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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

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Experimental implementation of phase triplicator gratings in a spatial light modulator

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Chinese Optics letters 2024年第2期22卷 64-69页

作者：高尚 María del Mar sánchez-lópez Ignacio Moreno Instituto de Bioingeniería Universidad Miguel HernándezElche 03202Spain Departamento de Física Aplicada Universidad Miguel HernándezElche 03202Spain Departamento de Ciencia de Materiales Óptica y Tec.Electr´onicaUniversidad Miguel HernándezElche 03202Spain

In this work,we compare different methods for implementing a triplicator,a phase grating that generates three equiintense diffraction *** design with optimal efficiency features a continuous phase profile,which cannot be easily reproduced,and is typically affected by *** compare its performance with binary and sinusoidal phase *** also analyze the effect of quantizing the phase ***,a random approach is adopted to eliminate the additional harmonic *** all cases,a liquid-crystal-on-silicon spatial light modulator is employed to experimentally verify and compare the different approaches.

关键词： diffraction gratings phase modulation triplicator spatial light modulators

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litterfall production modeling based on climatic variables and nutrient return from stands of Eucalyptus grandis Hill ex Maiden and Pinus taeda l.

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Journal of Forestry Research 2024年第5期35卷 26-36页

作者： andrés Baietto andrés Hirigoyen Jorge Hernández Amabelia del Pino Forest Department Faculty of AgronomyUniversity of the Republic12900 MontevideoUruguay National Research Program of Forest Production National Agriculture Research InstituteINIA97000 TacuarembóUruguay soil and Water Department Faculty of AgronomyUniversity of the Republic12900 MontevideoUruguay

Native grasslands in the Pampas of south America are increasingly being replaced by Eucalyptus and Pinus *** short rotation regimes used for the stands require high nutrient levels,with litterfall being a major source of nutrient *** model the litterfall production using climatic variables and assess the nutrient return in 14-year-old Eucalyptus grandis and Pinus taeda stands,we measured litter production over 2 years,using conical litter traps,and monitored climatic *** temperature,accumulated precipitation,and mean maximum vapor pres-sure deficit at the seasonal level influenced litterfall produc-tion by ***;seasonal accumulated precipitation and mean maximum temperature affected litterfall by *** regression tree modeling based on these climatic vari-ables had great accuracy and predictive power for ***(N=33;MAE(mean absolute error)=0.65;RMsE(root mean square error)=0.91;R^(2)=0.71)and ***(N=108;MAE=1.50;RMsE=1.59;R^(2)=0.72).The nutrient return followed a similar pattern to litterfall deposition,as well as the order of importance of macronutrients(***:Ca>N>K>Mg>P;***:N>Ca>K>Mg>P)and micronutrients(*** and ***:Mn>Fe>Zn>Cu)in both *** study constitutes a first approximation of factors that affect litterfall and nutrient return in these systems.

关键词： Afforestation litterfall Nutrient recycling Climate modeling Myrtaceae Pinaceae

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Elevation transition of aquatic insects closely matches a thermal feature in the Yungas of Northwestern Argentina

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Journal of Mountain science 2024年第2期21卷 433-448页

作者： Alexandra BUITRAGO-GUACANAME Carlos MOlINERI andrés lIRA-NORIEGA Daniel andrés DOs sANTOs Neotropical Biodiversity Institute(CONICET-UNT) UNT-DomesHorco Molle S/N4107 TucumánArgentina CONACYT Research Fellow Network of Advanced Molecular StudiesInstitute of Ecology A.COld Road to Coatepec 351El HayaCP 91073XalapaVeracruzMexico Biostatistics Chair Faculty of Natural Sciences and IMLNational University of TucumánSan Miguel de TucumánMiguel Lillo 2054000 TucumánArgentina

Temperature is a key factor that shapes the distribution of *** knowledge about how species respond to temperature is relevant to devise strategies for addressing the impacts of climate *** insects are particularly vulnerable to climate change,yet there is still much to learn about their ecology and *** the Yungas ecoregion of Northwestern Argentina,cold-and warm-adapted species of the orders Ephemeroptera,Plecoptera,and Trichoptera(EPT)are segregated by *** modeled the ecological niche of south American EPT species in this region using available data and projected their potential distribution in geographic *** were grouped based on their ecogeographic similarity,and we analyzed their replacement pattern along elevation gradients,focusing on the ecotone where opposing thermal preferences *** this interface,we identified critical points where the combined incidence of cold and warm assemblages maximizes,indicating a significant transition *** found that the Montane Cloud Forest holds the interface,with a particularly greater suitability at its lower *** main axis of the interface runs in a N-s direction and falls between 14°C-16°C mean annual *** probability of a particular location within a basin being classified as part of the interface increases as Kira’s warmth index approaches a score around *** the interface is critical for defining the thermal limits of species distribution and designing biomonitoring *** in the location of thermal constants related to mountainous ecotones may cause vertical displacement of aquatic insects and vegetation *** have recognized significant temperature thresholds that serve as indicators of suitability for the *** global warming is anticipated to shift these indicators,we suggest using them to monitor the imprints of climate change on mountain ecosystems.

