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Microstructural evaluation and nanohardness of an AlcocucrFeNiTi high-entropy alloy

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International Journal of Minerals,Metallurgy and Materials 2019年第5期26卷 634-641页

作者： c.d.gómez-esparza R.Peréz-Bustamante J.M.Alvarado-Orozco J.Mu?oz-Salda?a R.Martínez-Sánchez J.M.Olivares-Ramírez A.duarte-Moller centro de Investigación en Materiales Avanzados (cIMAV) Laboratorio Nacional de Nanotecnología cONAcYT-corporación Mexicana de Investigación en Materiales S.A.de c.V.(cOMIMSA) centro de Ingeniería y desarrollo Industrial Querétaro Campus centro de Investigación y de Estudios Avanzados del IPN Unidad Querétaro Universidad Tecnológica de San Juan del Río Escuela de Ingeniería civil Industrialy Mecánica Universidad De La Salle Bajío

An AlcocucrFeNiTi high-entropy alloy(HEA) was prepared by mechanical alloying and sintering to study the effect of Ti addition to the widely studied AlcocucrFeNi system. The structural and microstructural characteristics were investigated by X-ray diffraction(XRd), scanning electron microscopy(SEM), and transmission electron microscopy(TEM). The formation of four micrometric phases was detected: a cu-rich phase with a face-centered cubic(fcc) structure, a body-centered cubic(bcc) solid solution with cu-rich plate-like precipitates(fcc), an ordered bcc phase, and a tetragonal structure. The XRd patterns corroborate the presence of a mixture of bcc-, fcc-, and tetragonal-structured phases. The Vickers hardness of the alloy under study was more than twice that of the AlcocucrFeNi alloy. Nanoindentation tests were performed to evaluate the mechanical response of the individual phases to elucidate the relationship between chemical composition, crystal structure, and mechanical performance of the multiphase microstructure of the AlcocucrFeNiTi HEA.

关键词： high-entropy alloys mechanical alloying microstructure nanoindentation

Targeting epidermal growth factor receptor signaling to facilitate cortical injury repair?

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Neural Regeneration Research 2024年第5期19卷 935-936页

作者： Ricardo gómez-Oliva Pedro Nunez-Abades carmen castro Área de Fisiología Facultad de Medicina Universidad de CádizCadizSpain Instituto de Investigación e Innovación en Biomedicina de cádiz CadizSpain departamento de Fisiología Facultad de FarmaciaUniversidad de SevillaSevilleSpain

The existence of neural stem cells(NSc)in specific areas of the adult mammalian brain leads to the generation of new neurons involved in homeostatic *** is the case of the NSc of the subventricular zone(SVZ)that produces olfactory bulb(OB)*** neurons integrate into circuits to modulate sensory information and participate in olfactory processing(Bragado Alonso et al.,2019).A series of hierarchical events need to take place to produce OB neurons from NSc of the ***,the activation of quiescent NSc is necessary to produce intermediate transit amplifying progenitors(TAP),which will generate *** latter are cells that maintain a proliferative phenotype while in an immature ***,once they initiate migration toward the OB,they progressively undergo their differentiation into neurons(Kjell et al.,2020).

关键词： ventricular maintain

Stress tensors and quantification of fracture patterns to analyze connectivity and potential fluid flow in a mesa landform of the Northern Andes

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Journal of Mountain Science 2024年第1期21卷 271-291页

作者： gARcÍA-ARIAS Sergio VELANdIA Francisco ALVAREZ Angélica SANABRIA-gÓmez Joséd TARAZONA Yessenia VARgAS María camila Escuela de geología Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia Escuela de Física Universidad Industrial de SantanderCra.27 Calle 9BucaramangaColombia

This work applies stress tensors inversions and quantification of fracture patterns along the Mesa de Los Santos, in the Eastern cordillera of colombia, to better understand the potential fluid flow. It thus contributes to the conceptual hydrogeological model. The area was subdivided into three blocks, separated by the NW Potreros and the Los Santos faults, having minor inner faults of different orientations. This separation facilitates the analysis of the fractures measured in the field, which in general show high dip angles and a conjugate geometry in the northern block, tension fractures(Mode I) in the central block, and a random distribution in the southwestern block. WinTensor treatment of slickensides yielded a maximum horizontal stress(SHmax) of 111o, which coincides with the WNW-ESE tensor observed from the conjugate and tension joints. We then used Frac Pa Q to generate interpolation maps of fracture intensity and density. The maps show the highest values in the central block and the lowest in the northern block,where the precipitation is higher, causing intensive rock weathering and homogenization of the fracture planes. Although the highest values of connectivity by line are found to the south of the mesa, we suggest the possibility of greater flow from the recharge zone(NE) along bedding planes and open NW-SE fractures.

