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Influence of manganese rate on structural, optical and electrochemical properties of CeO_(2) thin films deposited by spray pyrolysis:Supercapacitor applications

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Journal of Rare Earths 2022年第10期40卷 1611-1618页

作者： J.Zimou K.Nouneh A.Talbi L.El Gana A.El-Habib R.Hsissou M.Addou Laboratory of Materials Physics and Subatomic Department of PhysicsFaculty of ScienceIbn Tofail UniversityBP 13314000KenitraMoroco Thin Film and Nanomaterial Research Team Faculty of Science and TechiquesAbdelmalek Essadi UniversityTangerMorocco Laboratory of Organic Chemistry Catalysis and EnvironmentFaculty of SciencesIbn Tofail UniversityBP 24214000KenitraMorocco

The present work aimed to investigate the electrochemical properties of ITO substrates in propylene carbonate(PC) with 0.5 mol/L lithium perchlorate(LiClO_(4)) medium in the presence of elaborated thin films of cerium dioxide pure and doped with manganese at varying ***_(1-x)Mn_(x)O_(2)(x=0 wt%,2 wt%,4 wt% and 6 wt%) were successfully deposited by the spray pyrolysis(SP) technique on the glass substrate and ITO at 450℃.The effects of manganese(Mn) doped thin films Ce_(1-x)Mn_(x)O_(2) were studied and investigated by using different analyses namely X-ray diffraction(XRD) analysis,Raman spectroscopy method,UV-Vis spectrophotometer technique,atomic force microscopy(AFM) analysis and electrochemical *** data obtained present a polycrystalline with a face-centred cubic structure of fluorite *** results of undoped and Mn doped thin films show two peaks at 465 and 600 cm^(-1),due to the formation of extrinsic oxygen vacancies by the incorporation of Mn into Ce1-xMnxO_(2) *** dispersive spectroscopy(EDS) data show the presence of Ce,O,and Mn elements in the elaborated *** AFM results reveal that the surface roughness decreases with increasing Mn ***,band gap energy of thin films decreases with increasing in Mn rate due to the formation of defect state between valence and conduction *** storage capacity of the elaborated Ce_(1-x)Mn_(x)O_(2)/ITO/PC+LiClO_(4) electrode reaches a maximum of 1.997 mF in the presence of 6 wt% of Mn.

关键词： Ce1-xMnxO_(2)thin films Electrochemical properties ITO substrates XRD/UV-Vis/AFM Band gap energy Storage capacity

Pharmacological properties and related constituents of stem bark of Pterocarpus erinaceus Poir.(Fabaceae)

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Asian Pacific Journal of Tropical Medicine 2012年第1期5卷 46-51页

作者： Ouedraogo Noufou Sawadogo Richard Wamtinga Tibiri Andre Bayet Christine Lompo Marius Hay A Emmanuelle Koudou Jean Dijoux Marie-Genevieve Guissou Innocent Pierre Departement de medecine-pharmacopee traditionnelle/pharmacie(IRSS/CNRST) 03 bp 7192 Ouagadougou 03 Burkina Faso Laboratoire de pharmacologie et toxicologie UFR/SDSUniversite de Ouagadougou 03 BP 7021 Ouagadougou 03Burkina Faso Universite de Lyon F-69622LyonFrance Universite Lyon I Villeurbanne CNRS UMR 5557Ecologie MicrobienneISPB69373 LyonFrance Laboratoire de chimie des substances naturelles Faculte des SciencesUniversite de Bangui.BP908Bangui.Republique Centrafricaine Departement de medecine-pharmacopee traditionnelle/pharmacie(IRSS/CNRST) 03 bp 7192 Ouagadougou 03 Burkina Faso Laboratoire de pharmacologie et toxicologieUFR/SDSUniversite de Ouagadougou 03 BP 7021 Ouagadougou 03Burkina Faso

Objective:To sereen methanol and dichloromethane extracts of stem bark of Pterocarpus erinaceus for anti-inflammatory,*** vitro antioxidant activities and phytochemical ***:Anti-inflammatory activity was detcrmined by using carrageenan inducededema of mice paw and croton oil-induced edema of mice ear:analgesic effect was evaluated using acetic acid-induced *** screening of extracts was performed by thin layer *** chromatographic fractionation led to the isolation of main active components as *** and *** structures were established hy TLC and nuclear magnetic resonance ***:Both methanol and dichloromethane extracts, *** and epicatechin showed a significant anti—inflammatory effect using croton oil induced—ear ***,the action of dichloroinethane extract was more important. At the doses of 100 and 200 mg/*** methanol extract was able to reduce the carrageeuan induced-hind paw edema,while al the doses of 100.200 and 400 mg/*** showed an important analgesic effect against writhing induced by acetic acid injection of 38.8%.68.0%and 74.3%, *** properties of methanol extract and its dichloromethane and ethyl acetate fractions were assessed by using the 1,1—diphenyl—2—picrylhydrazyl *** methanol extract showed the stronger radical scavenging activity than dichloromethane and ethyl acetate fractions,with an antiradical power of 5.3.5 and 2 *** main components isolated from these extracts as friedelin,lupeol and epicathechin were responsible of these ***:The results suggest that the stem hark extracts of Pterocarpus erinaceus possessed important *** activities and strong antioxidant properties, therefore,they could he used as natural potential ingredients for pharma ceutical industry.

