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Stability of Projection Methods for Incompressible Flows Using high Order Pressure-Velocity Pairs of Same Degree:Continuous and Discontinuous Galerkin Formulations

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Communications in Computational Physics 2014年第8期16卷 817-840页

作者： E.Ferrer D.Moxey r.h.j.Willden S.j.Sherwin ETSIA–School of Aeronautics Universidad Politecnica de MadridPza.Cardenal Cisneros 3MadridE-28040Spain. Department of Aeronautics Imperial College LondonLondonSW72AZUK. Department of Engineering Science University of OxfordParks RoadOxfordOX13PJUK.

This paper presents limits for stability of projection type schemes when using high order pressure-velocity pairs of same *** high order h/p variational methods encompassing continuous and discontinuous Galerkin formulations are used to explain previously observed lower limits on the time step for projection type schemes to be stable[18],when h-or p-refinement strategies are *** addition,the analysis included in this work shows that these stability limits do not depend only on the time step but on the product of the latter and the kinematic viscosity,which is of particular importance in the study of high reynolds number *** show that high order methods prove advantageous in stabilising the simulations when small time steps and low kinematic viscosities are *** upon this analysis,we demonstrate how the effects of this instability can be reduced in the discontinuous scheme by introducing a stabilisation term into the global ***,we show that these lower limits are compatible with CourantFriedrichs-Lewy(CFL)type restrictions,given that a sufficiently high polynomial order or a mall enough mesh spacing is selected.

关键词： Incompressible Navier-Stokes equations projection methods velocity-correction continuous Galerkin discontinuous Galerkin inf-sup LBB condition.

Mapping Sea Level rise Behavior in an Estuarine Delta System：A Case Study along the Shanghai Coast

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Engineering 2018年第1期4卷 156-163页

作者： h.Q. Cheng j.Y. Chen Z.j. Chen r.L. ruan G.Q. Xu G. Zeng j.r. Zhu Z.j. Dai X.Y. Chen S.h. Gu X.L. Zhang h.M. Wang State Key Laboratory of Estuarine and Coastal research East China Normal University Shanghai 200062 China Shanghai Water Planning Design and research Institute Shanghai 200232 China Shanghai Water Authority Shanghai 200050 China School of Urban and regional Science East China Normal University Shanghai 200062 China School of Ecological and Environmental Sciences East China Normal University Shanghai 200062 China Shanghai hydrological Station Shanghai 200232 China Shanghai Municipal Bureau of Urban Planning and Land resources Shanghai 200003 China Shanghai Institute of Geological Survey Shanghai 200072 China

Sea level rise （SLr） is a major projected threat of climate change that is expected to affect developing coastal cities located in estuarine delta regions, Shanghai is one such city, being located in the Yangtze river Delta （YrD）, It is difficult, however, for decision-makers to implement adaptation due to the uncer- tain causes, magnitudes, and timings of SLr behaviors, This paper attempts to map the causes and mag- nitudes of SLr behaviors on a decadal scale, We analyze the tidal level records from 11 tidal gauge stations and the corresponding bathymetry measurements around these stations since 1921, We identify three new SLr behaviors along the Shanghai coast due to anthropogenic geomorphologic changes （AGCs）, besides the well-known eustatic sea level rise （ESLr）, tectonic subsidence （TS）, and urban land subsidence （ULS）, The first new behavior is regional sea level rise （rSLr）, which occurs as a result of land reclamation and deep waterway regulation, The second is regional sea level fall （rSLF）, which occurs because the channel bed is eroded due to sediment supply decline in the river catchment, The last SLr behavior is local tidal datum rise （LTDr）. Thus, we project that the magnitude of SLr for the Shanghai coast ranges from 10 cm to 16 cm from 2011 to 2030, Clarifying SLr behaviors is important to aid local decision- makers in planning structural and non-structural measures to combat escalating flood damage costs in an estuarine delta system; this field is full of future challenges,

关键词： Sea level rise behavior Anthropogenic geomorphologic change Local tidal datum Flood management Adaptation

Effect of pre-deformation on microstructure and mechanical properties of WE43 magnesium alloy II: Aging at 250 and 300℃

