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Excellent photoluminescence and electrochemical prop.r.ies of Sm^(3+) doped Ca_(2)MgSi_(2)O_(7) nanophosphor:Display and electrochemical sensor applications

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Journal of rare Earths 2024年第6期42卷 1046-1055,I0002页

作者： r.B.Basavaraj K.Sureshkumar D.p.Aarti M.B.Madhusudana reddy G.Nagaraju T.ramakrishnappa G.r.Navyashree K.r.Venkatesha Babu K.S.Hemalatha Dep.r.ment of physics BMS Institute of Technology and ManagementBangalore560064India Dep.r.ment of Chemistry BMS Institute of Technology and ManagementBangalore560064India Dep.r.ment of Chemistry School of Applied SciencesREVA UniversityBangalore560064India Energy Materials researchLaboratory Department of ChemistrySiddaganga Institute of TechnologyTumakuru57203KarnatakaIndia School of physical Sciences REVA UniversityBangalore560057Indi Dep.r.ment of physics Govt.Science CollegeBengaluru560001India Dep.r.ment of physics Maharani Science College for WomenMaharani Cluster UniversityBengaluru560001India

A series of orange-red light emitting Ca_(2)MgSi_(2)O_(7):Sm^(3+)nanopowders were fabricated via low-cost ecofriendly green combustion technique using Aloe vera gel as *** phase p.r.ty of the samples were confirmed by the powder X-ray diffraction(p.r.)*** single-phase tetragonal structure is observed from the p.r. results with no additional imp.r.ty *** band gap energy of the fabricated powders was estimated by diffuse reflectance spectra(DrS)and is found to be in the range of 4.01-5.98 eV.A high resolution scanning electron microscope(SEM)was used to study the morphological behaviour of the ***-like structures are observed from the SEM *** p.r.icle size was evaluated by transmission electron microscopy(TEM)and is found to be~50 *** interplanar distance is found to be 0.53 *** prop.r.ies were systematically studied in *** phosphors are successfully excited at 403 nm NUV light,producing reddish-orange characteristic *** emission peaks are centered at 558(^(4)G_(5/2)→^(6)H_(5/2)),607(^(4)G_(5/2)→^(6)H_(7/2))and 645 nm(^(4)G_(5/2)→^(6)H_(9/2)),*** the observed peaks the red emanation(^(4)G_(5/2)→^(6)H_(7/2))is stronger than the orange emission(^(4)G_(5/2)→^(6)H_(5/2))in the current *** photoluminescent concentration quenching is noticed above 5 mol%Sm^(3+)ion doping *** dipole-dipole interaction resulting in cross relaxation is found to be the principal cause of concentration quenching *** color features such as Commission Internationale de I’Eclairage(CIE)and correlated color temp.r.ture(CCT)were studied in *** optimized chromaticity coordinates were estimated to be(0.6363,0.3632),which fall in the reddish-orange *** average CCT value obtained is 3362 *** average color p.r.ty is found to be~82%.Sm^(3+)incorp.r.ted Ca_(2)MgSi_(2)O_(7) samples are possible contender for single white light generation commercial candidates owing to

关键词： Green combustion photoluminescence Orange-red emission Color p.r.ty Sensors rare earths

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Solid-liquid extraction for yttrium recovery using p.r.us polymeric resin(XAD-7) functionalized with D_(2)EHpA

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Journal of rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： p.A.Martínez-Montoya r.G.Sanchez-Alvarado D.Y.Medina-Velazquez M.L.Carrera-Jota p.Garnica-Chávez A.de J.Morales-ramirez Higher School of Chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHpA) as extracting *** extracting agents were supp.r.ed on a macro p.r.us polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were p.r.ormed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHpA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all exp.r.ments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,exp.r.ments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,sep.r.ting it from various metals from the studied residue.

关键词： Yttrium recovery rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

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Europium recovery process by means of polymeric nanop.r.icles functionalized with acrylic acid,curcumin and fumaramide

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Journal of rare Earths 2024年第10期42卷 1950-1959页

