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A lattice Boltzmann exploration of two-phase displacement in 2D porous media under various pressure boundary conditions

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1782-1798页

作者： Guanxi Yan Zi Li Thierry Bore sergio andres galindo torres Alexander Scheuermann Ling Li School of Civil Engineering University of QueenslandSt LuciaBrisbaneQLD4072Australia School of Engineering Westlake UniversityHangzhou310024China Institute of Advanced Technology Westlake Institute for Advanced StudyHangzhou310024China

While experimental designs developed in recent decades have contributed to research on dynamic nonequilibrium effects in transient two-phase flow in porous media,this problem has been seldom investigated using direct numerical simulation(DNS).Only a few studies have sought to numerically solve Navier—Stokes equations with level-set(LS)or volume-of-fluid(VoF)methods,each of which has constraints in terms of meniscus dynamics for various flow velocities in the control volume(CV)*** Shan—Chen multiphase multicomponent lattice Boltzmann method(SC-LBM)has a fundamental mechanism to separate immiscible fluid phases in the density domain without these ***,this study applied it to explore two-phase displacement in a single representative elementary volume(REV)of two-dimensional(2D)porous *** a continuation of a previous investigation into one-step inflow/outflow in 2D porous media,this work seeks to identify dynamic nonequilibrium effects on capillary pressure—saturation relationship(P_(c)—S)for quasi-steady-state flow and multistep inflow/outflow under various pressure boundary *** simulation outcomes show that P_(c),S and specific interfacial area(a_(nw))had multistep-wise dynamic effects corresponding to the multistep-wise pressure boundary *** finer adjustments to the increase in pressure over more steps,dynamic nonequilibrium effects were significantly alleviated and even finally disappeared to achieve quasisteady-state inflow/outflow ***,triangular wave-formed pressure boundary conditions were applied in different periods to investigate dynamic nonequilibrium effects for hysteretical Pc—*** results showed overshoot and undershoot of P_(c)to S in loops of the nonequilibrium *** addition,the flow regimes of multistep-wise dynamic effects were analyzed in terms of Reynolds and capillary numbers(Re and Ca).The analysis of REV-scale flow regimes showed higher Re(1

关键词： Two-phase flow Porous media Dynamic effects Multistep in/outflow Capillary pressure Interfacial area Flow regimes

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颗粒柱塌落中的尺寸效应和瞬态流变性研究

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计算力学学报 2022年第3期39卷 381-388页

作者：满腾葛转 Herbert EHuppert sergio andres galindo torres 西湖大学工学院浙江省海岸带环境与资源研究重点实验室杭州310024 剑桥大学国王学院英国剑桥CB21ST

颗粒材料是自然界和工程中广泛存在和普遍应用的材料,泥石流、滑坡和混凝土等均可视为颗粒材料。颗粒材料研究有助于更好地控制相关自然灾害或利用其某些特性。对颗粒材料柱体的塌落动力学研究不仅可以方便理解颗粒材料在瞬态流动时的... 详细信息

颗粒材料是自然界和工程中广泛存在和普遍应用的材料,泥石流、滑坡和混凝土等均可视为颗粒材料。颗粒材料研究有助于更好地控制相关自然灾害或利用其某些特性。对颗粒材料柱体的塌落动力学研究不仅可以方便理解颗粒材料在瞬态流动时的流变性,还可以引申到泥石流等岩土材料的运动与堆积形态。本文利用扩展多面体离散单元法对颗粒堆积柱的塌落进行了细致的研究,探索高宽比、摩擦系数以及颗粒柱相对尺寸等对柱体塌落的影响。对颗粒集合进行分网并分析每个网格内的应力与应变率之间的关系,讨论其瞬态本构关系。相关研究对于深入理解颗粒材料重力流的动力学性质以及颗粒集合体的堆积形态具有重要意义。

关键词：颗粒材料尺寸效应流变性离散元扩展多面体

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Parametric study on smoothed particle hydrodynamics for accurate determination of drag coefficient for a circular cylinder