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journal of Magnesium and Alloys 2020年第1期8卷 103-110页

作者： Y.h.Kang Z.h.huang S.C.Wang h.Yan r.S.Chen j.C.huang Guangdong-hong Kong joint research and Development Center on Advanced Manufacturing Technology for Light Alloys Guangdong Institute of Materials and ProcessingGuangzhou 510650China Institute of Metal research Chinese Academy of Sciences Shenyang 110016China hong Kong Institute for Advanced Study Department of Materials Science and EngineeringCity University of Hong KongHong KongChina

In this work,the microstructural evolution and mechanical properties of a pre-deformed WE43 magnesium alloy when aged at 250 and 300℃ were further *** is found that the abundant deformation twins introduced by pre-deformation were maintained within the alloy during the aging *** particles formed at the twin boundaries and coarsened with aging time,especially at 300℃.When peak-aged at 250℃,the fine metastable β'''and β' precipitates formed in the un-deformed alloy have been transformed into relatively large β1 and β precipitates by the *** peak-aged at 300℃,the pre-deformation obviously refined the β *** properties indicate that pre-deformation can increase the yield strength by 19MPa and 54MPa for the peak-aged alloy at 250℃ and 300℃,respectively,and will not obviously deteriorate the tensile elongations.

关键词： WE43 magnesium alloy Pre-deformation Aging Microstructure Mechanical properties

resolution beyond classical limits with spatial frequency heterodyning

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Chinese Optics Letters 2006年第3期4卷 148-151页

作者： A.Mudassar A.r.harvey A.h.Greenaway j.D.C.jones School of Engineering and Physical Sciences Heriot-Watt UniversityUK

A technique for coherent imaging based on spatial frequency heterodyning is described. Three images corresponding to three physical measurements are recorded. For the first measurement, a scene is simply illuminated with a coherent beam and for measurements 2 and 3, the scene is projected with cosine and sine fringes, respectively. Due to spatial frequency heterodyning, upper and lower side hand information falls in the pass band of the imager. These bands are separated and correct phases and positions are assigned to these bands in the spatial frequency domain. An extension of bandwidth is achieved in the frequency domain and the inverse frequency domain data then give a high resolution coherent image.

关键词： resolution beyond classical limits with spatial frequency heterodyning

IMEX Evolution of Scalar Fields on Curved Backgrounds

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Communications in Computational Physics 2009年第10期6卷 1063-1094页

作者： S.r.Lau h.P.Pfeiffer j.S.hesthaven Division of Applied Mathematics Brown UniversityProvidenceRI 02912USA Theoretical Astrophysics and relativity Group 130-33 California Institute of TechnologyPasadenaCA 91125USA Also at the Department of Mathematics and Statistics University of New MexicoAlbuquerqueNM 87131USA.

Inspiral of binary black holes occurs over a time-scale of many orbits,far longer than the dynamical time-scale of the individual black *** evolutions of a binary system therefore require excessively many time-steps to capture interesting *** present a strategy to overcome the Courant-Friedrichs-Lewy condition in such evolutions,one relying on modern implicit-explicit ODE solvers and multidomain spectral methods for elliptic *** analysis considers the model problem of a forced scalar field propagating on a generic curved ***,we encounter and address a number of issues pertinent to the binary black hole problem in full general *** to the Schwarzschild geometry in KerrSchild coordinates,we document the results of several numerical experiments testing our strategy.

关键词： Implicit-explicit schemes spectral methods numerical relativity black holes

Physical properties of sprayed antimony doped tin oxide thin films:The role of thickness

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journal of Semiconductors 2011年第5期32卷 10-17页

作者： A.r.Babar S.S.Shinde A.V.Moholkar C.h.Bhosale j.h.Kim K.Y.rajpure Electrochemical Materials Laboratory Department of PhysicsShivaji UniversityKolhapur-416 004India Department of Materials Science and Engineering Chonnam National University300 Yongbong-DongBuk-GuGwangju500-757South Korea