作者： p.A.Martínez-Montoya J.M del río A.de J.Morales-ramirez M.Corea Escuela Sup.r.or de Ingeniería Química e Industrias Extractivas ESIQIE-IPNDepartamento de Ingeniería Metalúrgica UPALM S/N Col.LindavistaGustao A.MaderoCDMXC.P.07738Mexico Escuela Sup.r.or de Ingenieria Química e Industrias Extractivas ESIQIE-IPNLaboratorio de Investigación en Polímeros y NanomaterialesUPALM S/N Col.LindavistaGustavoA.MaderoCDMXC.P.07738Mexico Centra de Investigación e Innovación Tecnológica CIITEC-IPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P.02250CDMXMexico

polymeric nanop.r.icles of poly(methyl methacrylate)were obtained by emulsion polymerization techniques in a proce ss of two *** p.r.icles were functionalized with acrylic acid,curcumin,and fumaramide and three series of polymeric p.r.icles were *** incorp.r.tion of functional groups was confirmed by Fourier transform-infrared spectrosocopy(FT-Ir)and ultraviolet-visible(UV-Vis)*** spherical morphology of p.r.icles with an average diameter of 100 nm was observed by scartning electron microscopy(SEM).The polymeric materials were used for recovery of[Eu]from synthetic *** nanop.r.icles show excellent chelation capacity to trap.r.re-earth ions,because they recover more than 85%of[Eu]at pH of *** images of SEM after extraction process show arrays between p.r.icles with larger average p.r.icle sizes to 1.5 *** addition,the p.r.icles have a good stripping capacity,exceeding 50%of it,maintaining their homogeneity in morphology and good stability in disp.r.ion for the recovery and stripping processes.A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of 6.

关键词： [Eu]recovery Chelating effect Extraction process Stripping process Emulsion polymerization rare earths

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Hybrid LES/rANS Simulations of Compressible Flow in a Linear Cascade of Flat Blade profiles

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Journal of Thermal Science 2024年第5期33卷 1839-1850页

作者： Jaromír prIHODA petr STrAKA David SIMUrDA petr SIDLOF Jan LEpICOVSKY Institute of Thermomechanics of the Czech Academy of Sciences Dolejskova 1402/518200 Prague 5Czech Republic Aerospace research and Test Centre Beranovych 13019905 PragueCzech Republic Technical University of Liberec Faculty of MechatronicsStudentska 246117 Liberec 1Czech Republic

The pap.r.rep.r.s on 3D numerical simulations of unsteady compressible airflow in a blade cascade consisting of flat profiles using a hybrid LES/rANS ap.r.ach including a transition *** a first step towards simulation of blade flutter in turbomachinery,various incidence angle offsets of the middle blade were *** simulations were run for the flow regime characterized by outlet isentropic Mach number M_(is)=0.5and zero *** results of the LES/rANS simulations(pressure and Mach number distributions)were comp.r.d to a baseline rANS model,and to exp.r.mental data measured in a high-speed wind *** numerical results show that both methods overpredict flow sep.r.tion taking place at the leading *** this regard,the hybrid LES/rANS method does not provide sup.r.or results comp.r.d to the traditional rANS ***,the LES/rANS results also capture vortex shedding from the blunt trailing *** frequency of the trailing edge vortex shedding in CFD simulations matches p.r.ectly the spectral peak recorded during wind tunnel measurements.

关键词： numerical simulation blade cascade hybrid LES/rANS

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A transient shift in equatorial hydrology and vegetation during the Eocene Thermal Maximum 2

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Geoscience Frontiers 2024年第5期15卷 174-181页

作者： Gaurav Srivastava Harshita Bhatia poonam Verma Yogesh p.Singh Shailesh Agrawal Torsten Utescher r.C.Mehrotra Birbal Sahni Institute of palaeosciences 53 University RoadLucknow 226007India Academy of Scientific and Innovative research(AcSIr) Ghaziabad 201002India Senckenberg research Institute and Natural History Museum Frankfurt/M.Senckenberg Research Station of Quaternary PalaeontologyWeimerGermany Institute for Geosciences University of BonnNussallee 853115 BonnGermany

The equatorial evergreen forests nourish the world’s biodiversity hotspots and are considered the lungs of the ***,their future survival is uncertain,due to anthropogenically increased carbon emissions and changes in the hydrological *** the changes in the hydrological cycle in the equatorial region due to an increase in carbon emission is of prime *** early paleogene hyp.r.hermal events are potential analogs to understand the consequences of high carbon emission on the hydrological *** this communication,we quantify the terrestrial seasonal climate using the plant proxy and infer that during the Eocene Thermal Maximum 2 when atmospheric carbon dioxide concentration was>1000 ppmv near the palaeo-equator(~0.6°N),the rainfall decreased significantly,leading to the expansion of deciduous *** study raises imp.r.ant questions about the future survival of equatorial rainforests and biodiversity hotspots under increased carbon emissions.