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Water Science and Engineering 2017年第2期10卷 143-153页

作者： Maziar Gholami Korzani sergio A. galindo-torres Alexander Scheuermann David J. Williams School of Civil Engineering The University of Queensland St Lucia Brisbane QLD 4072 Australia School of Mathematics and Physics The University of Queensland St Lucia Brisbane QLD 4072 Australia

Simulations of two-dimensional(2D) flow past a circular cylinder with the smoothed particle hydrodynamics(SPH) method were conducted in order to accurately determine the drag coefficient. The fluid was modeled as a viscous liquid with weak compressibility. Boundary conditions,such as a no-slip solid wall, inflow and outflow, and periodic boundaries, were employed to resemble the physical problem. A sensitivity analysis, which has been rarely addressed in previous studies, was conducted on several SPH parameters. Hence, the effects of distinct parameters, such as the kernel choices and the domain dimensions, were investigated with the goal of obtaining highly accurate results. A range of Reynolds numbers(1-500) was simulated, and the results were compared with existing experimental data. It was observed that the domain dimensions and the resolution of SPH particles, in comparison to the obstacle size, affected the obtained drag coefficient significantly. Other parameters, such as the background pressure, influenced the transient condition, but did not influence the steady state at which the drag coefficient was determined.

关键词： Smoothed particle hydrodynamics Drag coefficient Reynolds number Sensitivity analysis Viscous flow

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Corrosion Behavior of Ψ and β Quasicrystalline Al–Cu–Fe Alloy

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Acta Metallurgica Sinica(English Letters) 2015年第9期28卷 1117-1122页

作者： Alvaro torres sergio Serna Cristobal Patio Gerardo Rosas Facultad de Ciencias Químicas e Ingeniería P.A. Ing.Mecnica UAEM Av. Universidad 1001 Col. Chamilpa62210 Cuernavaca Mor. Mexico Centro de Investigación en Ingeniería y Ciencias Aplicadas UAEM Av. Universidad 1001 Col. Chamilpa62210 Cuernavaca Mor. Mexico Facultad de Ingeniería Universidad Autónoma del CarmenCampus Ⅲ Avenida Central S/N Esq. con Fracc. MundoMaya C.P. 24115 Ciudad del Carmen Campeche Mexico Instituto de Investigaciones Metalurgicas UMSNH Edificio U. Ciudad Universitaria Morelia Mich. 58000 Mexico

Two nanostructured A1-Cu-Fe alloys, A164Cu24Fe12 and A162.5Cu25.2Fe12.3, have been studied. Icosahedral quasicrystalline （ψ） A164CH24FeI2 and crystalline cubic （ β） ***25.2Fe12.3 cylindrical ingots were first produced using normal casting techniques. High-energy mechanical milling was then conducted to obtain β icosahedral and β intermetallic nanostructured powders. Electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization were used to investigate the electrochemical corrosion characteristics of the powders in solutions with different pH values. Current density （icorr）, polarization resistance （Rp）, and impedance modulus （121） were determined. The results showed that regardless of pH value, increasing the solution temperature enhanced the corrosion resistance of the both phases. However, the electrochemical behavior of the phase indicated that its stability depends on the submerged exposure time in neutral and alkaline environments. This behavior was related to the type of corrosion products present on the surfaces of the particles along with the diffusion and charge-transfer mechanisms of the corrosion process.

关键词： Nano-quasicrystalline AI-Cu-Fe alloy Mechanical alloying Corrosion

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Semiosic Translation:a Bayesian-heuristic theory of translation and translating

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Language and Semiotic Studies 2024年第2期10卷 167-202页

作者： sergio torres-Martínez Universidad de Antioquia Cll.67#53–108MedellínAntioquiaColombia

In the context of Semiosic Translation,two elements are essential for a translation to emerge:the body–brain–context interface(extended mind)and the sign systems making up a translation *** this paper,I explain how a renewed view of the body as a Bayesian-heuristic Semiotic Prior helps to understand in a more holistic manner the motivations and agentive character of translation,defined herein as a phenomenological grasp of the *** to the present proposal is the idea that bodily self-stabilization(homeostasis)and brain-driven correction(allostasis)provide translator-agents with maps of action upon the world that are semiotic in *** this occurs thanks to information weighing(Bayesian)and cue-driven(heuristic)types of inference whereby exteroceptive(exogenous)and interoceptive(inner-body)signals converge to create a sense of bodily awareness responsible for the construction of the symbolic persona(the translator-agent).

