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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

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of gdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped gdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped gdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in gdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped gdNbO4phosphors.

关键词： Eu 3+ gdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

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)

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KsTAR托卡马克设计

国外核聚变 2002年第2期 67-72页

作者： g.s.lee 王尚柄等

韩国超导托卡马克（KsTAR）探索性研究项目是韩国国家聚变计划的重点项目，其主要工作是研制能稳态运行的先进超导托卡马克，为具有吸引力的聚变堆建立科学技术基础。该托卡马克的主要参数是，大半径1.8m，小半径0.5m，环向场3．5T，环... 详细信息

韩国超导托卡马克（KsTAR）探索性研究项目是韩国国家聚变计划的重点项目，其主要工作是研制能稳态运行的先进超导托卡马克，为具有吸引力的聚变堆建立科学技术基础。该托卡马克的主要参数是，大半径1.8m，小半径0.5m，环向场3．5T，环向场3．5T，等离子体电流2MA，并具有强变形的等离子体横截面和双零偏滤器。最初由极向磁系统提供的脉冲长度为20s，但是通过非感应电流驱动脉冲长度可以增大到300s。等离子体加热和电流驱动系统包括中性束，离子回旋波，低杂波和电子回旋波，它们都可用于灵活的剖面控制。全套诊断设备计划用于等离子体控制和特性计算以及对物理学的了解。该项目已经完成概念设计阶段，进入到工程设计阶段。首次产生等离子体的日期确定在2002年。

关键词： KsTAR项目超导托卡马克聚变反应堆聚变计划韩国

ROs-induced metabolic reprogramming to one-carbon metabolism and s-adenosylmethionine-mediated epigenetic modification in IL-10-producing B cells for the resolution of pneumonia

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Cellular & Molecular Immunology 2024年第2期21卷 203-204页

作者： sujin lee Tae Jin Kim Department of Immunology Sungkyunkwan University School of MedicineSuwon16419Republic of Korea

B cells have an essential immunoregulatory function,which is mediated by the secretion of IL-10 and TgFβand interaction with activated CD4^(+)T *** antibody-independent function of B cells contributes to ameliorating autoimmune diseases or infection-induced tissue *** this Cellular and Molecular Immunology issue,Fu et *** that regulatory B(Breg)cells play a critical role in resolving Pseudomonas aeruginosa-induced pneumonia[1].

关键词： metabolism pneumonia Immunology

superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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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

Present status of the KsTAR superconducting Magnet system Development

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Plasma science and Technology 2004年第5期6卷 2445-2450页

作者： Keeman Kim H.K.Park K.R.Park B.s.Lim s.I.lee M.K.Kim Y.Chu W.H.Chung s.H.Baek J.Y.Cho H.Yonekawa A.Chertovskikh Y.B.Chang J.s.Kim C.s.Kim D.J.Kim N.H.song K.P.Kim Y.J.song I.s.Woo W.s.Han D.K.lee Y.K.Oh K.W.Cho J.s.Park g.s.lee H.J.lee T.K.Ko s.J.lee National NationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalNationalKorea Atomic Energy Research InstituteDaejeonRepublic of KoreaYonsei UniversitySeoulRepublic of KoreaYonsei UniversitySeoulRepublic of Korea Fusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science InstituteDaejeonRepublic of KoreaFusion R&D CenterKorea Basic Science

The mission of Korea superconducting Tokamak Advanced Research (KsTAR)project is to develop an advanced steady-state superconducting tokamak for establishing a scientificand technological basis for an attractive fusion reactor. Because one of the KsTAR mission is toachieve a steady-state operation, the use of superconducting coils is an obvious choice for themagnet system. The KsTAR superconducting magnet system consists of 16 Toroidal Field (TF) coils and14 Poloidal Field (PF) coils. Internally-cooled Cable-In-Conduit Conductors (CICC) are put into usein both the TF and PF coil systems. The TF coil system provides a field of 3.5 T at the plasmacenter and the PF coil system is able to provide a flux swing of 17 V-sec. The major achievement inKsTAR magnet-system development includes the development of CICC, the development of a full-size TFmodel coil, the development of a coil system for background magnetic-field generation , theconstruction of a large-scale superconducting magnet and CICC test facility. TF and PF coils are inthe stage of fabrication to pave the way for the scheduled completion of KsTAR by the end of 2006.

