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Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)N-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of Semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán Solís-Cisneros Carlos Alberto Hernández-Gutiérrez Enrique Campos-González Máximo lópez-lópez Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico Departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico Departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInN layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInN was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on Si(111)substrates using AlN as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).Cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the Fermi level by valence band ***-doped AlInN layers were studied for use as the electron-blocking layer(EBl)in lED *** varied the Al composition in the EBl from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using SIlVACO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInN layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInN DUV-lED EBl simulation

Oligodendroctyes:the forgotten players of diabetes pathophysiology

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Neural Regeneration Research 2024年第11期19卷 2349-2350页

作者： Juan Antonio lópez-Villodres Beatriz García-Díaz Departamento Fisiología Humana Histología HumanaAnatomía Patológica y Educación Física y DeportivaFacultad de MedicinaUniversidad de MálagaMálagaSpain UGC Neurociencia.Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina(IBIMA Plataforma Bionand) MálagaSpain

Oligodendrocytes(Ols),glial cells that provide myelin sheaths to axons in the central nervous system(CNS),have a dual ***,this myelin fatty cover around the axons protects the nerves and is crucial for the saltatory propagation of action *** and not less important,Ols provide trophic support to neurons and ***,Ol metabolism is important for Ol well-being and the proper accomplishment of their functions,and Ol metabolism energetics directly affect the energy metabolism of neighboring neurons.

关键词： metabolism nerves myelin

Experimental and numerical investigation to elucidate the fluid flow through packed beds with structured particle packings

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Particuology 2024年第6期89卷 218-237页

作者： Shirin Patil Christian Gorges Joel lòpez Bonilla Moritz Stelter Frank Beyrau Berend van Wachem laboratory of Technical Thermodynamics Otto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany Chair of Mechanical Process Engineering Otto-von-Guericke-Universität MagdeburgUniversitätsplatz 239106 MagdeburgGermany

The present paper presents an experimental and numerical investigation of the dispersion of the gaseous jet flow and co-flow for the simple unit cell(SUC)and body-centred cubic(BCC)configuration of particles in packed *** experimental setup is built in such a way that suitable and simplified boundary conditions are imposed for the corresponding numerical framework,so the simulations can be done under very similar conditions as the ***,a porous plate is used for the co-flow to achieve the uniform velocity and the fully developed flow is ensured for the jet *** SUC and BCC particle beds consist of 3D-printed spheres,and the non-isotropy near the walls is mostly eliminated by placing half-spheres at the channel *** flow velocities are analysed directly at the exit of the particle bed for both beds over 36 pores for the SUC configuration and 60 pores for the BCC configuration,for particle Reynolds numbers of 200,300,and *** particle image velocimetry is experimentally arranged in such a way that the velocities over the entire region at the exit of the packed bed are obtained *** numerical method consists of a state-of-the-art immersed boundary method with adaptive mesh *** paper presents the pore jet structure and velocity field exiting from each pore for the SUC and BCC packed particle *** numerical and experimental studies show a good agreement for the SUC configuration for all flow *** the BCC configuration,some differences can be observed in the pore jet flow structure between the simulations and the experiments,but the general flow velocity distribution shows a good overall *** axial velocity is generally higher for the pores located near the centre of the packed bed than for the pores near the *** addition,the axial velocities are observed to increase near the peripheral pores of the packed *** behaviour is predominant for the BCC configuration as compared to t

关键词： Uniform particle packing Packed bed reactor Stereo particle image velocimetry Immersed boundary method

Digital Social Connectedness as a lifeline for Older People: Use and Non-use of VinclesBCN During the Pandemic

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International Journal of Disaster Risk Science 2024年第2期15卷 251-264页

作者： Israel Rodríguez‑Giralt daniel lópez‑Gómez Roser Beneito‑Montagut CareNet IN3Universitat Oberta de Catalunya08018 BarcelonaSpain School of Social Sciences Cardif UniversityCardif CF103NSWalesUK