关键词： Mesa de Los Santos colombia Win-Tensor FracPaQ Strike-slip faults Fractured aquifers

High cO_(2)permeation using a new ce_(0.85)gd_(0.15)O_(2-δ)-LaNiO_(3)composite ceramic–carbonate dual-phase membrane

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Journal of Environmental Sciences 2024年第6期140卷 219-229页

作者： daniela gonzález-Varela JFrancisco gómez-garcía gustavo Tavizon Heriberto Pfeiffer Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de MéxicoCd.UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMéxico departamento de Física y Química Teórica Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCd.UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMéxico 不详

This work shows the synthesis,characterization and evaluation of dense-ceramic membranes made of ce_(0.85)gd_(0.15)O_(2-δ)-LaNiO_(3)(cg-LN)composites,where the fluorite-perovskite ratio(cg:LN)was varied as follows:75:25,80:20 and 85:15 wt.%.Supports were initially characterized by XRd,SEM and electrical conductivity(using vacuum and oxygen atmospheres),to determine the composition,microstructural and ionic-electronic conductivity ***,supports were infiltrated with an eutectic carbonates mixture,producing the corresponding dense dual-phase membranes,in which cO_(2)permeation tests were ***,cO_(2)permeation experiments were performed from 900 to 700℃,in the presence and absence of oxygen(flowed in the sweep membrane side).Results showed that these composites possess high cO_(2)permeation properties,where the O_(2)addition significantly improves the ionic conduction on the sweep membrane ***,the gc80-LN20 composition presented the best results due to the following physicochemical characteristics:high electronic and ionic conductivity,appropriate porosity,interconnected porous channels,as well as thermal and chemical stabilities between the composite support and carbonate phases.

关键词： cO_(2)permeation doped ceO_(2) LaNiO_(3) Impedance ceramic carbonate membrane

Anthropogenic mineral generation and its potential resource supply:The case of niobium

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Science china Earth Sciences 2024年第8期67卷 2583-2591页

作者： Xianlai ZENg Moisés gómez Mahmoud BAKRY Yong gENg Jinhui LI School of Environment Tsinghua UniversityBeijing 100084China School of Environmental Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of International and Public Affairs Shanghai Jiao Tong UniversityShanghai 200030China

The strategy of carbon neutrality is reshaping the global landscape of resource flow and *** the final sink of geological minerals,the proliferated anthropogenic minerals,also called secondary resources,play an increasingly important role in resource supply *** is a critical metal that lacks full concern for its *** fundamental principle of niobium circularity is to recycle and maintain the material as close to the manufacturing process as *** we estimate the niobium-containing applications lost at their end-of-life,underscoring the imperative to minimize such ***,we elucidate the extraction processes for scrap and alloy quantities throughout the industry's *** from anticipated waste generated by the majority of niobium applications,a forecast indicates a potential loss of approximately 168 kt by 2090 in the absence of ***,with a recycling efficiency of 90%for niobium,the projected loss diminishes to approximately 16 *** delve into the significance of niobium's circular economy and explore various aspects that demand further investigation for a seamless transition from linear to circular practices.

关键词： Niobium Anthropogenic mineral circular economy Recycling Sustainability

Estimation of Equivalent Model of Photovoltaic Array Using Unscented Kalman Filters

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Journal of Modern Power Systems and clean Energy 2024年第3期12卷 819-827页

作者： M.A.gonzález-cagigal JoséA.Rosendo-Macías A.gómez-Expósito the department of Electrical Engineering University of SevilleSpainand A.Gómez-Expósito is also with ENGREEN Laboratory of Engineering for Energy and Environmental SustainabilitySevilleSpain

This paper proposes the use of the unscented Kalman filter to estimate the equivalent model of a photovoltaic(PV)array,using external measurements of current and voltage at the inverter *** estimated model is of interest to predict the power output of PV plants,in both planning and operation scenarios,and thus improves the efficient operation of power systems with high penetration of renewable *** proposed technique has been assessed in several simulated scenarios under different operating *** results show that accurate estimates are provided for the model parameters,even in the presence of measurement noise and abrupt variations under the external conditions.

