检索结果-内蒙古大学图书馆

Low-temperature sintering of Li0.33La0.55TiO3 electrolyte for all-solid-state Li batteries

学校读者我要写书评

暂无评论

Journal of the European Ceramic Society 2023年第16期43卷 7543-7552页

作者： Lin, Che-an Ihrig, Martin Kung, Kuan-chen Chen, Hsiang-ching Scheld, Walter Sebastian Ye, Ruijie Finsterbusch, Martin Guillon, Olivier Lin, Shih-kang Department of Materials Science and Engineering National Cheng Kung University Tainan70101 Taiwan Institute of Energy and Climate Research – Materials Synthesis and Processing Forschungszentrum Jülich GmbH Jülich52425 Germany Department of Chemical Engineering National Taiwan University of Science and Technology No. 43 Keelung Rd. Section 4 Da'an Dist Taipei City106 Taiwan Helmholtz Institute Münster: Ionics in Energy Storage Corrensstr. 46 Münster48149 Germany Research Center National Cheng Kung University Tainan70101 Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan70101 Taiwan Core Facility Center National Cheng Kung University Tainan70101 Taiwan

Ceramic solid-state Li batteries have promising electrochemical properties. However, their device integration is hampered by the required high sintering temperature step to obtain good ionic conductivity. The sintering temperature often leads to thermal decomposition of the cathode active material. Advanced sintering techniques, such as field-assisted sintering technology/spark plasma sintering (FAST/SPS), utilizing applied mechanical pressure to achieve a lower sintering temperature and shorter dwell time, are helpful in overcoming thermal stability challenges. While thermal stability issues are overcome by a lower sintering temperature, new challenges in the form of surface impurities arise. Low-temperature sintering does not thermally decompose surface impurities which causes low grain boundary conductivity and thus low total ionic conductivity. In this work, a cleaning method and a low-temperature sintering process is exemplarily developed for Li0.33La0.55TiO3 (LLTO) and the impact of applied mechanical pressure during FAST/SPS on the total ionic conductivity and the phase stability of LLTO is revealed. © 2023 Elsevier Ltd

关键词： Spark plasma sintering

Dehydration drives damage in the freezing of brittle hydrogels

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Yang, Shaohua Gerber, Dominic Feng, Yanxia Bain, Nicolas Kuster, Matthias de Lorenzis, Laura Xu, Ye Dufresne, Eric R. Style, Robert W. School of Mechanical Engineering and Automation Beihang University Beijing China Department of Materials ETH Zürich Zürich8093 Switzerland University of Lyon Université Claude Bernard Lyon 1 CNRS Institut Lumière Matière VilleurbanneF-69622 France Department of Mechanical and Process Engineering ETH Zürich Zürich8093 Switzerland Department of Materials Science & Engineering Cornell University Ithaca United States Laboratory of Atomic and Solid State Physics Cornell University Ithaca United States

It is widely known that freezing breaks soft, wet materials. However, the mechanism underlying this damage is still not clear. To understand this process, we freeze model, brittle hydrogel samples, while observing the growth of ice-filled cracks that break these apart. We show that damage is not caused by the expansion of water upon freezing, or the growth of ice-filled cavities in the hydrogel. Instead, local ice growth dehydrates the surrounding hydrogel, leading to drying-induced fracture. This dehydration is driven by the process of cryosuction, whereby undercooled ice sucks nearby water towards itself, feeding its growth. Our results highlight the strong analogy between freezing damage and desiccation cracking, which we anticipate being useful for developing an understanding of both topics. Our results should also give useful insights into a wide range of freezing processes, including cryopreservation, food science and frost heave. Copyright © 2024, The Authors. All rights reserved.

关键词： Hydrogels

Experimental Optimization of Jet Self-Priming Centrifugal Pump Based on Orthogonal Design and Grey-Correlational Method

学校读者我要写书评

暂无评论

Journal of Thermal science 2020年第1期29卷 241-250页

作者： CHANG Hao SHI Weidong LI Wei WANG Chuan ZHOU Ling LIU Jianrui YANG Yongfei RAMESH KAgarwal Research Center of Fluid Machinery Engineering and Technology Jiangsu UniversityZhenjiang 212013China Department of Mechanical Engineering&Materials Science Washington University in St.LouisSt.Louis 63130USA School of Mechanical Engineering Nantong UniversityNantong 226019China School of Hydraulic Energy and Power Engineering Yangzhou UniversityYangzhou 225002China

