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Feedback Stabilization for a Scalar Conservation Law with PID Boundary Control

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Chinese Annals of Mathematics,Series B 2015年第5期36卷 763-776页

作者： jean michel CORON Simona Oana TAMASOIU Sorbonne Universités UPMC University Paris 06 NUMR 7598 Laboratoire Jacques-Louis Lions F-75005Paris France Université Paris Sud F-91405 Orsay France

This paper deals with a scalar conservation law in 1-D space dimension, and in particular, the focus is on the stability analysis for such an equation. The problem of feedback stabilization under proportional-integral-derivative(PID for short) boundary control is addressed. In the proportional-integral(PI for short) controller case, by spectral analysis, the authors provide a complete characterization of the set of stabilizing feedback parameters, and determine the corresponding time delay stability interval. Moreover, the stability of the equilibrium is discussed by Lyapunov function techniques, and by this approach the exponential stability when a damping term is added to the classical PI controller scheme is proved. Also, based on Pontryagin results on stability for quasipolynomials, it is shown that the closed-loop system sub ject to PID control is always unstable.

关键词： Boundary feedback FID controllers Linear scalar conservation law

Assessment of Technical and Economic Impacts of EV User Behavior on EV Aggregator Smart Charging

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Journal of Modern Power Systems and Clean Energy 2020年第2期8卷 356-366页

作者： jean-michel Clairand Javier Rodriguez-Garcia Carlosalvarez-Bel the Facultad de Ingenieria y Ciencias Agropecuarias Universidad de las Americas-Ecuador170122 QuitoEcuador the Institute for Energy Engineering Universitat Politecnica de Valencia46022 ValenciaSpain

The increase in global electricity consumption has made energy efficiency a priority for ***,there has been a focus on the efficient integration of a massive penetration of electric vehicles(EVs)into energy *** study presents an assessment of various strategies for EV *** this analysis,the smart charging methodology proposed in a previous study is *** smart charging technique employs charging power rate modulation and considers user *** adopt several strategies,this study simulates the effect of these actions in a case study of a distribution system from the city of Quito,*** actions are simulated,and the EV aggregator costs and technical conditions are evaluated.

关键词： Electric vehicle(EV) smart grid aggregator smart charging charging power modulation charging strategies

Zircon U-Pb and Lu-Hf isotope constraints on Archean crustal evolution in Southeastern Guyana Shield

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Geoscience Frontiers 2019年第4期10卷 1477-1506页

作者： Joao Marinho Milhomem Neto jean-michel Lafon Programa de Pos-graduacao em Geologia e Geoquimica-PPGG Instituto de Geociencias-IGUniversidade Federal do Para-UFPA66075-110BelemParaBrazil Laboratório de Geologia Isotópica-Pará-Iso IG-UFPA66075-110BelémParáBrazil

The southeastern Guyana Shield,northeast Amazonian Craton,in the north of Brazil,is part of a widespread orogenic belt developed during the Transamazonian orogenic cycle(2.26-1.95 Ga)that includes a large Archean continental landmass strongly reworked during the Transamazonian orogeny,named Amapa *** consists mainly of a high-grade metamorphic granulitic-migmatitic-gneiss complex,of Meso-to Neoarchean age and Rhyacian granitoids and supracrustal *** the first time,coupled U-Pb and Lu-Hf isotope data were obtained on zircon by LA-ICP-MS from five tectono-stratigraphic units of the Archean basement and one Paleoproterozoic intrusive rock,in order to investigate the main episodes of crustal growth and ***-rock Sm-Nd isotope data were compared to the zircon Lu-Hf *** main magmatic episodes were defined by U-Pb zircon dating,two in the Mesoarchean(~3.19 Ga and 2.85 Ga)and one in the Neoarchean(~2.69-2.65 Ga).SubchondriticεHf(t)values obtained for almost all investigated units indicate that crustal reworking processes were predominant during the formation of rocks that today make up the Amapa ***-TDMC model ages,ranging from2.99 Ga to 3.97 Ga,indicate that at least two important periods of mantle extraction and continental crust formation occurred during the Archean in southeastern Guyana Shield,an older one in the Eoarchean(~4.0 Ga)and a younger one in the Mesoarchean(~3.0-3.1 Ga).The latter is recognized as an important period of crustal accretion *** recognition of an Eoarchean episode to the southeastern most part of the Guyana Shield is unprecedented and was not recorded by whole-rock Sm-Nd data,which were restricted to the Meso-Paleoarchean(2.83 Ga to 3.51 Ga).This finding reveals t hat continental crust generation in the Amazonian Craton began at least 500 Ma earlier than previously suggested by the SmNd systematics.