关键词： embodiment Bayesian semiosis heuristic semiosis semiotics Semiosic Translation translator-agents

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Human CD4 ＋ effector T lymphocytes generated upon TCR engagement with self-peptides respond defectively to IL-7 in their transition to memory cells

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Cellular & Molecular Immunology 2013年第3期10卷 261-274页

作者： Gabriela Gonzalez-Perez Norma C Segovia Amaranta Rivas-Carvalho Diana P Reyes Honorio torres-Aguilar sergio R Aguilar-Ruiz Claudine Irles Gloria Soldevila Carmen Sainchez-torres 1Department of Molecular Biomedicine Centre de Investigacion y de Estudios Avanzados del I.P.N. (CINVESTAV-IPN) Mexico City Mexico Department of Physiology Facultad de Medicina Mexico City Mexico Department of Immunology Institute de Investigaciones Biomedicas Universidad Nacional Autonoma de Mexico (UNAM) Mexico City Mexico

The peripheral repertoire of CD4＋ T lymphocytes contains autoreactive cells that remain tolerant through several mechanisms. However, nonspecific CD4＋ T cells can be activated in physiological conditions as in the course of an ongoing immune response, and their outcome is not yet fully understood. Here, we investigate the fate of human naive CD4＋ lymphocytes activated by dendritic cells （DCs） presenting endogenous self-peptides in comparison with lymphocytes involved in alloresponses. We generated memory cells （Tmem） from primary effectors activated with mature autologous DCs plus interleukin （IL）-2 （Tmauto）, simulating the circumstances of an active immune response, or allogeneic DCs （Tmallo）. Tmem were generated from effector cells that were rested in the absence of antigenic stimuli, with or without IL-7. Tmem were less activated than effectors （demonstrated by CD25 downregulation） particularly with IL-7, suggesting that this cytokine may favour the transition to quiescence. Tmauto and TmaHo showed an effector memory phenotype, and responded similarly to polyclonal and antigen-specific stimuli. Biochemically, IL-7-treated Tma^o were closely related to conventional memory lymphocytes based on Erk-l/2 activation, whereas Tmauto were more similar to effectors. Autologous effectors exhibited lower responses to IL-7 than allogeneic cells, which were reflected in their reduced proliferation and higher cell death. This was not related to IL-7 receptor expression but rather to signalling deficiencies, according to STAT5 activation These results suggest that ineffective responses to IL-7 could impair the transition to memory cells of naive CD4＋ T lymphocytes recognizing self-peptides in the setting of strong costimulation.

关键词： human CD4+ T cells IL-7 memory self-peptides

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Long-term Decomposition Process of the Leaf Litter, Carbon and Nitrogen Dynamics under Different Forest Management in the Sierra de Francia, Salamanca, Spain

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Journal of Agricultural Science and Technology(B) 2012年第3期2卷 312-328页

作者： sergio Salazar Luz-Estela Sanchez Purificacion galindo Ignacio Santa-Regina Institute of Natural Resources and Agrobiology of Salamanca IRNASA-CSIC Cordel de Merinas 40-52 Salamanca 37008 Spain Department of Mathemaies University of Antioquia Colombia Department of Statistics University of Salamanca Spain

