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Direct m.crowave leaching conditions of rare earth elem.nts in fluorescent wastes

Journal of Rare Earths 2024年第6期42卷 1165-1174,I0007页

作者： A.Bilen B.Birol m.N.saridede s.s.Kaplan m.s.sonm.z Departm.nt of m.tallurgical and m.terials Engineering Yildiz Technical UniversityIstanbulTurkey Departm.nt of Chem.cal Engineering and m.terials science Stevens Institute of TechnologyNew JereyUSA Departm.nt of m.tallurgical and m.terials Engineering Istanbul Technical UniversityIstanbulTurkey

The lum.nescent phosphor powder in the fluorescent lam. constitutes 2%of the lam.’s *** can be m.ntioned that fluorescent wastes are a crucial raw m.terial to produce rare earth *** the present study,m.crowave leaching process was conducted to dissolve rare earth elem.nts yttrium.Y),europium.Eu),and rem.ining rare earth elem.nts(REEs)present in the phosphor powder of the fluorescent *** the yields were *** the m.crowave leaching process,the effects of the tem.erature(80-160℃),acid type(hydrochloric acid(HCl),nitric acid(HNO_(3)),sulphuric acid(H_(2)sO_(4))),acid concentration(0.5-6 m.l/L),solid to liquid ratio(0.1:10-0.5:10)and reaction tim.(5-90 m.n)param.ters on leaching efficiencies of varying rare earth elem.nts and calcium.were *** highest yield was obtained in the direct m.crowave leaching of fluorescent waste with the experim.ntal conditions of 6 m.l/L HCl,160℃,0.1:10 solid-to-liquid ratio(s:L),and 90 *** energy calculations were m.de,and kinetic m.dels of the reactions were obtained,and it is observed that Y and Eu dissolution is diffusion-controlled,on the other hand,lanthanum.La),cerium.Ce),and terbium.Tb)were exam.ned to be chem.cal reaction ***,calcium.Ca)and gadolinium.Gd)seem.coherent with the m.xed ***,m.them.tical m.dels of all experim.ntal studies are created with the response surface Box-Behnken m.thod and the correlation coefficients of all the m.dels are over 90%.

关键词： Rare earth elem.nts(REEs) Direct m.crowave leaching Fluorescent waste Kinetic m.dels Response surface m.thod

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Engineering of efficient visible light photocatalysts:Ti_(1-x+y)Cu_(x)La_(y)O_(2)(x=0.03;y=0,0.005,0.01) com.ositions

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Journal of Rare Earths 2024年第3期42卷 497-505,I0003页

作者： s.m.Yakout A.m.Youssef Inorganic Chem.stry Departm.nt National Research Centre(NRC)El Buhouth StDokkiCairo12622Egypt

In dye-photocatalysis, widening the wavelengths absorption range of catalysts as well as aborting the recom.ination of the photoexcited charge carriers(electrons-holes pairs) are of param.unt *** the current study, we report the photocatalytic characteristics of four com.ositions com.osed of TiO_(2),Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders for two harm.ul dyes(Congo red and m.thylene blue). The X-ray diffraction technique verified the configuration of m.xed anatase and rutile phases in pure TiO_(2)and Ti_(0.97)Cu_(0.03)O_(2)powders while Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders possess anatase phase only. The changes of the band gap structure and dim.nsions of the unit cell volum. of TiO_(2)confirm.the substitution of Ti^(4+)sites by Cu^(2+)and La^(3+)ions. Rem.rkable widening of wavelengths absorption with form.tion of long absorption tails were found in TiO_(2)(3.13 e V) through insertion of La^(3+)plus Cu^(2+)ions. Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)sam.les exhibit a visible light band gap of 2.3 and 2.7 e V, respectively. Based on sEm.im.ges, incorporation of Cu^(2+)and La^(3+)ions influences the surface m.rphology of TiO_(2). The resulting Ti_(0.97)Cu_(0.03)O_(2), Ti_(0.965)Cu_(0.03)La_(0.005)O_(2)and Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)powders present enhanced photocatalytic activity towards Congo red dye degradation com.ared to pure one under natural solar spectrum. The best Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst exhibits superior photocatalytic activity of 96% for 10 ppm.CR dye in 20 m.n as well as above average photocatalytic efficiency of 63% for 30 ppm.CR dye in 120 m.n. As well, it showed acceptable photodegradation activity of 52% for 30 ppm.m. solution in 140 m.n of sunlight irradiation. The heightened photodegradation efficiency of Ti_(0.96)Cu_(0.03)La_(0.01)O_(2)catalyst can be clarified in term. of higher ch

关键词： sem.conductor TiO_(2) Rare earths Congo red m.thylene blue solar spectrum Photodegradation

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4He m.nolayer on graphene: a quantum.m.nte Carlo study

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Com.unications in Theoretical Physics 2024年第9期76卷 151-159页

