检索结果-内蒙古大学图书馆

Nitridation Effects of a GaAs Epitaxial Layer on Extending of the Decay Time of Terahertz Electromagnetic Waves Emitted from Coherent Longitudinal Optical Phonons Observed with the Use of Terahertz Time-Domain Spectroscopy

Nitridation Effects of a GaAs Epitaxial Layer on Extending o...

引用

International Conference on Infrared and Millimeter Waves

作者： Hideo Takeuchi Kai Matsunaga Yusuke Sengi Jared Mitchell Rachel Goldman Department of Physics and Elecronics Osaka Metropolitan University (formerly Osaka City University) Osaka Japan Department of Applied Physics Osaka City University (Currently Osaka Metropolitan Univ.) Osaka Japan Applied Physics Program University of Michigan Ann Arbor Michigan U.S.A. Materials Science and Engineering University of Michigan Ann Arbor Michigan U.S.A.

ISBN: (数字)9798350370324

ISBN: (纸本)9798350370331

We observed that, in an undoped GaAs 1-x N x single epilayer, terahertz electromagnetic waves from coherent GaAs-like longitudinal optical (LO) phonons have a long decay time in comparison with terahertz waves from coherent LO phonons in a GaAs single crystal. We attributed the origin of the present phenomena to the fact photogenerated electron-LO-phonon scattering is suppressed owing to reduction of the ultrafast photocurrent acceleration that originates both from relatively large electron effective mass caused by the band anticrossing and from the alloying effect due to the nitridation.

关键词： Spectroscopy Stimulated emission Epitaxial layers Gallium arsenide Phonons Ultrafast optics Optical scattering Photoconductivity Time-domain analysis Electrons

来源：评论

学校读者我要写书评

暂无评论

Correction to: Two‑dimensional variations of the coda Q in Northern Morocco and their interpretation

引用

Journal of Seismology 2023年第4期27卷 821-825页

作者： Boulanouar, Abderrahim Dobrynina, Anna Rahmouni, Abdelaali Samaouali, Abderrahim Harnafi, Mimoun Sebbani, Jamal Laboratory of Applied Sciences Modeling Optimization and Structural Dynamics in Civil Engineering National School of Applied Sciences Abdelmalek Essaadi University Al Hoceima Morocco Institute of the Earth’s crust Siberian Branch of Russian Academy of Science Irkutsk Russia Geological Institute Siberian Branch of Russian Academy of Science Ulan-Ude Russia Laboratory of Solid State Physics Department of Physics Faculty of Science Dhar El Mahraz Sidi Mohamed Ben Abdellah University Fez Morocco Laboratory of Thermodynamics Department of Physics Faculty of Science Mohammed V University Rabat Morocco Earth Science Department Scientific Institute Mohamed V University Rabat Morocco Mechanics and Materials Team Faculty of Science Mohammed V University Rabat Morocco

来源：评论

学校读者我要写书评

暂无评论

Emulating complex synapses using interlinked proton conductors

引用

Physical Review applied 2025年第1期23卷 014027-014027页

作者： Lifu Zhang Ji-An Li Yang Hu Jie Jiang Rongjie Lai Marcus K. Benna Jian Shi Department of Materials Science and Engineering Rensselaer Polytechnic Institute Troy New York 12180 USA Neurosciences Graduate Program University of California San Diego La Jolla California 92093 USA Department of Mathematics Purdue University West Lafayette Indiana 47907 USA Department of Neurobiology School of Biological Sciences University of California at San Diego La Jolla California 92093 USA Department of Physics Applied Physics and Astronomy Rensselaer Polytechnic Institute Troy New York 12180 USA

In terms of energy efficiency and computational speed, neuromorphic electronics based on nonvolatile memory devices are expected to be one of most promising hardware candidates for future artificial intelligence (AI). However, catastrophic forgetting, networks rapidly overwriting previously learned weights when learning new tasks, remains a pivotal obstacle in either digital or analog AI chips for unleashing the true power of brainlike computing. To address catastrophic forgetting in the context of online memory storage, a complex synapse model (the Benna-Fusi model) was proposed recently [M. K. Benna and S. Fusi, Nat. Neurosci. 19, 1697 (2016)], the synaptic weight and internal variables of which evolve following diffusion dynamics. In this work, by designing a proton transistor with a series of charge-diffusion-controlled storage components, we have experimentally realized the Benna-Fusi artificial complex synapse. Memory consolidation from coupled storage components is revealed by both numerical simulations and experimental observations. Different memory timescales for the complex synapse are engineered by the diffusion length of charge carriers and the capacity and number of coupled storage components. The advantages of the demonstrated complex synapse for both memory capacity and memory consolidation are revealed by neural network simulations of face-familiarity detection. Our experimental realization of the complex synapse suggests a promising approach to enhance memory capacity and to enable continual learning.

