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Evaluation of Microstructure and Magnetic Properties in Non-oriented Electrical Steel Strained by Tension

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journal of Iron and Steel Research International 2016年第2期23卷 166-170页

作者： j.SALINAS B. A.SALINAS R. Engineering Metallurgical Research Center and Advanced Studies of National Polytechnic Institute

The effects of deformation on the microstructure and magnetic properties of non oriented electrical steels were investigated. Box annealed electrical steel sheets were deformed by tension at four different strains： 3%, 8%, 12 % and 25 % The internal grain misorientation caused by tensile deformation was measured by electron backscat- tering diffraction （EBSD） with grain orientation spread （GOS） as an indicator of the lattice distortion. The experi- mental results showed that the average GOS value increases with the strain. The microstructure and crystallographic texture of deformed samples did not show a significant change in samples strained below 25 %. However, the mag- netic properties were strongly affected： coercivity was directly proportional to the square root of the GOS value and energy losses increased as the strain level was increased.

关键词： non-oriented electrical steel tensile deformation internal misorientation magnetic property EBSD

Effects of inner sleeves on the inner frictional resistance of open-ended piles driven into sand

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Frontiers of Structural and Civil Engineering 2016年第4期10卷 499-505页

作者： janaka j. KUMARA Yoshiaki KIKUCHI Takashi KURASHINA Takahiro YAjIMA Department of Civil Engineering Tokyo University of Seience Noda 278-8510 Japan Maeda Corporation Tokyo 102-8151 Japan

In open-ended piles, inner friction is developed between inner pile shaf and the inner soil. Inner frictional resistance depends largely on the degree of soil plugging, which is influenced by many factors including pile diameter, relative density and end conditions of piles. In this paper, effects of inner sleeves on inner frictional resistance are discussed. The experiments were conducted on a medium-dense sandy ground using laboratory-scale piles. It was observed that the piles penetrated under partially-plugged or unplugged state. The results suggest that inner fiictional resistance, Qin increases with sleeve height, l linearly and requires 2D （D is pile outer diameter） of l to produce a large as 50% of Qt by Qin （Qt is total resistance）. The results also indicate that bearing capacity increases with wall thickness at the pile tip, which can be attributed to the increase in annular area. The results also indicate that soil plug height is independent of sleeve height. The results also reveal that the penetration of straight piles is closer to unplugged state than the sleeved piles. The results of incremental filling ratio and plug length ratio also indicate that the degree of soil plugging is affected by the sleeve height.

关键词： bearing capacity inner frictional resistance inner sleeve open-ended piles soil plugging

Fast calculation of wave front amplitude propagation: a tool to analyze the 3D image on a hologram(Invited Paper)

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Chinese Optics Letters 2014年第6期12卷 95-98页

作者： j.-S.Chen D.P.Chu University of Cambridge Photonics and Sensors Group Department of Engineering9 JJ Thomson Avenue Cambridge UK

A simple approach to calculate the amplitude component of a wave front propagating in space from a hologram is proposed. It is able to calculate the amplitude distribution on a plane at any distance rapidly using a st... 详细信息

关键词： wave Fast calculation of wave front amplitude propagation a tool to analyze the 3D image on a hologram

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.

Chinese life cycle impact assessment factors

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journal of Environmental Sciences 2001年第2期13卷 205-209页

作者： Yang, j.-X. Nielsen, P.H. Research Cntr. for Eco-Envtl. Sci. Chinese Academy of Sciences Beijing 100085 China

The methodological basis and procedures for determination of Chinese normalization references and weighting factors according to the EDIP-method is described. According to Chinese industrial development intensity and population density, China was divided into three regions and the normalization references for each region were calculated on the basis of an inventory of all of the region's environmental emissions in 1990. The normalization reference was determined as the total environmental impact potential for the area in question in 1990(EP(j)90) divided by the population. The weighting factor was determined as the normalization reference (ER(j)90) divided by society's target contribution in the year 2000 based on Chinese political reduction plans, ER(j)T2000. This paper presents and discuss results obtained for eight different environmental impact categories relevant for China: global warming, stratospheric ozone depletion, acidification, nutrient enrichment, photochemical ozone formation and generation of bulk waste, hazardous waste and slag and ashes.

关键词： Environmental impact Global warming Life cycle Ozone Sustainable development

Theoretical assessment of the impact of environmental contamination on the dynamical transmission of polio

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International journal of Biomathematics 2019年第2期12卷 1-35页

作者： C.Balde M.Lam A.Bah S.Bowong j.j.Tewa Department of Mathematics Faculty of Science and Technic University Cheikh Anta DiopDakarSenegal Department of Computer Engineering National Advanced School of Engineering University Cheikh Anta Diop DakarSenegal Laboratory of Mathematics Department of Mathematics and Computer Science Faculty of Science University of Douala P.O.Box 24157 DoualaCameroon National Advanced School of Engineering University of Yaounde I P.O.Box 8390 YaoundeCameroon IRD Sorbonne UniversityUHH1SCOF-93143BondyFrance Team GRIMCAPEYaoundeCameroon The African Center of Excellence in Information and Communication Technologies(CETIC)University of Yaounde 1Cameroon