关键词： Austral Yungas Ecological Niche Model Ephemeroptera Kira’s warmth index Plecoptera Trichoptera

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On Isodual Double Toeplitz Codes

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Journal of systems science & Complexity 2024年第5期37卷 2196-2206页

作者： sHI Minjia XU li solé Patrick Key laboratory of Intelligent Computing and signal Processing Ministry of Education School of Mathematical Sciences Anhui University state Key laboratory of Information security Institute of Information Engineering Chinese Academy of Sciences CNRs University of Aix Marseille Centrale Marseille

Double Toeplitz（shortly DT） codes are introduced here as a generalization of double circulant codes. The authors show that such a code is isodual, hence formally self-dual（FsD）. FsD codes form a far-reaching generalization of self-dual codes, the most important class of codes of rate one-half. self-dual DT codes are characterized as double circulant or double negacirculant. likewise, even binary DT codes are characterized as double circulant. Numerical examples obtained by exhaustive search show that the codes constructed have best-known minimum distance, up to one unit, amongst formally self-dual codes, and sometimes improve on the known values. For q = 2, the authors find four improvements on the best-known values of the minimum distance of FsD codes. Over F4an explicit construction of DT codes, based on quadratic residues in a prime field, performs equally well. The authors show that DT codes are asymptotically good over Fq. specifically, the authors construct DT codes arbitrarily close to the asymptotic Varshamov-Gilbert bound for codes of rate one half.

关键词： Double circulant codes double Toeplitz codes formally self-dual codes isodual codes

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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

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Assistive Robotics for Upper limb Physical Rehabilitation:A systematic Review and Future Prospects

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Chinese Journal of Mechanical Engineering 2024年第4期37卷 50-73页

作者： andrés Guatibonza leonardo solaque Alexandra Velasco lina Peñuela Department of Engineering Mechatronics EngineeringMilitar Nueva Granada UniversityBogotá1101111Colombia

Physical assistive robotics are oriented to support and improve functional capacities of *** physical rehabilitation,robots are indeed useful for functional recovery of affected ***,there are still open questions related to technological *** work presents a systematic review of upper limb rehabilitation robotics in order to analyze and establish technological challenges and future directions in this area.A bibliometric analysis was performed for the systematic literature *** from the last six years,conducted between August 2020 and May 2021,was *** methodology for the literature search and a bibliometric analysis of the metadata are *** a preliminary search resulted in 820 articles,a total of 66 articles were included.A concurrency network and bibliographic analysis were *** an analysis of occurrences,taxonomy,and rehabilitation robotics reported in the literature is *** review aims to provide to the scientific community an overview of the state of the art in assistive robotics for upper limb physical *** literature analysis allows access to a gap of unexplored options to define the technological prospects applied to upper limb physical rehabilitation robotics.

关键词： Upper limb Rehabilitation Assistive robotics Human-machine interaction Robotic systems Virtual reality Rehabilitation monitoring

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Grazing Pressure and Plant Functional Types in Puna Highlands,Northwestern Argentina

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Phyton-International Journal of Experimental Botany 2024年第5期93卷 1067-1080页

作者： Quiroga Mendiola Mariana Tálamo andrés IPAF NOA—INTA(National Institute for Agricultural Technology) Posta de HornillosJujuy4622Argentina Facultad de Ciencias Naturales Universidad Nacional de SaltaSalta4400Argentina Instituto de Bio y Geociencias del NOA(IBIGEO) UNSa-CONICET.Laboratorio de Ecología Aplicada a la Conservación(LEAC)Facultad de Ciencias NaturalesUniversidad Nacional de SaltaSalta4400Argentina Maestría en Gestión Ambiental Escuela de NegociosUniversidad Católica de Salta(UCASAL)Salta4400Argentina

The Puna grasslands support grazing systems that produce meat and wool in multi-species herds,especially from llama(lama glama)and ***,it is yet unknown whether grazing pressure can modify grassland structure and Plant Functional Types diversity and cover in Puna *** analyzed the relationship between grazing pressure and Plant Functional Types by comparing transects located near stockyards(high grazing pressure)and far from them(low pressure)and by evaluating the relationship between the Plant Functional Types cover to a Grazing Pressure Index(GPI).This index incorporates the heterogeneity of traditional pastoral *** two ecological sites(Ciénego and Tolar),we sampled paired transects(near-far).Plots near and far from corrals were similar in all the variables measured except for plots in Tolar,which tend to have higher total cover,possibly due to fecal fertilization near ***,we recorded an increase in total cover and grass cover at higher GPI in Ciénego,while in Tolar we found lower values of total cover and herbaceous dicotyledonous cover at intermediate intensities of *** only negative relationship found was the cover of clonal and non-clonal shrubs,possibly explained by the greater use of these shrubs as firewood near *** summary,our study does not show important changes in Plant Functional Types as a function of grazing pressure in the studied grasslands probably because grazing pressure is diluted or diminished when livestock rotates in different areas and grazing durations ***,the long grazing history with which the Puna has evolved could also contribute to the co-structuration between native vegetation and livestock farming.

关键词： Natural grasslands Puna herbivory ecological perturbation

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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

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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

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