关键词： Equivalent model parameter estimation photovoltaic energy unscented Kalman filter

Spark Plasma Sintering of Boron carbide Using Ti_(3)Sic_(2) as a Sintering Additive

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 645-650页

作者： Hülya Biçer Mustafa Tuncer Hasan göçmez Iurii Bogomol Valerii Kolesnichenko Andrey Ragulya Kutahya dumlupinar University School of EngineeringDepartment of Metallurgical and Materials EngineeringKütahya 43100Tur-key Boron Based Advanced ceramics Application and Research center Kütahya Dumlupınar UniversityKütahya 43100Turkey Advanced Technologies center(İLTEM) Kütahya Dumlupınar UniversityKütahya 43000Turkey department of High-Temperature Ma-terials and Powder Metallurgy National Technical University of Ukraine“Igor Sikorsky Kyiv Polytechnic Institute”Kyiv 03056Ukraine Frantsevich Institute for Problems of Materials Science National Academy of Sciences of UkraineKyiv 03056Ukraine

Boron carbide has unique properties for wide application possibilities;however,poor sinterability limits its *** approach to overcome this limitation is the addition of secondary phases into boron *** carbide based composite ceramics are produced by the direct addition of secondary phases into the structure or via reactive sintering using a sintering *** present study investigated the effect of Ti_(3)Sic_(2) addition to boron carbide by reactive spark plasma sintering in the range of 1700-1900℃.Ti_(3)Sic_(2) phase decomposed at high temperatures and reacted with B4c to form secondary phases of TiB2 and *** results demonstrated that the increase of Ti_(3)Sic_(2) addition(up to 15 vol%)effectively promoted the densification of B4c and yielded higher ***,as the amount of Ti_(3)Sic_(2) increased further,the formation of microstructural inhomogeneity and agglomeration of secondary phases caused a decrease in hardness.

关键词： reactive sintering SPS boron carbide MAX phase

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.d.gital service

Tri-axial accelerometry allows to determine parental food provisioning behaviour in a marine bird

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Avian Research 2024年第3期15卷 345-351页

作者： Monserrat del caño Flavio Quintana giacomo dell’Omo Agustina gómez-Laich Instituto de Biología de Organismos Marinos(IBIOMAR) CONICETBoulevard Brown 2915U9120ACDPuerto MadrynChubutArgentina Ornis Italica Piazza Crati 1500199RomeItaly departamento de Ecología Genética y Evolución(EGE)and Instituto de EcologíaGenética y Evolución de Buenos Aires(IEGEBA)CONICETFacultad de CienciasExactas y NaturalesUniversidad de Buenos AiresPabellón II Ciudad UniversitariaC1428EGACiudad Autónoma de Buenos AiresArgentina

The study of parental food provisioning is essential for understanding the breeding ecology of *** conducted the first study using accelerometry to detect food provisioning in birds,using Support Vector Machine(SVM)models to identify when adults feed chicks of three different age *** were attached to the head of adult female Imperial Shags(Leucocarbo atriceps),and various attributes derived from the acceleration signals were used to train SVM models for each chick age *** performance improved with chick age class,with SVM models achieving high overall accuracy(>88%)and highest sensitivity in older chick categories(>91%).However,precision values,especially for younger chicks,remained relatively low(between 26%and 45%).The application of a time filter based on the minimum duration of the observed food provisioning behaviours for each chick age category,improved model performance by reducing false provisioning behaviours,particularly in the model for older chicks,which showed the highest precision(72.4%).This study highlights the effectiveness of accelerometry and machine learning in studying parental food provisioning in birds,providing a rapid and accurate data collection method to complement traditional *** described methodology can be applied to any bird species that exhibits distinctive movements while feeding its offspring and has suitable characteristics for attaching an accelerometer to the body part that best captures this ***,it is hoped that the results of this study will contribute to future research on key questions in parental investment theory and reproductive strategies in birds.

关键词： Accelerometry Food provisioning Imperial shag Leucocarbo atriceps Seabird Support vector machine