关键词： Nonvolatile storage

来源：评论

学校读者我要写书评

暂无评论

Fabrication of sandwich-structured capacitor containing core@shell polystyrene@graphene oxide microspheres for switchable removal of dyes from water by dielectrophoresis force

引用

Separation and Purification Technology 2024年 331卷

作者： Chen, Wei-Liang Cheng, Chih-Chia Lu, Chien-Hsing Chen, Jem-Kun Department of Materials Science and Engineering National Taiwan University of Science and Technology 43 Sec. 4 Keelung Road Taipei 106 Taiwan Division of Gastroenterology and Hepatology Department of Internal Medicine Chung Shan Medical University Hospital Taichung City402 Taiwan Graduate Institute of Applied Science and Technology National Taiwan University of Science and Technology Taipei10607 Taiwan Department of Obstetrics and Gynecology Taichung Veterans General Hospital Taichung40705 Taiwan Institute of Biomedical Sciences Ph.D. Program in Translational Medicine and Rong-Hsing Research Center for Translational Medicine National Chung-Hsing University Taichung940227 Taiwan

Absorption rates for traditional adsorbents were predominately determined by the concentration gradient from bulk to absorbents and surface area. A novel sandwich-structured capacitor (SSC) containing adsorbents is designed to reduce the time consuming of absorption of pollutants by dielectrophoresis force (FDEP). Graphene oxide (GO) are coated on polystyrene microspheres (PSs) as the core/shell PS@GO adsorbents that were encapsulated within the SSC to treat the solution of dye-emulsified micells (DEM). The FDEP results the assembling of PS@GOs and DEMs under polarization and enhance the adsorption rate ca. 1 ∼ 2 times with polarization at 3 V and 200 kHz. Additionally, most adsorbents are recycled with secondary pollution. Only two-fifth pure water volume of the wastewater through the SSC could achieve the recycling of the adsorbents at 900 kHz. The high complex permittivity of GO coating at high frequency allows ultrafast alternative spinning of the induced dipoles in the PS@GOs facilitates desorption and hinders the re-adsorption of the DEM during the recycling of PS@GOs. The PS@GOs was reused ca. 10 times at 20 mL min−1 of flow rate through the SSC without damages between 200 and 900 kHz. The designed SSC containing PS@GOs accomplishes either reusing of adsorbents or concentrating of dyes with low secondary pollution in practice through frequency manipulation. © 2023 Elsevier B.V.

关键词： Graphene

来源：评论

学校读者我要写书评

暂无评论

Fast spreading of liquid on Leidenfrost vapor layer surface

引用

Colloids and Surfaces A: Physicochemical and engineering Aspects 2023年 677卷

作者： Tsai, Hsiang Yu Lin, Yu Zhu Shieh, Jiann Hsu, Chin Chi Department of Mechanical Engineering National United University No. 2 Lienda Miaoli36063 Taiwan Institute of Applied Mechanics National Taiwan University No. 1 Section 4 Roosevelt Rd Taipei10617 Taiwan Department of Materials Science and Engineering National United University No. 2 Lienda Miaoli36063 Taiwan

Previous studies found that a surface with a Leidenfrost vapor layer can effectively decrease the drag of the flow field and even increase the slip length on the boundary flow. This study investigated this phenomenon by the experiment of impact of water droplets on surfaces both with and without Leidenfrost vapor layers in the film boiling regime. The rapid spreading behaviors are dominated by the inertia of the droplet, which mainly depends on the surface with or without Leidenfrost vapor film. In the cases with higher inertia force of critical Weber numbers, this study observed that a surface with a Leidenfrost vapor film can effectively increase the wetting velocity and induce larger maximum spreading factor, especially in the case of rough surfaces. © 2023

