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在加速器真空盒中内表面镀有NEG薄膜的Multipacting测试

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在加速器真空盒中内表面镀有NEG薄膜的Multipacting测试

2005'全国真空冶金与表面工程学术会议

作者：宋洪 jean-michel laurent 中国科学院高能物理所 LHC CERN Geneva

目前正在欧洲核子中心(CERN)建造的LHC(Large Hadron Collider)是世界上最大的加速器,它是一个具有高能量(7TeV)大流强(0.53A)的质子加速器。在它的直线节真空系统中,绝大部分的真空盒内表面将被镀上NEG薄膜。这样在又细又长的真空盒里... 详细信息

目前正在欧洲核子中心(CERN)建造的LHC(Large Hadron Collider)是世界上最大的加速器,它是一个具有高能量(7TeV)大流强(0.53A)的质子加速器。在它的直线节真空系统中,绝大部分的真空盒内表面将被镀上NEG薄膜。这样在又细又长的真空盒里,当有束流通过时,NEG薄膜不仅可以作为分布式吸气剂泵使用,而且NEG薄膜还具有降低二次电子发射系数的作用,因此了解NEG薄膜的性能是很重要的。

关键词：真空盒的测试、多次电子撞击、NEG薄膜、激活温度

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使用低磁场的分布溅射离子泵

真空 1980年第5期 54-57页

作者： jean—michel laurent ,Oswald Grobner,刘志满瑞士、日内瓦、欧洲原子核研究中心北京高能所

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

Flocculation and magnetically-assisted sedimentation of size-sorted beidellite platelets mixed with maghemite nanoparticles

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Nano Research 2020年第11期13卷 3001-3011页

作者： Sofia Housni Sébastien Abramson jean-michel Guigner Pierre Levitz laurent Michot Laboratoire de PHysico-chimie des Electrolytes et Nanosystèmes InterfaciauX(PHENIX UMR 8234 Sorbonne Université-CNRS)Sorbonne UniversitéParis75252France Institut de Minéralogie de Physique des Matériaux et de Cosmochimie(IMPMC UMR 7590Sorbonne Université-IRD-CNRS-MNHN)Sorbonne UniversitéParis75252France

In this study,the flocculation and the subsequent decantation step of mixed suspensions of 10 nm-sizedγ-Fe_(2)O_(3) magnetic nanoparticles and 500 nm-sized beidellite clay platelets was *** work may find application in the field of water treatment,specifically the flocculation processes with magnetically assisted *** a short description of the preparation and characterization of the raw materials(nanoparticles and clays),the influence of several parameters(pH,concentrations of nanoparticles and clays etc.)on the amount of flocculated materials was examined,which gave information on the concentration ranges allowing a complete flocculation,together with a better understanding on the interactions between nanoparticles and clays responsible for *** optimal conditions for magnetically assisted settling were then determined by comparing for each sample sedimentation velocities under gravity and in the presence of a Nd-Fe-B ***,the complex multiscale structure of the flocs in water was explored,through the measurement of several bulk properties(zeta-potential and volume measurements,laser granulometry),while the organization of the materials at a microscopic scale was investigated by cryo-transmission electron microscopy(cryo-TEM)and small-angle X-ray scattering(SAXS).

关键词： magnetic separation nanoparticles clay flocculation decantation characterization

Continuous frequency and phase spectrograms: a study of their 2D and 3D capabilities and application to musical signal analysis

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第2期9卷 199-206页

作者： laurent NAVARRO Guy COURBEBAISSE jean-Charles PINOLI Ecole Nationale Supérieure des Mines de Saint-Etienne Centre Ingénierie et Santé (CIS) and LPMG UMR 5148 CNRS 158 cours Fauriel 42023 Saint-Etienne cedex 2 France Medical Imaging Research Center (CREATIS-LRMN) UMR 5220 CNRS U630 INSERM Université Lyon 1 INSA Lyon Bat. Blaise Pascal 7 Av. Jean Capelle 69621 Villeurbanne France

A new lighting and enlargement on phase spectrogram （PS） and frequency spectrogram （FS） is presented in this paper. These representations result from the coupling of power spectrogram and short time Fourier transform （STFT）. The main contribution is the construction of the 3D phase spectrogram （3DPS） and the 3D frequency spectrogram （3DFS）. These new tools allow such specific test signals as small slope linear chirp, phase jump case of musical signal analysis is reported. The main objective is to and small frequency jump to be analyzed. An application detect small frequency and phase variations in order to characterize each type of sound attack without losing the amplitude information given by power spectrogram

