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Preparation and Characterization of Fe-Based Metallic Glasses with Pure and Raw Elements

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Chinese Physics Letters 2012年第11期29卷 207-210页

作者： Nassima Seghairi badis Bendjemil Gabriel Lavorato Alberto Castellero Marcello Baricco Dipartimento di Chimica I.F.M/NIS/CNISM/INSTM Universitàdi TorinoVia Giuria 910125 TrinoItaly University of Larbi Ben M'hidi Oum El BouaghiAlgeria LASEA Faculty of SciencesDepartment of ChimistryUniversity of AnnabaAlgeria University of Guelma P.O.Box 1224000 GuelmaAlgeria

Amorphous alloys with a composition(at.%)Fe_(48)Cr_(15)Mo_(14)C_(15)B_(6)Y_(2) were prepared by using either pure elements(alloy B1)or a commercial AISI430 steel as a base material(B2).When prepared from pure elements,alloy(B1)could be cast in plate form with a fixed thickness of 2 mm and variable lengths between 10 and 20 mm by means of copper-mold injection in an air *** the case of alloy B2,prepared by using commercial grade raw materials,rods of 2 mm diameter are ***(B1 and B2)of width 5 mm and thickness about 30μm are prepared from the arc-melted ingots using a single roller melt spinner at a wheel speed of 40 m/*** thermal and structural properties of the samples are measured by a combination of differential scanning calorimetry(DSC),x-ray diffraction and scanning electron *** compositions are checked by energy dispersive spectroscopy analysis.X-ray diffraction and scanning electron microscopy observations confirm that an amorphous structure is obtained in all the samples.A minor fraction of crystalline phases(oxides and carbides)is detected on the as-cast *** of hardness and Young modulus were measured by nanoindentation for both the *** effects of adverse casting conditions(such as air atmosphere,non-conventional injection copper mold casting and the partial replacement of pure elements with commercial grade raw materials)on the glass formation and properties of the alloy are discussed.

关键词： alloy casting roller

Crystallization Behavior of Fe_(50−x)Cr_(15)Mo_(14)C_(15)B_(6)M_(x)(x=0,2 and M=Y,Gd)Bulk Metallic Glasses and Ribbons by in situ High Temperature X-Ray Diffraction

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Chinese Physics Letters 2012年第10期29卷 235-238页

作者： badis Bendjemil Abderrezak Bouchareb Ahmed Belbah Jamel Bougdira Rafael Piccin Marcello Baricco LEREC Department of PhysicsUniversity of Badji-mokhtar-AnnabaAlgeria 2Department of Mechanical EngineeringFaculty of Science and TechnologyUniversity of 8 Mai 1945 GuelmaAlgeria 3Institut Jean LAMOURUniversity Henri poincarréNancyFrance 4IFM/NISUniversitàdi TorinoVia P.Giuria 910125 TorinoItaly

The effect of rare earth addition on thermal stability of Fe_(50−x)Cr_(15)Mo_(14)C_(15)B_(6)M_(x)(x=0,2 and M=Y,Gd)is *** and structural properties are measured using differential scanning calorimetry and x-ray diffraction,*** microstructure is observed by using a scanning electron microscope,and chemical composition is checked by energy dispersive spectroscopy *** effect of high temperature on the isothermal crystallization of Fe_(50−x)Cr_(15)Mo_(14)C_(15)B_(6)M_(x)(x=0,2 and M=Y,Gd)bulk metallic glass and ribbons is investigated by high-temperature x-ray *** is found that the crystallization behavior of Fe_(50−x)Cr_(15)Mo_(14)C_(15)B_(6)M_(x)(x=0,2 and M=Y,Gd)bulk metallic glass strongly depends on the annealing *** different crystallization behavior is believed to be due to the different structures that the metallic glass possesses at different temperatures.