关键词： Pterocarpus erinaceus Phytochemical Anti-inflammatory Analgesic Antioxidant

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

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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

Independent continuous mapping for topological optimization of frame structures

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Acta Mechanica Sinica 2006年第6期22卷 611-619页

作者： Yunkang Sui Jiazheng Du Yingqiao Guo Department of Mechanics Beijing University of Technology Beijing 100022 China Lab. GMMS University of Reims Champagne-Ardenne BP1039 51687 Reims France

Based on the Independent Continuous Mapping method （ICM）, a topological optimization model with continuous topological variables is built by introducing three filter functions for element weight, element allowable stress and element stiffness, which transform the 0-1 type discrete topological variables into continuous topological variables between 0 and 1. Two methods for the filter functions are adopted to avoid the structural singularity and recover falsely deleted elements： the weak material element method and the tiny section element method. Three criteria （no structural singularity, no violated constraints and no change of structural weight） are introduced to judge iteration convergence. These criteria allow finding an appropriate threshold by adjusting a discount factor in the iteration procedure. To improve the efficiency, the original optimization model is transformed into a dual problem according to the dual theory and solved in its dual space. By using MSC/Nastran as the structural solver and MSC/Patran as the developing platform, a topological optimization software of frame structures is accomplished. Numerical examples show that the ICM method is very efficient for the topological optimization of frame structures.

关键词： Frame structures Topological optimization ICM method Filter functions Element elimination

Study of the behaviour of the dielectric constant in Cu,Fe:BaTiO_3

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 429-434页

作者： Alioune OUEDRAOGO Kalifa PALM Issaka OUEDRAOGO Guy CHANUSSOT Laboratory of Applied Organic Chemistry and Physics UFR/SEA University of Ouagadougou BP 7021 Ouagadougou Burkina Faso Laboratory of Dielectrics University of Dijon 21000 Dijon France)

In this work we study the behaviour of the dielectric constant of BaTiO3 single crystals doped with Cu and Fe for different ion percentages, particularly, the influence of these hetemvalent substitutions on the ferroelectric-paraelectric phase transition whose temperature is found at Tc=120℃ for pure samples. The dielectric constant e in terms of temperature shows that the Curie temperature decreases when the quantity of impurities increases and presents a broadening and flattering of the maximum oft（T） within higher values, with the transition becoming more and more diffuse. It is interesting to have a material with very high permittivity （high-k） because of its capacity to store an important quantity of electric charges. The t anisotropy and the Curie-Weiss law are also verified with a good ratio between the slopes ofε^-l（T） from both sides of the transition, leading to a Curie constant： C= 13 × 10^4 K for BaTiO3：1.6%Fe in the polar phase. BaTiO3 is a displacive ferroelectric going through a first-order phase transition. The substitutions have an effect on the dynamics of the perovskite lattice. They induce charges transfer to Ti and a diminution of elastic forces in BaTiO3. Then we discuss the transition but on the nature of the material. fact that the maximum of permittivity does not depend on the phase

关键词： Phase transition Ferroelectric BaTiO3 Remeika single crystals Dielectric constant Curie constant

Effect of Zn Substitution on Magnetic Properties of CuFe_2O_4： a High-Temperature Series Expansions Study

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Chinese Physics Letters 2018年第1期35卷 95-98页

作者： S.Salmi R.Masrour A.El Grini K.Bouslykhane A.Hourmatallah N.Benzakour M.Hamedoun Laboratoire de Physique du Solide Universite Sidi Mohammed Ben Abdellah Faculte des sciences Dhar Mahraz BP 1796 Fes Morocco Laboratory of Materials Processes Environment and Quality Cady Ayyed University National School of Applied Sciences Route Sidi Bouzid-BP 63 46000 Sail Morocco Equipe de Physique du Solide Laboratoire LIPI Ecole Normale Superieure BP 5206 Bensouda Fes Morocco MASc IR Foundation Institut of Nanomaterials and Nanotechnologies Materials & Nanomaterials Center B.P. 10100Rabat Morocco

The magnetic properties of spinel ferrites Cu_（1-x）Zn_xFe_2O_4 are studied using high-temperature series expansions combined with the Padé approximates. The exchange interactions, inter and intra-sublattices J_（AA）, J_（BB） and J_（AB） are obtained using a probability distribution law. The critical exponent associated with the magnetic susceptibility is obtained.

