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journal of Materials Science & Technology 2002年第5期18卷 387-391页

作者： DaCHeN j.M.McNaney e.Saiz A.p.Tomsia R.O.Ritchie Dept. of Mat. Sci. Shanghai Jiaotong Univ. Shanghai 200030 China Dept. of Mat. Sci. and eng. Univ. of California Berkeley CA 94720 United States Mat. Sci. Div. Lawrence Berkeley Natl. Lab. Berkeley CA 94720 United States

Based on a series of newly developed bioactive glasses having suitable thermo-mechanical properties to allow application as fixation agents between bone and titanium alloy biomedical implants, the stress corrosion crack growth (SCCG) behavior of their interfaces with Ti6AI4V was investigated in simulated body fluid (SBF) with the objective of discerning the salient mechanisms of crack advance and to assess the reliability of the bonds. Results indicated that crack growth rates in Ti6AI4V/glass/Ti6AI4V sandwich specimens were nearly the same as or slightly lower than those in the bulk glasses at comparable stress intensities; indeed, cracks would prefer to propagate off the interface, suggesting that the Ti6AI4V/glass interface has relatively good crack-growth resistance. Mechanistically, interfacial crack growth appears to be controlled by the classic stress corrosion mechanisms for silicate glasses, with no discernible effect of bioactivity on the SCCG behavior being observed.

关键词： Stress corrosion Titanium alloy Bioactive glass Crack growth

An accurately fast algorithm of calculating reflection/transmission coefficients

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Science China(physics,Mechanics & Astronomy) 2008年第7期51卷 823-846页

作者： CASTAGNA j p Department of earth and Atmospheric Sciences University of Houston

For the boundary between transversely isotropic media with a vertical axis of symmetry (VTI media), the interface between a liquid and a VTI medium, and the free-surface of an elastic half-space of a VTI medium, an accurately fast algorithm was presented for calculating reflection/transmission (R/T) coefficients. Specially, the case of post-critical angle incidence was considered. Although we only performed the numerical calculation for the models of the VTI media, the calculated results can be extended to the models of transversely isotropic media with a horizontal axis of rotation symmetry (HTI media). Compared to previous work, this algorithm can be used not only for the calculation of R/T coefficients of the boundary between ellipsoidally anisotropic media, but also for that between generally anisotropic media, and the speed and accuracy of this algorithm are faster and higher. According to the anisotropic parameters of some rocks given by the published literature, we performed the calculation of R/T coefficients by using this algorithm and analyzed the effect of the rock anisotropy on R/T coefficients. We used Snell's law and the energy balance principle to perform verification for the calculated results.

关键词： reflection/transmission coefficient AVO analysis anisotropy VTI medium HTI medium

ReITeRATeD HOMOGeNIZATION OF NONLIneAR MONOTOne OpeRATORS

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Chinese Annals of Mathematics,Series B 2001年第1期22卷 1-12页

作者： j.L.LIONS D.LUKKASSeN L.e.peRSSON p.WALL CollegedeFrance 3rued＇Ulm75231Pariscedex05France NarvikInstituteofTechnologyandNorutTechnologyLtd. N-8505NarvikNorway DepartmentofMathematics LuleaUniversityofTechnologyS-97187LuleaSweden

In this paper, the authors study reiterated homogenization of nonlinear equations of the form --div(a(x, x/ε x/ε, Duε) = f, where a is periodic in the first two arguments and monotone in the third. It is proved that ue converges weakly in W1,p(Ω) (and even in some multiscale sense), as ε→ 0 to the solution uo of a limit problem. Moreover, an explicit expression for the limit problem is given. The main results were also stated in [15]. This article presents the complete proofs of these results.

关键词： Homogenization Nonlinear monotone operators Nonlinear equation

Restructuring of plasmonic nanoparticle aggregates with arbitrary particle size distribution in pulsed laser fields

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Chinese physics B 2016年第11期25卷 563-570页

作者： A e ershov A p Gavrilyuk S V Karpov S p polyutov Institute of Computational Modeling Russian Academy of SciencesKrasnoyarsk 660036Russia L.V.Kirensky Institute of physics of the Russian Academy of Sciences Krasnoyarsk 660036Russia Siberian Federal University Krasnoyarsk 660028Russia Siberian State Aerospace University Krasnoyarsk 660037Russia

We have studied processes of interaction of pulsed laser radiation with resonant groups of plasmonic nanoparticles（resonant domains） in large colloidal nanoparticle aggregates having different interparticle gaps and particle size *** processes are responsible for the origin of nonlinear optical effects and photochromic reactions in multiparticle *** describe photo-induced transformations in resonant domains and alterations in their absorption spectra remaining after the pulse action,we introduce the factor of spectral *** on calculation of changes in thermodynamic,mechanical,and optical characteristics of the domains,the histograms of the spectrum photomodification factor have been obtained for various interparticle gaps,an average particle size,and the degree of *** in spectra have been analyzed depending on the intensity of laser radiation and various combinations of size characteristics of *** obtained results can be used to predict manifestation of photochromic effects in composite materials containing different plasmonic nanoparticle aggregates in pulsed laser fields.

