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Identification of boundary surfaces in flows

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Applied Mathematics and Mechanics(English Edition) 2010年第9期31卷 1097-1104页

作者： B.HErrErA j.PALLArES Department d'Enginyeria Informàtica i Matematiques Universitat Rovira i VirgiliAvinguda Pasos Catalans 26Tarragona 43007Spain Department d'Enginyeria Mecànica Universitat Rovira i VirgiliAvinguda Pasos Catalans 26Tarragona 43007Spain

In this study, boundary surfaces of a flow field are defined as stream surfaces, on which the shear rates vanish, and a procedure is proposed to find them. The method, based on calculations using the velocity vector f... 详细信息

关键词： interracial surfaces structure of flow kinematics

Extracellular vesicles and angiotensin-converting enzyme 2 in COVID-19 disease

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BIOCELL 2024年第1期48卷 1-8页

作者： YU LIU rOBErT j.KASPEr NATALIE j.S.CHOI Department of Family and Community Medicine Northwestern University Feinberg School of MedicineChicagoIllinois

Extracellular vesicles(EVs)are membranous vesicular structures released from almost all eukaryotic cell types under different physiological or pathological *** evidence demonstrates that EVs can serve as mediators of intercellular communication between donor and recipient cells or microorganism-infected and noninfected *** disease 2019(COVID-19)disease is caused by infection of the severe acute respiratory syndrome coronavirus 2(SArS-CoV-2)of host cells in the respiratory system and various extra-pulmonary tissue/organs,resulting in complications of multiple organ *** the cell surface receptor,angiotensin-converting enzyme 2(ACE2)mediates cellular entry of SArS-CoV-2 into the host cells in patients with *** studies have found that ACE2 can be released with EVs,which have been shown to interfere with the entry of the virus into host cells and thus may be involved in COVID-19 *** addition,ACE2,neprilysin(NEP),and thimet oligopeptidase(TOP)are the key enzymes that regulate angiotensin metabolism by converting angiotensin II or angiotensin I to angiotensin 1-7,the latter of which has protective effects in counterbalancing the harmful effects of angiotensin II in COVID-19 *** review summarizes the recent research progress regarding EV-associated ACE2,NEP,and TOP and the perspectives of their potential involvement in the pathophysiology of COVID-19 disease.

关键词： Extracellular vesicles COVID-19 Angiotensin converting enzyme 2 Thimet oligopeptidase

MrI Brain Tumor Segmentation with Intuitionist Possibilistic Fuzzy Clustering and Morphological Operations

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Computer Systems Science & Engineering 2022年第10期43卷 363-379页

作者： j.Anitha M.Kalaiarasu Department of Information Technology Sri Ramakrishna Engineering CollegeCoimbatore641022India

Digital Image Processing(DIP)is a well-developed field in the biological sciences which involves classification and detection of *** medical science,automatic brain tumor diagnosis is an important *** tumor detection is performed by Computer-Aided Diagnosis(CAD)*** human image creation is greatly achieved by an approach namely medical imaging which is exploited for medical and research *** Automatic brain tumor detection from MrI images has become the emerging research area of medical *** tumor diagnosis mainly performed for obtaining exact location,orientation and area of abnormal *** and edema regions inference from brain magnetic resonance imaging(MrI)information is considered to be great challenge due to brain tumors complex structure,blurred borders,besides exterior features like *** noise compassion is mainly reduced along with segmentation stability by suggesting efficient hybrid clustering method merged with morphological process for brain cancer *** form of Median Modified Wiener filter(CMMWF)is chiefly deployed for denoising,and morphological operations which in turn eliminate nonbrain tissue,efficiently dropping technique’s sensitivity to *** proposed system contains the main phases such as preprocessing,brain tumor extraction and post *** segmentation is greatly achieved by presenting Intuitionist Possibilistic Fuzzy Clustering(IPFC)*** algorithm’s stability is greatly enhanced by this clustering along with clustering parameters sensitivity ***,the post processing of images are done through morphological operations along with Hybrid Median filtering(HMF)for attaining exact tumors ***,suggested algorithm is substantiated by comparing with other existing segmentation *** outcomes reveal that suggested algorithm achieves improved outcomes pertaining to accuracy,sensitivity,specificity,and recall.

