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Electro-Hydrodynamics and Kinetic Modeling of Dry and Humid Air Flows Activated by Corona Discharges

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Plasma Science and Technology 2016年第5期18卷 469-472页

作者： J. P. SARRETTE O. EICHWALD F. MARCHAL O. DUCASSE M. YOUSFI CNRS LAPLACE Toulouse F-31062 France Universite de toulouse UPS INPTLAPLXCE (Laboratoire Plasma et Conversion d'Energie) Toulouse Cedex 9 F-31062 France

The present work is devoted to the 2D simulation of a point-to-plane Atmospheric Corona Discharge Reactor （ACDR） powered by a DC high voltage supply. The corona reactor is periodically crossed by thin mono filamentary streamers with a natural repetition frequency of some tens of kHz. The study compares the results obtained in dry air and in air mixed with a small amount of water vapour （humid air）. The simulation involves the electro-dynamics~ chemical kinetics and neutral gas hydrodynamics phenomena that influence the kinetics of the chemical species transformation. Each discharge lasts about one hundred of a nanosecond while the post- discharge occurring between two successive discharges lasts one hundred of a microsecond. The ACDR is crossed by a lateral dry or humid air flow initially polluted with 400 ppm of NO. After 5 ms, the time corresponding to the occurrence of 50 successive discharge/post-discharge phases, a higher NO removal rate and a lower ozone production rate are found in humid air. This change is due to the presence of the HO2 species formed from the H primary radical in the discharge zone.

关键词： DC corona discharge humid air chemistry plasma simulation NO treatment

Determination of Electron Collision Cross Sections Set for Tetramethysilane

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Plasma Science and Technology 2007年第6期9卷 756-759页

作者： Marie-Claude BORDAGE toulouse University LAPLACE UMR 5213 CNRS-UPSPaul Sabatier University118Route de Narbonne31062 Toulouse CedexFrance

A swarm analysis technique based on the solution of the Boltzmann equation is used to derive low energy electron collision cross sections for tetramethylsilane （TMS）. The calculated swarm parameters with this first available cross sections set is consistent with measured values of the swarm parameters. Calculations of transport parameters in mixtures of TMS with argon are also presented.

关键词： tetramethysilane electron cross section swarm parameters

All Speed Scheme for the Low Mach Number Limit of the Isentropic Euler Equations

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Communications in Computational Physics 2011年第6期10卷 1-31页

作者： Pierre Degond Min Tang Institute of Mathematics of toulouse Universite Paul Sabatier118route de Narbonne31062 Toulouse cedexFrance

An all speed scheme for the Isentropic Euler equations is presented in thispaper. When the Mach number tends to zero, the compressible Euler equations converge to their incompressible counterpart, in which the density becomes a constant. Increasing approximation errors and severe stability constraints are the main difficultyin the low Mach regime. The key idea of our all speed scheme is the special semiimplicit time discretization, in which the low Mach number stiff term is divided intotwo parts, one being treated explicitly and the other one implicitly. Moreover, the fluxof the density equation is also treated implicitly and an elliptic type equation is derivedto obtain the density. In this way, the correct limit can be captured without requesting the mesh size and time step to be smaller than the Mach number. Compared withprevious semi-implicit methods [11,13,29], firstly, nonphysical oscillations can be suppressed by choosing proper parameter, besides, only a linear elliptic equation needs tobe solved implicitly which reduces much computational cost. We develop this semiimplicit time discretization in the framework of a first order Local Lax-Friedrichs (orRusanov) scheme and numerical tests are displayed to demonstrate its performances.