关键词： Wetting

来源：评论

学校读者我要写书评

暂无评论

Rheology and 3d Printing of Alginate Bio-Stabilized Earth Concrete

SSRN

引用

SSRN 2023年

作者： Maierdan, Yierfan Armistead, Samuel J. Mikofsky, Rebecca A. Huang, Qiqi Ben-Alon, Lola Srubar, Wil V. Kawashima, Shiho Columbia University Department of Civil Engineering and Engineering Mechanics New YorkNY10027 United States Columbia University Graduate School of Architecture Planning and Preservation New YorkNY10027 United States University of Colorado Boulder Department of Civil Environmental and Architectural Engineering United States University of Colorado Boulder Materials Science and Engineering Program United States

Driven by the need for sustainable construction solutions, there is renewed interest in earth-based materials. Biopolymer stabilizers can enhance the rheological and structural properties of these materials to facilitate their use in 3D printing. This research examined the influence of sodium alginate on the stability, particle interaction, rheology, and 3D printability of kaolinite, a commonly found clay mineral in soils deemed suitable for construction. Findings revealed that sodium alginate could boost electrostatic interactions to enhance the stability of kaolinite suspensions. This rise in repulsive potential energy also reduced storage modulus and yield stress by orders of magnitude. However, as the alginate content increased beyond its cross-linking concentration (0.12% - 0.6%), a reverse trend was observed, which was attributed to the formation of a three-dimensional polymer network. Furthermore, alginate addition shifted the "printability window" of kaolinite suspensions to mixtures with higher solid contents, which has positive implications on strength and shrinkage. © 2023, The Authors. All rights reserved.

关键词： Biomolecules

来源：评论

学校读者我要写书评

暂无评论

Topological prime

引用

science China(Technological sciences) 2020年第7期63卷 1314-1322页

作者： YANG XuXu YANG CanHui LIU JunJie YAO Xi SUO ZhiGang John A.Paulson School of Engineering and Applied Sciences Kavli Institute for Bionano Science and TechnologyHarvard UniversityCambridge MA 02138USA State Key Laboratory of Fluid Power&Mechatronic System Key Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceDepartment of Engineering Mechanics and Center for X-MechanicsZhejiang UniversityHangzhou 310027China Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen 518055China Key Lab for Special Functional Materials of Ministry of Education Henan UniversityKaifeng 475004China

This paper describes a general method, called topological prime, to stitch functional groups to a substrate of entropic polymer network. The precursor of a topological primer contains polymers, crosslinkers, and coupling agents. When the precursor is applied on the surface of the substrate, the crosslinkers link the primer polymers into a primer network, in topological entanglement with the substrate network, while the coupling agents link the primer network to the functional groups. The use of topological prime is demonstrated by priming a hydrophobic elastomer of an arbitrary shape for hydrophilic coating. We describe an approach that fulfills two fundamental requirements: wetting and adhesion. The coated elastomer maintains hydrophilicity and lubricity after stretch, scratch, swell, and slide. As a further demonstration, a hydrogel substrate is primed for hydrophobic coating. Topological prime opens an enormous space for applications in engineering and biomedicine.

关键词： elastomer hydrogel hydrophilic coating topological prime functional groups

来源：评论

学校读者我要写书评

暂无评论

Mechanical plasticity of cell membranes enhances epithelial wound closure

引用

Physical Review Research 2024年第1期6卷 L012036-L012036页

作者： Andrew T. Ton Arthur K. MacKeith Mark D. Shattuck Corey S. O'Hern Department of Physics Yale University New Haven Connecticut 06520 USA Integrated Graduate Program in Physical and Engineering Biology Yale University New Haven Connecticut 06520 USA Department of Mechanical Engineering & Materials Science Yale University New Haven Connecticut 06520 USA Benjamin Levich Institute and Physics Department City College of New York New York New York 10031 USA Department of Applied Physics Yale University New Haven Connecticut 06520 USA

During epithelial wound healing, cell morphology near the healed wound and the healing rate vary strongly among different developmental stages even for a single species like Drosophila. We develop deformable particle (DP) model simulations to understand how variations in cell mechanics give rise to distinct wound closure phenotypes in the Drosophila embryonic ectoderm and larval wing disc epithelium. We find that plastic deformation of the cell membrane can generate large changes in cell shape consistent with wound closure in the embryonic ectoderm. Our results show that the embryonic ectoderm is best described by cell membranes with an elasto-plastic response, whereas the larval wing disc is best described by cell membranes with an exclusively elastic response. By varying the mechanical response of cell membranes in DP simulations, we recapitulate the wound closure behavior of both the embryonic ectoderm and the larval wing disc.

