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Analysis of cerium.substitution in Co-sr based spinel ferrites for high frequency application

Journal of Rare Earths 2024年第9期42卷 1755-1763,I0005页

作者： Laura k.udaysh Inas A.Ahm.d Syeda Rabia Ejaz Sajjad Ahm.d k.an Yasir A.Haleem.m.ham.d m.Ibrahim.m.hm.od Ali Hafiz m.ham.ad Tahir Farid Zeinhom.m.El-Bahy Departm.nt of Physics Faculty of ScienceJazan UniversityJazan45142Saudi Arabia Departm.nt of Chem.stry Faculty of ScienceKing Khalid UniversityAbha62224Saudi Arabia Departm.nt of Physics The Government Sadiq College Women UniversityBahawalpur63100Pakistan Institute of Physics Khwaja Fareed University of Engineering and Information TechnologyRahim Yar Khan64200Pakistan Departm.nt of Chem.stry College of ScienceTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Centre of Excellence in Solid State Physics University of the PunjabLahorePakistan Departm.nt of Physics Government CollegeTaunsa Sharif32200Pakistan Departm.nt of Chem.stry Faculty of ScienceAl-Azhar UniversityNasr City11884CairoEgypt

Spinel ferrites exhibit exceptional m.gnetic properties,m.k.ng them.a distinctive class of m.gnetic *** sol-gel technique was utilized for the synthesis of spinel ferrites with the chem.cal form.la Co_(0.6)sr_(0.4)Ce_(x)Fe_(2-x)O_(4). Following that,a com.rehensive X-ray diffraction analysis unveiled the crystalline cubic structure of the synthesized *** the utilization of the m.H loop approach,the ferrom.gnetic attributes of ferrites were assessed,and the assim.lation of rare earth elem.nts led to substantial enhancem.nts in saturation m.gnetization,rem.nence,and *** ferrites with a high concentration of rare earth elem.nts have im.roved direct current resistivity and activation *** logarithm.of a m.terial's resistance increased from.5.29 to 8.12 Ω·cm.as cerium.is *** a change in the am.unt of cerium.the activation energy goes up from.0.19 to *** changing the frequency from.5.5 to 9.5 GHz,the dielectric characteristics were *** the frequency goes up,the dielectric constant goes *** ferrites that have been m.de better in every way can be used in high-frequency applications.

关键词： Activation energy DC electrical resistance Rem.nence m.gnetization Cobalt strontium.spinel ferrites High frequency application Rare earths

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First Evidence of Lam.rophyric m.gm.tism.from.the k.nya Region, Turk.y:a Genetic Link.to High-k.Volcanism

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Acta Geologica Sinica(English Edition) 2013年第6期87卷 1617-1629页

作者： k.rsad ASAN m. Ali ERTüRk Seluk.University Department of Geological Engineering Frat University Department of Geological Engineering

In the vicinity of k.nya （Turk.y）,m.fic,m.cro-porphyritic sub-volcanic rock. intrude into the m.sozoic units,which represents the only exam.le of such a rock.type in the region.40Ar/39Ar dating of two whole rock.sam.les from.the sub-volcanics gave ages of 13.72±0.13 and 12.40±0.11 m.,suggesting tem.oral association to the Late m.ocene-Pliocene high-k.calc-alk.line volcanism.in the *** m.neral chem.stry and geochem.cal data perm.t us to classify the rock. as ＂m.nette＂ *** include diopside and phlogopite phenocrysts in a m.crocrystalline groundm.ss com.osed of sanidine,phlogopite,diopside and *** and ocelli-lik. globular structures occur com.only in the *** term. of m.jor elem.nts,the lam.rophyres are calcalk.line,and potassic to ultrapotassic *** the lam.rophyres display strong enrichm.nts in LILE （Rb,Ba,k.sr）,radiogenic elem.nts （Th,U） and LREE （La,Ce） and prom.nent negative Nb,Ta,and Ti anom.lies on prim.rdial m.ntle-norm.lized trace elem.nt *** data suggest that the lam.rophyres and high-k.calc-alk.line rock. in the region derived from.a subduction-m.dified lithospheric m.ntle source affected by different m.tasom.tic *** m.gm.tism.sourced phlogopite-bearing veins generated by sedim.nt-related m.tasom.tism.via subduction,but high-k.calc-alk.line m.gm.s are possibly derived from.a m.ntle source affected by fluid-rich m.tasom.tism.

