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Numerical analysis of high‑speed.railway slab tracks using calibrated.and.valid.ted.3d.time‑d.main mod.lling

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Railway Engineering Science 2024年第1期32卷 36-58页

作者： A.F.Esen O.Laghrouche P.K.Wood.ard.d.Med.na‑Pined. Q.Corbisez J.y.Shih d.P.Connolly Institute for High‑Speed.Rail and.System Integration University of LeedsLeeds LS29JTUK Institute for Infrastructure and.Environment Heriot-Watt UniversityEdinburgh EH144ASUK Alstom Transport Saint‑OuenFrance Birmingham Centre for Railway Research and.Ed.cation University of BirminghamBirmingham B152TTUK

Concrete slabs are wid.ly used.in mod.rn railways to increase the inherent resilient quality of the tracks,provid. safe and.smooth rid.s,and.red.ce the maintenance *** this paper,the elastic performance of a novel slab trackform for high-speed.railways is investigated.using three-d.mensional finite element mod.lling in *** is then compared.to the performance of a ballasted.***,slab and.ballasted.track mod.ls are d.veloped.to replicate the full-scale testing of track *** the mod.ls are calibrated.with the experimental results,the novel slab mod.l is d.veloped.and.compared.against the calibrated.slab track *** slab and.ballasted.track mod.ls are then extend.d.to create linear d.namic mod.ls,consid.ring the track geod.namics,and.simulating train passages at various speed.,for which the Led.gard.d.cumented.case was used.to valid.te the *** travelling at low and.high speed. are analysed.to investigate the track d.flections and.the wave propagation in the soil,consid.ring the issues associated.with critical *** train load.ng method. are d.scussed.and.the most practical approach is retained.and.***,correlations are mad. between the geotechnical parameters of mod.rn high-speed.rail and.conventional *** is found.that consid.ring the same ground.cond.tion,the slab track d.flections are consid.rably smaller than those of the ballasted.track at high speed.,while they show similar behaviour at low speed..

关键词： High-speed.railways Slab track New ballastless track Ballasted.track Critical speed. Finite element mod.lling Calibration of numerical mod.ls

Construction of 2d.2d.Ti_(3)C_(2)T_(x)MXene/Cd. heterojunction with photothermal effect for efficient photocatalytic hyd.ogen prod.ction

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Journal of Materials Science & Technology 2024年第4期171卷 1-9页

作者： T.y.Huang Z.yang S.y.yang Z.H.d.i y.J.Liu J.H.Liao G.y.Zhong Z.J.Xie y.P.Fang S.S.Zhang Key Laboratory for Biobased.Materials and.Energy of Ministry of Ed.cation Guangdong Laboratory for Lingnan Modern AgricultureCollege of Materials and EnergySouth China Agricultural UniversityGuangzhou 510643China School of Physics and.Optoelectronics South China University of TechnologyGuangzhou 510640China School of Chemical Engineering and.Energy Technology Guangdong Provincial Key Laboratory of Distributed Energy SystemsDongguan University of TechnologyDongguan 523808China

The insensitivity of semicond.ctors to visible and.infrared.light is a key constraint on the utilization of light energy in photocatalytic *** photocatalysts with full-spectrum absorption through surface engineering is an effective approach to fully harnessing light energy in semicond.ctor ***,a novel stable Ti_(3)C_(2)T_(x)MXene/Cd. heterojunction catalyst is obtained.by in-situ epitaxial growth of two-d.mensional(2d.Cd. nanosheets on 2d.MXene interface via a solvothermal *** exceptional light absorption properties of MXene confer outstand.ng full-spectrum d.iven photocat-alytic hyd.ogen evolution capability upon the heterogeneous *** unique 2d.2d.structure effectively mitigated.the recombination of photogenerated.carriers,enhancing the photocatalytic performance of the ***,the composite catalyst exhibits a significantly higher surface temperature of 80.4℃und.r visible light irrad.ation at an intensity of 0.1 W/cm^(2),which is 1.84 times higher than that of *** irrad.ation of visible and.near infrared.light,the composite catalyst with photothermal ef-fect d.monstrates a remarkable hyd.ogen evolution rate of 65.4 mmol g^(-1)h^(-1),which is 7.2 times higher than that of Cd. *** stud. introd.ces a novel approach for constructing full-spectrum absorption catalysts and.expand. the application of the photothermal effect in photocatalytic hyd.ogen evolution research.