关键词： superconducting magnet KsTAR CICC

Azimuthal rotation-controlled nanoinscribing for continuous patterning of period-and shapetunable asymmetric nanogratings

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Microsystems & Nanoengineering 2024年第3期10卷 207-218页

作者： Useung lee Hyein Kim Dong Kyo Oh Nayeong lee Jonggab Park Jaewon Park Hyunji son Hyunchan Noh Junsuk Rho Jong g.Ok Department of Mechanical and Automotive Engineering Seoul National University of Science and TechnologySeoul 01811Republic of Korea Department of Mechanical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea Department of Chemical Engineering Pohang University of Science and Technology(POSTECH)Pohang 37673Republic of Korea POsCO-POsTECH-RIsT Convergence Research Center for Flat Optics and Metaphotonics Pohang 37673Republic of Korea National Institute of Nanomaterials Technology(NINT) Pohang 37673Republic of Korea Present address:Department of Mechanical Engineering Korea University145 Anam-roSeongbuk-guSeoul 02841Republic of Korea Research Team Hyundai Motor Group150 Hyundaiyeonguso-roHwaseong-siGyeonggi 18280Republic of Korea

We present an azimuthal-rotation-controlled dynamic nanoinscribing(ARC-DNI)process for continuous and scalable fabrication of asymmetric nanograting structures with tunable periods and shape profiles.A sliced edge of a nanograting mold,which typically has a rectangular grating profile,slides over a polymeric substrate to induce its burrfree plastic deformation into a linear *** this continuous nanoinscribing process,the“azimuthal angle,”that is,the angle between the moving direction of the polymeric substrate and the mold’s grating line orientation,can be controlled to tailor the period,geometrical shape,and profile of the inscribed *** modulating the azimuthal angle,along with other important ARC-DNI parameters such as temperature,force,and inscribing speed,we demonstrate that the mold-opening profile and temperature-and time-dependent viscoelastic polymer reflow can be controlled to fabricate asymmetric,blazed,and slanted nanogratings that have diverse geometrical profiles such as trapezoidal,triangular,and ***,period-and profile-tunable ARC-DNI can be utilized for the practical fabrication of diverse optical devices,as is exemplified by asymmetric diffractive optical elements in this study.

关键词： tunable asymmetric rotation

study of hybrid nanofluid flow in a stationary cone-disk system with temperature-dependent fluid properties

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Applied Mathematics and Mechanics(English Edition) 2024年第4期45卷 677-694页

作者： A.s.JOHN B.MAHANTHEsH g.LORENZINI Center for Mathematical Needs Department of MathematicsCHRIST(Deemed to be University)Karnataka 560029India school of Mathematical and statistical sciences The University of Texas Rio Grande ValleyTexas 78539U.S.A. Department of Engineering and Architecture University of ParmaParma 43124Italy

Cone-disk systems find frequent use such as conical diffusers,medical devices,various rheometric,and viscosimetry *** this study,we investigate the three-dimensional flow of a water-based Ag-Mg O hybrid nanofluid in a static cone-disk system while considering temperature-dependent fluid *** the variable fluid properties affect the dynamics and heat transfer features is studied by Reynolds's linearized model for variable viscosity and Chiam's model for variable thermal *** single-phase nanofluid model is utilized to describe convective heat transfer in hybrid nanofluids,incorporating the experimental *** model is developed as a coupled system of convective-diffusion equations,encompassing the conservation of momentum and the conservation of thermal energy,in conjunction with an incompressibility condition.A self-similar model is developed by the Lie-group scaling transformations,and the subsequent self-similar equations are then solved *** influence of variable fluid parameters on both swirling and non-swirling flow cases is ***,the Nusselt number for the disk surface is *** is found that an increase in the temperature-dependent viscosity parameter enhances heat transfer characteristics in the static cone-disk system,while the thermal conductivity parameter has the opposite effect.

关键词： hybrid nanofluid cone-disk system laminar flow variable fluid property Nusselt number