关键词： Frequency spectrogram (FS) Phase spectrogram (PS) Time-frequency representations Musical signals

Sedimentary facies and paleoenvironmental interpretation of a Holocene marsh in the Gironde Estuary in France

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Acta Oceanologica Sinica 2006年第6期25卷 52-62页

作者： WANG Jianhua MASSE laurent TASTET jean -Pierre Department of Earth Sciences Sun Yat-sen （Zhongshan） University Guangzhou 510275 China Départment de Géologie et Océanographie Université Bordeaux I 33405 Talence cédèx France

The Monards Marsh is located on the northeastern bank of the Gironde Estuary in France. Lithological, sedimentolngical and mi- cropalacontological investigations were made on four cores to determine the evolution of Holocene sedimentary environments and processes in this area over the last 6 000 a. Three main lithological facies are distinguished from bottom to top：（ 1 ） grey laminated silty-sandy clay ; （2） homogeneous dark grey silty clay ; and （ 3 ） compact silty clay. About 26 benthic foraminifera species are identified and divided into six groups according to their ecological characteristics. In association with lithology, sedimentary structures and grainuiometry, the distribution of foraminifera group is used to define external slikke, internal slikke, external schorre, internal schorre, and continental marsh facies. Combined with 14C（AMS） dating, these data indicate four successive paleoenvironments in the Monards Marsh：（ 1 ） Holocene transgression resuited in the development of a basal schorre facies overlying fluvial deposits that transformed to slikke facies sedimentation; the transgression maximum occurred around 5 600 to 5 4430 a BP and was inferred to be associated with the last phase of the rapid Holocene sea-level rise; （2） post-trangressive maximum sedimentation resuited in a regressive sequence of deposits prograding towards the estuary, corresponding to the stahilisation of sea level after 5 4430 a BP; （3） a slight positive tendency in the sea level around 2 800 a BP recorded in the central part of the marsh; and （4） the wetland to a continental marsh environment. The sequential pattern for the evolution of wetlands in this estuarine area during the Holocene is fluvial facies - blackish schorre facies - slikke facies - blackish schorre facies - continental marsh facies. Characteristics of sedimentary facies distribution and evolution reveal that the development of Holocene salt marsh in this area was controlled by the sea-level change and tidal r

关键词： marsh sedimentation benthic foraminifera,^ 14C dating Holocene sea-level fluctuation paleoenvironment

Removing harvest residues from hardwood stands affects tree growth, wood density and stem wood nutrient concentration in European beech (Fagus sylvatica) and oak (Quercus spp.)

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Forest Ecosystems 2022年第2期9卷 147-159页

作者： Sanjoy Roy jean-michel Leban Bernhard Zeller Gregory van der Heijden Arnaud Reichard Marie-Christine Gehin Philippe Santenoise laurent Saint-Andre INRAE BEFF-54000 NancyFrance IGN Laboratoire de l’Inventaire ForestierNancyF-54000France Universite de Lorraine AgroParisTechINRAESILVAF-54000 NancyFrance

Background:Higher exportation of harvest residues from forests due to increased demand for woody biomass,has reportedly diminished soil mineral resources and may lead to degraded tree nutrition as well as ***,as nutrients become less available in the soil,the remobilization of nutrients in biomass tissues(plant internal cycling)helps sustain tree *** study aims to quantify the impact of Removing Harvest Residues and Litter(RHRL)during five years on tree growth,wood density,and stem wood nutrient concentrations in young beech and oak forest ***:Our study found that,RHRL significantly decreased tree growth ring width by 14%,and wood density by 3%,in beech trees,in near bark *** also significantly reduced nutrient concentration in near bark and near pith areas of both studied ***,Na and S were found lower by 44%,76%,and 56%,respectively,in near bark area of beech *** near bark area of oak trees,K,Ca,Mg,Na,S,and Fe were lower by 20%,25%,41%,48%,41%,and 16%,respectively.K and Mg concentrations decreased more strongly in near pith area compared to near bark area suggesting internal translocation of these two ***:In beech trees,wood density proved to be an important factor while quantifying the effect of removing harvest residuals on tree growth and *** nutrient loss intensified the remobilization of nutrients con-tained in older tree rings(close to the pith)towards newly formed rings(close to bark).In our study,in beech trees,K was found to be the most recycled major *** results demonstrate the potential of such analysis for providing valuable insight into the effect of RHRL in premature stands on the physiological adaptive strategies of trees and an indication of soil fertility status.

关键词： Harvest residues Fagus sylvatica Quercus petraea Dendroecology Dendrochemistry Radial growth Wood density Tree growth Ring width Translocation

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