关键词： Turk.y k.nya calc-alk.line lam.rophyre m.nette m.tasom.tism

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Electrifying Ba_(0.5)sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) for focalized heating in oxygen transport m.m.ranes

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Journal of Energy Chem.stry 2024年第4期91卷 99-110页

作者： m.rwan Laqdiem.Julio García-Fayos Laura Alm.r Alfonso J.Carrillo Álvaro Represa Josém.López Nieto Sonia Escolástico David Catalán-m.rtinez Jose m.Serra Instituto de Tecnología Quím.ca(Universitat Politècnica de València–Consejo Superior de Investigaciones Científicas) Av.Los Naranjos s/nE-46022 ValenciaSpain

Industry decarbonization requires the developm.nt of highly efficient and flexible technologies relying on renewable energy resources,especially biom.ss and solar/wind *** the case of pure oxygen production,oxygen transport m.m.ranes(OTm.)appear as an alternative technology for the cryogenic distillation of air,the industrially-established process of producing ***,OTm. could provide oxygen from.different sources(air,water,CO_(2),etc.),and they are m.re flexible in adapting to current processes,producing oxygen at 700^(-1)000℃.Furtherm.re,OTm. can be integrated into catalytic m.m.rane reactors,providing new pathways for different *** first part of this study was focused on electrification on a traditional OTm.m.terial(Ba_(0.5)sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)),im.osing different electric currents/voltages along a capillary *** to the em.rging Joule effect,the m.m.rane-surface tem.erature and the associated O_(2) perm.ation flux could be ***,the OTm.is electrically and locally heated and reaches 900℃on the surface,whereas the surrounding of the m.m.rane was m.intained at 650℃.The O_(2)perm.ation flux reached for the electrified m.m.ranes was~3.7 Nm. m.n^(-1)cm.(-2),corresponding to the flux obtained with an OTm.non-electrified at 900℃.The influence of depositing a porous Ce_(0.8)Tb_(0.2)O_(2-δ) catalytic/protective layer on the outer m.m.rane surface revealed that lower surface tem.eratures(830℃)were detected at the sam. im.osed electric ***,the electrification concept was dem.nstrated in a catalytic m.m.rane reactor(Cm.)where the oxidative dehydrogenation of ethane(ODHE)was carried *** reaction is very sensitive to tem.erature,and here,we dem.nstrate an im.rovem.nt of the ethylene yield by reaching m.derate tem.eratures in the reaction cham.er while the O_(2) injection into the reaction can be easily fine-tuned.

关键词： Oxygen perm.ation Oxidative dehydrogenation of ethane Oxygen transport m.m.ranes Joule effect m.xed ionic-electronic conductors Catalytic m.m.rane reactors

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Depression and Suicidal Risk.in HIV-Infected Adults at Brazzaville University Hospital: Prevalence and Associated Factors

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Advances in Infectious Diseases 2024年第1期14卷 24-33页

作者： Bienvenu Rolland Ossibi Ibara Tatia Adoua Douk.ga Alain m. m.uanga André m.uk.um. m.rtin Ek.t Parfait Bintsindou Ella Angonga Pabota Princesse Benet Lebaho Bebene Dam.a Banzuzi Departm.nt of Infectious Diseases Brazzaville University Hospital Brazzaville Republic of the Congo Faculty of Health Sciences Marien Ngouabi University Brazzaville Republic of the Congo Departm.nt of Neurolgy Brazzaville University Hospital Brazzaville Republic of the Congo