A mathematical model for the dynamical transmission of polio is considered,with the aim of investigating the impact of environment *** model captures two infection pathways through both direct human-to-human transmission and indirect human-to-environment-to-human transmission by incorporating the environment as a transition and/or reservoir of *** derive the basic reproduction number R0^env We show that the disease free equilibrium is globally asymptotically stable(GAS)if R0^env1,there exists a unique endemic equilibrium which is locally asymptotically stable(LAS).Similar results hold for environmental contamination free sub-model(without the incorporation of the indirect transmission).At the endemic level,we show that the number of infected individuals for the model with the environ mental-related contagion is greater than the corresponding number for the environmental contamination free *** conjunction with the inequality R0

关键词： Poliovirus environment contamination human shedding rate mathematical models stability

Application of laser scanning for rock mass characterization and discrete fracture network generation in an underground limestone mine

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International journal of Mining Science and Technology 2019年第1期29卷 131-137页

作者： juan j.Monsalve jon Baggett Richard Bishop Nino Ripepi Mining and Minerals Department Virginia Polytechnic Institute&State University

Terrestrial laser scanning(TLS) is a useful technology for rock mass characterization. A laser scanner produces a massive point cloud of a scanned area, such as an exposed rock surface in an underground tunnel,with millimeter precision. The density of the point cloud depends on several parameters from both the TLS operational conditions and the specifications of the project, such as the resolution and the quality of the laser scan, the section of the tunnel, the distance between scanning stations, and the purpose of the scans. One purpose of the scan can be to characterize the rock mass and statistically analyze the discontinuities that compose it for further discontinuous modeling. In these instances, additional data processing and a detailed analysis should be performed on the point cloud to extract the parameters to define a discrete fracture network(DFN) for each discontinuity set. I-site studio is a point cloud processing software that allows users to edit and process laser scans. This software contains a set of geotechnical analysis tools that assist engineers during the structural mapping process, allowing for greater and more representative data regarding the structural information of the rock mass, which may be used for generating DFNs. This paper presents the procedures used during a laser scan for characterizing discontinuities in an underground limestone mine and the results of the scan as applied to the generation of DFNs for further discontinuous modeling.

关键词： Rock mass characterization Laser scanning Discrete fracture network I-site studio

On continuum modeling using kinetic-frictional models in high shear granulation

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Particuology 2014年第2期12卷 124-127页

作者： P.j.Abrahamsson S.Sasic A.Rasmuson Department of Chemical Engineering Chalmers University of TechnologySE-412 96 GothenburgSweden Department of Applied Mechanics Division of Fluid DynamicsChalmers University of TechnologySE-412 96 GothenburgSweden

This short communication demonstrates why extreme caution has to be taken when applying conven- tional kinetic-frictional closures to continuum modeling of high shear granulation （HSG）, Conventional models refer to closure laws where the kinetic and frictional stresses are summed up to obtain the total stress field, In the simple, dense, and sheared system ofa Couette shear cell, the effect of the lack of scale separation on the model predictions is examined, both quantitatively and qualitatively. It is observed that the spatial resolution has a significant effect on the magnitude of the kinetic and frictional contributions to the solid phase stresses. With this new investigation and previous studies of HSG, it is concluded that conventional kinetic-frictional models are inadequate for continuum modeling of HSG.

关键词： Kinetic theory of granular flowFrictional stressSeparation of scalesHigh shear granulationCouette shear cell

Unsteady magnetohydrodynamic stagnation point flow — closed-form analytical solutions

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Applied Mathematics and Mechanics(English Edition) 2019年第4期40卷 449-464页

作者： T.G.FANG F.j.WANG Bo GAO Mechanical and Aerospace Engineering Department North Carolina State University School of Energy & Power Engineering Jiangsu University

This paper investigates the unsteady stagnation point flow and heat transfer of magnetohydrodynamic(MHD) fluids over a moving permeable flat surface. The unsteady Navier-Stokes(NS) equations are transformed into a similarity nonlinear ordinary differential equation, and a closed form solution is obtained for the unsteadiness parameter of 2. The boundary layer energy equation is transformed into a similarity equation,and is solved for a constant wall temperature and a time-dependent uniform wall heat flux case. The solution domain, velocity, and temperature profiles are calculated for different combinations of parameters including the Prandtl number, mass transfer parameter, wall moving parameter, and magnetic parameter. Two solution branches are obtained for certain combinations of the controlling parameters, and a stability analysis demonstrates that the lower solution branch is not stable. The present solutions provide an exact solution to the entire unsteady MHD NS equations, which can be used for validating the numerical code of computational fluid dynamics.

关键词： unsteady stagnation point flow stretching/shrinking sheet magnetohy-drodynamic(MHD) Navier-Stokes(NS)equation