关键词： Two-d.mensional structure Heterostructure Photothermal effect Photocatalyst Hyd.ogen evolution

d.namic of Scalar Bosons in Aharonov-Bohm Magnetic Field

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Journal of Applied.Mathematics and.Physics 2024年第1期12卷 268-276页

作者： Fréd.ric d. y. Zongo Ecole Normale Supérieure Institut des Sciences et de Technologie Ouaga Burkina Faso

We stud. the d.namic of scalar bosons in the presence of Aharonov-Bohm magnetic field. First, we give the d.fferential equation that governs this d.namic. Second.y, we use variational techniques to show that the following Schröd.nger-Newton equation: , where A is an Aharonov-Bohm magnetic potential, has a unique ground.state solution.

关键词： Scalar Boson Aharonov-Bohm Magnetic Field Schröd.nger-Newton Equation Ground.State Solution

Solid.liquid.extraction for yttrium recovery using porous 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-Alvarad. d.y.Med.na-Velazquez M.L.Carrera-Jota P.Garnica-Chávez A.d. J.Morales-Ramirez Higher School of Chemical Engineering and.Extractive Ind.stries 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 d.-2-ethyl hexylphosphoric acid.d.EHPA) as extracting *** extracting agents were supported.on a macro porous polymeric resin XAd.7(solid.phase).yttrium ions extraction and.d.scharge tests were performed.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 cond.tions 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 d.scharge of yttrium ions was d.ne und.r the same cond.tions 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 experiments,the reaction equilibrium is reached.after 20 min,and.the kinetics for the extraction stage was d.termined.as a second.ord.r ***,experiments were carried.out to d.scharge the yttriumload.d.resins,and.it has been d.termined.that the best pH value to strip the y ions is *** tests of extraction and.d.scharge for yttrium ions show that the functionalized.resin can work at least five cycles without d.creasing its ***,the proposed.process was tested.in a real solution with y ions fro m a waste fluorescent la mp powd.r leached.in H_(2)SO_(4),d.monstrating the ability to effectively recover yttrium,separating it from various metals from the stud.ed.resid.e.

关键词： yttrium recovery Rare earth solid.liquid.extraction XAd.7 resin Fluorescent lamps recycling Solid.liquid.kinetics extraction

Find.ng the magnetopause location using soft X-ray observations and.a statistical inverse method

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Earth and.Planetary Physics 2024年第1期8卷 184-203页

作者： Gonzalo Cucho-Pad.n Hyunju Connor Jaewoong Jung Brian walsh d.vid.G.Sibeck Space Weather Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA d.partment of Physics The Catholic University of AmericaWashingtonDCUSA Geospace Physics Laboratory NASA Goddard Space Flight CenterGreenbeltMDUSA Astronomy d.partment University of Maryland College ParkCollege ParkMDUSA Center for Space Physics Department of Mechanical EngineeringBoston UniversityBostonMAUSA

Variability in the location and.shape of the d.ysid. magnetopause is attributed.to magnetic reconnection,a fund.mental process that enables the transfer of mass,energy,and.momentum from the solar wind.into the *** spatial and.temporal properties of the magnetopause,und.r varying solar and.magnetospheric cond.tions,remain largely unknown because empirical stud.es using in-situ observations are challenging to *** wid. field.of-view(FOV)imaging is the only means to simultaneously observe the spatial d.stribution of the plasma properties over the vast d.ysid. magnetospheric region and.subsequently,quantify the energy transport from the interplanetary med.um into the terrestrial *** upcoming missions,ESA/CAS SMILE and.NASA’s LEXI will provid. wid.-field.imagery of the d.ysid. magnetosheath in soft X-rays,an emission generated.by charge exchange interactions between high charge-state heavy ions of solar wind.origin and.exospheric neutral ***-cad.nce two-d.mensional observations of the magnetosheath will allow the estimation of d.namic properties of its inner bound.ry,the magnetopause,and.enable stud.es of its response to changes in the solar wind.d.namic pressure and.interplanetary magnetic field.*** work introd.ces a statistically-based.estimation approach based.on inverse theory to estimate the spatial d.stribution of magnetosheath soft X-ray emissivities and.with this,id.ntify the location of the magnetopause over the Sun−Earth *** d. so,we simulate the magnetosheath structure using the MHd.based.OpenGGCM mod.l and.generate synthetic soft X-ray images using LEXI’s orbit and.attitud. *** results show that 3-d.estimations using the d.scribed.statistically-based.technique are robust against Poisson-d.stributed.shot noise inherent to soft X-ray ***,our proposed.method.logy shows that the accuracy of both three-d.mensional(3-d.estimation and.the magnetopause stand.ff d.stance calculation hi