关键词： Morphological Image Processing(MIP) Magnetic resonance Imaging(MrI) brain tumor clustering K-means clustering image segmentation Fuzzy-CMeans(FCM)

review of Moirésuperconductivity and application of the roeser-Huber formula

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Superconductivity 2024年第1期9卷 9-28页

作者： Michael r.Koblischka Anjela Koblischka-Veneva Institute of Experimental Physics Saarland UniversityCampus C 6366123 SaarbrückenGermany

Moirésuperconductivity represents a new class of superconducting materials since the discovery of superconductivity in magic‐angle(1.1°)twisted bi‐layer graphene(MATBG),forming a Moirélattice with a much bigger crystal parameter as the original lattice constant of ***,experimentally changing the Moirétwist angle,0.93°≤Θ≤1.27,leads to a variation of the superconducting properties and enables a new way of engineering 2D superconducting *** of the robust superconducting state of MATBG as function of charge carrier density,temperature and applied magnetic fields are *** influence of the top/bottom hexagonal boron nitride layer thickness on the superconducting properties of MATBG was also demonstrated in the *** all fabricated MATBG devices,changing of the charge carrier density leads to the appearance of insulating,metallic and even ferromagnetic states,which separate several superconducting domes in the phase diagram(longitudinal resistance,rxx,as function of temperature T and charge carrier density,n).Further works have considered MATBG combined with WSe2‐layers,twisted bi‐layer WSe2,magic‐angle trilayer graphene(MATTG),and most recently,four‐layer(MAT4G)and five‐layer(MAT5G)*** differences between the layered,cuprate high‐Tc superconductors and the Moirésuperconductors are compiled *** collected information is then used to apply the roeser‐Huber formalism to Moiré‐type superconductivity to calculate the superconducting transition temperature,Tc,using only information of the Moirélattice and the electronic *** account for the different charge carrier densities in the experimental data sets and the low charge carrier mass demands that a new parameterηmust be introduced to the roeser‐Huber formalism to enable the description of several superconducting domes found in the phase diagram for a given Moiré*** so,the calculated data fit well to the correlation curve defined within the roeser‐Hube

关键词： MoiréSuperconductors Twisted bilayer graphene Magic angle Multilayer graphene stacks Superconducting transition temperature roeser‐Huber formalism

Convergence and exact solutions of spline finite strip method using unitary transformation approach

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Applied Mathematics and Mechanics(English Edition) 2011年第11期32卷 1407-1422页

作者： j. KONG D. THUNG Division of Building Science and Technology City University of Hong Kong Hong Kong P. R. China School of Creative Media City University of Hong Kong Hong Kong P. R. China

The spline finite strip method （FSM） is one of the most popular numerical methods for analyzing prismatic structures. Efficacy and convergence of the method have been demonstrated in previous studies by comparing only numerical results with analytical results of some benchmark problems. To date, no exact solutions of the method or its explicit forms of error terms have been derived to show its convergence analytically. As such, in this paper, the mathematical exact solutions of spline finite strips in the plate analysis are derived using a unitary transformation approach （abbreviated as the U-transformation method herein）. These exact solutions are presented for the first time in open literature. Unlike the conventional spline FSM which involves assembly of the global matrix equation and its numerical solution, the U-transformation method decouples the global matrix equation into the one involving only two unknowns, thus rendering the exact solutions of the spline finite strip to be derived explicitly. By taking Taylor＇s series expansion of the exact solution, error terms and convergence rates are also derived explicitly and compared directly with other numerical methods. In this regard, the spline FSM converges at the same rate as a non-conforming finite element, yet involving a smaller number of unknowns compared to the latter. The convergence rate is also found superior to the conventional finite difference method.

关键词： spline finite strip U-transformation plate symmetry

Geographic variation in sexual selection and implications for speciation in the Barn Swallow

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Chinese Birds 2015年第1期5卷 30-42页

作者： Elizabeth SC Scordato rebecca j Safran Department of Ecology and Evolutionary Biology The University of Colorado

Barn Swallows(Hirundo rustica), a group of passerine birds comprised of six closely related subspecies, are well known throughout their nearly worldwide distribution, in part because of their close association with human settlements.A tractable species for both individual-based and population-level studies, Barn Swallows are a prominent model system in evolutionary, ecological, and behavioral research. Here we review work on sexual selection and population divergence in this species complex, focusing on comparative studies among populations and *** summarize variation in the targets of mate choice and in the information conveyed by sexually selected traits, and conclude that the benefits advertised by different traits may vary geographically. Finally, we consider the role of sexual selection as a driver of population divergence in this widespread and phenotypically variable species complex.