The novel jet self-priming centrifugal pump,as important modern irrigation equipment,is widely used in large-scale irrigation,mine drainage and so *** order to improve the profile streamline of blade,the inlet shape of impeller was designed as distorted and the outlet shape as cylindrical,which can not only improve the pump efficiency,but also shorten the self-priming ***,the novel jet self-priming system was proposed,by employing the jet nozzle and check valve to improve the velocity of ***,nine different structure jet nozzles were designed based on the orthogonal design method,and the relevant self-priming experiments were performed on I level accuracy test bench in Jiangsu *** to the greycorrelational analysis,the influence of the nozzle geometry parameters on the self-priming performance was *** relationship between self-priming time and self-priming height was *** test results showed that the hydraulic design of jet self-priming centrifugal pump was reasonable;all indicators met the Chinese national standard;the head reached 21.04 m and efficiency was 72.8%under the design flow *** is more,the self-priming performance was obviously improved by adjusting the geometrical parameters of *** the height of the self-priming process was 5.3 m,the self-priming time reached 62 s,which was much shorter than the national ***,this research could provide reference for designing the structure of jet self-priming centrifugal pump.

关键词： self-priming centrifugal pump design optimization orthogonal experiment grey-correlational

Spin configuration of an array of quantum rings controlled by cavity photons

学校读者我要写书评

暂无评论

Physical Review B 2025年第11期111卷 115304-115304页

作者： Vidar Gudmundsson Vram Mughnetsyan Hsi-Sheng Goan Jeng-Da Chai Nzar Rauf Abdullah Chi-Shung Tang Valeriu Moldoveanu Andrei Manolescu Science Institute University of Iceland Dunhaga 3 IS-107 Reykjavik Iceland Department of Solid State Physics Yerevan State University Alex Manoogian 1 0025 Yerevan Armenia Department of Physics and Center for Theoretical Physics National Taiwan University Taipei 106319 Taiwan Center for Quantum Science and Engineering National Taiwan University Taipei 106319 Taiwan Physics Division National Center for Theoretical Sciences Taipei 106319 Taiwan Physics Department College of Science University of Sulaimani 501 Sulaimania Kurdistan Region Iraq Department of Mechanical Engineering National United University Miaoli 360302 Taiwan National Institute of Materials Physics PO Box MG-7 Bucharest-Magurele Romania Department of Engineering Reykjavik University Menntavegur 1 IS-102 Reykjavik Iceland

We model a change of the spin configuration in a two-dimensional square array, or a lateral superlattice, of quantum rings in an external perpendicular homogeneous magnetic field. The electron system is placed in a circular cylindrical far-infrared photon cavity with a single circularly symmetric photon mode. Our numerical results reveal that the spin ordering of the two-dimensional electron gas in each quantum ring can be influenced or controlled by the electron-photon coupling strength and the energy of the photons. The Coulomb interaction between the electrons is described by a spin-density functional approach, but the para- and diamagnetic electron-photon interactions are modeled via a configuration interaction formalism in a truncated many-body Fock-space, which is updated in each iteration step of the density functional approach. In the absence of external electromagnetic pulses this reordering of the spin configuration is replicated in the orbital magnetization of the rings. The change in the spin configuration can be suppressed by a strong electron-photon interaction. In addition, fluctuations in the spin configuration are found in dynamical calculations, where the system is excited by a time-dependent coupling scheme to a cylindrical cavity mode for emphasizing the diamagnetic electron-photon interaction not leading to simple electrical dipole oscillations. The diamagnetic interaction is enhanced by the rotational electric field of the particular cavity mode.

关键词： Diamagnetism

Rapid quantification of dynamic and spall strength of metals across strain rates

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Prameela, Suhas Eswarappa Walker, Christopher C. DiMarco, Christopher S. Mallick, Debjoy D. Sun, Xingsheng Hernandez, Stephanie Sasaki, Taisuke Wilkerson, Justin W. Ramesh, K.T. Pharr, George M. Weihs, Timothy P. Department of Materials Science and Engineering MIT CambridgeMA United States Department of Aeronautics and Astronautics MIT CambridgeMA United States Department of Materials Science and Engineering Johns Hopkins University BaltimoreMD21218 United States Hopkins Extreme Materials Institute Johns Hopkins University BaltimoreMD21218 United States Department of Materials Science and Engineering Texas A&M University College StationTX77843 United States Sindri Materials Corp. West ChesterPA19382 United States DEVCOM Army Research Laboratory 321 Colleran Road Aberdeen Proving GroundMD21005-5066 United States Department of Mechanical and Aerospace Engineering University of Kentucky LexingtonKY40506 United States Department of Mechanical Engineering Johns Hopkins University BaltimoreMD21218 United States National Institute for Materials Science Tsukuba305-0047 Japan Kyoto University Yoshida Honmachi Sakyo Kyoto606-8501 Japan Department of Mechanical Engineering Texas A&M University College StationTX77843 United States