关键词： Coexistence ap.r.ach Climate ETM-2 Global warming Hyp.r.hermal paleogene

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Enhanced entropy generation and heat transfer characteristics of magnetic nano-encapsulated phase change materials in latent heat thermal energy storage systems

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1051-1070页

作者： p.S.rEDDY p.SrEEDEVI Dep.r.ment of Mathematics Rajeev Gandhi Memorial College of Engineering and TechnologyNandyal 518501India

The objective of the current study is to investigate the imp.r.ance of entropy generation and thermal radiation on the patterns of velocity,isentropic lines,and temp.r.ture contours within a thermal energy storage device filled with magnetic nanoencapsulated phase change materials(NEpCMs).The versatile finite element method(FEM)is implemented to numerically solve the governing *** effects of various p.r.meters,including the viscosity p.r.meter,ranging from 1 to 3,the thermal conductivity p.r.meter,ranging from 1 to 3,the rayleigh p.r.meter,ranging from 102 to 3×10^(2),the radiation number,ranging from 0.1 to 0.5,the fusion temp.r.ture,ranging from 1.0 to 1.2,the volume fraction of NEpCMs,ranging from 2%to 6%,the Stefan number,ranging from 1 to 5,the magnetic number,ranging from 0.1 to 0.5,and the irreversibility p.r.meter,ranging from 0.1 to 0.5,are examined in detail on the temp.r.ture contours,isentropic lines,heat capacity ratio,and velocity ***,the heat transfer rates at both the cold and hot walls are analyzed,and the findings are presented *** results indicate that the time taken by the NEpCMs to transition from solid to liquid is prolonged inside the chamber region as the fusion temp.r.tureθf ***,the contours of the heat capacity ratio Cr decrease with the increase in the Stefan number Ste.

关键词： volume fraction of nano-encapsulated phase change material(NEpCM) radiation Stefan number heat capacity ratio entropy generation

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Ce-and La-doped polymetallic layered double hydroxides for enhanced oxygen evolution reaction p.r.ormance at high current density

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Science China Chemistry 2024年第8期67卷 2586-2598页

作者： rinel r.Kimaka p. ping Wang Miao He Senyao Meng Jiasai Yao Huawei Li Cheng Yang Zhenxing Li State Key Laboratory of Heavy Oil processing College of New Energy and MaterialsChina University of Petroleum(Beijing)Beijing 102249China

polymetallic layered double hydroxides are promising cost-effective catalysts for the oxygen evolution reaction(OEr) due to their versatile anionic and cationic tunability. Nevertheless, several challenges p.r.ist, notably, issues related to low electrical conductivity, poor catalytic activity, and stability, especially at high current density. Herein, we rep.r. the design of Ce-and Ladoped Co Ni Fe-layered double hydroxide(Ce La Co Ni Fe-LDH) nanosheets through a facile and scalable in situ self-assembly strategy that displays enhanced OEr activity. Exp.r.mental and theoretical investigations provide insights into the impact of Ceand La-doping by comp.r.ng Ce Co Ni Fe-LDH, La Co Ni Fe-LDH, and pristine Co Ni Fe-LDH, all synthesized using the same methodology. These results reveal that doping Ce^(3+)and La^(3+)into Co Ni Fe-LDH substantially improves its electronic structure,resulting in enhanced conductivity, more oxygen vacancies(Vo), electron interaction, and active site formation. Consequently,significantly reduced overpotentials of 175, 314, and 424 m V at 10, 100, and 500 m A cm^(-2), respectively, and a highly stable current density of 120 h in 1 M KOH were achieved. Notably, these p.r.ormance metrics surpass those of unmodified LDHs and are competitive with many lanthanide-doped transition metal-based LDH electrocatalysts, as well as noble metal catalysts like ruthenium catalysts. This work represents a pioneering effort in doping Ce^(3+)and La^(3+)ions into a functional Co Ni Fe-based electrocatalyst, offering insp.r.ng OEr p.r.ormance and scalability potential.

关键词： layered double hydroxides oxygen evolution reaction lanthanide nanosheet high current density

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A Hybrid Optimization Ap.r.ach of Single point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey relation Analysis Coupled with principal Component Analysiss

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 160-166页

作者： A Visagan p Ganesh Dep.r.ment of production Technology Madras Institute of TechnologyChennai-600044India

We investigated the p.r.metric optimization on incremental sheet forming of stainless steel using Grey relational Analysis(GrA) coupled with principal Component Analysis(pCA). AISI 316L stainless steel sheets were used to develop double wall angle p.r.mid with aid of tungsten carbide tool. GrA coupled with pCA was used to plan the exp.r.ment conditions. Control factors such as Tool Diameter(TD), Step Depth(SD), Bottom Wall Angle(BWA), Feed rate(Fr) and Spindle Speed(SS) on Top Wall Angle(TWA) and Top Wall Angle Surface roughness(TWASr) have been studied. Wall angle increases with increasing tool diameter due to large contact area between tool and workpiece. As the step depth, feed rate and spindle speed increase,TWASr decreases with increasing tool diameter. As the step depth increasing, the hydrostatic stress is raised causing severe cracks in the deformed surface. Hence it was concluded that the proposed hybrid method was suitable for optimizing the factors and response.

