检索结果-南通市图书馆

Nano Research 2011年第5期4卷 511-521页

作者： Izabela Janowska Maria-Simona Moldovan Ovidiu Ersen Herve Bulou Kambiz Chizari Marc J. Ledoux Cuong Pham-Huu laboratoire des materiaux Surfaces et ProcEdEs pour la Catalyse （LMSPC UMR 7515 CNRS） 25 rue Becquerel F-67087 Strasbourg Cedex 02 France Institut de Physique et Chimie des materiaux de Strasbourg （IPCMS UMR 7504 CNRS） 23 rue du Loess F-67037 Strasbourg Cedex 08 France

Heterogeneous catalytic reactions involve the use of highly dispersed active phases such as metal, metal oxide, or metal sulphide nanoparticIes on thermally stable supports. Fluctuations of the reaction temperature during the reactions can induce sintering of the particles. The stability of such small particles represents a crucial parameter in the development of new families of catalysts with high activity in many fields. Here we report the stability of platinum nanoparticles （2-3 nm） on a few-layer graphene （FLG） surface as studied by in situ high temperature transmission electron microscopy.

关键词： Graphene platinium nanoparticles diffusion catalysis TEM annealing

Pyrolysis of olive residue/low density polyethylene mixture：Part Ⅰ Thermogravimetric kinetics

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

燃料化学学报 2008年第6期36卷 672-678页

作者： ABOULKAS A E1 HARFI K El BOUADILI A laboratoire de Recherche sur la Reactivites des materiaux et l Optimisation des procedes ＂REMATOP＂ Departement de chimie Faculte des Sciences Semlalia Universite Cadi Ayyad BP 2390 40001 Marrakech Maroc departement de chimie Faculte polydisciplinaire de Beni-Mellal Universite Sultan Moulay Slimane BP 592 23000 Beni-Mellal Maroc laboratoire de Chimie Organique et Analytique Departement de chimie Faculte des Sciences et Techniques de Beni-Mellal Universite Sultan Moulay Slimane BP 523 23000 Beni-Mellal Maroc

This paper demonstrates the thermal pyrolysis of olive residue,low density polyethylene(LDPE) and olive residue/LDPE mixture in an inert atmosphere of N2 using thermogravimetric analysis(TGA).Measurements were carried out in the temperature range 300K^973K at heating rates of 2K/min,10K/min,20K/min and 50K/*** on the results obtained,three temperature regimes were selected for studying the non-isothermal kinetics of olive residue/LDPE *** first two were dominated by the olive residue pyrolysis,while the third was linked to the LDPE pyrolysis,which occurred at much higher *** between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on *** maximum degradation temperatures of each component in the mixture were higher than those the individual components;thus an increase in thermal stability was *** kinetic parameters associated with thermal degradation were determined using Friedman isoconversional method.

关键词：高温分解反应低密度聚乙烯动力学 LDPE

Electrodeposition and characterization of Cu2O thin films using sodium thiosulfate as an additive for photovoltaic solar cells

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2018年第2期26卷 421-427页

作者： Hassiba Rahal Rafiaa Kihal Abed Mohamed Affoune Samia Rahal laboratoire d'Analyses lndustrielles et Genie des materiaux Departement de Genie des ProcedesFaculte des Sciences et de la TechnologieUniversite 8 Mai 1945 GuelmaBP 401 Cuelma 24000Algeria Universite 20 Aout 1955 Skikda BP 26Route El-Hadaiek21000Algeria Universite Abbes Laghrour Khenchela BP 1252Rue de BatnaKhenchela 40004Algeria laboratoire d'etude des Surfaces et Interfaces de la Matiere Solide LESIMS Departement de PhysiqueFaculte des SciencesBadji Mokhtar UniversiteAnnabaAlgeria

Cuprous oxide （Cu2O） thin films have been grown by electrodeposition technique onto ITO-coated glass substrates from aqueous copper acetate solutions with addition of sodium thiosulfate at 60 ℃ The effects of sodium thiosulfate on the electrochemical deposition of Cu2O films were investigated by cyclic voltammetry and chronoamperometry techniques. deposited films were obtained at - 0.58 V vs. SCE and characterized by X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FrIR）, scanning electron microscopy （SEM）, and optical, photoelectrochemical and electrical measurements. X-ray diffraction results indicated that the synthesized Cu2O films had a pure cubic phase with a marked preferential orientation peak along （200） plane and with lattice constants a = b = c = 0.425 rim. FFIR results confirmed the presence of Cu2O films at peak 634 cm 1. SEM images of Cu2O films showed a better compactness and spherical-shaped composition. Optical properties of Cu2O films reveal a high optical transmission （〉80%） and high absorption coefficient （α 〉 104 cm- 1 ） in visiblelight region. The optical energy band gap was found to be 2.103 eV. Photoelectrochemical measurements indicated that Cu2O films had n-type semiconductor conduction, which confirmed by Hall Effect measurements. Electrical properties of Cu2O films showed a low electrical resistivity of 61.30 Ω. cm-1, carrier concentration of-4.94×1015cm -3andmobility of20.61cm2.V 1,*** Cu2O thin films with suitable properties are promising semiconductor material for fabrication of photovoltaic solar cells,