关键词： U-Pb-Lu-Hf isotopes Zircon Archean crustal evolution Southeastern Guyana Shield Amazonian Craton

Convergence to a Single Wave in the Fisher-KPP Equation(Dedicated to Haim Brezis,with admiration and respect)

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Chinese Annals of Mathematics,Series B 2017年第2期38卷 629-646页

作者： James NOLEN jean-michel ROQUEJOFFRE Lenya RYZHIK Department of Mathematics Duke UniversityDurhamNC 27708USA Institut de Mathématiques(UMR CNRS 5219) Université Paul Sabatier118 route de Narbonne31062 Toulouse cedexFraxlce Department of Mathematics Stanford UniversityStanford CA94305USA.

The authors study the large time asymptotics of a solution of the Fisher-KPP reaction-diffusion equation, with an initial condition that is a compact perturbation of a step function. A well-known result of Bramson states that, in the reference frame moving as 2t-(3/2 )log t+x∞, the solution of the equation converges as t → +∞ to a translate of the traveling wave corresponding to the minimal speed c_* = 2. The constant x∞ depends on the initial condition u(0, x). The proof is elaborate, and based on probabilistic *** purpose of this paper is to provide a simple proof based on PDE arguments.

关键词： Traveling waves, KPP, Front propagation, Asymptotic analysis,Reaction-diffusion

Modelling and mathematical results arising from ferromagnetic problems

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Science China Mathematics 2012年第5期55卷 1053-1067页

作者： DESCLOUX jean FLUECK michel RAPPAZ Jacques Department of Mathematics Ecole Polytechnique Fdrale de Lausanne (EPFL)Lausanne 1015Switzerland

Abstract In this article, we investigate the equations of magnetostaties for a configuration where a ferromagnetic material occupies a bounded domain and is surrounded by vacuum. Furthermore, the ferromagnetic law takes the form B=μ0μr（｜H｜）Hi i.e., the magnetizing field H and the magnetic induction B are collinear, but the relative permeability μr is allowed to depend on the modulus of H. We prove the well-posedness of the magnetostatic problem under suitable convexity assumptions, and the convergence of several iterative methods, both for the original problem set in the Beppo-Levi space W1（R3）, and for a finite-dimensional approximation. The theoretical results are illustrated by numerical examples, which capture the known physical phenomena.

关键词： ferromagnetism nonlinear elliptic problems finite element methods optimisation algorithms

Hybrid Materials Prepared from Polymers and Self-assembled Systems by Physical Processes

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复旦学报（自然科学版） 2007年第5期46卷 645-646页

作者： jean-michel Guenet Institut Charles Sadron CNRS UPR22 BP 400166 rue BoussingaultF-67083 STRASBOURG CedexFrance

1 Results A new type of hybrid materails prepared from ternary systems polymer/bicopper organic complex/solvent is *** binary system displays differing types of behaviour: The polymer solutions produce thermoreversible gels while the bicopper organic complex (designated as CuS8) forms randomly-dispersed,self-assembling threads in organic solvents (See Fig.1(a),(b)).Fig.1 The CuS8 and ips thermoreversible gels Thermoreversible gels possess a fibrillar morphology with a typical mesh size ra...