关键词： Low Mach number Isentropic Euler equations compressible flow incompressible limit asymptotic preserving Rusanov scheme

Nile tilapia(Oreochromis niloticus)invasion impacts trophic position and resource use of commercially harvested piscivorous fishes in a large subtropical river

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Ecological Processes 2023年第1期12卷 313-329页

作者： Fangmin Shuai Jie Li Sovan Lek Pearl River Fisheries Research Institute CAFSGuangzhou 510380China Universitéde toulouse-PaulSabatier 118 Route de Narbonne31062 Toulouse CedexFrance

Background Although freshwater ecosystems cover less than 1%of the earth’s surface,they support extremely high levels of biodiversity and provide vital ecosystem ***,due to the introduction of non-native fishes,aquatic ecosystem functioning has been altered,and in some cases,declined *** the impacts of invasive species has proven *** this study,we examined the relative trophic position of native piscivorous fishes to estimate the effects of invasive Nile tilapia on food webs in the downstream sections of an invaded large subtropical river,the Pearl River,***,we quantified how native piscivorous fish diets changed as the Nile tilapia invasion *** The trophic position of the widely distributed and locally important economically harvested piscivorous culter fish(Culter recurviceps),mandarinfish(Siniperca kneri),and catfish(Pelteobagrus fulvidraco)lowered significantly in the invaded Dongjiang River compared to an uninvaded reference Beijiang *** lower trophic position of these piscivorous fishes was reflected by a major reduction in the proportion of prey fish biomass in their diets following the Nile tilapia *** fishes in the diet of culter fish from the reference river(33%small fishes,17%zooplankton)shifted to lower trophic level zooplankton prey in the invaded river(36%zooplankton,25%small fish),possibly due to the presence of Nile ***,small fishes in the diet of mandarinfish in the reference river(46%small fishes,11%aquatic insects)declined in the invaded river(20%aquatic insects,30%small fishes).Similarly,the diet of catfish from the reference river shifted from fish eggs(25%fish eggs,25%aquatic insects)to aquatic insects in the invaded river(44%aquatic insects,5%fish eggs).Conclusions The results of this study contributed to a growing body of evidence,suggesting that Nile tilapia can modify trophic interactions in invaded *** is crucial to understand t

关键词： Nile tilapia Invasion Stable isotope ratio Trophic position Stable isotope mixing model

Benchmarks of 3D Laplace Equation Solvers in a Cubic Configuration for Streamer Simulation

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Plasma Science and Technology 2016年第5期18卷 538-543页

作者： Joseph-Marie PLEWA Olivier DUCASSE Philippe DESSANTE Carolyn JACOBS Olivier EICHWALD Nicolas RENON Mohammed YOUSFI Universite de toulouse UPS INPT LAPLACE (Laboratoire Plasma et Conversion d'Energie) Toulouse Cedex 9 F-31062 France Group of Electrical Engineering-Paris (GeePs) UMR 8507 CNRS CentraleSupelec Universite Paris-Sud-UPMC 11 rue Joliot-Curie Plateau de Moulon 91192 Gif-sur-Yvette Cedex F-91192 France CALMIP Universite de Toulouse-CNRS-INPT-INSA-UPS UMS 3667 France CNRS LAPLACE Toulouse F-31062 France

The aim of this paper is to test a developed SOR R＆B method using the Chebyshev accelerator algorithm to solve the Laplace equation in a cubic 3D configuration. Comparisons are made in terms of precision and computing time with other elliptic equation solvers proposed in the open source LIS library. The first results, obtained by using a single core on a HPC, show that the developed SOR R＆B method is efficient when the spectral radius needed for the Chebyshev acceleration is carefully pre-estimated. Preliminary results obtained with a parallelized code using the MPI library are also discussed when the calculation is distributed over one hundred cores.

关键词： numerical methods for elliptic equations high performance computing 3Dstreamer simulation SOR IDR BiCGSTAB

Microwave irradiation: Novel and facile methods for the synthesis of new pyrimidinones

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Chinese Chemical Letters 2014年第8期25卷 1207-1210页

作者： Aida Chaker Fathi Zribi Franoise Nepveu Fakher Chabchoub Department of Chemistry University of Sfax Road Soukra km 4-3000 SfaxTunisia UPS UMR 152 PHARMA-DEV University of Toulouse III 118 road of Narbonne F-31062 Cedex 9 Toulouse France Department of Chemistry University of Sfax Road Soukra km 4-3000 Sfax Tunisia IRD UMR 152 F-31062 Cedex 9 Toulouse France

We describe here a rapid process for the preparation of new 9-chloromethyl-12-aryl-10,12-dihydrobenzo[5,6]chromeno[2,3-d]pyrimidin-11-ones 5a-d and 10-chloromethyl-7-aryl-7,9-dihydrobenzo[7,8]chromeno[2,3-d]pyrimidin-8-ones 6a-d by two different methods utilizing microwave irradiation. This methodology provides better yields（72%–80%） and high purity of the title compounds.