Over the last few decades, numerous small-scale mechanical testing techniques have been developed to evaluate the fundamental deformation mechanisms and failure behavior of metals. However, many of these techniques are insufficient to accurately predict material behavior at extreme strain rates, critical for applications such as car crashes, meteoroid impact on satellites, launch and re-entry of rockets, and protection materials to stop bullets. The response of metals and their microstructures under extreme dynamic conditions can be markedly different from that under quasistatic conditions. Traditionally, high strain rates and shock stresses are measured using cumbersome and expensive methods such as the Kolsky bar or large spall experiments. These methods are low throughput and do not facilitate high-fidelity microstructure-property linkages. In this work, we combine two powerful small-scale testing methods, custom nanoindentation, and laser-driven micro-flyer shock, to measure the dynamic and spall strength of metals. The nanoindentation system is configured to test samples from quasistatic to dynamic strain rate regimes (10−3 s−1 to 10+4 s−1). The laser-driven micro-flyer shock system can test samples through impact loading between 10+5 s−1 to 10+7 s−1 strain rates, triggering spall failure. The model material used for testing is Magnesium alloys, which are lightweight, possess high-specific strengths and have historically been challenging to design and strengthen due to their mechanical anisotropy. Here, we modulate their microstructure by adding or removing precipitates to demonstrate interesting upticks in strain rate sensitivity and evolution of dynamic strength. At high shock loading rates, we unravel an interesting paradigm where the spall strength of these materials converges, but the failure mechanisms are markedly different. Peak aging, considered to be a standard method to strengthen metallic alloys, causes catastrophic failure, faring much worse than s

关键词： Strain rate

High-order AMR in two-dimensional magnetic monolayers from spin mixing

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Dong, M.Q. Guo, Zhi-Xin State Key Laboratory for Mechanical Behavior of Materials School of Materials Science and Engineering Xi’an Jiaotong University Shaanxi Xi’an710049 China Institute of Computational Physical Sciences State Key Laboratory of Surface Physics Department of Physics Fudan University Shanghai200433 China

Anisotropic magnetoresistance (AMR) is a well-known magnetoelectric coupling phenomenon, commonly exhibiting two-fold symmetry relative to the magnetic field. In this study, we reveal the existence of high-order AMRs in two-dimensional (2D) magnetic monolayers. Based on density functional theory (DFT) calculations of Fe3GeTe2 and CrTe2 monolayers, we find that different energy bands contribute uniquely to AMR behavior. The high-order AMR is attributed to strong spin mixing at band crossing points, which induces significant Berry curvature. This curvature also contributes to the AMR for electrons with dominant spin-up or spin-down polarization characteristics. However, for electrons exhibiting strong spin mixing, the Berry curvature effect becomes nontrivial, resulting in high-order AMR. Our findings provide an effective approach to identifying and optimizing materials with high-order AMR, which is critical for designing high-performance spintronic devices. Copyright © 2024, The Authors. All rights reserved.

关键词： Monolayers

Exact and model exchange-correlation potentials for open-shell systems

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Kanungo, Bikash Hatch, Jeffrey Zimmerman, Paul M. Gavini, Vikram Department of Mechanical Engineering University of Michigan Ann ArborMI48109 United States Department of Chemistry University of Michigan Ann ArborMI48109 United States Department of Materials Science and Engineering University of Michigan Ann ArborMI48109 United States

The conventional approaches to the inverse density functional theory problem typically assume non-degeneracy of the Kohn-Sham (KS) eigenvalues, greatly hindering their use in open-shell systems. We present a generalization of the inverse density functional theory problem that can seamlessly admit degenerate KS eigenvalues. Additionally, we allow for fractional occupancy of the Kohn-Sham orbitals to also handle non-interacting ensemble-v-representable densities, as opposed to just non-interacting pure-v-representable densities. We present the exact exchange-correlation (XC) potentials for six open-shell systems—four atoms (Li, C, N, and O) and two molecules (CN and CH2)—using accurate ground-state densities from configuration interaction calculations. We compare these exact XC potentials with model XC potentials obtained using non-local (B3LYP, SCAN0) and local/semi-local (SCAN, PBE, PW92) XC functionals. Although the relative errors in the densities obtained from these DFT functionals are of O(10−3 − 10−2), the relative errors in the model XC potentials remain substantially large—O(10−1 − 100). Copyright © 2023, The Authors. All rights reserved.

