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chinese Annals of mathematics,Series B 2017年第2期38卷 513-538页

作者： Alexander LORZ Benoit PERTHAmE cécile TAING Sorbonne Universits UPMC Univ Paris 06InriaLaboratoire Jacques-Louis Lions UM R CNRS 7598F75005 ParisFrance

This paper deals with a non-local parabolic equation of Lotka-Volterra type that describes the evolution of phenotypically structured populations. Nonlinearities appear in these systems to model interactions and competition phenomena leading to selection. In this paper, the equation on the structured population is coupled with a differential equation on the nutrient concentration that changes as the total population *** methods aimed at showing the convergence of the solutions to a moving Dirac mass are reviewed. Using either weak or strong regularity assumptions, the authors study the concentration of the solution. To this end, BV estimates in time on appropriate quantities are stated, and a constrained Hamilton-Jacobi equation to identify where the solutions concentrates as Dirac masses is derived.

关键词： Adaptive evolution, Asymptotic behaviour, chemostat, Dirac concentrations,Hamilton-Jacobi equations, Lotka-Volterra equations, Viscosity solutions

High-cycle Fatigue Life Extension of Glass Fiber/Polymer composites with carbon Nanotubes

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Journal of Wuhan University of Technology(materials Science) 2009年第2期24卷 167-173页

作者： christopher S Grimmer c K H Dharan Berkeley composites Laboratory University of California 5135 Etcheverry Hall Berkeley CA94720-1740 USA

The present work shows that the addition of small volume fractions of multi-walled carbon nanotubes （cNTs） to the matrix results in a significant increase in the high-cycle fatigue life. It is proposed that carbon nanotubes tend to inhibit the formation of large cracks by nucleating nano-scale damage zones. In addition, the contribution to energy absorption from the fracture of nanotubes bridging across nano-scale cracks and from nanotube pull-out from the matrix are mechanisms that can improve the fatigue life. An energy-based model was proposed to estimate the additional strain energy absorbed in fatigue. The distributed nanotubes in the matrix appear to both distribute damage as well as inhibit damage propagation resulting in an overall improvement in the fatigue strength of glass fiber composites.

关键词： glass fiber composites carbon nanotubes fatigue strain energy

Fault Locator Using Two-end Unsynchronized measurements for UHV Series compensated Double-circuit Lines

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高电压技术 2008年第12期34卷 2523-2529页

作者： m. Fulczyk P. Balcerek J. Izykowski E. Rosolowski m. m. Saha ABB corporate Research center Starowislna 13A 31-038 Krakow Poland Wroclaw University of Technology Wyspianskiego 27 50-370 Wroclaw Poland ABB AB SE 721 59 Vasteras Sweden

An accurate fault location algorithm for double-circuit series compensated lines is *** of two-end unsynchronized measurements of current and voltage signals is *** algorithm applies two subroutines,designated for locating faults on particular line sections,and additionally the procedure for selecting the valid *** subroutines are formulated with use of the generalized fault loop model and the distributed parameter line model is *** ATP-EmTP based evaluation has shown the validity of the derived fault location algorithm and its high accuracy.

关键词：两端非同步测量法串联补偿线路故障定位仪 ATP-EmTP

multivariate adaptive regression splines and neural network models for prediction of pile drivability

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Geoscience Frontiers 2016年第1期7卷 45-52页

作者： Wengang Zhang Anthony T.c.Goh School of civil and Environmental Engineering Nanyang Technological UniversitySingapore 639798Singapore

Piles are long, slender structural elements used to transfer the loads from the superstructure through weak strata onto stiffer soils or rocks. For driven piles, the impact of the piling hammer induces compression and tension stresses in the piles. Hence, an important design consideration is to check that the strength of the pile is sufficient to resist the stresses caused by the impact of the pile hammer. Due to its complexity, pile drivability lacks a precise analytical solution with regard to the phenomena *** situations where measured data or numerical hypothetical results are available, neural networks stand out in mapping the nonlinear interactions and relationships between the system’s predictors and dependent responses. In addition, unlike most computational tools, no mathematical relationship assumption between the dependent and independent variables has to be made. Nevertheless, neural networks have been criticized for their long trial-and-error training process since the optimal configuration is not known a priori. This paper investigates the use of a fairly simple nonparametric regression algorithm known as multivariate adaptive regression splines（mARS）, as an alternative to neural networks, to approximate the relationship between the inputs and dependent response, and to mathematically interpret the relationship between the various parameters. In this paper, the Back propagation neural network（BPNN） and mARS models are developed for assessing pile drivability in relation to the prediction of the maximum compressive stresses（mcS）, maximum tensile stresses（mTS）, and Blow per foot（BPF）. A database of more than four thousand piles is utilized for model development and comparative performance between BPNN and mARS predictions.