关键词： Electrodeposition Cuprous oxide Thin films Semiconductor Cyclic voltammetry Photoelectrochemical measurements

Characterization and Photoluminescence Properties of Alumina Nanowires Elaborated by Arc-Plasma

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2006年第1期22卷 127-129页

作者： C.Arnoult X.devaux H.Rinnert M.Vergnat laboratoire de Physique des materiaux UMR CNRS 7556Ecole des MinesCS14234F54042 Nancy cedexPrance

Ultrafine powders containing alumina nanowires are synthesized by DC arc plasma from pure aluminium metal. Nanowires grow only when reactive gases are composed of nitrogen and less than ten percent of oxygen. Nanowires have the diameters ranging from 20 to 80 nm and lengths ranging from hundreds nanometers to tens of micrometers. A first assumption of the mechanism process is proposed, in which nanowires grow starting directly from the aluminium. Photoluminescence measurements show that the powders have three emission peaks around 435, 530 and 750 nm resulting from different kinds of defects such as oxygen vacancies, aluminium interstitial ions and surface defects.

关键词： Nanowires Alumina Arc plasma Photoluminescence

Numerical investigation of Ar–NH3 mixture in homogenous DBDs

在线全文

学校读者我要写书评

暂无评论

Plasma science and Technology 2018年第3期20卷 72-77页

作者： Barkahoum LAROUCI Soumia BENdeLLA Ahmed BELASRI laboratoire de Physique des Plasmas materiaux Conducteurs et leurs Applications Faculte de PhysiqueUniversite des Sciences et de la Technologie d'Oran Mohamed Boudiaf USTO-MB El M'Naoeur B.P.1505 31 000 Oran Algeria

In this paper, a study of homogenous dielectric barrier discharge Ar–NHwas made in order to investigate the electrical and the physical characteristics of homogenous discharge at atmospheric pressure. The discharge model includes the electrical module and the chemical kinetic module. The results obtained by the present model were compared with experimental work. The evolution of the plasmas voltage, the species densities, and the concentration of charged species are analyzed and discussed.

关键词： plasma simulation dielectric barrier discharge Ar-NH3 mixture

Numerical Study of Greenhouse Nocturnal Heat Losses

在线全文

学校读者我要写书评

暂无评论

Journal of Thermal science 2011年第4期20卷 377-384页

作者： F.Berroug E.K.Lakhal M.El Omari M.Faraji H.El Qarnia laboratoire d'Automatique de l'Environnement et Procédés de Transfert UniversitéCadi AyyadFacultédes Sciences Semlalia-Département de PhysiqueMarrakech-MarocAffiliéau CNRSTURAC 28 laboratoire de Physique des materiaux MicroelectroniqueAutomatique et TechniqueDepartement de PhysiquesFaculte des Sciences Ain ChockUniversite Hassan IICasablanca-Maroc

In this study we quantify and analyze different components of nocturnal losses from a heated greenhouse with the presence of vegetation for typical winter weather conditions in Marrakesh-Morocco,using a non linear model,based on the greenhouse heat and mass *** was found that 12% of the total input heat was dissipate as a sensible and latent leakage losses,66% was lost by convective exchange through air-inner *** gain of energy at the inner-cover is dissipated at the outer-cover by radiation(66%)and convection(34%).This results point toward some practical measures to reduce heat losses:increasing air tightness,using covering materials with low-emissivity in the long wave band or putting up an external thermal curtain should provide significant energy savings.

关键词： Greenhouse energy balance heat losses numerical analysis.

Texture Evolutions in Fe-6.5%Si Produced by Rapid Solidification and Chemical Vapor deposition

在线全文

学校读者我要写书评

暂无评论

Journal of Materials science & Technology 2002年第6期18卷 516-518页

作者： Liang ZUO Guangyong HU Yuhui SHA Claude ESLING School of Materials science and Metallurgy Northeastern UniversityShenyang 110004China laboratoire d'etude des Textures et Application aux materiaux CNRS UMR 7078Universite de Metz 57045 Metz Cedex 1France

Fe-Si ribbons and thin sheets with 6.5%Si content were prepared by means of the single roller rapid solidification and chemical vapor deposition (CVD), respectively. The initial textures of rapidly solidified Fe-6.5%Si ribbons were characteristic of the {100} fiber-type, which became weakened during primary recrystallization in various atmospheres. At the stage of secondary recrystallization, the {100} texture formed in Ar and the {110} texture in hydrogen, while there occurred a texture transformation from the {100} type to the {110} type in vacuum with the increase of annealing temperature. For Fe-6.5%Si sheets prepared by Si deposition in cold-rolled Fe-3%Si matrix sheets, their textures were dominated by the η-fiber (//RD) with the maximum density at the {120} orientations. After homogenization annealing, the η-fiber could evolve into the {130} type or become more concentrated on the {120} orientations, depending on the cold rolling modes of Fe-3%Si matrix sheets.