Transparent conducting antimony doped tin oxide （Sb：SnO2） thin films have been deposited onto pre- heated glass substrates using a spray pyrolysis technique by varying the quantity of spraying solution. The structural, morphological, X-ray photoelectron spectroscopy, optical, photoluminescence and electrical properties of these films have been studied. It is found that the films are polycrystalline in nature with a tetragonal crystal structure having orientation along the （211） and （112） planes. Polyhedrons like grains appear in the FE-SEM images. The average grain size increases with increasing spraying quantity. The compositional analysis and electronic behaviour of Sb：SnO2 thin films were studied using X-ray photoelectron spectroscopy. The binding energy of Sn3ds/2 for all samples shows the Sn^4＋ bonding state from SnO2. An intensive violet luminescence peak near 395 nm is observed at room temperature due to oxygen vacancies or donor levels formed by Sb^5＋ ions. The film deposited with 20 cc solution shows 70 % transmittance at 550 nm leading to the highest figure of merit （2.11 × 10^-3 Ω^-1）. The resistivity and carrier concentration vary over 1.22 × 10^-3 to 0.89 × 10^-3Ω cm and 5.19 ×10^20 to 8.52 × 10^20 cm^-3, respectively.

关键词： semiconductors microstructure optical properties electrical properties

ThE STErEOSTrUCTUrAL INVESTIGATION OF 3(r), 8-DIMEThYL-2(r), 5-BIS(1-METhYL-EThYL)-6-OXO-2, 3, 6, 7, 9, 10-hEXAhYDrO-1h-3A, 7- EThANOAZULENE-10-CArBONITrILE BY 2-D NMr SPECTrOSCOPY

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Chinese Science Bulletin 1990年第12期35卷 997-1002页

作者：韩秀文 h.rüEGGEr j.SONDErEGGEr Dalian Institute of Chemical Physics Academia Sinica Dalian 116012 PRC Spectrospin AG Zürich

A novel alkaloid compound with efficacious antihypertension activity was synthesized from one of heptatrienyl derivatives which was obtainod from curcumol by GUO Yong-tian et al. The structural determination of crystalline intermediate is very important for the structural elucidation of final reductive product and for designing and synthesizing

关键词： phase-sensitive COSY NOESY long-range C-h chemical shift correlation spectra BIrD pulses.

A Spectral Element Implementation for the M3D ExtendedMhD Code

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Communications in Computational Physics 2008年第8期4卷 506-518页

作者： h.r.Strauss B.hientzsch j.Chen New York University 251Mercer StreetNew YorkNY 10012USA Princeton Plasma Physics Laboratory PrincetonNJ 08570USA

A spectral element library has been developed and integratedwith theM3D extended MhD *** currently used linear triangular finite element implementation and the newhigh order quadrilateral spectral element implementation are directly compared on equilibrium,linear stability,and nonlinear evolution calculations run on the same problems.

关键词： Spectral elements extendedMhD M3D

relations between SMBh Parameters and jet Generation and Efficiency in Blazars

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research in Astronomy and Astrophysics 2023年第11期23卷 67-83页

作者： h.Zhang h.j.Zhang Department of Physics Yunnan Normal UniversityKunming 650092China

We analyzed the relationship between several basic parameters describing supermassive black holes such as jet power,black hole spin,accretion disk magnetic field,black hole mass,*** found that there is a general correlation between these parameters,such as jet power is significantly positively correlated with black hole spin,while black hole mass is significantly negatively correlated with black hole *** apprehend these relationships,we consider the Blandford–Znajek model to be superior to the Blandford–Payne *** is also found that the intrinsic gamma luminosity of the FSrQs has a positive correlation with the accretion disk magnetic field,while the intrinsic gamma luminosity of the BL Lacs has a negative correlation with the accretion disk magnetic field.A feedback effect may exist between accretion disk accretion rate and magnetic field,which may be the key to the evolution between BL Lacs and *** is no significant difference in the jet power and jet generation efficiency of FSrQs and BL Lacs,which suggests that the jets are generated by the same *** contribution rate of accretion rate to jet generation efficiency is high,while the contribution rate of accretion rate to jet power is very low.

关键词： galaxies:evolution galaxies:fundamental parameters galaxies:jets