检索结果-南通市图书馆

Single atom Cu-n-C catalysts for the electro-reduction of CO_(2) to CO assessed by rotating ring-disc electrode

在线全文

学校读者我要写书评

暂无评论

journal of Energy Chemistry 2024年第1期88卷 169-182,I0004页

作者： S.Pérez-Rodríguez m.Gutiérrez-Roa C.Giménez-Rubio D.Ríos-Ruiz P.Arévalo-Cid m.V.martínez-Huerta A.Zitolo m.j.Lázaro D.Sebastián Instituto de Carboquímica(CSIC) Miguel Luesma Castán 450018 ZaragozaSpain Instituto de Catálisis y Petroleoquímica(CSIC) Marie Curie 228049 MadridSpain Synchrotron SOLEIL L’Orme des MerisiersDépartementale 12891190France

The electrochemical CO_(2) reduction reaction(CO_(2)RR) to controllable chemicals is considered as a promising pathway to store intermittent renewable energy. Herein, a set of catalysts based on copper-nitrogendoped carbon xerogel(Cu-n-C) are successfully developed varying the copper amount and the nature of the copper precursor, for the efficient CO_(2)RR. The electrocatalytic performance of Cu-n-C materials is assessed by a rotating ring-disc electrode(RRDE), technique still rarely explored for CO_(2)RR. For comparison, products are also characterized by online gas chromatography in a H-cell. The as-synthesized Cu-nC catalysts are found to be active and highly CO selective at low overpotentials(from -0.6 to -0.8 V ***) in 0.1 m KHCO_(3), while H_(2) from the competitive water reduction appears at larger overpotentials(-0.9 V vs. RHE). The optimum copper acetate-derived catalyst containing Cu-n_(4) moieties exhibits a CO_(2)-to-CO turnover frequency of 997 h^(-1) at -0.9 V vs. RHE with a H_(2)/CO ratio of 1.8. These results demonstrate that RRDE configuration can be used as a feasible approach for identifying electrolysis products from CO_(2)RR.

关键词： Cu-n-C Carbon xerogel Rotating ring disc electrode Carbon dioxide reduction reaction Carbon monoxide

Greatly enhanced corrosion/wear resistances of epoxy coating for mg alloy through a synergistic effect between functionalized graphene and insulated blocking layer

在线全文

学校读者我要写书评

暂无评论

journal of magnesium and Alloys 2024年第1期12卷 332-344页

作者： Z.y.Xue X.j.Li j.H.Chu m.m.Li D.n.Zou L.B.Tong School of metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China State Key Laboratory of Advanced Design and manufacturing for Vehicle Body Hunan UniversityChangsha 410082China

The poor corrosion and wear resistances of mg alloys seriously limit their potential applications in various *** conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient *** the current study,we design a double-layer epoxy composite coating on mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly *** outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)*** FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier *** Ce film connects the outer layer with the substrate,showing the transition *** corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling *** synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of mg alloys.

关键词： mg alloy Functionalized graphene Epoxy coating Corrosion/wear resistance Blocking layer

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2024年第4期45卷 663-676页

作者： y.ZARE m.T.mUnIR G.j.WEnG K.y.RHEE Biomaterials and Tissue Engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and Technology American University of the Middle EastEgaila 54200Kuwait Department of mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

CO oxidation under lean and stoichiometric conditions over ceriazirconia with very low metal contents(Cu,Co,Ag and Pt)

在线全文

学校读者我要写书评

暂无评论

journal of Rare Earths 2024年第9期42卷 1669-1681页

作者： j.C.martínez-munuera m.P.yeste A.García-García mCmA Group Department of Inorganic Chemistry and Institute of MaterialsUniversity of Alicante Solid Chemistry and Catalysis Group Department of Materials ScienceMetallurgic Engineering and Inorganic ChemistryInstitute of Electronic Microscopy and Materials ResearchUniversity of Cádiz