关键词： microstructure crystallization metallic

Structural,morphological and photoluminescence characterizations of Sm^(3+) doped Y_(2)O_(3) nano-sized phosphors synthesized by ultrasound assisted sol-gel method

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Journal of Rare Earths 2023年第1期41卷 51-59页

作者： Lyes Lamiri badis Kahouadji Mourad Berd Abdelmoumen Abdellatif Lotfi Benchallal Lakhdar Guerbous Salim Ouhenia Abdelhafid Souici Leila Amiour Abdelhalim Zoukel Madani Samah Department of TCSN University of BejaiaBejaia06000Algeria Department of Technology University of BejaiaBejaia06000Algeria Department of Technology Laboratory of LECVEUniversity of BejaiaBejaiaO6000Algeria Department of Physics of Materials University of Science and Technology Houari BoumedieneAlgiersAlgeria Laser Department/Nuclear Research Center of Algiers(CRNA) 02Boulevard Frantz FanonB.P.399Algiers16000Algeria Laboratory of Physical-chemistry University of BejaiaBejaia06000Algeria Phase Transformation Laboratory Universite Freres Mentouri Constantine 1Algeria Laboratory Physico-Chemistry of Materials Laghouat UniversityTechnical Platform of Physico-Chemical Analysis(PTAPC-Laghouat-CRAPC)LaghouatAlgeria

Nanosized 1 at% Sm^(3+)doped Y_(2)O_(3)powders were prepared by an ultrasound assisted sol-gel method.Y_(2)O_(3):Sm^(3+)powders crystallize in Y_(2)O_(3)pure cubic phase and XRD analysis shows that the as-used agitation protocol affects strongly the crystallite’s shape and mean *** recorded emission spectra under λ_(em)=600 nm exhibit two absorption bands;the first one is assigned to O^(2-)→Sm^(3+)charge transfer state(CTS) with a maximum absorption at 223 nm,and the second is due to intraconfigurational transition 4f^(5)-4f^(5) of Sm^(3+) with a maximum absorption at 407 *** 223 and 407 nm transitions are attributed to characteristics intra-configurational transitions of Sm^(3+).All emission spectra are dominated by reddish/orange luminescence located at 606 nm and assigned to ^(4)G_(5/2)→^(6)H_(7/2) *** is found that the photoluminescence intensity of samples obtained under excitation at 407 nm is 60 times smaller than that obtained under 223 nm *** time measurements of the ^(4)G_(5/2)→^(6)H_(7/2) luminescence transition indicate that decay time of nano-sized powder is significantly shorter than bulk material one.

关键词： Y_(2)O_(3):Sm^(3+)nano-sized powder Sol-gel method Ultrasound Charge transfer Photoluminescence Rare earths

Dissipation of S-metolachlor and butachlor in agricultural soils and responses of bacterial communities:Insights from compound-specific isotope and biomolecular analyses

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Journal of Environmental Sciences 2020年第6期32卷 163-175页

作者： Ehssan Torabi Charline Wiegert Benoit Guyot Stéphane Vuilleumier gwenael Imfeld Department of Plant Protection Faculty of Agricultural Science and EngineeringCollege of Agriculture and Natural ResourcesUniversity of TehranDaneshkadeh St.P.O.Box#***-4111KarajIran Laboratory of Hydrology and Geochemistry of Strasbourg(LHyGeS) Universitéde StrasbourgUMR 7517 CNRS/EOST1 Rue Blessig67084Strasbourg CedexFrance Génétique Moléculaire GénomiqueMicrobiologie(GMGM)Universitéde StrasbourgUMR 7156 CNRS4 Allee Konrad Roentgen67000StrasbourgFrance