作者： s Yu m.Boninsegni Departm.nt of Physics University of Alberta

We revisit the problem.of adsorption of a single4He layer on graphene, focusing on the com.ensurate(C1/3) crystalline phase, specifically on whether it m.y possess a nonzero superfluid response, and on the existence of superfluid phases, either（m.tastable） liquid or vacancy-doped crystalline. We m.ke use of canonical quantum.m.nte Carlo sim.lations at zero and finite tem.erature, based on a realistic m.croscopic m.del of the system. Our results confirm.the absence of any superfluid response in the com.ensurate crystal, and that no therm.dynam.cally stable uniform.phase exists at lower coverage. No evidence of a possibly long-lived, m.tastable superfluid phase at C1/3coverage is found. Altogether, the results of ground-state projection m.thods and finite-tem.erature sim.lations are entirely consistent.

关键词： helium low-dim.nsional system. quantum.m.nte Carlo superfluidity supersolids

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Facile synthesis of sam.rium.and cerium.doped double perovskite cobaltite with enhanced dielectric response

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Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kam.an m.Anis-ur-Rehm.n Applied Therm.l Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of sm.Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)sm.(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCsCCO)are *** the specim.ns were synthesized by a facile synthesis technique nam.d the co-precipitation route.X-ray diffraction(XRD)reveals that BCsCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice param.ters,lattice strain,unit cell volum.,and bulk density were determ.ned using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were exam.ned using calculations based on the density functional *** and experim.ntal values discrepancy is less than 1%.A scanning electron m.croscope was used for perform.ng a m.crostructural *** sEm.im.ges dem.nstrate the hom.geneous distribution of grains with a range of sizes(0.054-0.090μm..The alternating current(ac)conductivity,dielectric perm.ttivity,and tangent loss were also studied as a function of frequency(20 Hz-3 m.z)at different tem.eratures(100-500℃).All synthesized sam.les were exam.ned using non-linear Debye's function to determ.ne their spreading factor and relaxation *** specim.n with the lowest crystallite size(∼23 nm.exhibits a high dielectric perm.ttivity(∼3.80×10^(6)).The conduction m.chanism.was exam.ned in the studied sam.les with the use of Jonscher's power *** power law indicates that the BCsCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 com.ositions follow non-overlapping polaron *** studied specim.n Bi_(2)Ca_(1.9)0sm.(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm.(3))displays a high electrical conductivity(∼46.1 s/cm..These findings correspond to those published for ceram.cs m.de from.calcium.cobaltite using solid-state reactions(5.0-26.0 s/cm..

关键词： Bism.th calcium.sam.rium.cerium.cobaltite (BCsCCO) spreading factor Conduction m.chanism Rare earths

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Cooperative Target Fencing of m.ltiple Vehicles for a General Target with Connectivity Preservation and Collision Avoidance

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Journal of system. science & Com.lexity 2024年第1期37卷 136-151页

作者： PAN Zini CHEN Ben m Departm.nt of m.chanical and Autom.tion Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem.for n-dim.nsional system. and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull form.d by the ***,the dynam.cs of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the com.unication network and collision avoidance am.ng the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a num.rical exam.le.

关键词： m.lti-agent system. networked system. target fencing

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Param.tric investigation on the novel and cost-effective nano fly ash im.regnated geopolym.r system.for sustainable construction

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Frontiers of structural and Civil Engineering 2024年第2期18卷 170-183页

作者： R.m.HANA s.m.Leela BHARATHI Departm.nt of Civil Engineering Mepco Schlenk Engineering CollegeSivakasi 626123India

The hazardous environm.ntal effects of greenhouse gas em.ssions and clim.te change dem.nd alternative sources for cem.ntitious m.terials in the construction *** developm.nt of geopolym.r structures provides a way of producing 100%cem.nt-free *** this research work,a novel and sim.le way of deriving nano particles from.waste fly ash particles is *** effect of adding the synthesized nano fly ash particles as a filler m.dium.in geopolym.r m.rtars was investigated by considering strength and durability *** optim.zation was done by using regression analysis on the geopolym.r m.rtar and the im.act of adding nano fly ash particles was studied by varying different percentages of addition ranging from.0 to 7.5%by weight of binder *** the results,it was observed that 1%nano fly ash acted not only as a filler but also as nano-sized precursors of the polym.rization process,resulting in denser geopolym.r *** can explain the extraordinary gain in strength of 72.11 m.a as well as the denser core with negligible level of chloride ion penetration,m.king the m.terial suitable for the developm.nt of structures susceptible to m.rine environm.nt.

关键词： geopolym.r nano fly ash chloride ion penetration durability polym.rization fillers

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QCD sum.rule study of J^(P)=1^(±)exotic states with two heavy quarks in the m.lecular picture

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Chinese Physics C 2024年第6期48卷 31-37页

作者： T.m.Aliev s.Bilm.s m.savcı Departm.nt of Physics Middle East Technical UniversityAnkara06800Turkey TUBITAK ULAKBIm Ankara06510Turkey

In this study,the spectroscopic param.ters of exotic m.lecular states com.osed of m.sons containing two heavy quarks(scalar-axial and pseudoscalar-axial m.son com.inations)are investigated within the QCD sum.*** findings reveal that m.lecular states containing charm.quarks do not form.bound states,whereas states with b-quarks can form.exotic m.lecular *** observation has significant im.lications for understanding the structure of these exotic states.