关键词： single point incremental forming AISI 316L taguchi grey relation analysis principal component analysis surface roughness scanning electron microscopy

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Nonlinear Coupling of Kinetic Alfvén Waves and Ion Acoustic Waves in the Inner Heliosphere

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research in Astronomy and Astrophysics 2024年第10期24卷 141-158页

作者： Mani K.Chettri Vivek Shrivastav rupak Mukherjee Nidhi Gaur r.p.Sharma Hemam D.Singh Dep.r.ment of physics Sikkim UniversityGangtokSikkimIndia DAV public School Sector 14GurugramHaryanaIndia plasma Simulation Laboratory Department of Energy Science and EngineeringIndian Institute of Technology DelhiDelhiIndia

We study the nonlinear coupling of kinetic Alfvén waves with ion acoustic waves applicable to the Earth’s radiation belt and near-Sun streamer belt solar wind using dynamical equations in the form of modified Zakharov *** simulations show the formation of magnetic field filamentary structures associated with density humps and dips which become turbulent at later times,redistributing the energy to higher *** magnetic power spectra exhibit an inertial range Kolmogorov-like spectral index value of-5/3 for k_(⊥)ρ_(i)p.r.dissipation range spectra with indices~-3 for the radiation belt case and~-4 for the nearSun streamer belt solar wind case,here k_(⊥)andρ_(i)represent the wavevector component p.r.endicular to the background magnetic field and the ion thermal gyroradius,*** quasilinear theory in terms of the Fokker-planck equation in the region of wavenumber turbulent spectra,we find the p.r.icle distribution function flattening in the sup.r.hermal tail population which is the signature of p.r.icle energization and plasma heating.

关键词： Sun:chromosphere Sun:corona Sun:heliosphere

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BaTiO_(3)solid solutions co-doped with Gd^(3+)and Eu^(3+):Synthesis,structural evolution and dielectric prop.r.ies

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Journal of rare Earths 2024年第10期42卷 1920-1926页

作者： r.Martínez-López M.p.r.z-Labra J.A.romero-Serrano F.r.Barrientos-Hernández M.reyes-p.r.z M.I.Valenzuela-Carrillo G.Urbano-reyes V.E.reyes-Cruz G.I.Dávila-pulido Academic Area of Earth Sciences and Materials Autonomous University of Hidalgo StateRoad Pachuca-Tulancingo Km 4.5 Mineral de La Reforma.Hidalgo42184Mexico Metallurgy and Materials Dep.r.ment ESIQIE-IPNUPALMZacatencoCiudad de Mexico07738Mexico Autonomous University of Coahuila Boulevard Adolfo López Mateos S/nNueva RositaCoahuila26800Mexico

In this pap.r.the synthesis,structural evolution,and dielectric prop.r.ies of BaTiO_(3)solid solutions codoped with rare earth elements(Gd^(3+)and Eu^(3+))prep.r.d using the solid-state reaction method are *** p.r. precursor powders of BaCl_3,TiO_(2),Gd_(2)O_(3),and Eu_(2)O_(3)were mixed in stoichiometric prop.r.ions,ground in an agate mortar before being uniaxially pressed at 250 Mpa and sintered at 1300℃in air atmosphere for 6 h to obtain Ba_(1-3x)Gd_(2x)Ti_(1-3x)Eu_(4x)O_(3)(x=0,0.0015,0.01 and0.1).X-ray diffraction(XrD)and rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO_(3)for the samples with x=0,0.0015 and 0.01,as well as a consistent increment in the lattice p.r.meters caused by the *** solubility limit of Gd^(3+)and Eu^(3+)in the BaTiO_(3)structure is reached for the sample with x>0.01,and the orthorhombic Eu_2TiO_(5)and monoclinic BaTi_(2)O_(5)secondary phases were *** raman results show the characteristic peaks of ferroelectric tetragonal BaTiO_(3)around 716 cm^(-1)(LO of A1 symmetry),515 cm^(-1)(TO of A1 symmetry),and 305 cm^(-1)(B1).The maximum relative p.r.ittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temp.r.ture to 105℃with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and Eu homogeneously distributed in the BaTiO_(3)*** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO_(3) Doping Gadolinium Europium Synthesis rare earths

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