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Microstructural Tailoring During Solid-State Transformation by EPM

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Journal of Iron and Steel Research International 2012年第S2期19卷 1023-1029页

作者： LI Zongbin ZHAO Xiang Zhang Yudong ESLING Claude ZUO Liang Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education) Northeastern University laboratoire d'Etude des Microstructures et de Mecanique des materiaux(LEM3) CNRS UMR 7239University of Lorraine

Ni-Mn-Ga ferromagnetic shape memory alloys can generate large output with fast dynamic response at the application of the magnetic field and is considered as a new class of functional *** the martensite of these alloys is highly magnetocrystalline anisotropic,introducing a magnetic field during their martensitic transformation could be an effective way to control variant distribution and realize *** this work,some of our recent results achieved in microstructural and crystallographic texture modification by EPM(Electromagnetic Processing of Materials) during solid-state phase transformations of Ni-Mn-Ga alloys were ***,the entropy change induced by magnetic field in Ni-Mn-Ga melt-spun ribbons were also presented.

关键词： EPM martensitic transformation Ni-Mn-Ga alloys magnetization magentocaloric effect

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

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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

Effect of SnCl2 and SnCl4 precursors on SnSx thin films prepared by ultrasonic spray pyrolysis

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Journal of Semiconductors 2017年第6期38卷 18-23页

作者： Z.Hadef K.Kamli A.Attaf M.S.Aida B.Chouial laboratoire des Semi-Conducteurs Faculte des Sciences Universite Badji Mokhtar Annaba Algeria laboratoire de physique des couches minces et applications LPCMA Universite de Biskra Algeria laboratoire de Couches Minces et Interfaces Faculte des Sciences Universite de Constantine Algeria

Thin films of SnSx,semiconductors,have been successfully synthesized by ultrasonic spray pyrolysis technique,using two precursors namely：tin（II）chloride and tin（IV）chloride,*** solutions were prepared by the dilution of different Sn molarities of the two precursors *** precursor molarities were varied from 0.04 to 0.07 mol/L,whereas that of S was fixed at 0.1 mol/*** present work focuses on the effect of the different precursor’s molarities on the nature and the properties of the prepared thin films in order to optimize the growth conditions.X-ray diffraction analysis reveals that the precursor’s molarities alter the grain size of the prepared films,which varied from 8 to 14 nm and from 12 to 16 nm,according to the used *** films analysis by SEM,shows that the SnS2 films are more dense and smooth than the SnS *** composition of the elements is analysed with an EDX spectrometer,and the obtained result for M（sn）=0：07 mol/L indicates that the atomic ratio of Sn to S is 51.57：48：43 and 36：64 for films synthesized from the first and second precursors *** measurements show that the conductivity behavior depends on the used precursors and their molarities.

关键词： precursors ultrasonic spray tin sulfide semiconductor thin films characterization

Zwitterionic and mesoionic liquids:Molecular aggregation in 3-methylsydnone

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Science China Chemistry 2010年第9期53卷 2063-2069页

作者： CASSEL Stéphanie RICO-LATTES Isabelle LATTES Armand laboratoire des IMRCP UMR 5623Université Paul Sabatier

Ionic liquids are green solvents with interesting properties:displaying low melting points and high boiling *** offer a new approach applicable in many ***,the presence of free ions can be a matter in some cases,*** the study of nucleophilic reactions,in electrochemistry,and in each situation where there is a competition between counter ions,as in micellization of ionic *** compounds having formal unit electrical charges of opposite sign,and the same physical properties than ionic liquids would be a nice alternative to these latter *** are two classes of chemical compounds having these characteristics:zwitterionic liquids(with no uncharged canonical representation) and mesoionic liquids(in which the negative and the positive charges are delocalized).In that last class we have chosen to work with 3-methylsydnone in order to examine,in this aprotic solvent,if it was possible to observe aggregation of surfactants in the same manner as in *** all kinds of surfactants studied(ionic,zwitterionic and mesoionic) we have been able to demonstrate the formation of direct micelles:hydrogen bonding is thus not mandatory for molecular *** of the behavior in water and in formamide showed that solvophobic interactions were qualitatively comparable but with a lower intensity.

关键词： ionic liquids zwitterionic liquids mesoionic liquids 3-methylsydnone molecular aggregation micellization solvophobicity

Existence results for unilateral contact problem with friction of thermo-electro-elasticity

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Applied Mathematics and Mechanics(English Edition) 2015年第7期36卷 911-926页

作者： H.BENAISSA EL-H.ESSOUFI R.FAKHAR laboratoire de Recherche en Mathématique Informatique et Sciences de l’Ingénieur (MISI) laboratoire de Science des Matériaux des Milieux et de la Modélisation (LS3M)Université Hassan 1

This work studies a mathematical model describing the static process of contact between a piezoelectric body and a thermally-electrically conductive foundation. The behavior of the material is modeled with a thermo-electro-elastic constitutive law. The contact is described by Signorini＇s conditions and Tresca＇s friction law including the electrical and thermal conductivity conditions. A variational formulation of the model in the form of a coupled system for displacements, electric potential, and temperature is de- rived. Existence and uniqueness of the solution are proved using the results of variational inequalities and a fixed point theorem.