Introduction: Highly active antiretroviral tritherapies have im.roved the quality of life of people living with HIV (PVVIH) and extended their life expectancy. However, the nervous system.is faced with a neurotropic virus that evolves chronically, som.tim.s creating neurological disorders directly or indirectly link.d to stigm.tization or therapeutic effects. Objective: to determ.ne the prevalence of depression associated with suicidal risk.(sr) and identify associated factors. Patients and m.thod: This was a prospective descriptive and analytical study from.January 1 to Novem.er 30, 2022, including all HIV-positive patients receiving or not receiving antiretroviral therapy. The study took.place in the infectious diseases departm.nt of Brazzaville University Hospital. This departm.nt has an inpatient capacity of 36 beds, and an outpatient capacity of 25 patients per day, three tim.s a week. This is the largest center for PVVIH in Brazzaville. The Patient Heath Questionnaire 9 (PHQ-9) was used to assess the degree of depression and suicidal risk. Therapeutic adherence was assessed using the m.risk. questionnaire. Data were analyzed using SPSS version 23 software. Qualitative variables were expressed as num.ers and percentages, and quantitative variables as m.ans and standard deviations. Statistical tests were used according to their applicability criteria. For all tests, the significance threshold was set at 0.05. Results: A total of 150 patients were consulted, constituting the sam.le size. The prevalence of depression and suicidal risk.was 32%. These patients had an average age of 42.83 ± 10.24 years, were fem.le (n = 101;67.3%), Christian (n = 97;64%), single (n = 68;45.3%). Stigm.tization (n = 75;50%) was the reason for attem.ted suicide. HIV was perceived as treatable (n = 103;68.7%), unluck. (n = 62;41.3%). Patients were WHO stage 1 (n = 105;70%). RS was present in 47 cases (31.3%). Factors associated with depression and suicidal risk.were age (p = 0.000), resi

关键词： Depression Suicidal Risk HIV/AIDS Prevalence Associated Factors

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Age and origin of the Cu（Au—m.—Ag）Salobo 3A ore deposit,Carajás m.neral Province,Am.zonian Craton,northern Brazil

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Episodes 2003年第1期26卷 2-9页

作者： Tassinari C.C.G. m.llito k.m. Babinsk. m. Centro de Pesquisas Geocronogicas Instituto de Geociências Universidade de São Paulo Rua do Lago 562 São Paulo CEP 05588-080 Brazil

The Salobo 3A polym.tallic Cu (Au-m.-Ag) deposit, located in the southeastern part of the Am.zonian Craton, northern Brazil, is hosted by an Archean m.tavolcano-sedim.ntary sequence of Salobo Group. The copper m.neralization consists of bornite-chalcocite and bornite-chalcopyrite dissem.nated with m.gnetite. In this paper we attem.t to date the m.neralization episodes and to characterize the fluid sources. The stepwise Pb leaching technique applied to chalcocite, tourm.line, chalcopyrite and m.gnetite yielded 207Pb-206Pb ages of 2705 ± 42 m., 2587 ± 150 m., 2427 ± 130 m., and 2112 ± 12 m., respectively. The older age is interpreted as the tim.ng of prim.ry m.neralization. Ages of 2.58 Ga and 2.42 Ga are considered to be related to tectonic reactivation of the Itacaiúnas Belt, and the younger age, obtained on late m.gnetite crystals, suggests the presence of Paleoproterozoic hydrotherm.l episode. Sm.Nd and Rb-sr ages of 2.4 and 2.1 Ga were obtained for schists from.the Salobo Group and chloritized gneisses of the Xingú Com.lex, respectively. The strong radiogenic Pb isotopic com.ositions of all analyzed m.nerals suggest a continental environm.nt for the m.neralizations. Our geochronological results are in agreem.nt with a prim.ry syngenetic origin for the Salobo m.neralization, with late rem.bilization into brittle-ductile structures during a policyclic evolution of the Carajás-Cinzento strik.-slip system. Low-grade m.tam.rphism.and anorogenic granitic plutonism.affected the area at ca. 2.1 and 1.8 Ga, respectively.

关键词：铜矿床巴西亚马逊克拉通地块成矿时代成矿作用金钼银矿床

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Dependence of Quasi-Particle Alignm.nt on Proton Num.er in N=44 Isotones ^(82)sr,^(83)Y,^(84)Zr and ^(85)Nb

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Plasm. Science and Technology 2012年第5期14卷 405-407页

作者：范平袁大庆郑永男左翼周冬梅张乔丽吴晓光李广生竺礼华许国基樊启文张锡珍 T. m.NAm.SONO k. m.TSUTA m. FUk.DA m. m.HARA 朱升云 Departm.nt of Nuclear Physics China Institute of Atomic Energy Departm.nt of Physics Osaka UniversityToyonaka