In this work,several ceria-zirconia based catalysts with very lo w（and equimolar） metal contents were prepared,characterised and tested for the CO oxidatio n reaction（under lean and stoichiometric conditions）,trying to emulate those conditions found in a diesel oxidation catalyst（DOC） system from a diesel engine and those encountered under gasoline exhaust（λ=1）.The metals chosen are Cu,Co,Ag and Pt（as a reliable benchmark）.The results reveal enormous differences among reducibility and catalytic activity despite quite similar structural and textural properties of the catalysts,showing differences among dispersion（Ag-catalyst seems to present a low level of dispersion）.This catalyst seems to be characterised,as well,by a strong electronic interaction between Ce and Ag centres which is suggested to yield an improved reducibility under H2-TPR ***,the order in catalytic activity（Cu>Ag>Co≈Pt>>support） seems not to follow the order found in reducibility and the Cu-catalyst seems to be the most active independently on the reaction conditions,yielding nearly overlapped CO oxidation catalytic *** restingly,a stro ng correlation between the catalytic activity under the two conditions tested and the OSC values of the Ce0.8Zr0.2O2-supported metal catalysts is ***,OSC parameter measured at 150℃ can be used as a relevant descriptor to evaluate the CO oxidation activity at low and medium conversions for the investigated catalysts,much better than the H2-TPR measurements.

关键词： CO oxidation Low metal content Ceria-zirconia Copper species OSC parameter Rare earths

A Tutorial on Federated Learning from Theory to Practice:Foundations,Software Frameworks,Exemplary Use Cases,and Selected Trends

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

IEEE/CAA journal of Automatica Sinica 2024年第4期11卷 824-850页

作者： m.Victoria Luzón nuria Rodríguez-Barroso Alberto Argente-Garrido Daniel jiménez-López jose m.moyano javier Del Ser Weiping Ding Francisco Herrera Department of Software Engineering Andalusian Research Institute in Data Science and Computational Intelligence(DaSCI)University of GranadaGranada 18071Spain Department of Computer Science and Artificial Intelligence Andalusian Research Institute in Data Science and Computational Intelligence(DaSCI)University of GranadaGranada 18071Spain Department of Communications Engineering University of the Basque Country(UPV/EHU)and also with TECNALIABasque Research&Technology Alliance(BRTA)Spain School of Information Science and Technology Nantong UniversityNantong 226019China

When data privacy is imposed as a necessity,Federated learning(FL)emerges as a relevant artificial intelligence field for developing machine learning(mL)models in a distributed and decentralized *** allows mL models to be trained on local devices without any need for centralized data transfer,thereby reducing both the exposure of sensitive data and the possibility of data interception by malicious third *** paradigm has gained momentum in the last few years,spurred by the plethora of real-world applications that have leveraged its ability to improve the efficiency of distributed learning and to accommodate numerous participants with their data *** virtue of FL,models can be learned from all such distributed data sources while preserving data *** aim of this paper is to provide a practical tutorial on FL,including a short methodology and a systematic analysis of existing software ***,our tutorial provides exemplary cases of study from three complementary perspectives:i)Foundations of FL,describing the main components of FL,from key elements to FL categories;ii)Implementation guidelines and exemplary cases of study,by systematically examining the functionalities provided by existing software frameworks for FL deployment,devising a methodology to design a FL scenario,and providing exemplary cases of study with source code for different mL approaches;and iii)Trends,shortly reviewing a non-exhaustive list of research directions that are under active investigation in the current FL *** ultimate purpose of this work is to establish itself as a referential work for researchers,developers,and data scientists willing to explore the capabilities of FL in practical applications.

关键词： Data privacy distributed machine learning federated learning software frameworks

Interpolation of closed ideals of bilinear operators

在线全文

学校读者我要写书评

暂无评论

Acta mathematica Sinica,English Series 2024年

作者： Fernando COBOS Luz m.FERnánDEZ-CABRERA Antón mARTínez Departamento de Análisis matemático y matemática Aplicada Facultad de MatemáticasUniversidad Complutense de Madrid Sección Departamental del Departamento de Análisis matemático y matemática Aplicada Facultad de Estudios EstadísticosUniversidad Complutense de Madrid Departamento de matemática Aplicada I Escuela de Ingeniería IndustrialUniversidad de Vigo

AbstractWe extend the （outer） measureγIassociated to an operator ideal I to a measureγjfor bounded bilinear *** I is surjective and closed,and j is the class of those bilinear operators such thatγj（T）=0,we prove that j coincides with the composition bideal I o *** I satisfies the ∑r-condition,we establish a simple necessary and sufficient condition for an interpolated operator by the real method to belong to ***,if in addition I is symmetric,we prove a formula for the measureγjof an operator interpolated by the real *** particular,results apply to weakly compact operators.