关键词： static frictional contozt thermo-piezoelectric material Signorini's condi-tion Tresca's friction frictional heat generation variational inequality fixed point process

Small scale biodiesel synthesis from waste frying oil and crude methanol in Morocco

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1178-1185页

作者： Fatiha Ouanji Marouane Nachid Mohamed Kacimi Leonarda F.Liotta Fabtizio Puleo Mahfoud Ziyad Universite Mohammed V Faculte des SciencesDepartement de ChimieLaboratoire de Physico-chimie des Materiaux et Catalyse(URAC26)Avenue lbn BattoutaBP.1014RabatMorocco Hassan 11 Academy of Sdence and Technology RabatMorocco lstituto per lo Studio dei Materiali Nanostrutturati(ISMN)-CNR via Ugo La Malfa15390146 PalermoItaly

Biodiesel was produced at small scale by transesterification of used frying oil（UFO） recovered from Moroccan pastry shops and fish frying restaurants. Biodiesel was first synthesised at laboratory scale in order to optimize the transesterification parameters. The cost of the final product was also optimized using low-cost raw *** UFO and the produced biodiesel were characterized with several techniques including gas chromatography,1H NMR,13 C NMR, FTIR, and TGA–TDA techniques.1H NMR gas chromatographic analyses of the final product confirmed that the transesterification in the chosen experimental conditions was completed. These results were confirmed by TGA–TDA analysis used as new techniques to monitoring triglyceride conversion. The biodiesel did not contain any trace of glycerol, and it did meet the international standards. The transesterification at low cost in small scale conditions was performed at 60 ℃ using 1.2% of KOH and a methanol/oil molar ratio of 6：1. A yield of 80.8% was achieved. The properties of the produced biodiesel were found to be as good as those of biodiesels obeying to European standards. The biodiesel production was also performed at small-scale for individual utilisation. Thus, the product was tested in a kerosene stove for heating and non-modified commercial diesel engine producing electricity.

关键词： Biodiesel Transesterification Small-scale Thermogravimetry

Research on fabrication and properties of nanoporous GaN epilayers

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Rare Metals 2006年第Z2期25卷 5-10页

作者： NOUET Gérard RUTERANA Pierre laboratoire Structures des Interfaces et Fonctionnalité des Couches Minces UMR CNRS 6176 ENSICAEN6 Boulevard du Maréchal Juin 14050 Caen Cedex France

Gallium nitride (GaN) epilayers with nanopore arrays were fabricated by inductive coupled plasma (ICP) etching using anodic aluminum oxide (AAO) as mask. Nanoporous AAO templates were formed by anodizing the Al films deposited on GaN epilayers. The diameter of the perforations in the AAO masks could be easily controlled by tuning the technique parameters of AAO fabrication process. Cl2/Ar and Cl2/He were employed as etching gas. Scanning electron microscopy (SEM) analysis shows that vertical nanoporous arrays with uniform distribution can directly be transferred from AAO masks to GaN films in some proper conditions. Photoluminescence (PL) spectra, X-ray diffraction (XRD) and Raman spectroscopy were applied to assess properties of the nanoporous GaN films with different average pore diameters and interpore distances.

关键词： nanoporous GaN ICP etching

Characterization and photoluminescence properties of ultrafine copper molybdate(α-CuMoO_4) powders prepared via a combustion-like process

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International Journal of Minerals,Metallurgy and Materials 2016年第11期23卷 1340-1345页

作者： Mohamed Benchikhi Rachida El Ouatib Sophie Guillemet-Fritsch Lahcen Er-Rakho Bernard Durand laboratoire de Physico-Chimie des Matériaux Inorganiques Faculté des Sciences Ain Chock Université Hassan Ⅱ Casablanca Institut Carnot CIRIMAT CNRS Université de Toulouse

We report a simple method for preparing copper（II） molybdate（CuMoO_4） powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the（CuMo）-precursor gel was studied by thermogravimetry–differential thermal analysis（TG–DTA）, Fourier transform infrared spectroscopy（FTIR）, and X-ray diffraction（XRD）. We observed that the crystallization of CuMoO_4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m^2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO_4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO_4^（2-）] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size.

关键词： copper molybdate chemical synthesis photoluminescence Jahn-Teller effect

Synthesis of Branched Poly(butylene succinate):Structure Properties Relationship

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Chinese Journal of Polymer Science 2016年第7期34卷 873-888页

作者： Marie Vandesteene Nicolas Jacquel Rene Saint-Loup Nadège Boucard Christian Carrot Alain Rousseau Francoise Fenouillot Unive Lyon INSA-LyonIngenierie des Materiaux PolymeresIMPUMR5223F-69621VilleurbanneFrance Univ Lyon Universite Jean MonnetIngenierie des Materiaux PolymeresIMPUMR5223F-42023 Saint-EtienneFrance Roquette Freres.Polymer Chemistry Department F-62136 LestremFrance MBD Texinov F-38110 Saint-Didier-de-la-TourFrance

A series of branched poly（butylene succinate）（PBS） were synthesized with several branching agents namely trimethylol propane（TMP）, malic acid, trimesic acid, citric acid and glycerol propoxylate. The structure of the branched polymers was analyzed by SEC and ~1H-NMR. The effect of branching agent structure on crystallization was also investigated and played a significant role. Isothermal studies showed that glycerol propoxylate could act as a nucleating agent. By contrast high content of TMP disturbed the regularity of the chain and hindered the crystallization of PBS. From the non-isothermal kinetic study, it was found that glycerol propoxylate increased noticeably the crystallization rate due to the flexible structure of the branching agent. A secondary nucleation was observed with glycerol propoxylate attributed to the crystallization of amorphous fraction included between crystallites formed at the primary crystallization. Chain topology was obtained through rheological investigations and the synthesized polymers showed a typical behavior of a mixture of linear and randomly branched PBS. The incorporation of branches improved the processability of PBS for film blowing application and the modulus and the stress at break of the resulting film were significantly increased.

关键词： Poly(butylene succinate) Branching Crystallization Properties