The dynamics of organic matter, carbon and nitrogen were studied during leaf decomposition over a three annual cycles period using the litterbag method at three permanently untilled and unfertilised plots. Our hypothesis is to determine if each litter type influences the decomposition and C and N releases from each other litter type （three plots and two species）. The main objective of this study is the comparison of decomposition dynamics in a climax forest with respect to that occurring in the chestnut managed plots on terrain suitable for oak to have further insight into the recycling of above ground organic matter and these two associated bioelements. As for the loss of dry matter, two-way analysis of variance, involving the treatment and year factors, revealed the existence of significant differences only for year, while no differences were observed for either treatment or interaction. At the end of the 2.4 years of the study, most of the treatment assays higher nitrogen concentrations than the initial ones were recorded. These three treatments the samplings prior to the last one revealed nitrogen concentrations higher than the initial ones, such that it may be concluded that the trend was towards an increase in concentration.

关键词： Litter decomposition mass loss carbon and nitrogen release litter bags forest ecosystems Castanea sativa Quercus pyrenaica.

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干颗粒系统的摩擦流变性研究

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Acta Mechanica Sinica 2023年第1期39卷 98-109页

作者：满腾张沛葛转佘吉鸿 Kimberly MHill Key Laboratory of Coastal Environment and Resources of Zhejiang Province School of Engineering Westlake University Hangzhou 310024 China College of Civil Engineering and Architecture Zhejiang University Hangzhou 310058 China Saint Anthony Fall Laboratory and the Department of Civil Environmental and Geo- Engineering University of Minnesota Minneapolis MN 55455 United States

颗粒材料在自然界和工程应用中极为常见,深入理解并合理利用其流变性对于预测与减轻自然灾害以及描述多种工程材料力学性质至关重要.然而,现有研究仍未建立起颗粒之间摩擦特性与颗粒集合体宏观的力学特性之间的物理联系.本文利用离散单... 详细信息

颗粒材料在自然界和工程应用中极为常见,深入理解并合理利用其流变性对于预测与减轻自然灾害以及描述多种工程材料力学性质至关重要.然而,现有研究仍未建立起颗粒之间摩擦特性与颗粒集合体宏观的力学特性之间的物理联系.本文利用离散单元法(DEM)考察了不同颗粒间摩擦系数对定压剪切条件下的颗粒材料的流变性的影响,试图建立基于粒间摩擦的颗粒流变学模型.本研究计算显示,增加颗粒之间的摩擦系数可以显著改变颗粒集合体的整体流变特性,增加颗粒系统的有效摩擦系数µeff,并减小定压剪切条件下的稳态固体体积分数ϕs.在此基础上,本报告提出用于描述不同粒间摩擦特性颗粒材料流变性的无量纲数M,并建立摩擦流变模型.同时考察了M和无量纲颗粒温度Θ之间的关系,分析了摩擦系数对于粒间作用力概率分布函数的影响.进一步延伸了传统的流变模型的应用范围,有助于建立更为普适的颗粒材料本构模型.

关键词：材料力学性质颗粒材料流变学模型概率分布函数颗粒系统摩擦特性无量纲数流变模型

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DNA metabarcoding reveals seasonal changes in diet composition across four arthropod-eating lizard species(Phrynosomatidae:Sceloporus)

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Integrative Zoology 2024年第3期19卷 480-495页

作者： Mauricio HERNÁNDEZ Stephanie HEREIRA-PACHECO Antton ALBERDI Aníbal H.DÍAZ DE LA VEGA-PÉREZ Arturo ESTRADA-torres sergio ANCONA Yendi E.NAVARRO-NOYA Doctorado en Ciencias Biológicas Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Estación Científica La Malinche Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Center for Evolutionary Hologenomics The Globe InstituteUniversity of CopenhagenCopenhagenDenmark Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de Biología de la Conducta Universidad Autónoma de TlaxcalaTlaxcalaMexico Departamento de Ecología Evolutiva Instituto de EcologíaUniversidad Nacional Autónoma de MéxicoMexico CityMexico Laboratorio de Interacciones Bióticas Centro de Investigación en Ciencias BiológicasUniversidad Autónoma de TlaxcalaSan Felipe IxtacuixtlaTlaxcalaMexico