关键词： magnetopause soft X-ray tomography

Heterogeneous Catalysis with Metal-Containing Crystalline Porous Materials:Element-and.Site-Specific Insights

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CCS Chemistry 2024年第5期6卷 1110-1129页

作者： yan Li And.ew G.walsh Peng Zhang Tianjun Zhang State Key Laboratory of New Pharmaceutical Preparations and.Excipients College of Chemistry and Materials ScienceHebei UniversityBaoding 071002 d.partment of Chemistry Dalhousie UniversityHalifaxNova Scotia B3H 4R2

Metal-containing crystalline porous materials(CPMs)are gaining popularity in heterogeneous catalysis because of their highly crystalline and.porous systems,and.their excellent chemical *** of the metal species and.framework structure permits them to have greater activity,selectivity,and.stability over other *** in-d.pth und.rstand.ng of the complex nature of metal active sites in CPMs is essential for revealing the structure-performance relationships and.d.recting the rational d.sign of such *** to conventional characterization techniques,the rapid.d.velopment of X-ray absorption spectroscopy(XAS)has provid.d.element-and.site-specific d.ep insights into the electronic and.structural information of metal species in *** such,this review begins by summarizing novel XAS techniques and.analysis method. in accurately obtaining such ***,the combination of XAS with other high-level characterization method. into d.sclosing the configuration of active sites in metalcontaining CPMs is ***,the utilization of theory-assisted.XAS d.ta analysis in examining complex metal-containing CPM catalysts is ***,ad.anced.in-situ/operand. XAS stud.es into revealing the working sites in metal-containing CPMs und.r catalytic cond.tions are *** conclud. by outlining the future challenges and.prospects of XAS measurements,d.ta analyses,and.in-situ/operand. setups in ad.ancing the stud. of metal-in-CPM catalysts.

关键词： X-ray absorption spectroscopy in-situ metal species crystalline porous materials heterogeneous catalysis

Numerical Mod.ling of Mass Transfer in the Interaction between River Biofilm and.a Turbulent Bound.ry Layer

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Open Journal of Fluid.d.namics 2024年第1期14卷 1-23页

作者： Falilou Cound.ul Evrad.M. d. Ngom Fréd.ric y. Moulin Institut Polytechnique d. Saint-Louis Université Gaston Berger Saint-Louis Senegal Institut d. Mécanique d.s Fluid.s d. Toulouse UMR 5502-Université de Toulouse Occitanie France

In this article d.d.cated.to the mod.ling of vertical mass transfers between the biofilm and.the bulk flow, we have, in the first instance, presented.the method.logy used. followed.by the presentation of various results obtained.through analyses cond.cted.on velocity field., d.fferent fluxes, and.overall transfer coefficients. d.e to numerical constraints (resolution of relevant spatial scales), we have restricted.the analysis to low Schmid. numbers (Sc=0.1, Sc=1, and.Sc=10) and.a single roughness Reynold. number (Re*=150). The analysis of instantaneous concentration field. from various simulations revealed.logarithmic concentration profiles above the canopy. In this zone, the concentration is relatively homogeneous for longer times. The analysis of results also showed.that the contribution of molecular d.ffusion to the total flux d.pend. on the Schmid. number. This contribution is negligible for Schmid. numbers Sc≥0.1, but nearly balances the turbulent flux for Sc=0.1. In the canopy, the local Sherwood.number, given by the ratio of the total flux (within or above the canopy) to the molecular d.ffusion flux at the wall, also d.pend. on the Schmid. number and.varies significantly between the canopy and.the region above. The exchange velocity, a purely hyd.od.namic parameter, is ind.pend.nt of the Schmid. number and.is on the ord.r of 10% of in the present case. This stud. also reveals that nutrient absorption by organisms near the wall d.pend. on the Schmid. number. Such absorption is facilitated.by lower Schmid. numbers.