The soil dissipation of the widely used herbicides S-metolachlor(SM)and butachlor(BUT)was evaluated in laboratory microcosms at two environmentally relevant doses(15 and 150μg/g)and for two agricultural soils(crop and paddy).Over 80%of SM and BUT were dissipated within 60 and 30 days,respectively,except in experiments with crop soil at 150μg/*** on compound-specific isotope analysis(CSIA)and observed dissipation,biodegradation was the main process responsible for the observed decrease of SM and BUT in the paddy *** SM,biodegradation dominated over other dissipation processes,with changes of carbon isotope ratios(Δδ13C)of up to 6.5‰after 60 days,and concomitant production of ethane sulfonic acid(ESA)and oxanilic acid(OXA)transformation *** crop soil experiments,biodegradation of SM occurred to a lesser extent than in paddy soil,and sorption was the main driver of apparent BUT *** of the 16 S rRNA gene showed that soil type and duration of herbicide exposure were the main determinants of bacterial community *** contrast,herbicide identity and spiking dose had no significant *** paddy soil experiments,a high(4:1,V/V)ESA to OXA ratio for SM was observed,and phylotypes assigned to anaerobic Clostridiales and sulfur reducers such as Desulfuromonadales and Syntrophobacterales were dominant for both *** soil microcosms,in contrast,were associated with a reverse,low(1:3,V/V)ratio of ESA to OXA for SM,and Alphaproteobacteria,Actinobacteria,and Bacillales dominated regardless of the *** results emphasize the variability in the extent and modes of SM and BUT dissipation in agricultural soils,and in associated changes in bacterial communities.

关键词： Chloroacetanilide herbicides Carbon isotope fractionation Pesticide degradation Bacterial diversity

High-Pass Block Replacement Attack of Watermarking

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China Communications 2011年第4期8卷 159-163页

作者：王慧琴 gwenael Doerr 张小红 Information and Control Engineering School Xi'an University of Architecture & Technology Adastral Park Postgraduate Researches and Teaching Campus University College London(UCL)the United Kingdom Management School Xi'an University of Architecture & Technology

To improve the watermark benchmarks database,a new BRA(Block Replacement Attack)method is introduced in this *** the typical BRA which exploits the self-similarity among blocks in image,the scheme utilizes the self-similarity in various scale and orientation bands in the wavelet domain of the *** search the replacement blocks from the blocks of the smaller sub-image at the next lower *** most important advantage of this scheme is that the pyramid sub-band decomposition acts as an automatic block classifier,with the result of simplifying the block search and block matching procedures and thus making the block replacement more ***,an improved algorithm based on Fuzzy set theory is introduced in which the number of blocks chosen for combination are modified adaptively to obtain the candidate replacement *** simplifies the procedure for searching the candidate replacement *** advantages are confirmed by the experimental results,which show that the performance of the scheme is superior to typical BRA methods.

关键词： watermarking block replacement attack wavelet fuzzy

The Mechanical Properties of the System and Training Zr59Nb5Cu18Ni8AL10 Bulk Metallic Glasses

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Advances in Chemical Engineering and Science 2013年第4期3卷 274-277页

作者： Nasr-Eddine Chakri badis Bendjemil M. Baricco LASEA Department of Physic University of Badji Mokhtar Annaba Algeria

In the present work, the glass formation of Zr59Nb5Cu18Ni8Al10 (numbers indicate at %) alloy with diameter of 2 mm was prepared through water-cooled copper mold casting and in a ribbon form by the single roller melt-spinning method. This study is primarily devoted to evaluating the results obtained with the two methods of the development. The thermal stability was evaluated by differential scanning calorimetry (DSC) at a heating rate of 10℃/mn. The characteristic data of the bulk metallic glass are presented, including glass transition temperature (Tg) and crystallization temperature (Tx). The microstructure and constituent phases of the alloy composite have been analyzed by using X-ray diffraction, and observed by Scanning Electron Microscopy (SEM). The mechanical properties of bulk Zr59Nb5Cu18Ni8Al10 were alloy measured by compression tests at room temperature.

关键词： Ribbon and Bulk Metallic Glasses Amorphous Fracture Morphology Mechanical Properties

Hybrid Amplification: An Efficient Scheme for Energy Saving in MIMO Systems

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Wireless Engineering and Technology 2012年第1期3卷 36-45页

作者： gwenael Poitau Ammar B. Kouki 不详

In this paper, a new amplification scheme for adaptive MIMO systems is proposed and tested. In this ‘hybrid amplification’ configuration, different amplifiers with different peak powers are used. In this way, each transmitter RF chain has a different DC-power consumption behavior. The adaptation algorithm, which chooses power and rate for each transmitter, uses these different amplifier behaviors to minimize the overall consumed energy. Several MIMO configurations designed for constant capacity applications have been simulated with different amplification schemes. Realistic amplifier models based on measured data are used. The difference between the amplifiers’ RF powers is set in order to keep optimal system performances. Then, it is shown that energy savings higher than 10% can be obtained with the hybrid amplification. The different tests are done for MQAM constellations in uncorrelated Rayleigh fading channels detected with a VBLAST ZF-SIC algorithm but can easily be extended to other correlated channels, detection algorithms or constellations.