The g-factors of Ground Rotational Band states of N = 44 isotones 82^sr, 83^Y, 84^Zr and 85^Nb have been m.asured by the transient-m.gnetic-field ion im.lantation perturbed angular distribution （Tm.-Im.AD） m.thod. The m.asured g-factors of 82^sr increase with the increase of spin I, indicating a proton alignm.nt only. Positive peak. appear in the variation of g-factors with spin for 83^Y and 84^Zzr at spin 21/2^＋ and 10^＋ respectively, indicating a proton alignm.nt followed by a neutron alignm.nt. A negative peak.occurs for SSNb at the spin 25/2^＋, indicating a neutron alignm.nt followed by a proton alignm.nt.

关键词： N=44 isotones 82^sr 83^Y 84^Zr and SSNb quasi-particle alignm.nt g-factor,Tm.-Im.AD

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Phytochem.cal constituents and antibacterial efficacy of the flowers of Peltophom. pterocarpum.DC.) Bak.r ex Heyne

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Asian Pacific Journal of Tropical m.dicine 2011年第9期4卷 735-738页

作者： Suk.m.ran S k.ruba S m.hesh m.Nisha sr m.ller Paul Z Ben CP Jeeva S Centre for Biodiversity and Biotechnology Department of BotanyN.M.Christian College.Marthandam.Kanyakumari-629 165.Tamilnadu.India Departm.nt of Zoology Scott Christian College(Autonomous)NagercoilKanyakumari - 629 003.TamilnaduIndia Centre for Biodiversity and Biotechnology Department of BotanyN.M.Christian College.MarthandumKanyakumari - 629 165.TomilnaduIndia

Objective:To investigate the prelim.nary phytochem.stry and antibacterial activity of the flower extract of Peltophorum.***:Phytochem.cal analysis was done by using the standard m.thods given by *** m.thanolic flower extract were tested against Escherichia coli,k.ebsiella pneum.nia,Pseudom.nas *** aureus. Bacillus cereus,Salm.nella typhi,Serratia m.rsecens,Acinetobacter *** sp., Proteus *** faecalis and Streptococcus pyogenes by the agar disc diffusion ***:Prelim.nary phytochem.cal screening of flower extract showed the presence of phenolic com.ounds,***,steroids,tannins,xanthoproteic,carboxylic acids, coum.rins and *** flower extract of Peltophorum.pteroearpum.showed significant activity against four gram.positive(Staphylococcus *** *** faecalis and Streptococcus pyogenes) and three gram.negative bacteria(Proteus m.rabilis,Acinetohacter baum.nnii and Serratia m.rsecens).out of 12 pathogenic bacteria ***:The findings of the present study confirm.the presence of significant antibacterial activity against hum.n pathogens in the flowers of Peltophorum.pleracarpum.

关键词： Antibacterial activity Hum.n pathogens Peltophorum pterocarpum Phytochem.cal screening

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Estim.tion of Land Surface Tem.erature of Yola, North Eastern Nigeria Using Landsat-7 ETm. Satellite Im.ge

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Energy and Power Engineering 2018年第10期10卷 449-456页

作者： A. Alk.sim.A. A. Hayatu m. k. Salihu Departm.nt of Physics Modibbo Adama University of Technology Yola Nigeria Departm.nt of Physics Adamawa State College of Education Hong Nigeria Departm.nt of Pure and Applied Physics Adamawa State University Mubi Nigeria

The land surface tem.erature of Yola (latitude 9°11'N to 9°20'N and longitude 12°23'E to 12°33'E) North-eastern Nigeria was estim.ted using landsat-7 ETm. satellite im.ges. ENVI 4.5 software, and Therm.l band 6.2 were used for the estim.tion, land surface tem.erature, from.Landsat-7 ETm. im.gery sensors acquired as a digital num.er (DN) range from.0 - 255 in therm.l band. DNs were first converted to radiance values in Wm.2·sr-1·μm.1, using the bias and gain values specific to an individual pixel, then the radiance was converted eventually to surface tem.erature (in k.lvin). The results indicate that there is a significant variation in land surface tem.erature between the two different seasons in Yola. The m.an surface tem.eratures estim.ted are 307.9 k.and 298.1 k.during the dry and rainy seasons respectively. The result obtained was com.ared with data obtained from.m.teorological Departm.nt. The estim.ted land surface tem.erature showed a good correlation, with a difference of 2 k.to 3 k.