关键词： resonant arbitrary pulsed dipole manifestation alterations extinction remaining aggregate colloidal

Velocity-Based Moving Mesh Methods for Nonlinear partial Differential equations

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Communications in Computational physics 2011年第8期10卷 509-576页

作者： M.j.Baines M.e.Hubbard p.K.jimack Department of Mathematics The University of ReadingRG66AXUK. School of Computing University of LeedsLS29JTUK

This article describes a number of velocity-based moving mesh numerical methods for multidimensional nonlinear time-dependent partial differential equations(pDes).It consists of a short historical review followed by a detailed description of a recently developed multidimensional moving mesh finite element method based on *** element algorithms are derived for both mass-conserving and non mass-conserving problems,and results shown for a number of multidimensional nonlinear test problems,including the second order porous medium equation and the fourth order thin film equation as well as a two-phase *** applications and extensions are referenced.

关键词： Time-dependent nonlinear diffusion moving boundaries finite element method Lagrangian meshes conservation of mass

Modular next generation fast-neutron detector for portal monitoring

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Nuclear Science and Techniques 2022年第1期33卷 140-148页

作者： e.Aboud S.Ahn G.V.Rogachev V.e.johnson j.Bishop G.Christian e.Koshchiy C.e.parker D.p.Scriven Cyclotron Institute Texas A&M UniversityCollege StationTX 77843USA Department of physics and Astronomy Texas A&M UniversityCollege StationTX 77843USA Department of Statistics Texas A&M UniversityCollege StationTX 77843USA

Nuclear nonproliferation is of critical importance for global *** fissile materials including highly enriched uranium and weapons-grade plutonium are especially important to *** interrogation techniques may result in much better sensitivity but are difficult with conventional portal monitors that rely on detecting thermal ***,most conventional portal monitoring systems rely on ^(3)He,which has a finite and continually decreasing *** designing a highly segmented array of organic scintillators,we posit that we can accurately and quickly identify fissile materials,including weapons-grade plutonium and highly enriched uranium,being *** propose a new design for a fast-neutron detector that overcomes the limitations of the current generation of portal ***6 simulations have been performed in conjunction with the UMpBT statistical model to determine the sensitivity limitations of the proposed *** suggest that the proposed detector may be 10 times more efficient than current-generation thermal neutron detectors and may be able to positively identify a 81 mg 235U source in as little as 192 seconds utilizing active interrogation techniques.

关键词： Fast-neutron detection portal monitoring Nonproliferation

Atomic-scale simulations of material behaviors and tribology properties for BCC metal film

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Chinese physics B 2016年第1期25卷 412-418页

作者： H D Aristizabal p A parra p Lopez e Restrepo-parra pCM Computational Applications Universidad Nacional de Colombia-Sede ManizalesA.A.127ManizalesColombi Universidad Cató1ica de Manizales A.A.357ManizalesColombia

This work has two main purposes：（i） introducing the basic concepts of molecular dynamics analysis to material scientists and engineers, and （ii） providing a better understanding of instrumented indentation measurements, presenting an example of nanoindentation and scratch test simulations. To reach these purposes, three-dimensional molecular dynamics （MD） simulations of nanoindentation and scratch test technique were carried out for generic thin films that present BCC crystalline structures. Structures were oriented in the plane （100） and placed on FCC diamond substrates. A pair wise potential was employed to simulate the interaction between atoms of each layer and a repulsive radial potential was used to represent a spherical tip indenting the sample. Mechanical properties of this generic material were obtained by varying the indentation depth and dissociation energy. The load-unload curves and coefficient of friction were found for each test; on the other hand, dissociation energy was varied showing a better mechanical response for films that present grater dissociation energy. Structural change evolution was observed presenting vacancies and slips as the depth was varied.

关键词： molecular dynamics pair wise potential repulsive radial potential dissociation energy

In vitro immunotoxicity of untreated and treated urbanwastewaters using various treatment processes to rainbow trout leucocytes

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journal of environmental Sciences 2013年第7期25卷 1400-1407页

作者： Franois Gagné Marlène Fortier Michel Fournier Shirley-Anne Smyth emerging Methods Aquatic Contaminants Research Division Water Science and Technology Environment Canada105 McGill Street Montral Qubec Canada INRS-Institut Armand-Frappier 531 boul.des Prairies Laval Qubec Canada effluents and Wastewaters Aquatic Contaminants Research Division Water Science and Technology Environment Canada867 Lakeshore Road BurlingtonOntario Canada