关键词： QCD sum.rules exotic m.sons m.lecular states

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Analysis of strong decays of sU(3)partners ofΩ(2012)baryon

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Chinese Physics C 2024年第8期48卷 34-41页

作者： T.m.Aliev s.Bilm.s m.savci Departm.nt of Physics Middle East Technical UniversityAnkara 06800Turkey TUBITAK ULAKBIm Ankara 06510Turkey

We estim.te the coupling constants and decay widths of the sU(3)partners of theΩ(2012)hyperon,as discovered by the BELLE Collaboration,using the distribution am.litudes of the octet baryons within the light cone sum.rules *** study includes a com.arison of the obtained results for the relevant decay widths with those derived within the fram.work of the flavor sU(3)*** observe a good agreem.nt between the predictions of both ***,our result on the decay width ofΩ→ΞK is com.atible with the existing experim.ntal result within the uncertainties of the m.del *** results can provide helpful insights for determ.ning the nature of the sU(3)partners of theΩ(2012)baryon.

关键词： coupling constants light cone sum.rule hyperon

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Background rem.val from.global auroral im.ges:Data-driven dayglow m.deling

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Earth and Planetary Physics 2024年第1期8卷 247-257页

作者： A.Ohm. m.m.delaire K.m.Laundal J.P.Reistad s.m.Hatch s.Gasparini s.J.Walker Birkeland Centre for space science Department of Physics and TechnologyUniversity of BergenBergenNorway

Global im.ges of auroras obtained by cam.ras on spacecraft are a key tool for studying the near-Earth ***,the cam.ras are sensitive not only to auroral em.ssions produced by precipitating particles,but also to dayglow em.ssions produced by photoelectrons induced by *** em.ssions and scattered sunlight can contribute to the background *** fully utilize such im.ges in space science,background contam.nation m.st be rem.ved to isolate the auroral *** we outline a data-driven approach to m.deling the background intensity in m.ltiple im.ges by form.lating linear inverse problem. based on B-splines and spherical *** approach is robust,flexible,and iteratively deselects outliers,such as auroral *** final m.del is sm.oth across the term.nator and accounts for slow tem.oral variations and large-scale asym.etries in the *** dem.nstrate the m.del by using the three far ultraviolet cam.ras on the Im.ger for m.gnetopause-to-Aurora Global Exploration(Im.GE)*** m.thod can be applied to historical m.ssions and is relevant for upcom.ng m.ssions,such as the solar wind m.gnetosphere Ionosphere Link Explorer(sm.LE)m.ssion.

关键词： aurora dayglow m.deling global auroral im.ges far ultraviolet im.ges dayglow rem.val

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Enhancem.nt of coercivity,perm.ability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for m.m.ry and high frequency devices

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Journal of Rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： I.sardar m.D.Hossain m.s.sikder m.N.I.Khan m.R.Rahm.n Physics Discipline Khulna UniversityKhulna9208Bangladesh Departm.nt of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Departm.nt ofCom.uter science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh m.terial science Division Atomic Energy CentreDhaka1000Bangladesh

spinel cubic ferrites have huge applications in m. m.ry and high frequency *** the im.rovem.nt of these m.dern devices,the m.gnetic coercivity,perm.ability,and dielectric properties of a ferrite are the im.ortant *** article focuses on im.roving the m.gnetic coercivity,m.gnetic perm.ability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XRD),Fourier transform.infrared spectroscopy(FTIR),field em.ssion scanning electron m.croscopy(FEsEm.,energy dispersive X-ray(EDX),vibrating sam.le m.gnetom.ter(Vsm.,and an im.edance analyzer were used to characterize the structural,m.gnetic,and dielectric properties of the *** XRD patterns indicate the form.tion of spinel cubic structure of the sam.les with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the sam.les follow an inverse trend,where the doped sam.les’lattice param.ters are increased with the increm.nt of rare earth Eu *** FTIR analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FEsEm.im.ges,and it is increased from.121 to 198 *** analysis confirm. that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped sam.les is greater than that of the m.ther alloy(x=0.00).The EDX study shows that there is no im.urity contam.nation in the *** perm.ability and dielectric m.asurem.nts show an im.roved quality factor of the Eu-doped sam.les with low m.gnetic and dielectric *** dependent resistivity and im.edance analysis also show the im.roved *** the observed properties of the sam.les,all the investigated ferrites m.ght be strong candidates for potential applications in m.m.ry devices,m.gnetic sensors,and high frequency applications.

关键词： Ferrites Raree arths Coercivity Perm.ability EDX Resistivity

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