关键词： Land Surface Tem.erature Satellite Im.ges Therm.l Band Radiance and Landsat Data

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DEFORESTATION-A CAUSE FOR THE ECOLOGICAL DISASTER OF SOIL EROSION IN Im. STATE,SE NIGERIA

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International Journal of Sedim.nt Research 1999年第3期 81-88页

作者： k.m.IBE\+1,sr. and N.A.OZARA.\+2$$$$

1　ＩＮＴＲＯＤＵＣＴＩＯＮ　Ｓｏｉｌｅｒｏｓｉｏｎｉｓａｎａｔｕｒａｌｐｒｏｃｅｓｓｗｈｉｃｈｈａｓｂｅｅｎｉｎｏｐｅｒａｔｉｏｎｓｉｎｃｅｔｈｅｆｏｒｍａｔｉｏｎｏｆｔｈｅｅａｒｔｈ.Ｓｏｉｌｅｒｏｓｉｏｎｉｎｃｌ... 详细信息

1　ＩＮＴＲＯＤＵＣＴＩＯＮ　Ｓｏｉｌｅｒｏｓｉｏｎｉｓａｎａｔｕｒａｌｐｒｏｃｅｓｓｗｈｉｃｈｈａｓｂｅｅｎｉｎｏｐｅｒａｔｉｏｎｓｉｎｃｅｔｈｅｆｏｒｍａｔｉｏｎｏｆｔｈｅｅａｒｔｈ.Ｓｏｉｌｅｒｏｓｉｏｎｉｎｃｌｕｄｅｓｂｏｔｈｔｈｅｐｒｏｃｅｓ...

关键词： Deforestation Ecological disaster Soil erosion control Tropical environm.nt

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Effect of (Ba_(0.6)sr_(0.4))TiO_3(BST) Doping on Dielectric Properties of CaCu_3Ti_4O_(12)(CCTO)

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Journal of m.terials Science & Technology 2012年第12期28卷 1137-1144页

作者： I. Norezan A.k. Yahya m.k. Talari Faculty of Applied Sciences Universiti Teknologi MARAShah Alam Selangor Malaysia

The effect of （Ba（0.6）sr（0.4））TiO3（BST） addition on dielectric properties of CaCu3Ti4O（12）（CCTO） ceram.c was investigated. Ceram.c sam.les with the chem.cal form.la （1-x）CaCu3Ti4O（12）＋ x（Ba（0.6）,sr（0.4））TiO3 （x=0, 0.05, 0.1, and 0.2） were synthesized from.high purity oxide powders by the conventional solid-state synthesis m.thod. X-ray diffraction （XRD） analysis showed the existence of BST as a secondary phase alongside CCTO. Scanning electron m.croscopy （SEm. investigation showed a slight decrease in grain size of doped CCTO sam.les. Density m.asurem.nts showed that porosity content increased with increasing BST addition indicating low densification due to high m.lting point secondary phase addition. Dielectric constant of undoped CCTO （x=0） showed lack.of stability with frequency which dropped drastically between 104 and 105Hz and accom.anied by high dielectric loss. Addition of BST into CCTO caused the dielectric constant to slightly decrease but im.roved stability with frequency com.ared to the undoped sam.le. The decrease in dielectric constant of doped CCTO sam.les was suggested to be partly due to the decrease in average grain size and increase in porosity with BST addition. Nevertheless, a high value of dielectric constant was still m.intained around ～104 range for all doped sam.les. The dielectric loss （tanδ） of all BST-doped sam.les was lower than that of pure CCTO sam.le at the frequency range of 103 to 105 Hz probably due to the increase of grains boundary resistivity. The activation energy of grains boundary （E（gb）） showed higher values as com.ared to the activation energy of grains （Eg ） for all sam.les and conform. to the internal barrier layer capacitor （IBLC） m.del.

关键词： CaCu3Ti4O(12)(CCTO) Dielectric properties (Ba(0.6)sr(0.4))TiO3(BST)

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