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A High-order coupled compact Integrated RBF Approximation Based domain decomposition Algorithm for Second-order differential Problems

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computer Modeling in Engineering & Sciences 2015年第4期104卷 251-304页

作者： c.M.t.tien N.Pham-Sy N.Mai-duy c.-d.tran t.tran-cong computational Engineering and Science Research centre Faculty of HealthEngineering and SciencesThe University of Southern QueenslandToowoombaQueensland 4350Australia

this paper presents a high-order coupled compact integrated RBF(cc IRBF)approximation based domain decomposition(dd)algorithm for the discretisation of second-order differential *** Schwarz dd algorithms,including one-level additive/multiplicative and two-level additive/multiplicative/hybrid,are *** ccIRBF based dd algorithms are analysed with different mesh sizes,numbers of subdomains and overlap sizes for Poisson *** convergence analysis shows that the ccIRBF two-level multiplicative version is the most effective algorithm among various schemes employed ***,the present ccIRBF two-level method converges quite rapidly even when the domain is divided into many subdomains,which shows great promise for either serial or parallel *** practical tests,we then incorporate the ccIRBF into serial and parallel two-level multiplicative *** numerical examples,including those governed by Poisson and Navier-Stokes equations are analysed to demonstrate the accuracy and efficiency of the serial and parallel algorithms implemented with the *** results show:(i)the ccIRBF-Serial and-Parallel algorithms have the capability to reach almost the same solution accuracy level of the ccIRBF-Single domain,which is ideal in terms of computational calculations;(ii)the ccIRBF-Serial and-Parallel algorithms are highly accurate in comparison with standard finite difference,compact finite difference and some other schemes;(iii)the proposed ccIRBF-Serial and-Parallel algorithms may be used as alternatives to solve large-size problems which the ccIRBF-Single domain may not be able to deal *** ability of producing stable and highly accurate results of the proposed serial and parallel schemes is believed to be the contribution of the coarse mesh of the two-level domain decomposition and the ccIRBF *** is noted that the focus of this paper is on the derivation of highly accurate serial and parallel algorithms

关键词： coupled compact integrated RBF (ccIRBF) Schwarz domain decomposition one-level two-level coarse meshes additive multiplicative hybrid serial parallel colouring technique Poisson equation Naiver-Stokes equation liddriven cavity

From a sequential pattern,temporal adjustments emerge in hummingbird traplining

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Integrative Zoology 2019年第2期14卷 182-192页

作者： Maria c.tELLO-RAMOS Andrew t.HURLY Susan d.HEALY School of Biology University of St AndrewsScotlandUK department of Biological Sciences University of LethbridgeAlbertaCanada

Animals that feed from resources that are constant in space and that refill may benefit from repeating the order in which they visit *** is a behavior known as traplining,a spatial ***,like other central-place foragers,use short traplines when moving between several rewarding *** we investigated whether traplining hummingbirds also use relevant temporal information when choosing which flowers to *** rufous hummingbirds that were allowed to visit 3 artificial flower patches in which flowers were refilled 20 min after they had been depleted repeated the order in which they visited the 3 *** they tended to visit the first 2 patches sooner than 20 min,they visited the third patch at approximately 20-min inter*** time between visits to the patches increased across the experiment,suggesting that the birds learned to wait longer before visiting a *** birds appeared to couple the sequential pattern of a trapline with temporal regularity,to some *** suggests that there is a temporal component to the repeated spatial movements flown by foraging wild hummingbirds.

关键词： foraging patterns interval timing rufous hummingbirds Selasphorus rufus

Wintering Swan Geese maximize energy intake through substrate foraging depth when feeding on buried Vallisneria natans tubers

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Avian Research 2019年第2期10卷 163-170页

作者： Yan chen Yong Zhang Lei cao Willem F.de Boer Anthony d.fox School of Life Sciences University of Science and Technology of ChinaHefei 230027China co-Innovation center for Sustainable Forestry in Southern china College of Biology and the EnvironmentNanjing Forestry UniversityNanjing 210037China Research center for Eco-Environmental Science Chinese Academic of Sciences18 Shuangqing RoadBeijing 100085China University of chinese Academy of Sciences 19 Yuquan RoadShijingshan DistrictBeijing 100049China Resource Ecology Group Wageningen UniversityDroevendaalsesteeg3a6708 PB WageningenThe Netherlands department of Bioscience Aarhus UniversityKalφGrenavej 148410 RφndeDenmark

