation with height reduction of 50%, 60%, 70%, 80%, and 85%. Effects of height reduction （HR） and deformation temperature on the structure and magnetic properties of the magnets were investigated. The crystal structure was evaluated by means of X-ray diffraction （XRD） and the microstructure was observed by transmission electron microscopy （TEM）. The magnetic properties of the magnets were investigated by vibrating sample magnetometer （VSM）. As the height reduction increased, the remanence （Br） of the magnets increased first, peaks at 1.3 T with HR=60%, then decreased again, and the coercivity （Hci） of the magnets decreased monotonically. On the other hand, as the deformation temperature increased, the Br of the magnets increased first, peaks at 1.36 T with HR=60%, then decreased again, and the H^i of the magnets decreased monotonically. Under optimal conditions, the hot deformed magnet possessed excellent magnetic properties as Brl.36 T, Hci=1143 kA/m, and （BH）max=370 kJ/m3, suggesting the good potential of the magnets in practical applications.

关键词： nanocrystalline Nd-Fe-B magnets hot pressing hot deformation microstructure magnetic properties rare earths

Fabrication of flexible thin organic transistors by trace water assisted transfer method

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Chinese Chemical Letters 2018年第11期29卷 1681-1684页

作者： Junjie Kan Shuguang Wang Zhongwu Wang Shujing Guo Wenchong Wang Liqiang Li Institute of Nanochemistry and Nanobiology School of Environmental and Chemical EngineeringShanghai University Advanced Nano-materials division Key Laboratory of Nano-Devices and ApplicationsSuzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of Sciences

The development of fabrication method for flexible thin organic electronic device is highly important for the flexible and wearable products. Herein, we develop a facile peel-off method to transfer organic thin film to various substrates. In this strategy, polyacrylonitrile （PAN） film can be easily peeled offwith trace water and further transferred to various substrates. Using PAN as supporting and dielectric layers, high performance flexible organic transistors are fabricated. Remarkably, the method uses only micro volume water as an assist to peel off PAN film, which reduces the risk of contamination by solvent and greatly contributes to the performance maintenance.

关键词： Transfer Flexible Thin film organic transistor Peel-off