关键词：

Characterization of bright betatron radiation generated by direct laser acceleration of electrons in plasma of near critical density

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

matter and Radiation at Extremes 2024年第2期9卷 26-35页

作者： j.Cikhardt m.Gyrdymov S.Zähter P.Tavana m.m.Günther n.Bukharskii n.Borisenko j.jacoby X.F.Shen A.Pukhov n.E.Andreev O.n.Rosmej Faculty of Electrical Engineering Czech Technical University in Prague16627 Prague 6Czech Republic Goethe University FrankfurtMax-von-Laue-Straße 160438 Frankfurt am MainGermany GSI Helmholtzzentrum für Schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany Focused Energy GmbH Im Tiefen See 4564293 DarmstadtGermany national Research nuclear University mEPhI Kashirskoe shosse 31115409 MoscowRussian Federation Lebedev Physical Institute RAS Leninskiy Prospekt 53119991 MoscowRussian Federation Heinrich-Heine-University Düsseldorf Universitätsstrasse 1DüsseldorfGermany joint Institute for High Temperatures RASIzhorskaya st.13Bldg.2125412 MoscowRussian Federation moscow Institute of Physics and Technology Institutskiy Pereulok 9141700 DolgoprudnyRussia

Directed x-rays produced in the interaction of sub-picosecond laser pulses of moderate relativistic intensity with plasma of near-critical density are investigated. Synchrotron-like (betatron) radiation occurs in the process of direct laser acceleration (DLA) of electrons in a relativisticlaser channel when the electrons undergo transverse betatron oscillations in self-generated quasi-static electric and magnetic fields. In anexperiment at the PHELIX laser system, high-current directed beams of DLA electrons with a mean energy ten times higher than the ponderomotive potential and maximum energy up to 100 meV were measured at 10^(19) W/cm^(2)laser intensity. The spectrum of directed x-raysin the range of 5–60 keV was evaluated using two sets of Ross filters placed at 0°and 10°to the laser pulse propagation axis. The differential x-ray absorption method allowed for absolute measurements of the angular-dependent photon fluence. We report 10^(13) photons/sr withenergies >5 keV measured at 0°to the laser axis and a brilliance of 10^(21) photons s^(−1) mm^(−2) mrad−2(0.1%BW)−1. The angular distributionof the emission has an FWHm of 14°–16°. Thanks to the ultra-high photon fluence, point-like radiation source, and ultra-short emissiontime, DLA-based keV backlighters are promising for various applications in high-energy-density research with kilojoule petawatt-class laserfacilities.

关键词： laser acceleration critical

Solid-liquid extraction for yttrium recovery using porous polymeric resin（XAD-7） functionalized with D2EHPA

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Rare Earths 2024年第9期42卷 1764-1773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 Engineering metropolitan Autonomous University Department of MaterialsBasic Sciences and Engineering Center for Research and Technological Innovation CIITECIPN

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 supported on a macro porous polymeric resin XAD-7（solid phase）.yttrium ions extraction and discharge 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 conditions for yttrium ions extraction are;20 vol% D2EHPA 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 [H2SO4] 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 determined as a second-order ***,experiments 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 H2SO4,demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

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

Experimental test of a building thermal system for preventive maintenance based on thermoeconomic analysis

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Energy Storage and Saving 2024年第1期3卷 42-51页

作者： I.Prol-Godoy A.Picallo-Perez j.m.Sala-Lizarraga j.Rey-martínez Research group EnEDI Department of Thermal EngineeringUniversity of the Basque Country(UPV/EHU)Bilbao48013Spain Research Group Termotecnia University of ValladolidValladolid47002Spain

An analysis of the sectorial structure of energy consumption shows that residential and tertiary sector buildings are the third-highest consumers,responsible for 29.5%of a city’s final energy *** Building Quality Control Laboratory of the Basque Government aims to promote quality,innovation,and sustainability in *** accomplish this goal,it has constructed an experimental facility with different energy generation technologies and a very versatile control system for testing different energy systems and operation *** this study,we tested a facility for supplying domestic hot water and heating for a multi-family house by means of a condensing boiler and an aerothermal heat pump(together with the corresponding control).This installation could reproduce the thermal demands required to be satisfied by the generation equipment through a programmed operation of the installation based on real ***,this installation was analyzed using thermoeconomics(TE)to solve problems unable to be solved using traditional energy analyses based on the First Law of *** problems include:(1)Determining the costs of the products of the installation based on physical criteria,(2)detecting the places where losses actually occur,evaluating their costs,and proposing cost-effective improvements,and(3)diagnosing issues in the *** a result,this paper suggests a solution to the preventive maintenance problems confronting the technical maintenance personnel for thermal installations in buildings by applying TE knowledge and using real data collected from sensors.

关键词： Experimental essay Energy savings in thermal systems Thermoeconomics Thermoeconomic costs Diagnosis