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journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.jeong S.W.lee W.j.Kim Department of Materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 819-836页

作者： D.lee S.ChANG j.lee Department of Automotive Engineering Hanyang UniversitySeoul 04763Republic of Korea School of Mechanical Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation substructuring

Fabrication of SAW Sensor for Detecting Chemical Agent

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稀有金属材料与工程 2006年第A3期35卷 433-435页

作者： j h lee B S joo j S huh D D lee School of Electronic & Electrical Engineering Kyungpook National UniversityKorea Dept.of Materials Science and Metallurgy Kyungpook National UniversityKorea

SAW sensors using five different types of polymer to detect of chemical agents(DMMP,Ch_3CN,Ch_2Cl_2,DCP) have been fabricated and its gas response characteristics were extensively *** polymers used as the sensing material are polyisobutylene(PIB),polyepichlorohydrin(PECh),polydimethylsiloxane(PDMS),polyisoprene(PIP)and polybutadiene(PBD).Their thin films were coated on quartz substrate by spin coating *** types of simulants gases,dimethylmethylphosphonate(DMMP),acetonitrile(Ch_3CN)and dichloromethane(Ch_2Cl_2),dichloropentane(DCP)were used as target gases,instead of the real nerve,blood,choking and vesicant *** spin coating of PIB and PECh,the substrates were heated to 65℃with N_2 flow for 1 h to remove the cyclohexane and ethylacetate which was used as solvent. PDMS was heated to 75℃with N_2 flow for 2 h to remove the ethylacetate which was used as *** and PIP on the substrate were heated to 60℃with N_2 flow for 1 h to remove the benzen which was used as *** sensing characteristics of the SAW sensors were measured by using E-5061A network analyzer.

关键词： SAW DMMP Ch3CN Ch2Cl2 DCP polymer film

Effect of Solute Contents of Al-Ni-Sr Alloy on Glass Forming Ability and Thermal Stability

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journal of Rare Earths 2004年第Z2期22卷 73-77页

作者： Taek Soo Kim j K lee h j Kim j C Bae Advanced Materials R&D Center Korea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea

Glass forming ability (GFA) and structural characterization of a new amorphous Al-Ni-Sr alloy melt spun were investigated on the theory of the factors for the glass formation. The GFA was varied with the ratio of Ni to Sr in detail and successful amorphous phase dispersed with 2 ～ 5 nm precipitates was prepared from Al-Ni5-Sr3. Thermal stability and crystallization behavior of the amorphous phase were determined by continuous and isothermal heating technique on DCS, resulting that the crystallization occurs by the growth of fcc Al nanocrystals on the preexistent nuclei.

关键词： glass formation crystallization Al base amorphous alloys rapid solidification

Numerical Experiment on Two-Dimensional Line Thermal

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China Ocean Engineering 2002年第4期17卷 453-467页

作者： j.h.W.lee 陈国谦 Department of Civil Engineering University of Hong KongHongkongChina National Laboratory for Turbulence Peking UniversityBeijing 100871China

The time evolution of a two-dimensional line thermal-a turbulent flow produced by an initial element with significant buoyancy released in a large water body, is numerically studied with the two-equation k - epsilon model for turbulence closure. The numerical results show that the thermal is characterized by a vortex pair flow and a kidney shaped concentration structure with double peak maxima; the computed flow details and scalar mixing characteristics can be described by self-similar relations beyond a dimensionless time around 10. There are two regions in the flow field of a line thermal: a mixing region where the concentration of tracer fluid is high and the flow is turbulent and rotational with a pair of vortex eyes, and an ambient region where the concentration is zero and the flow is potential and well-described by a model of doublet with strength very close to those given by early experimental and analytical studies. The added virtual mass coefficient of the thermal motion is found to be approximately 1. The aspect ratio for the kidney-shaped sectional thermal is found to be around 1.45 for the self-similar phase. The predicted thermal spreading and mixing rate compares well with experimental data.