关键词： Density functional theory

Surface Modification of Cu Native Oxide: Ag Displacement for Homogeneous Layering

学校读者我要写书评

暂无评论

Surface Modification of Cu Native Oxide: Ag Displacement for...

International Conference on Electronics Packaging (ICEP)

作者： Shubhayan Mukherjee Akitsu Shigetou Shih-kang Lin Department of Materials Science and Engineering National Cheng Kung University Tainan Taiwan National Institute for Materials Science Ibaraki Japan Hierarchical Green-Energy Materials (Hi-GEM) Research Centre National Cheng Kung University Tainan Taiwan Program on Smart and Sustainable Manufacturing Academy of Innovative Semiconductor and Sustainable Manufacturing National Cheng Kung University Tainan Taiwan

ISBN: (数字)9784991191190

ISBN: (纸本)9798331514747

Cu's electrical and thermal conductivity makes it a vital material in various industrial applications, but its susceptibility to oxidation under ambient conditions can compromise performance, particularly in the semiconductor industry. This study presents an innovative surface modification technique to inhibit the growth of native oxide on Cu prior to Ag coating to enhance a galvanic replacement (GR) reaction under good adhesion between Ag and Cu. Ag-coated Cu electrodes are effective in removing the surface oxide on Cu and acting as deformable and low-resistance Cu interconnects. The surface modification process utilizes vacuum ultraviolet (VUV) treatment in an ethanol atmosphere, forming a stable, hydroxylated surface layer that minimizes reoxidation before Ag deposition. X-ray photoelectron spectroscopy (XPS) confirmed the effective suppression of reoxidation, and scanning electron microscopy (SEM) revealed a homogeneous Ag coating with optimal surface coverage. This methodology significantly enhances the oxidation resistance of Cu.

关键词： Scanning electron microscopy Surface resistance Ethanol Atmosphere Thermal conductivity Oxidation Coatings Copper Surface treatment Thermal stability

Efficient Optical Control of Magnon Dynamics in van der Waals Ferromagnets

学校读者我要写书评

暂无评论

Ultrafast science 2024年第6期4卷 53-60页

作者： Yu Gong Zhonghua Yang Alem Teklu Ti Xie Noah Kern Andrew F.May Michael McGuire Christian Brennan Er-Jia Guo Narayanan Kuthirummal John Cetin Qian Zhang Ming Hu Cheng Gong Department of Physics and Astronomy College of CharlestonCharlestonSC 29424USA Department of Mechanical Engineering University of South CarolinaColumbiaSC 29208USA College of Architecture and Civil Engineering Shenyang University of TechnologyShenyang 110870China Department of Electrical and Computer Engineering and Quantum Technology Center University of MarylandCollege ParkMD 20742USA Materials Science and Technology Division Oak Ridge National LaboratoryOak RidgeTN 37831USA Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China

Optical control of magnons in two-dimensional(2D)materials promises new functionalities for spintronics and magnonics in atomically thin ***,we report control of magnon dynamics,using laser polarization,in a ferromagnetic van der Waals(vdW)material,*** magnon amplitude,frequency,and lifetime are controlled and monitored by time-resolved pump-probe *** show substantial(over 25%)and continuous modulation of magnon dynamics as a function of incident laser *** results suggest that the modification of the effective demagnetization field and magnetic anisotropy by the pump laser pulses with different polarizations is due to anisotropic optical *** implies that pump laser pulses modify the local spin environment,which enables the launch of magnons with tunable *** first-principles calculations confirm the anisotropic optical absorption of different crystal *** findings suggest a new route for the development of opto-spintronic or opto-magnonic devices.

关键词： magnon dynamics atomically thin devicesherewe control magnon dynamicsusing van der waals ferromagnets optical control modulation magnon dynamics ferromagnetic van der waals vdw materialfe co gete optical control magnons