关键词： Cu Zn Effect of Zn Substitution on Magnetic Properties of CuFe_2O_4

A high-entropy spinel ceramic oxide as the cathode for proton-conducting solid oxide fuel cells

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Journal of Advanced Ceramics 2022年第5期11卷 794-804页

作者： Yangsen XU Xi XU Lei BI School of Resource Environment and Safety Engineering University of South ChinaHengyang 421001China Department of Materials Imperial College London SW72BPUK

A high-entropy ceramic oxide is used as the cathode for the first time for proton-conducting solid oxide fuel cells(H-SOFCs).The Fe_(0.6)Mn_(0.6)Co_(0.6)Ni_(0.6)Cr_(0.6)O_(4)(FMCNC)high-entropy spinel oxide has been successfully prepared,and the in situ chemical stability test demonstrates that the FMCNC material has good stability against CO_(2).The first-principles calculation indicates that the high-entropy structure enhances the properties of the FMCNC material that surpasses their individual components,leading to lower O_(2)adsorption energy for FMCNC than that for the individual *** HSOFC using the FMCNC cathode reaches an encouraging peak power density(PPD)of 1052 mW·cm^(-2)at 700℃,which is higher than those of the H-SOFCs reported *** comparison was made between the high-entropy FMCNC cathode and the traditional Mn_(1.6)Cu_(1.4)O_(4)(MCO)spinel cathode without the high-entropy structure,revealing that the formation of the high-entropy material allows the enhanced protonation ability as well as the movement of the O p-band center closer to the Fermi level,thus improving the cathode catalytic *** a result,the high-entropy FMCNC has a much-decreased polarization resistance of 0.057Ω·cm^(2)at 700℃,which is half of that for the traditional MCO spinel cathode without the high-entropy *** excellent performance of the FMCNC cell indicates that the high-entropy design makes a new life for the spinel oxide as the cathode for HSOFCs,offering a novel and promising route for the development of high-performance materials for H-SOFCs.

关键词： proton-conducting oxides high-entropy oxides cathode solid oxide fuel cells(SOFCs)

Shear reinforcement effect of reinforced concrete tie-columns on the lateral resistance of confined masonry walls

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 313-324页

作者： Samir Bouhedja Abdelkrim Bourzam Ahmed Boukhaled Ammar Nechnech University of Sciences and Technology Houari Boumediene(USTHB)Faculty of Civil EngineeringLaboratory of EnvironmentWaterGeomechanics and Structures(LEEGO)BP 32 El AliaBab EzzouarAlgiers16111Algeria University of Sciences and Technology Houari Boumediene(USTHB)Faculty of Civil EngineeringLaboratory of Built Environment Research(LBE)BP 32 El AliaBab EzzouarAlgiers16111Algeria

Tie-columns improve significantly the lateral resistance of masonry bearing walls against persistent, transient and accidental loads. The research work described herein has been carried out to assess the lateral resistance of confined masonry walls, where contribution of the masonry panel is evaluated according to material mechanics and tie-columns effect is estimated by a proposed analytical formulation based on a model reported on previously. This approach takes into account the effect of dowel support on the reaction of its adjacent shear reinforcement： the conditions for the various contributions of transverse reinforcements are better defined following a clear evaluation of the participation ratio of these reinforcements. Lateral resistances of confined masonry walls measured in full-scale tests and gleaned from the literature are compared and checked with resistances calculated using the present approach.

关键词： reinforcement columns confined reinforced walls Shear formulation panel participation herein

Complex dynamics and bifurcation analysis for a Beverton-Holt population model with Allee effect

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International Journal of Biomathematics 2023年第7期16卷 165-196页

作者： Karima Mokni Mohamed Ch-Chaoui MRI Laboratory FacultéPolydisciplinaire Khouribga Sultan Moulay Slimane University BP:145 Khouribga Principale25000Kingdom of Morocco

In this paper,we have derived a discrete evolutionary Beverton-Holt population *** model is built using evolutionary game theory methodology and takes into consideration the strong Allee effect related to predation *** have discussed the existence of the positive fixed point and examined its asymptotic ***,we demonstrated that the derived model exhibits Neimark-Sacker bifurcation when the maximal predator intensity is at lower *** chaotic behaviors are justified ***,to avoid these chaotic features and achieve asymptotic stability,we implement two chaos control methods.

关键词： Evolutionary game theory asymptotic stability Neimark-Sacker bifurcation chaos control