关键词： thermals and puffs turbulence modeling plumes and jets environmental fluid mechanics vortex flow added virtual mass mixing and transport

Development of mathematical model with a genetic algorithm for automatic arc welding process

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Acta Metallurgica Sinica(English Letters) 2010年第3期23卷 230-240页

作者： D.T.Thao I.S.Kim j.W.jeong j.h.lee j.Y.Shim h.h.Kim Department of Mechanical Engineering Mokpo National University

This paper is to represent new algorithms to predict process parameters on top-bead width in robotic gas metal arc（GMA） welding *** models have been developed：linear, curvilinear and intelligent model based on full factorial design with two *** analysis was employed for optimization of the coefficients of linear and curvilinear models, while genetic algorithm（GA） was utilized to estimate the coefficients of an intelligent *** only the fitting of these models were checked and compared by using a variance test（ANOVA）, but also the prediction on top-bead width using the developed models were carried out based on the additional *** developed models were employed to investigate the characteristic between process parameters and top-bead *** solutions and graphical representation showed that the intelligent model developed can be employed for prediction of bead geometry in GMA welding process.

关键词： Top-bead width Genetic algorithm Multiple regression Robotic arc welding GMA welding

Computational Analysis of a Variable Ejector Flow

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journal of Thermal Science 2006年第2期15卷 140-144页

作者： h.D. KIM j.h. lee T. SETOGUChI S.MATSUO School of Mechanical Engineering Andong National University 388 Songchun-dong Andong 760-749 Korea Department of Mechanical Engineering Saga University 1 Honjo Saga 840-8502 Japan

现在的学习探讨能改进驱逐者效率并且在固定操作压力比率下面控制再通行比率的一个可变驱逐者。可变驱逐者是一台设备由改变驱逐者喉咙区域比率在给定的操作压力比率下面获得特定的再通行比率。数字模拟被执行在可变驱逐者内提供流动特... 详细信息

现在的学习探讨能改进驱逐者效率并且在固定操作压力比率下面控制再通行比率的一个可变驱逐者。可变驱逐者是一台设备由改变驱逐者喉咙区域比率在给定的操作压力比率下面获得特定的再通行比率。数字模拟被执行在可变驱逐者内提供流动特征的理解。声音、超声的嘴在驱逐者系统，和活动的锥柱体作为主要的开车的嘴被采用，插入了到一个常规驱逐者弥漫的系统，被用来改变驱逐者喉咙区域比率。数字模拟基于可压缩的、平均 Reynolds 的海军司烧方程的一个充分含蓄的有限体积计划。结果证明可变驱逐者能在固定操作压力比率控制再通行比率。关键词可变驱逐者 - 驱逐者喉咙区域比率 - 再通行比率 CLC 数字

关键词：变量排出器再环流比排出口面积比排出效率

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL j.ChOI S.F.ShAh C.lee S.lee Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyCo_(z)O_(2)(x>0.8)(NMC)

肿瘤-膀胱壁接触长度为VIRADS评分为2～3病变提供有效风险分层

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国际医学放射学杂志 2024年第1期 128-128页

作者： h.Ahn T.M.Kim S.I.hwang h.j.lee G.Choe S.K.hong 曹琳

摘要目的评价肿瘤接触长度（TCL）对预测膀胱影像报告和数据系统（VIRADS）评分为2～3的病变中肌层浸润性膀胱癌（MIBC）的诊断效能。方法回顾性纳入一个机构2019

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应用图像卷积神经网络预测大脑年龄诠释早产儿神经发育轨迹

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国际医学放射学杂志 2024年第4期 500-500页

作者： M.T.Liu M.h.Lu S.Y.Kim h.j.lee B.A.Duffy S.Y.Yuan 杨程

摘要目的婴儿大脑在妊娠晚期会发生显著的形态变化。探讨应用图像卷积网络（GCN）根据孕晚期胎儿皮质形态预测的大脑年龄（PBA）与产后异常和神经发育结局是否存

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