关键词： MIMO VBLAST Power Amplifiers Power Efficiency Hybrid Amplification

Synthesis of Ti3SiC2-Bicarbide Based Ceramic by Electro-Thermal Explosion

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Advances in Chemical Engineering and Science 2014年第2期4卷 242-249页

作者： Nasr-Eddine Chakri Zoubida Habes Abdelaziz Toubal badis Bendjemil 1Physic Department Badji-Mokhtar University Annaba Algeria 2Laboratory Environmentally Security and Alimentary (LASEA) Badji-Mokhtar University Annaba Algeria Laboratory Environmentally Security and Alimentary (LASEA) Badji-Mokhtar University Annaba Algeria Physic Department Badji-Mokhtar University Annaba Algeria

A polycrystalline dense Ti3SiC2 based ceramic material has been produced by several techniques. The effect of addition of TiC and SiC is also studied. The Ti3SiC2 material shows extraordinary electrical, thermal and mechanical properties. Furthermore, it shows a damage tolerance capability and oxidation resistance. In this work, we have synthesized Ti3SiC2 by electro-thermal explosion chemical reaction (ETE) with high current density (900 Amperes/a.u) followed by uniaxial pressure. The structural properties of the as-prepared materials are studied by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX) techniques. The chemical cartography, imaging and electronic properties are investigated using Ultra-STEM and electron high energy loss resolution spectroscopy (EELS) techniques, respectively. The surface of Ti3SiC2 is characterized by means of X-ray photoelectron spectroscopy (XPS). High resolution C 1s, Si 2p, Ti 2p, Ti 3s core level spectra are explained in terms of crystallographic and electronic structure. Valence band spectrum is performed to confirm the validity of the theoretical calculations.

关键词： Ti3SiC2 Based Ceramic Intermetallic Bicarbide Electro-Thermal Explosion Reaction (ETE) Valence Band Spectra Core Level Excitation

Crystallization Kinetics and Magnetic Properties of Fe40Ni40B20Bulk Metallic Glass

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Advances in Chemical Engineering and Science 2014年第1期4卷 36-38页

作者： Nasr-Eddine Chakri badis Bendjemil M. Baricco LASEA Department of Chemistry University of Badji Mokhtar Annaba Algeria LASEA Department of Chemistry University of Badji Mokhtar Annaba Algeria University of 08 mai 1945 Guelma Guelma Algeria Università di Torino Via P. Giuria 9 Torino Italy Università di Torino Via P. Giuria 9 Torino Italy

Fe-based bulk metallic glasses (BMGs) have been extensively studied due to their potential technological applications and their interesting physical properties such as a low modulus of elasticity, high yielding stress and good magnetic properties. In the present work, the bulk metallic glass (BMG) formation of Fe40Ni40B20 (numbers indicate at %) with a ribbon form was fabricated by the single roller melt-spinning method. Rapid solidification leads to a fully amorphous structure for all compositions. The thermal properties associated with crystallization temperature of the glassy samples were measured using differential scanning calorimetry (DSC) at a heating rate of 10℃/mn. The microstructure and constituent phase of the alloy composite have been analyzed by using X-ray diffractometry (XRD). The effect of high temperature on the isothermal crystallization of Fe40Ni40B20 ribbon was investigated by HTX-ray diffraction. In addition, these ribbon glasses also exhibit good soft magnetic properties with M-H curvature measured under the magnetic fields between –1 kOe and 1 kOe.

关键词： Bulk Metallic Glasses DSC XRD Method HTX Magnetic Properties