This article presents the results of a study that evaluated VinclesBCN during COVID-19. This digital-based public social service aims to prevent loneliness and isolation in +65-year-old adults living in Barcelona. Through service user(N = 12) and professional(N = 6) interviews and a questionnaire with service users(N = 255), we demonstrate the pivotal role of digital connectedness in transforming VinclesBCN into a lifeline during the pandemic. The analysis revealed the importance of sociability, social support, and, especially, entertainment in coping with pandemic fatigue and facilitating social connectivity and support among users. Users engaged in activities such as sharing images, songs, memes, and daily greetings to provide proximity, sociability, and care among users, whether they belonged to preexisting groups or were newly introduced to the platform. It also facilitated the identification of individuals who needed companionship, comfort, or more specialized support. The findings emphasize the significance of entertainment as a resilience-building strategy during times of uncertainty. Despite the positive impact, not all users equally used the platform. Non-use was strongly associated with being a woman, having a low educational level, having preexisting social relationships, less time of enrolment in the platform, as well as a high perception of loneliness, poor self-reported health, and low mood. The article underscores the need for further research into older adults' digital engagement during crises, its role in building resilience, and advocating for inclusive digital interventions that take into account diverse older adults' needs and experiences in crisis contexts.

关键词： Barcelona COVID-19 pandemic Digital social connectedness Entertainment Older adult resilience Public digital service

Anomalous negative magnetoresistance in quantum dot Josephson junctions with Kondo correlations

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 3-13页

作者： Mingtang Deng Chunlin Yu Guangyao Huang Rosa lópez Philippe Caroff Sepideh Ghalamestani Gloria Platero Hongqi Xu Institute for Quantum Information&State Key laboratory of High Performance Computing College of Computer Science and TechnologyNational University of Defense TechnologyChangsha 410073China Nanolund and Division of Solid State Physics Lund UniversityLund S-22100Sweden China Greatwall Quantum laboratory Changsha 410006China Institut de Física Interdisciplinària i de Sistemes Complexos IFISC Palma de Mallorca E-07122Spain Instituto de Ciencia de Materiales de Madrid Madrid 28049Spain Beijing Key laboratory of Quantum Devices Key Laboratory for the Physics and Chemistry of Nanodevicesand Department of ElectronicsPeking UniversityBeijing 100871China Beijing Academy of Quantum Information Sciences Beijing 100193China Hefei National laboratory Hefei 230088China

The interplay between superconductivity and the Kondo effect has stimulated significant interest in condensed matter *** compete when their critical temperatures are close and can give rise to a quantum phase transition that can mimic Majorana zero ***,we have fabricated and measured Al-InSb nanowire quantum dot-Al *** the Kondo regime,a supercurrent-induced zero-bias conductance peak *** zero-bias peak shows an anomalous negative magnetoresistance(NMR)at weak magnetic *** attribute this anomalous NMR to quasiparticle trapping at vortices in the superconductor leads as a weak magnetic field is *** trapping effect lowers the quasiparticle-caused dissipation and thus enhances the Josephson *** work connects the vortex physics and the supercurrent tunneling in Kondo regimes and can help further understand the physics of Josephson quantum dot system.

关键词： quantum dot Kondo correlation InSb nanowire quasiparticle trapping

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Resource management at the network edge for federated learning

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Digital Communications and Networks 2024年第3期10卷 765-782页

作者： Silvana Trindade luiz F.Bittencourt Nelson l.S.da Fonseca Institute of Computing State University of CampinasCampinasBrazil

Federated learning has been explored as a promising solution for training machine learning models at the network edge,without sharing private user *** limited resources at the edge,new solutions must be developed to leverage the software and hardware resources as the existing solutions did not focus on resource management for network edge,specially for federated *** this paper,we describe the recent work on resource manage-ment at the edge and explore the challenges and future directions to allow the execution of federated learning at the *** such as the discovery of resources,deployment,load balancing,migration,and energy effi-ciency are discussed in the paper.

关键词： Resource management Edge computing Federated learning Machine learning

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中国户籍登记系统漏登合成估计方法研究

系统科学与数学 2024年

作者：黄艳华 lópez-carr david 胡桂华重庆工商大学成渝地区双城经济圈建设研究院 University of California Santa Barbara Department of Geography 重庆工商大学数学与统计学院统计智能计算与监测重庆市重点实验室

中国户籍登记系统存在漏登人口问题,但政府部门尚未开展户籍漏登估计工作.联合国统计司建议各国采用的单重漏登估计量未覆盖全部漏登人口,低估漏登率.本文提出用合成漏登估计量替代单重漏登估计量,并通过案例研究,比较了合成漏登估计量... 详细信息

中国户籍登记系统存在漏登人口问题,但政府部门尚未开展户籍漏登估计工作.联合国统计司建议各国采用的单重漏登估计量未覆盖全部漏登人口,低估漏登率.本文提出用合成漏登估计量替代单重漏登估计量,并通过案例研究,比较了合成漏登估计量与单重漏登估计量.实证研究结果表明:四种合成漏登估计量估计的漏登率均高于单重漏登估计量;除其中一种合成漏登估计量估计的漏登率的抽样标准差略高于单重漏登估计量外,其他三种合成漏登估计量估计结果的抽样标准差均小于单重漏登估计量.研究结果为统计局和公安部未来制定户籍登记系统漏登估计方案提供重要参考,提高方案的科学性和可操作性.