Background: Foraging theory predicts that animals select patches that offer the highest net rate of energy gain. Hence, prey distribution patterns and spatiotemporal heterogeneity play important roles in determining animal feeding patch selection. For waterfowl foraging on buried aquatic plant tubers, the distribution and biomass of these plant organs vary with depth in the substrate. Since excavation costs also increase with depth, the energy intake of the animals foraging on these plants is highly sediment depth dependent. Methods: Here, using observations of Swan Geese (Anser cygnoides) foraging on Vallisneria natans tubers, we test our hypothesis that geese feeding on tubers buried at intermediate sediment depth maximize their daily energy intake because of the interaction between tuber size and abundance with depth. to do this, we measured the distribution patterns of buried Vallisneria tubers under both undisturbed conditions and post-exploitation by geese (i.e. giving-up conditions). We investigated the relationship between tuber size and burial depth, and total tuber biomass within each sediment layer in undisturbed and exploited plots. Finally, we compared modelled Swan Goose daily energy intake feeding on Vallisneria tubers buried at different sediment layers (1–10, 11–20 and 21–30 cm below the surface). Results: dry weight of Vallisneria tubers linearly increased with burial depth, while average total dry weight density of tubers showed a unimodal relationship, peaking at intermediate levels. Not surprisingly, Swan Geese foraged most intensively on tubers buried at intermediate sediment depths, where they maximize their daily energy intake. Our results support our hypothesis that Swan Geese feeding on tubers at intermediate depths maximize their daily energy intake. conclusions: Our study is the first to quantify foraging strategies of Swan Geese during the wintering period, emphasizing the importance of plant traits on foraging selection of belowground f

关键词： Energetic trade-off Optimal foraging Shengjin Lake Substrate tuber burial depth Yangtze River

the role of cd6 in autoimmune diseases

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cellular & Molecular Immunology 2018年第11期15卷 1001-1002页

作者： david A.fox division of Rheumatology and clinical Autoimmunity center of Excellence University of MichiganAnn ArborMIUSA

In a recent publication in the cellular and Molecular Immunology,consuega-Fernandez and colleagues present new data from patients with psoriasis,linking the cd6 lymphocyte surface structure to the pathogenesis of this disease.1 In this commentary,I will discuss these new findings in the context of accumulating evidence for important roles of cd6 in a variety of autoimmune *** cd6 was one of the earliest“cd antigens”to be described,it is only recently that attention has refocused on the potential for cd6 as a treatment target in immune-mediated diseases.

关键词： autoimmune Immunology diseases

Nonlinear thermo-mechanical stability of eccentrically stiffened functionally graded material sandwich doubly curved shallow shells with general sigmoid law and power law according to third-order shear deformation theory

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Applied Mathematics and Mechanics(English Edition) 2017年第2期38卷 191-216页

作者： d.V.dUNG d.t.dONG Faculty of Mathematics Mechanics and Informatics Vietnam National University Hanoi 100000 Vietnam Faculty of civil Engineering University of Transport Technology Hanoi 100000 Vietnam

In this paper, the nonlinear analysis of stability of functionally graded ma- terial （FGM） sandwich doubly curved shallow shells is studied under thermo-mechanical loads with material properties obeying the general sigmoid law and power law of four ma- terial models. Shells are reinforced by the FGM stiffeners and rest on elastic foundations. theoretical formulations are derived by the third-order shear deformation theory （tSdt） with the von Karman-type nonlinearity taking into account the initial geometrical im- perfection and smeared stiffener technique. the explicit expressions for determining the critical buckling load and the post-buckling mechanical and thermal load-deflection curves are obtained by the Galerkin method. two iterative algorithms are presented. the effects of the stiffeners, the thermal element, the distribution law of material, the initial imper- fection, the foundation, and the geometrical parameters on buckling and post-buckling of shells are investigated.

关键词： functionally graded material (FGM) sandwich double curved shallow shell,thermo-mechanical stability FGM stiffener elastic foundation

StORMWAtER NAtURE POcKEtS: A cASE FOR USING GREEN INFRAStRUctURE tO cREAtE ENGAGING cHILdHOOd SPAcES

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Journal of Green Building 2015年第3期10卷 14-27页

作者： Adrienne cizek Andrew fox Stormwater Solutions Engineering LLC North carolina State University department of Landscape Architecture

Urban areas require stormwater *** there has been a movement towards more nature-based,green infrastructure approaches for managing *** systems have also demonstrated additional ecosystem benefits much needed in urban *** the same time,decades of research support the need for access to nature for healthy childhood *** and locating nature-based stormwater systems where children frequent renders systems as multi-functional spaces,providing synergetic opportunities,which benefit individuals and *** to integrating these spaces include safety,cost,and management,all of which can be overcome by smart and appropriate *** design requires collaboration between different skillsets and stakeholders through some minimal,but essential changes in the consultation and design ***,integrating nature-based stormwater practices into children’s outdoor spaces will provide economic,environmental,and social benefits to urban areas.