关键词： Fe-6.5%Si alloy Texture Rapid solidification Chemical vapor deposition

Effects of acid treatments on Moroccan Tarfaya oil shale and pyrolysis of oil shale and their kerogen

在线全文

学校读者我要写书评

暂无评论

燃料化学学报 2009年第6期37卷 659-667页

作者： ABOULKAS A El HARFI K laboratoire de Recherche sur la Reactivites des materiaux et IOptimisation des procedes 《REMATOP》 Departement de chimie Faculte des Sciences Semlalia Universite Cadi Ayyad BP 2390 40001 Marrakech Maroc laboratoire lnterdisciplinaire de Recherche en sciences et Techniques Faculte polydisciplinaire de Beni-Mellal Universite Sultan Moulay Slimane BP 592 23000 Beni-Mellal Maroc

In this study,the kerogen of oil shale from Moroccan Tarfaya deposits was isolated and the changes in the initial organic matter during the removal of the mineral matrix were *** extraction of the oil shale increases the intensity of the peaks in the X-ray *** spectra and X-ray diffractograms reveal the presence of mineral,calcite,quartz,kaolinite,and pyrite in the mineral matrix of the oil *** and hydrofluoric acids dissolution do not alter the organic *** nonisothermal weight loss measurements indicate that thermal decomposition of the isolated kerogen can be described by first-order reaction.A single kinetic expression is valid over the temperature range of kerogen pyrolysis between 433K and ***,the results indicate that the removal of mineral matter causes a decrease in the activation energies of the pyrolysis reactions of oil shale.

关键词：页岩矿物方解石氢氟酸

A Lattice Boltzmann Model to Study Sedimentation Phenomena in Irrigation Canals

在线全文

学校读者我要写书评

暂无评论

Communications in Computational Physics 2013年第3期13卷 880-899页

作者： Olivier Marcou Bastien Chopard Samira El Yacoubi Boussad Hamroun Laurent Lefevre Eduardo Mendes Institut de Modelisation et Analyse en Geo-Environnement et Sante Universite de Perpignan Via DomitiaPerpignanFrance Computer science department University of GenevaSwitzerland laboratoire d’Automatique et de Genie des procedes Universite Claude BernardLyonFrance laboratoire de Conception et Integration des Systemes Grenoble INPValenceFrance

Fresh water is one of the most significant resources for human activities and survival,and irrigation is among the most important uses of *** sustainibility and performance of irrigation canals can be greatly affected by sediment transport and *** our previous works,we proposed a Lattice Boltzmann model for simulating a free surface flow in an irrigation canal,as an alternative to more traditional models mainly based on shallow water *** we introduce the sedimentation phenomenon into our model by adding a new algorithm,based on the earlier work by ***,*** and ***[9,11,12,27].Transport,erosion,deposition and toppling of sediments are taken into account and enable the global sedimentation algorithm to simulate different transport modes such as bed load and suspended *** the present work,we study both the behaviour of a sediment deposit located at an underflow submerged gate(depending on the gate opening and the flow discharge)and the influence of the presence of such a deposit on the *** numerical and experimental validations have been *** experiments were realized on the micro-canal of the LCIS laboratory at Valence,*** comparisons between simulations and experiments give good qualitative agreement.

关键词： Lattice Boltzmann method irrigation canals modeling sedimentation

Laboratory study on the formation of Al2O3 inclusions at the on-set of deoxidation and during reoxidation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Materials science 2011年第1期5卷 69-76页

作者： Marie-Aline VAN ENde Muxing GUO Bart BLANPAIN Patrick WOLLANTS department of Metallurgy and Materials Engineering Katholieke Universiteit Leuven Kasteelpark Arenberg 44- bus 2450 BE-3001 Leuven Belgium Unite d＇lngeniede des materiaux et des procedes Universite Catholique de Louvain Place Sainte Barbe 2 B-1348 Louvain-la-Neuve Belgium

The formation of Al2O3 inclusions in liquid iron has been investigated in a resistance heated tube furnace to obtain deoxidation and reoxidation related data. The formation of inclusions during the early stages of deoxidation was simulated by bringing a piece of AI in contact for a short time with liquid Fe containing different dissolved oxygen levels. Reoxidation was studied by exposing AI containing Fe melts to a CO/CO2 atmosphere, Through modeling, an estimate of the local and time-dependent growth conditions for the inclusions can be made and linked to the inclusion characteristics.

关键词： steel cleanliness Al2O3 inclusions deoxidation reoxidation morphology