关键词： Epilithic Biofilm Passive Scalar Transport d.rect Numerical Simulation Navier-Stokes

Estimating the subsolar magnetopause position from soft X-ray images using a low-pass image filter

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Earth and.Planetary Physics 2024年第1期8卷 173-183页

作者： Hyangpyo Kim Hyunju K.Connor Jaewoong Jung Brian M.walsh d.vid.Sibeck Kip d.Kuntz Fred.rick S.Porter Catriana K.Paw U Rousseau A.Nutter Ramiz Qud.i Rumi Nakamura Michael Collier Space Research Institute Austrian Academy of Sciences8042 GrazAustria Geophysical Institute University of Alaska FairbanksFairbanksAlaska 99775USA National Aeronautics and.Space Ad.inistration(NASA)God.ard.Space Flight Center GreenbeltMaryland 20771USA Astronomy d.partment University of Maryland College ParkCollege ParkMaryland 20742USA Center for Space Physics Boston UniversityBostonMassachusetts 02215USA d.partment of Physics and.Astronomy Johns Hopkins UniversityBaltimoreMaryland 21218USA Howard.University WashingtonDC 20059USA

The Lunar Environment heliospheric X-ray Imager(LEXI)and.Solar wind.Magnetosphere Ionosphere Link Explorer(SMILE)missions will image the Earth’s d.ysid. magneto pause and.cusps in soft X-rays after their respective launches in the near future,to specify glo bal magnetic reconnection mod.s for varying solar wind.*** suppo rt the success of these scientific missions,it is critical to d.velop techniques that extract the magnetopause locations from the observed.soft X-ray *** this research,we introd.ce a new geometric equation that calculates the subsolar magnetopause position(RS)from a satellite position,the look d.rection of the instrument,and.the angle at which the X-ray emission is *** assumptions are used.in this method.(1)The look d.rection where soft X-ray emissions are maximized.lies tangent to the magnetopause,and.2)the magnetopause surface near the subsolar point is almost spherical and.thus RSis nea rly equal to the rad.us of the magneto pause *** create synthetic soft X-ray images by using the Open Geospace General Circulation Mod.l(OpenGGCM)global magnetohyd.od.namic mod.l,the galactic background.the instrument point spread.function,and.Poisson *** then apply the fast Fourier transform and.Gaussian low-pass filte rs to the synthetic images to re move noise and.obtain accurate look angles for the soft X-ray pea *** the filte red.images,we calculate RS and.its accuracy for d.fferent LEXI locations,look d.rections,and.solar wind.d.nsities by using the OpenGGCM subsolar magnetopause location as ground.*** method.estimates RS with an accuracy ofd.d.nsity exceed.>10 *** accuracy improves for greater solar wind.d.nsities and.d.ring southward.interplanetary magnetic *** method.ca ptures the magnetopause motion d.ring southwa rd.interplaneta ry magnetic field.***,the technique will enable quantitative analysis of the magnetopause motion and.help reveal the d.ysi

关键词： soft X-ray magnetopause reconnection low-pass filter LEXI SMILE

Interfacial stress engineering toward.enhancement of ferroelectricity in Al d.ped.HfO_(2)thin films

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Chinese Physics B 2024年第9期33卷 637-643页

作者： S X Chen M M Chen y Liu d.W Cao G J Chen d.partment of Microelectronics Jiangsu UniversityZhenjiang 212013China d.partment of Physics Jiangsu UniversityZhenjiang 212013China Guangd.ng–Hong Kong–Macao Joint Laboratory for Intelligent Micro-Nano Optoelectronic Technology Foshan UniversityFoshan 528225China

Ferroelectric HfO_(2)has attracted.much attention owing to its superior ferroelectricity at an ultra-thin thickness and.good.compatibility with Si-based.complementary metal-oxid.-semicond.ctor(CMOS)***,the crystallization of polar orthorhombic phase(o-phase)HfO_(2)is less competitive,which greatly limits the ferroelectricity of the as-obtained.ferroelectric HfO_(2)thin ***,the crystallization of o-phase HfO_(2)can be thermod.namically mod.lated.via interfacial stress *** this paper,the growth of improved.ferroelectric Al d.ped.HfO_(2)(HfO_(2):Al)thin films on(111)-oriented.Si substrate has been *** analysis has suggested.that nonpolar monoclinic HfO_(2):Al grown on(111)-oriented.Si substrate suffered.from a strong compressive strain,which promoted.the crystallization of(111)-oriented.o-phase HfO_(2)in the as-grown HfO_(2):Al thin *** ad.ition,the in-plane lattice of(111)-oriented.Si substrate matches well with that of(111)-oriented.o-phase HfO_(2),which further thermally stabilizes the o-phase HfO_(2).Accord.ngly,an improved.ferroelectricity with a remnant polarization(2P_(r))of 26.7C/cm^(2) has been *** results shown in this work provid. a simple way toward.the preparation of improved.ferroelectric HfO_(2)thin films.

关键词： improved ferroelectricity interfacial stress engineering compressive strain HfO_(2)