Municipal effluents are known to impede the immune system of aquatic organisms. The purpose of this studywas to examine the immunotoxicity of urbanwastewaters before and after 6 treatment processes from 12 cities toward trout leucocytes. Freshly prepared trout leucocyteswere exposed to increasing concentrations of solid phase （C18） extracts ofwastewaters for24 hr at 15°C. Immunocompetencewasdetermined by following changes in leucocyte viability and the proportion of cells able to ingest at least one （immunoactivity） and at least three （immunoefficiency） fluorescent beads. The influentswere treated by sixdifferent treatment strategies consisting of facultative aerated lagoons, activated sludge, biological aerated filter, biological nutrient removal, chemically-assisted physical treatment and trickling filter/solid contact. Water quality parameters of thewastewaters revealed that the plants effectively removed total suspended solids and reduced the chemical oxygendemand. The results revealed that the effluents＇ immunotoxic propertieswere generally more influenced by the properties of the untreatedwastewaters than by the treatment processes. About half of the incoming influentsdecreased leucocyte viabilitywhile4 treatment plantswere able to reduce toxicity. The influents readily increased phagocytosis activity for 8/12 influentswhile itwasdecreased in4/12 influents. This increasewas abolished for4/12 of the effluents using treatments involving biological and oxidative processes. In conclusion, municipal effluents have the potential to alter the immune system in fish and more researchwill be needed to improve the treatments ofwastewaters to better protect the quality of the aquatic environment.

关键词： municipal effluents fish leucocytes viability phagocytosis

Systematic study of the dependence of magnetic and structural properties of Nd2Fe14B powders on the average particle size

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journal of Rare earths 2020年第9期38卷 961-968,I0002页

作者： j.F.Durán perdomo G.A.pérez Alcázar H.D.Colorado j.A.Tabares L.e.Zamora j.j.S.Garitaonandia Department of physics University of ValleA.A.25360 CaliColombia Applied physics II Department Basque Country University48080 BilbaoSpain

A systematic study of the magnetic and structural properties dependence on the particle size was *** this,commercial NdFeB powder was separated into five different mean particle sizes using ***,from the original powder,eleven samples were also produced by mechanical milling assisted by surfactant,using various milling times.A total of sixteen samples were studied by scanning electron microscopy(SeM),X-ray diffraction(XRD),vibrating sample magnetometry(VSM),and Mdssbauer spectrometry(MS).The particle sizes of the samples vary from the micrometer to the nanometer *** crystallite size decreases with decreasing particle *** result indicates that the Nd2Fe14B phase is found in all the samples,and the presence of this phase is also corroborated by MS using six sextets for fitting their spectra,with an additional singlet corresponding to the Nd1.1Fe4B4 *** mean hyperfine magnetic field increases with increasing particle size because the magnetic dipolar interaction between the magnetic moment of the particles increases with particle *** the VSM measurements the magnetic energy density(BH)max values were calculated for different particle sizes,and their maximum value of 34.45 MGOe is obtained for the sample with the particle size of 60μm.

关键词： Hard magnetic material XRD Mossbauer spectrometry Magnetization particle size Rare earths

jacobi Structures on Affine Bundles

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Acta Mathematica Sinica,english Series 2007年第5期23卷 769-788页

作者： j.GRABOWSKI D.IGLeSIAS j.C.MARReRO e.pADRN p.URBA■SKI Mathematical Institutepolish Academy of Sciences Sniadeckich 8p.O.Box 2100-956 Warsawpoland Instituto de Matemáticas y Física FundamentalConsejo Superior de Investigaciones CientificasSerrano 12328006 MadridSpain Departamentode Matemática FundamentalFacultad de MatemáticasUniversidad de la LagunaLa LagunaTenerifeCanary IslandsSpain Division of Mathematical Methods in physicsUniversity of Warsaw Hoia 7400-682 Warsawpoland

Abstract We study affine jacobi structures （brackets） on an affine bundle π ： A → M, i.e. jacobi brackets that close on affine functions. We prove that if the rank of A is non-zero, there is a one-toone correspondence between affine jacobi structures on A and Lie algebroid structures on the vector bundle A^＋ = ∪p∈M Aff（Ap, R） of affine functionals. In the case rank A = 0, it is shown that there is a one-to-one correspondence between affine jacobi structures on A and local Lie algebras on A^＋. Some examples and applications, also for the linear case, are discussed. For a special type of affine jacobi structures which are canonically exhibited （strongly-affine or affine-homogeneous jacobi structures） over a real vector space of finite dimension, we describe the leaves of its characteristic foliation as the orbits of an affine representation. These affine jacobi structures can be viewed as an analog of the Kostant-Arnold-Liouville linear poisson structure on the dual space of a real finite-dimensional Lie algebra.

关键词： Vector and affine bundles jacobi manifolds Lie algebroids