关键词： Back propagation neural network multivariate adaptive regression splines Pile drivability computational efficiency Nonlinearity

control of dislocation density maximizing precipitation strengthening effect

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Journal of materials Science & Technology 2022年第32期127卷 133-143页

作者： c.Xu W.J.Dai Y.chen Z.X.Qi G.Zheng Y.D.cao J.P.Zhang c.c.Bu G.chen mIIT Key Laboratory of Advanced metallic and Internetallic materials Technology Engineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China

The strength-ductility trade-off has been the most challenging problem for structural metals for *** strengthening is an ideal approach to enhance the strength without significantly sacrificing the *** nanoprecipitates have been successfully acquired by nanostructural design,but the number density of nanoprecipitates cannot be further *** attempted to enhance number density by introducing highly potent nucleation sites(e.g.,dislocations).However,there remains controversy over the influence of dislocations on the nucleation and growth of coherent nanoprecipitates with minimized nucleation ***,cu-rich nanoprecipitates in an HSLA steel,as a typical type of coherent nanoprecipitates,are *** combining analytical calculation and experiments,we show that dislocations are harmful for the formation of large numbered cu-rich nanoprecipitates in a certain density *** dislocations deprive solute atoms which decrease homogenous precipitation that cannot be compensated by the increase in heterogeneous *** such circumstance,cu-rich nanoprecipitates have smaller number density but larger size and higher fraction of incoherent structures due to rapid Ostwald *** a result,by controlling dislocation density,the yield strength is increased by 24%without obvious loss in ductility as compared with traditional solution-quench-age *** work would help to optimize composition and processing routes that fully exploit the nanoprecipitation strengthening effect.

关键词： cu-rich nanoprecipitates crystallographic defects Nucleation Structural transformation Ostwald ripening

Fabrication and Properties of SiB6-B4c with Phenolic Resin as a carbon Source

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Journal of materials Science & Technology 2008年第1期24卷 102-104页

作者： G. c.Hwang J.matsushita United Graduate School of Science and Engineering Tokai University 1117 Kitakaname Hiratsuka 259-12921 Japan

Si-B-c ceramic composites were synthesized using SiB-6,B-4c,and phenolic resin as a carbon source by pressureless sintering in an Ar ***,the Si-B-c ceramic composites were fabricated to determine their potential for applications as high hardness and high temperature *** X-ray diffraction patterns of sintered bodies of SiB-6-B-4c with carbonized phenolic resin can be seen that SiB-6 and c changed to B-4c and *** this study,it is obtained that carbonized phenolic resin is good addition material as a reaction material comparing to carbon powder at 1683 K for 1 h by pressureless sintering in an Ar atmosphere.

关键词： Silicon boride Boron carbide Phenolic resin

coag-Flocculation Studies of Afzelia Bella coagulant (ABc) in coal Effluent Using Single and Simulated multi Angle Nephelometry

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Journal of minerals and materials characterization and Engineering 2011年第3期10卷 279-298页

作者： m.c. menkiti O.D. Onukwuli Department of chemical Engineering Nnamdi Azikiwe University Awka Nigeria.

