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数学年刊第22卷B辑第1期(2001)目次和提要

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数学年刊A辑(中文版) 2001年第1期 127-128页

作者： J.l.lions ,D.lukassen　,l.e.persson ,P. Wall

Iterative Subregion Correction Preconditioners with Adaptive Tolerance for Problems with Geometrically localized Stiffness

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Communications on Applied Mathematics and Computation 2024年第2期6卷 811-836页

作者： Michael Franco Per-Olof persson Will Pazner Department of Mathematics University of CaliforniaBerkeleyBerkeleyCA 94720-3840USA Fariborz Maseeh Department of Mathematics and Statistics Portland State UniversityPortlandOR 97201USA

We present a class of preconditioners for the linear systems resulting from a finite element or discontinuous Galerkin discretizations of advection-dominated *** preconditioners are designed to treat the case of geometrically localized stiffness,where the convergence rates of iterative methods are degraded in a localized subregion of the *** convergence may be caused by a number of factors,including the mesh size,anisotropy,highly variable coefficients,and more challenging *** approach taken in this work is to correct well-known preconditioners such as the block Jacobi and the block incomplete lU(IlU)with an adaptive inner subregion *** goal of these preconditioners is to reduce the number of costly global iterations by accelerating the convergence in the stiff region by iterating on the less expensive reduced *** tolerance for the inner iteration is adaptively chosen to minimize subregion-local work while guaranteeing global convergence *** present analysis showing that the convergence of these preconditioners,even when combined with an adaptively selected tolerance,is independent of discretization parameters(e.g.,the mesh size and diffusion coefficient)in the *** demonstrate significant performance improvements over black-box preconditioners when applied to several model convection-diffusion ***,we present performance results of several variations of iterative subregion correction preconditioners applied to the Reynolds number 2.25×10^(6)fluid flow over the NACA 0012 airfoil,as well as massively separated flow at 30°angle of attack.

关键词： Subregion correction Nested Krylov Geometrically localized stiffness

Solvation effects on the Dielectric Constant of 1 M liPF6 in ethylene Carbonate:ethyl Methyl Carbonate 3:7

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energy & environmental Materials 2024年第1期7卷 253-256页

作者： Julian Self Nathan T.Hahn Kristin A.persson Department of Chemical engineering Polytechnique MontrealMontrealQC H3T 1J4Canada Department of Materials Science and engineering University of CaliforniaBerkeleyCA 94720USA energy Technologies Area Lawrence Berkeley National LaboratoryBerkeleyCA 94720USA Material Physical and Chemical Sciences CenterSandia National LaboratoriesAlbuquerqueNM 87185USA

We report the dielectric constant of 1 M liPF_(6)in eC:eMC 3∶7 w/w(ethylene carbonate/ethyl methyl carbonate)in addition to neat eC:eMC 3∶7 w/*** three Debye relaxations,the static permittivity value,or dielectric constant,is extrapolated to 18.5,which is compared to 18.7 for the neat solvent *** eC solvent is found to strongly coordinate with the li^(+)cations of the salt,which results in a loss of dielectric contribution to the ***,the small amplitude and large uncertainty in relaxation frequency for eMC cloud definitive identification of the li^(+)solvation ***,the loss of the free eC permittivity contribution due to li^(+)solvation is almost completely balanced by the positive contribution of the associated liPF_(6)salt,demonstrating that a significant quantity of dipolar ion pairs exists in 1 M liPF_(6)in eC:eMC 3∶7.

关键词： batteries dielectric relaxation spectroscopy electrolytes

Cellulose synthesis in land plants

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Molecular Plant 2024年第2期17卷 359-361页

作者： Gustav B.Pedersen leonard Blaschek Kristian e.H.Frandsen lise C.Noack Staffan persson 不详

After the original publication of the above article,we and/or attentive readers identified several instances of unclear or erroneous writing that needed correcting,as *** are added for emphasis.

关键词： synthesis instance identif

Simplified seismic scenario analysis of existing masonry buildings accounting for local site effects

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Frontiers of Structural and Civil engineering 2024年第2期18卷 309-318页

作者： Ayşe e.ÖZSOYÖZBAY Işıl SANRI KARAPINAR Zehra N.KUTlU İsmail e.KIlIÇ Department of Civil engineering Maltepe UniversityIstanbul 34857Turkey School of engineering and Construction Oryx Universal CollegeDoha 12253Qatar

This study discusses the effects of local sites and hazard amplification on the seismic vulnerability assessment of existing masonry *** this context,a rapid seismic evaluation procedure was implemented on an old masonry building stock in the historical center Galata,located inİstanbul,to determine the seismic risk priority of the built *** scenarios were generated for all soil classes,different moment magnitudes,and source-to-site distances to obtain more accurate results for the seismic vulnerability assessment of the studied building ***,damage distributions estimated under nine different scenarios with/without site effects were compared and illustrated in maps to discuss changes in vulnerability owing to amplification *** this study,by re-examining the rapid seismic evaluation procedure by including geo-hazard-based assessment,the importance of site effects on the vulnerability and risk assessment of built heritage was *** proposed framework integrating field data and local site effects is believed to advance the current applications for vulnerability assessment of masonry buildings and provide an improvement in the application of rapid seismic assessment procedures with more reliable results.