关键词： Microwave-irradiation Aminonitriles naphtopyraniques Chloroacetylchloride Pyrimidinones

Macroscopic,thermodynamic,kinetic and microscopic study of nitric acid pickling of Elektron 21(EV31A)magnesium alloy

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Journal of Magnesium and Alloys 2014年第4期2卷 363-376页

作者： Benjamin Mouls Laurent Arurault Pierre-Louis Taberna Corine Bonningue Universitéde toulouse CIRIMATUPS/INPT/CNRS118 route de Narbonne 31062Toulouse Cedex 9France

The study of pickling of the EL21T6 substrate in a nitric acid bath firstly provided knowledge of the influence of the different experimental parameters(concentration of acid,temperature and stirring of the solution)in relation to the etching *** experimental part led to the choice of standard pickling(T_(bath)=25℃,moderate stirring(250 rpm),[HNO_(3)]=1.20 mol/L,duration of 2 min)so as to obtain constant removal of material,even after several uses of the pickling *** observations also confirmed that in these operating conditions,pickling concerns both the grains of the matrix and the precipitates of type Mg3(Nd,Gd),leading to uniform removal of material from the *** from a number of assumptions,thermodynamic and chemical kinetic studies then allowed a pickling mechanism to be proposed and led to obtaining values for the corresponding kinetic parameters(order of reaction,constant of mean rate,activation energy)to be obtained.

关键词： Magnesium alloy Elektron 21 Pickling Nitric acid Chemical kinetic Thermodynamic

A Generalized Stationary Algorithm for Resonant Tunneling:Multi-Mode Approximation and High Dimension

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Communications in Computational Physics 2011年第9期10卷 882-898页

作者： Naoufel Ben Abdallah Hao Wu Department of Mathematical Sciences Tsinghua UniversityBeijing10084China Institut de Math´ematiques de toulouse Universite Paul Sabatier118route de Narbonne31062 Toulouse CedexFrance.

The multi-mode approximation is presented to compute the interior wave function of Schr¨odinger *** idea is necessary to handle the multi-barrier and high dimensional resonant tunneling problems where multiple eigenv... 详细信息

关键词： Schrodinger equation numerical scheme resonant tunneling multi-mode approximation high dimension.

New Breakdown Electric Field Calculation for SF6 High Voltage Circuit Breaker Applications

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Plasma Science and Technology 2007年第6期9卷 690-694页

作者： Ph.ROBIN-JOUAN M.YOUSFI AREVA T & D High Voltage Switchgear Research Centre 130 rue L.BLUM 69611 VilleurbanneFrance University of toulouse LAPLACE-UMR 5213 CNRSUPS118 Route de Narbonne31062 Toulouse Cedex 9France

The critical electric fields of hot SF6 are calculated including both electron and ion kinetics in wide ranges of temperature and pressure, namely from 300 K up to 4000 K and 2 atmospheres up to 32 atmospheres respectively. Based on solving a multi-term electron Boltz- mann equation the calculations use improved electron-gas collision cross sections for twelve SF6 dissociation products with a particular emphasis on the electron-vibrating molecule interactions. The ion kinetics is also considered and its role on the critical field becomes non negligible as the temperature is above 2000 K. These critical fields are then used in hydrodynamics simulations which correctly predict the circuit breaker behaviours observed in the case of breaking tests.

关键词： breakdown electric field hot dissociated SF6 high voltage gas-circuit-breaker