Following the need for the use of environmentally friendly, renewable resource in industrial processes, this work explores the potential of an effective application in pilot scale of Afzelia bella seed as a coag-flocculant. The study evaluates the coag-flocculation efficiency and functional kinetic parameter response to varying pH and dosage of coal washery effluent and ABc respectively. The maximum coag-flocculation performance is recorded at rate constant, K of 3.3333 x 10-3m3/kg.s, dosage of (0.3 and 0.2kg/m3);pH of 2 and coagulation period, τ1/2of 28.1216 s while the minimum is recorded at K of 1.6667 x 10-4m3/kg.s, dosage of 0.2kg/m3, pH of 10 and τ1/2 of 562.365 s. The least value of coag-flocculation efficiency, E (%)>89.00. Simulated and unsimulated values of rate constants Ks and K respectively are in close agreement, validating the concept of perikinetics. The potential of ABc as an effective organic coag-flocculant has been established. The results confirm that theory of rapid coagflocculation holds for the aggregation of coal washery effluent using ABc and at the conditions of the experiment.

关键词： Afzelia bella coag-flocculation coal effluent kinetics nephelometry.

Elimination of Quench cracking by controlling Agitation Uniformity

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材料热处理学报 2004年第5期25卷 457-461页

作者： cANALE Lauralice c.F TOTTEN George E Departamento de materials Automobilistica e Aerondutica da EESC da Universidade de Sao Paulo - USP Sao Carlos SP BrazilPortland State University USA

Uniform agitation of the quenchant is a critically important control parameter in optimizing distortion control and reducing steel cracking. Quenching with ultrasonic agitation or in the presence of electrical and magnetic fields provide uniform agitation leading to improved uniformity of the stress fields within the metal not readily achievable with more traditional agitation methods such as propeller pumps and sprays. These methods provide the additional potential advantage of varying agitation throughout the cooling cycle to achieve a wide range of cooling profiles not readily achievable with quenchants and more traditional agitation systems currently in use.

关键词：热处理淬火裂纹搅拌均匀性超声搅拌

Development of Lattice Boltzmann Flux Solver for Simulation of Incompressible Flows

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Advances in Applied mathematics and mechanics 2014年第4期6卷 436-460页

作者： c.Shu Y.Wang c.J.Teo J.Wu Department of mechanical Engineering National University of Singapore10 Kent Ridge CrescentSingapore 119260 Department of Aerodynamics College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

A lattice Boltzmann flux solver(LBFS)is presented in this work for simulation of incompressible viscous and inviscid *** new solver is based on chapman-Enskog expansion analysis,which is the bridge to link Navier-Stokes(N-S)equations and lattice Boltzmann equation(LBE).The macroscopic differential equations are discretized by the finite volume method,where the flux at the cell interface is evaluated by local reconstruction of lattice Boltzmann solution from macroscopic flow variables at cell *** new solver removes the drawbacks of conventional lattice Boltzmann method such as limitation to uniform mesh,tie-up of mesh spacing and time interval,limitation to viscous *** is validated by its application to simulate the viscous decaying vortex flow,the driven cavity flow,the viscous flow past a circular cylinder,and the inviscid flow past a circular *** obtained numerical results compare very well with available data in the literature,which show that LBFS has the second order of accuracy in space,and can be well applied to viscous and inviscid flow problems with non-uniform mesh and curved boundary.

关键词： chapman-Enskog analysis flux solver incompressible flow Navier-Stokes equation lattice Boltzmann equation

Leaching of Electronic Waste Using Biometabolised Acids

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chinese Journal of chemical Engineering 2012年第3期20卷 530-534页

作者： m.Saidan B.Brown m.Valix material and mineral Processing Research Unit School of Chemical and Biomolecular EngineeringThe Univer-sity of SydneyNSW 2006Australia

The revolution in information and communication technology has brought huge technical benefits and wealth, but has created a major global problem： the generation of vast amounts of electronic waste, or e-waste through product obsolesce. The challenge in managing e-waste will be in developing sustainable recycling tech- nologies that are able to address the volume and complexity of this waste using cost effective and ecologically sen-sitive methods. In this study, the capability or microorganism metabolic acids in dissolving the metallic tractions from waste printed circuit boards was examined. Several factors were considered in the examination of the activityof the acids-including secondary reactions, solution pH, temperature and the nature of ligands in solutions （or bioacid constituents）. The leaching tests were cgnducted ex-situ, using synthetic organic acids. Leaching was performed for periods of up to 6 hat 70-90 ℃ and 1000 r-min-1.

关键词： bioleaching e-waste organic acids secondary reactions copper