关键词： Barn Swallow Geographic variation Natural selection Sexual selection Speciation Tail streamers Ventral color

Combined heat and mass transfer by mixed convection MHD flow along a porous plate with chemical reaction in presence of heat source

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Applied Mathematics and Mechanics(English Edition) 2010年第10期31卷 1217-1230页

作者： j.ZUECO S.AHMED ETS Ingeniería Industrial Departamento de Ingeniería Térmicay FluidosUniversidad Politécnica de Cartagena Fluid Dynamics research Department of MathematicsGoalpara College

An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass transfer are presented.A uniform magnetic field is assumed to be applied transversely to the direction of the flow with the consideration of the induced magnetic field with viscous and magnetic dissipations of *** porous plate is subjected to a constant suction velocity as well as a uniform mixed stream *** governing equations are solved by the perturbation technique and a numerical *** analytical expressions for the velocity field,the temperature field,the induced magnetic field,the skin-friction,and the rate of heat transfer at the plate are *** numerical results are demonstrated graphically for various values of the parameters involved in the *** effects of the Hartmann number,the chemical reaction parameter,the magnetic Prandtl number,and the other parameters involved in the velocity field,the temperature field,the concentration field,and the induced magnetic field from the plate to the fluid are *** increase in the heat source/sink or the Eckert number is found to strongly enhance the fluid velocity *** induced magnetic field along the x-direction increases with the increase in the Hartmann number,the magnetic Prandtl number,the heat source/sink,and the viscous *** is found that the flow velocity,the fluid temperature,and the induced magnetic field decrease with the increase in the destructive chemical *** of the study arise in the thermal plasma reactor modelling,the electromagnetic induction,the magnetohydrodynamic transport phenomena in chromatographic systems,and the magnetic field control of materials processing.

关键词： MHD perturbation technique network simulation method Eckert number mixed convection induced magnetic field viscous dissipation heat source/sink

Key networks to create disaster resilient Smart Cities Mission: A case for remodeling India’s Smart Cities Mission to include disaster resilience

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Resilient Cities and Structures

resilient Cities and Structures 2024年第4期3卷 52-62页

作者： Yamini Meduri r.Singh Geetha Manoharan Assistant Professor ICFAI Business SchoolICFAI Foundation for Higher EducationIndia research Scholar SR UniversityIndia Assistant Professor School of BusinessSR UniversityIndia

Amidst a concerning surge in urban losses attributed to disasters,this research paper explores the intricate relationship between urban development,disaster mitigation,and resilience emphasizing the significance of addressing disaster vulnerability in urban settings,where a substantial portion of the population faces risks stemming from high population density,limited resilience,and inadequate coping *** study advocates for the integration of disaster resilience principles into the Smart Cities Mission of India,placing particular emphasis on the necessity of developing infrastructure,establishing early warning systems,and fostering community engagement to bolster urban ***,the paper draws comparisons and parallels between the components of smart cities,mitigation strategies,and disaster resilience,illuminating their interconnectedness and potential *** conclusion,the study recommends the incorporation of essential network elements to establish a Smart Cities Mission that is resilient to disasters,ultimately aiming to safeguard urban communities from the adverse impacts of future calamities.

关键词： Disaster resilience Smart city mission Disaster mitigation Disaster management

Measuring user preferences and behaviour in a topographic immersive virtual environment(TopoIVE)of 2D and 3D urban topographic data

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International journal of Digital Earth 2021年第12期14卷 1835-1867页

作者： Łukasz Halik Alexander.j.Kent Department of Cartography and Geomatics Adam Mickiewicz UniversityPoznańPoland School of Psychology and Life Sciences Canterbury Christ Church UniversityCanterburyUK

This paper investigates user preferences and behaviour associated with 2D and 3D modes of urban representation within a novel Topographic Immersive Virtual Environment(TopoIVE)created from official 1:10,000 *** participants were divided into two groups:the first were given a navigational task within a simulated city and the second were given the freedom to explore it.A Head-Mounted Display(HMD)Virtual reality(Vr)app allowed participants to switch between 2D and 3D representations of buildings with a remote controller and their use of these modes during the experiment was *** performed mental rotation tests before entering the TopoIVE and were interviewed afterwards about their experiences using the *** results indicate that participants preferred the 3D mode of representation overall,although preference for the 2D mode was slightly higher amongst those undertaking the navigational task,and reveal that different wayfinding solutions were adopted by participants according to their ***,the findings suggest that users exploit different aspects of 2D and 3D modes of visualization in their wayfinding strategy,regardless of their *** potential to combine the functionality of 2D and 3D modes therefore offers substantial opportunities for the development of immersive virtual reality products derived from topographic datasets.

关键词： Virtual reality(Vr) immersive virtual environment(IVE) 2D versus 3D wayfinding topographic data