Diet composition and its ecological drivers are rarely investigated in coexisting closely related *** used a molecular approach to characterize the seasonal variation in diet composition in four spiny lizard species inhabiting a mountainous *** metabarcoding revealed that the lizards Sceloporus aeneus,***,***,and *** mostly consumed arthropods of the orders Hemiptera,Araneae,Hymenoptera,and *** terrestrial lizards *** and *** mostly predated ants and spiders,whereas the arboreal–saxicolous *** and saxicolous *** largely consumed grasshoppers and *** taxonomic and phylogenetic diversity of the prey was higher during the dry season than the rainy season,likely because reduced prey availability in the dry season forced lizards to diversify their diets to meet their nutritional *** and phylogenetic composition varied seasonally depending on the species,but only dietary composition varied with *** dietary turnover was greater in *** than in ***,suggesting site-specific seasonal variability in prey availability;no other differences among species were ***,which lives at the highest altitude in our study site,displayed interseasonal variation in diet *** differences were correlated with the species’feeding strategies and elevational distribution,which likely contributed to the coexistence of these lizard species in the studied geographic area and beyond.

关键词： arthropod-eating lizards diet breadth environmental barcoding mountainous ecosystem seasonal dietary shifts

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Spectrum of neuropsychiatric symptoms in chronic post-stroke aphasia

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World Journal of Psychiatry 2022年第3期12卷 450-469页

作者： Lisa Edelkraut Diana López-Barroso María Josétorres-Prioris sergio E Starkstein Ricardo E Jorge Jessica Aloisi Marcelo L Berthier Guadalupe Dávila Department of Psychobiology and Methodology of Behavioral Science Faculty of Psychology and Speech TherapyUniversity of MalagaMalaga 29071Spain Cognitive Neurology and Aphasia Unit Centro de Investigaciones Médico-SanitariasUniversity of MalagaMalaga 29010Spain Instituto de Investigación Biomédica de Málaga University of MalagaMalaga 29010Spain School of Psychiatry and Neurosciences The University of Western AustraliaPerth 6009Australia Department of Psychiatry and Behavioral Sciences Baylor College of MedicineHoustonTX 77030United States

BACKGROUND Neuropsychiatric symptoms(NPS)have been insufficiently examined in persons with aphasia(PWA)because most previous studies exclude participants with language and communication *** To report a two-part study consisting of a literature review and an observational study on NPS in post-stroke *** Study 1 reviewed articles obtained from PubMed,PsycINFO,Google Scholar and Cochrane databases after cross-referencing key words of post-stroke aphasia to NPS and *** 2 examined language deficits and activities of daily living in 20 PWA(median age:58,range:28-65 years;13 men)with the Western Aphasia Battery-Revised and the Barthel Index,*** of these 20 PWA were proxy-evaluated with the Neuropsychiatric Inventory and domain-specific scales,including the Stroke Aphasia Depression Questionnaire-10 item version and the Starkstein Apathy *** addition,an adapted version of the Hospital Anxiety and Depression Scale was directly administered to the PWA *** observational study is based on the baseline assessment of an intervention clinical trial(EudraCT:2017-002858-36;*** identifier:NCT04134416).RESULTS The literature review revealed a broad spectrum of NPS in PWA,including depression,anxiety,apathy,agitation/aggression,eating and sleep disorders,psychosis,and hypomania/*** findings alert to the need for improving assessment and treatment approaches of NPS taking into consideration their frequent occurrence in *** 2 showed that the 20 participants had mild-to-moderate aphasia severity and were functionally independent.A wide range of comorbid NPS was found in the post-stroke aphasic population(median number of NPS:5,range:1-8).The majority of PWA(75%)had depressive symptoms,followed by agitation/aggression(70%),irritability(70%),anxiety(65%)and appetite/eating symptoms(65%).Half of them also presented symptoms of apathy,whereas euphoria and psychotic symptoms were rare(5%).Domain

关键词： Aphasia Stroke Neuropsychiatric symptoms Anxiety Apathy Depression

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