关键词： Cell mechanics Jamming Cell membrane Epithelial cells

来源：评论

学校读者我要写书评

暂无评论

Understanding Complex Magnetic Spin Textures with Simulation-Assisted Lorentz Transmission Electron Microscopy

引用

Physical Review applied 2021年第4期15卷 044025-044025页

作者： Arthur R.C. McCray Timothy Cote Yue Li Amanda K. Petford-Long Charudatta Phatak Materials Science Division Argonne National Laboratory Lemont Illinois 60439 USA Applied Physics Program Northwestern University Evanston Illinois 60208 USA Department of Materials Science and Engineering Northwestern University Evanston Illinois 60208 USA

There is an increased interest in topologically nontrivial magnetic spin textures such as skyrmions and chiral domain-wall solitons, both from a point of fundamental physics understanding as well as potential technological interest in low-power memory applications. In order to control their behavior, it is necessary to understand their complex spin texture at the nanoscale. Lorentz transmission electron microscopy (LTEM) is a suitable technique for studying these systems due to its high spatial resolution and capability to simultaneously characterize magnetic texture and microstructure. In this work, we present the application of PyLorentz, an open-source software suite that we have developed, for quantitative image analysis of Néel-type skyrmions in thin-film heterostructures. PyLorentz enhances LTEM capabilities by enabling reconstruction of magnetic induction maps from experimental images, as well as simulating LTEM images using micromagnetic simulation data. We demonstrate this for simulated Néel skyrmions as well as experimental data from [Pt/Co/W] multilayer heterostructures. We also show how simulation-assisted LTEM analysis is crucial for understanding these complex magnetic spin textures, in which the reconstructed magnetic induction map (seen in the LTEM images) differs significantly from the magnetization configuration.

关键词： Skyrmions Spin texture Spintronics Imaging & optical processing Lorentz microscopy Micromagnetic modeling

来源：评论

学校读者我要写书评

暂无评论

Hyperuniformity of maximally random jammed packings of hyperspheres across spatial dimensions

引用

Physical Review E 2023年第6期108卷 064602-064602页

作者： Charles Emmett Maher Yang Jiao Salvatore Torquato Department of Chemistry Princeton University Princeton New Jersey 08544 USA Materials Science and Engineering Arizona State University Tempe Arizona 85287 USA Department of Physics Arizona State University Tempe Arizona 85287 USA Department of Physics Princeton University Princeton New Jersey 08544 USA Princeton Materials Institute Princeton University Princeton New Jersey 08544 USA Program in Applied and Computational Mathematics Princeton University Princeton New Jersey 08544 USA

The maximally random jammed (MRJ) state is the most random (i.e., disordered) configuration of strictly jammed (mechanically rigid) nonoverlapping objects. MRJ packings are hyperuniform, meaning their long-wavelength density fluctuations are anomalously suppressed compared to typical disordered systems, i.e., their structure factors S(k) tend to zero as the wave number |k| tends to zero. Here we show that generating high-quality strictly jammed states for Euclidean space dimensions d=3,4, and 5 is of paramount importance in ensuring hyperuniformity and extracting precise values of the hyperuniformity exponent α>0 for MRJ states, defined by the power-law behavior of S(k)∼|k|α in the limit |k|→0. Moreover, we show that for fixed d it is more difficult to ensure jamming as the particle number N increases, which results in packings that are nonhyperuniform. Free-volume theory arguments suggest that the ideal MRJ state does not contain rattlers, which act as defects in numerically generated packings. As d increases, we find that the fraction of rattlers decreases substantially. Our analysis of the largest truly jammed packings suggests that the ideal MRJ packings for all dimensions d≥3 are hyperuniform with α=d−2, implying the packings become more hyperuniform as d increases. The differences in α between MRJ packings and the recently proposed Manna-class random close packed (RCP) states, which were reported to have α=0.25 in d=3 and be nonhyperuniform (α=0) for d=4 and d=5, demonstrate the vivid distinctions between the large-scale structure of RCP and MRJ states in these dimensions. Our paper clarifies the importance of the link between true jamming and hyperuniformity and motivates the development of an algorithm to produce rattler-free three-dimensional MRJ packings.

关键词： Granular solids

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：