关键词：抽样调查事后分层三系统估计量刀切法

Relationship between land use and user’s behavior along the street:A case study of da Nang City,Viet Nam

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Frontiers of Architectural Research 2024年第1期13卷 144-163页

作者： Duy Thinh do Duy Thao do Faculty of Civil Engineering Ho Chi Minh City University of Technology and Education(HCMUTE)Ho Chi Minh City 71307Viet Nam School of Computing Korea Advanced Institute of Science and TechnologyDaejeon 34141Republic of Korea

Human activities on street spaces are affected by both physical and non-physical settings on *** two aspects are primarily impacted by land use which results in the uneven distribution of different activities on *** research investigates land use patterns and their characteristics in association to user’s *** using mixed qualitative and quantitative research methods,e.g.,place-centered behavioral map,observation,visual encounter surveys,machine learning,the relationship between user’s behavior and land use characteristics along the street is *** user behaviors along both types of streets were classified into six main categories,with 26 *** observation results show that the residential use of land along the street was transformed into the commercial use for various types of shophouses based on the resident’s *** is a great correlation between land use and user’s *** findings give support to authorities to manage urban streets and develop a sustainable policy for improving street ***,this research contributes useful information to urban designers and planners in creating a successful street space that is appropriate for the Vietnam Community.

关键词： land use pattern User’s behavior da Nang Street space data mining

Enhancement of the CO_(2)adsorption and hydrogenation to CH_(4)capacity of Ru–Na–Ca/γ–Al_(2)O_(3)dual function material by controlling the Ru calcination atmosphere

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Journal of Environmental Sciences 2024年第6期140卷 292-305页

作者： Alejandro Bermejo-lópez Beñat Pereda-Ayo Jon A.Onrubia-Calvo JoséA.González-Marcos Juan R.González-Velasco Department of Chemical Engineering Faculty of Science and TechnologyUniversidad del País Vasco UPV/EHUBarrio Sarrienas/n48940 LeioaBizkaiaSpain

Integrated CO_(2)capture and utilization(ICCU)technology requires dual functional materials(DFMs)to carry out the process in a single reaction *** influence of the calcination atmosphere on efficiency of 4%Ru-8%Na_(2)CO_(3)-8%CaO/γ-Al_(2)O_(3)DFM is *** adsorbent precursors are first co-impregnated onto alumina and calcined in ***,Ru precursor is impregnated and four aliquotes are subjected to different calcination protocols:static air in muffle or under different mixtures(10%H_(2)/N_(2),50%H_(2)/N_(2)and N_(2))*** are characterized by XRD,N_(2)adsorption-desorption,H_(2)chemisorption,TEM,XPS,H_(2)-TPD,H_(2)-TPR,CO_(2)-TPD and *** catalytic behavior is evaluated,in cycles of CO_(2)adsorption and hydrogenation to CH_(4),and temporal evolution of reactants and products concentrations is *** calcination atmosphere influences the physicochemical properties and,ultimately,activity of *** data and catalytic performance discover the acccomodation of Ru nanoparticles disposition and basic sites is mostly influencing the catalytic *** calcined under N_(2)flow(RuNaCa-N_(2))shows the highest CH_(4)production(449μmol/g at 370℃),because a well-controlled decomposition of precursors which favors the better accomodation of adsorbent and Ru phases,maximizing the specific surface area,the Ru-basic sites interface and the participation of different basic sites in the CO_(2)methanation ***,the calcination in a N_(2)flow is revealed as the optimal calcination protocol to achieve highly efficient DFM for integrated CO_(2)adsorption and hydrogenation applications.

关键词： CO_(2)methanation Integrated CO_(2)capture and utilization(ICCU) Dual functional material(DFM) Ru calcination atmosphere