关键词： green infrastructure low impact development outdoor learning environments nature play stormwatersoil biology plant factor evapotranspiration drip irrigation organic maintenance hands-on workshop

Physical,Mechanical,and tribological Attributes of Stir-cast AZ91/Sic_p composite

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Acta Metallurgica Sinica(English Letters) 2014年第2期27卷 295-305页

作者： K.K.Ajith Kumar Abhilash Viswanath t.P.d.Rajan U.t.S.Pillai B.c.Pai Material Science and technology division CSIR-National Institute for Interdisciplinary Science and Technology

In the present investigation, composites with silicon carbide particle （Sicp） as reinforcement and AZ91 magnesium alloy as matrix have been synthesized using liquid metal stir-casting technique with optimized processing conditions. the composites with good particle distribution in the matrix, and better grain refinement and good interfacial bonding between the matrix and reinforcement have been obtained. the effect of Sicp content on the physical, mechanical, and tribological properties of Mg-based metal matrix composite （MMc） is studied with respect to particle distribution, grain refinement, and particle/matrix interfacial reactions. the electrical conductivity, coefficient of thermal expansion, microas well as macro-hardness, tensile and compressive properties, and the fracture behavior of the composites along with dry sliding wear of the composites have been evaluated and compared with the base alloy.

关键词： composite AZ91d alloy casting alloy Mechanical properties Wear

A new design of dual-constituent triangular lattice metamaterial with unbounded thermal expansion

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Acta Mechanica Sinica 2019年第3期35卷 507-517页

作者： Y.c.Zhang Y.J.Liang S.t.Liu Y.d.Su State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China New Functional Structural design and Verification Key Laboratory of Aeronautical technology Shenyang 110035China

triangular lattice metamaterials composed of bi-layer curved rib elements (called the Lehman-Lakes lattice) possess unbounded thermal expansion, high stiffness and impossibility of thermal buckling, which are highly desirable in many engineering structural applications subjected to large fluctuations in temperature. However, the requirement of such lattice metamaterial is that it must be a hinged joint in order to achieve the bending deformation upon heating freely, which directly leads to poor manufacturability, especially in small dimensions. In this study, a new design of dual-constituent triangular lattice metamaterial (dtLM) with good manufacturability is proposed to achieve the identical unbounded thermal expansion. In this lattice, a special bi-layer curved rib element where layer one is partially covered by layer two is presented, where the hinge joints are not necessary because the flexural rigidity in the single-layer part is much smaller than that in the bi-layer part, and the desirable thermal bending deformation can be achieved. A sample fabricated by additive manufacturing is given in order to show the good manufacturability;simultaneously, the multifunctional performance of the tailored dtLM with zero, large positive or negative coefficient of thermal expansion (ctE) can remain excellent, as well as the Lehman-Lakes lattice. Examples illustrate that the dtLM with zero ctE has about 34.2% improvement in stiffness and meanwhile has 17% reduction in weight compared with the Lehman-Lakes lattice. the stiffness of the dtLM has a moderate reduction when achieving the same large positive or negative ctE. In addition, the thermomechanical properties of the dtLM are given by the closed-form analytical solution and their effectiveness is verified by the detailed numerical simulation.

关键词： Metamaterial Zero thermal expansion Lattice material Multifunctional design Additive manufacturing

An important criterion for reliable multi-monochromatic x-ray imager diagnostics and its impact on the reconstructed images

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High Power Laser Science and Engineering 2015年第3期3卷 59-65页

作者： t.Nagayama R.c.Mancini d.Mayes R.tommasini R.Florido Physics department University of Nevada Lawrence Livermore National Laboratory departamento de Física Universidad de Las Palmas de Gran Canaria

temperature and density asymmetry diagnosis is critical to advance inertial confinement fusion(IcF) science. A multimonochromatic x-ray imager, MMI, records the spectral signature from an IcF implosion core with time resolution, 2d spatial resolution and spectral resolution. While narrow-band images and 2d space-resolved spectra from the MMI data constrain the temperature and the density spatial structure of the core, the accuracy of the images and the spectra highly depends on the quality of the MMI data and the processing tools. Here, we synthetically investigate the criterion for reliable MMI diagnostics and its effects on the accuracy of the reconstructed images. the pinhole array tilt determines the object spatial sampling efficiency and the minimum reconstruction width, w. When the spectral width associated with w is significantly narrower than the spectral linewidth, the line images reconstructed from the MMI data become reliable. the MMI setup has to be optimized for every application to meet this criterion for reliable IcF diagnostics.

关键词： high power laser inertial confinement fusion monochromatic imager x-ray diagnostics