关键词： masonry buildings seismic vulnerability assessment cultural heritage local site effect

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On B(5,20)2-Groups

Algebra Colloquium 2024年第3期31卷 429-440页

作者： e.A.Alhassan Y.l.Tan Y.li School of Mathematical Sciences Jiangsu UniversityZhenjiangJiangsu 212013China Department of Mathematics Brock UniversitySt.CatharinesOntario L2S 3A1Canada

A finite group G is said to be a B(n,k)group if for any n-element subset[a_(1),…,a_(n)]of G,|{a_(i)a_(j)|1≤i,j≤n}|≤*** is of interest to characterize the structure of B(n,k)groups for n(n+1)/2≤k≤n^(2)-*** B(5,k)groups for 15≤k≤19 have been investigated by several *** this paper,we give a complete characterization of B(5,20)2-groups by showing there are five classes of such groups which are nontrivial and nonabelian.

关键词： B(n,k)groups small squaring property central extension GAP

When Fleeing Matters:Differences in escape Behaviours of Three Northeast Asian Anurans

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Asian Herpetological Research 2024年第1期15卷 41-48页

作者： Yoonjung YI Zoljargal PUReVDORJ Irina MASlOVA Yikweon JANG Amaël BORZÉe laboratory of Animal Behaviour and Conservation College of Life SciencesNanjing Forestry UniversityNanjing 210037JiangsuChina Division of ecoScience and Department of life Sciences Ewha Womans UniversitySeoul 03760Republic of Korea Department of Biology School of MathematicsMongolian State University of EducationUlaanbaatar 210648Mongolia Department of Forest and environmental Resources Chungnam National UniversityDaejeon 34134Republic of Korea Federal Scientific Center of the east Asia Terrestrial Biodiversity Far Eastern Branch of Russian Academy of SciencesVladivostok 690022Russia

Prey species may have their own optimal escape strategy to balance predation risks and the energetic cost of *** species have an advantage when maintaining a short fleeing distance,while others may favour an earlier escape based on microhabitat,size,or body ***,we examined the escape behaviour of the three syntopic Northeast Asian anuran species:Mongolian toads(Strauchbufo raddei),Amur brown frogs(Rana amurensis),and Japanese treefrogs(Dryophytes japonicus)in Mongolia,Russia,China and DPR *** examined flight initiation distance(FID;the distance from a potential predator to the point when the individual starts to flee)and distance fled(DF;distance between flight initiation and flight termination points)of each species and the effects of microhabitat,sex,and body *** raddei and *** had a longer FID than ***,and *** also had a longer DF than *** trends remained similar when dividing FID and DF by a size proxy(snout-vent length)for all *** suggests that the treefrog *** used a strategy to stay immobile even when they were detected,and the toad *** reacted quicker and more sensitively to predators despite the presence of *** *** had a significantly longer FID than males suggesting that females are more sensitive to predation risk in this species,but body size was not significant for any of the three *** results indicate that the three sympatric species have different escaping strategies,likely related to differences in physiology and crypticity.

关键词： amphibian distance fled escape behaviour flight initiation distance predation

Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

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Petroleum 2024年第1期10卷 150-164页

作者： leonardo Goliatt C.M.Saporetti l.C.Oliveira e.Pereira Department of Computational and Applied Mechanics Federal University of Juiz de ForaJuiz de ForaBrazil Department of Computational Modeling Polytechnic InstituteRio de Janeiro State UniversityNova FriburgoBrazil Petrobras Rio de JaneiroBrazil Department of Stratigraphy and Paleontology Rio de Janeiro State UniversityRio de JaneiroBrazil

Rock samples'TOC content is the best indicator of the organic matter in source *** origin rock samples’analysis is used to calculate it manually by *** method requires time and resources because it relies on samples from many well intervals in source ***,research has been done to aid this *** learning algorithms can estimate total organic carbon instead of well logs and stratigraphic *** light of these efforts,the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and *** algorithms,differential evolution,particle swarm optimization,grey wolf optimization,artificial bee colony,and evolution strategies were used to improve machine learning models to predict *** six metaheuristics were integrated into four machine learning methods:extreme learning machine,elastic net linear model,linear support vector regression,and multivariate adaptive regression *** samples from the YuDong-Nan shale gas field,located in the Sichuan basin,were used to evaluate the hybrid *** findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict *** results show that,independent of the metaheuristic used to guide the model selection,optimized extreme learning machines attained the best performance scores according to six *** hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： Total organic carbon Hybrid models Automated machine learning evolutionary algorithms Geology

Phanerozoic co-evolution of O2-CO2 and ocean habitability

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National Science Review 2024年第6期11卷 18-21页

作者： Zunli lu Rosalind e.M.Rickaby Jonathan l.Payne Ashley N.Prow Department of earth & environmental Sciences Syracuse University Department of earth Sciences University of Oxford Department of earth and Planetary Sciences Stanford University

Atmospheric carbon dioxide and oxygen concentrations are partially linked via the geological cycle of organic carbon （Fig. 1A–C; e.g. CO2+H2O■CH2O+O2）. The history of these two biologically active components, controls on their concentrations, and implications for the complexity of the biosphere and habitability of earth have been hotly debated, but are generally considered independently.

关键词： CO2-CONCeNTRATING MeCHANISM OXYGeN eVOlUTION ANOXIA