关键词： Rybrid mate rials self-assembled CuS8

Reaction zone characterization of counter-flow diffusion flame with diluted and preheated reactants

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International Journal of Minerals,Metallurgy and Materials 2009年第3期16卷 278-284页

作者： Yu-ying Liu jean-michel Most Philipp Bauer Alain Claverie School of Jet Propulsion Beijing University of Aeronautics ＆ Astronautics Beijing 100083 China Laboratoire de Combustion et de Détonique （UPR 9028 au CNRS） F-86961 Futuroscope Cedex Poitiers France

Reaction zone characteristics were studied using hydroxy radical planar laser-induced fluorescence （OH-PLIF） technique for a counter-flow preheated （CH4＋N2）/（Air＋N2） diluted diffusion flames. The effects of preheat temperature and dilute ratio on the reaction zone characteristics were investigated by demonstrating the OH intensity distribution and reaction zone thickness from OH-PLIF images. Under the experimental conditions of constant cold flow velocity, the results show that the OH intensity and reaction zone thickness decrease with the increase of dilute ratio at constant preheat temperature and increase with preheat temperature at fixed dilute ratio. The OH maximum intensity shifts towards the ＂lean＂ side of counter flow at constant preheat temperature, and it shifts towards the fuel side with the increase of dilute ratio of fuel stream and towards the oxidizer side with the increase of dilute ratio of oxidizer stream respectively. The feasibility of OH as a reaction zone marker in this diluted combustion is verified further. The variation of diffusion and chemical reaction rate of reactants due to preheat and dilution contributes to the reaction zone characteristics simultaneously. The effect of strain on the flame reaction zone should be included in the future work.

关键词： counter-flow preheat diluted combustion reaction zone OH-PLIF

Effect of temperature in the conversion of methanol to olefins （MTO） using an extruded SAPO-34 catalyst

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Frontiers of Chemical Science and Engineering 2018年第2期12卷 226-238页

作者： Ignacio Jorge Castellanos-Beltran Gnouyaro Palla Assima jean-michel Lavoie Universit6 de Sherbrooke Chaire de Recherche Industrielle sur l'Ethanol Cellulosique et les Biocommodities (CRIEC-B) Sherbrooke QC Canada J1L 2Y4

The methanol-to-olefin （MTO） reaction was investigated in a bench-scale, fixed-bed reactor using an extruded catalyst composed of a commercial SAPO-34 （65 weight percentage, wt-%） embedded in an amorphous SiO2 matrix （35 wt-%）. The texture properties, acidity and crystal structure of the pure SAPO-34 and its extruded form （E-SAPO-34） were analyzed and the results indicated that the extrusion step did not affect the properties of the catalyst. Subsequently, E-SAPO-34 was tested in a temperature range between 300 and 500 ~C, using an aqueous methanol mixture （80 wt-% water content） fed at a weight hour space velocity （WHSV） of 1.21 h-1. At 300 ~C, a low conversion was observed combined with the catalyst deactivation, which was ascribed to oligomeriza-tion and condensation reactions. The coke analysis showed the presence of diamandoid hydrocarbons, which are known to be inactive molecules in the MTO process. At higher temperatures, a quasi-steady state was reached during a 6 h reaction where the optimal temperature was identified at 450℃, which incidentally led to the lowest coke deposition combined with the highest H/C ratio. Above 450℃, surges of ethylene and methane were associated to a combination of H-transfer and protolytic cracking reactions. Finally, the present work underscored the convenience of the extrusion technique for testing catalysts at simulated scale-up conditions.

关键词： MTO SAPO-34 temperature extrusion coke light alkanes

On the Liquid-Vapor Phase-Change Interface Conditions for Numerical Simulation of Violent Separated Flows

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Fluid Dynamics & Materials Processing 2020年第2期16卷 359-381页

作者： Matthieu Ancellin Laurent Brosset jean-michel Ghidaglia UniversitéParis-Saclay ENS Paris-SaclayCNRSCentre BorelliGif-sur-YvetteFrance GTT(Gaztransport&Technigaz) Saint-Rémy-lès-ChevreuseFrance

Numerous models have been proposed in the literature to include phase change into numerical simulations of two-phase *** review paper presents the modeling options that have been taken in order to obtain a model for violent separated flows with application to sloshing wave impacts.A relaxation model based on linear non-equilibrium thermodynamics has been chosen to compute the rate of phase *** integration in the system of partial differential equations is done through a non-conservative advection *** each of these modelling choices,some alternative models from the literature are presented and *** theoretical framework for all phase change model(conservation equations and entropy growth)is also summarized.

关键词： Phase change modeling two-phase flow non-equilibrium thermodynamics compressible flow hyperbolic system of conservation laws