检索结果-南通市图书馆

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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1期42卷 66-75页

作者： s.W.Wi Y.s.Lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 Codoping of Li + Photoluminescence sensitizer Rare earths

fast efficient photon deceleration in plasmas by using two laser pulses at different frequencies

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3期9卷 11-18页

作者： Y.X.Wang X.L.Zhu s.M.Weng P.Li X.f.Li H.Ai H.R.Pan Z.M.sheng Key Laboratory for Laser Plasmas(moe) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of IfsA Shanghai Jiao Tong UniversityShanghai 200240China Research Center of Laser fusion of China Academy of Engineering Physics MianyangSichuan 621900China state key Laboratory of High field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghai 201800China Tsung-dao Lee Institute Shanghai Jiao Tong UniversityShanghai 200240China

The generation of ultrashort high-power light sources in the mid-infrared(mid-IR)to terahertz(THz)range is of interest for applications in a number of fields,from fundamental research to biology and *** conventional laser technology,photon deceleration in plasma wakes provides an alternative approach to the generation of ultrashort mid-IR or THz ***,we present a photon deceleration scheme for the efficient generation of ultrashort mid-IR or THz pulses by using an intense driver laser pulse with a relatively short wavelength and a signal laser pulse with a relatively long *** signal pulse trails the driver pulse with an appropriate time delay such that it sits at the front of the second wake bubble that is driven by the driver *** to its relatively long wavelength,the signal pulse will be subjected to a large gradient of the refractive index in the plasma wake ***,the photon deceleration in the plasma wake becomes faster and more efficient for signal pulses with longer *** greatly enhances the capacity and efficiency of photon deceleration in the generation of ultrashort high-power light sources in the long-wavelength IR and THz spectral ranges.

关键词： laser ultrashort photon

Collisionless shock acceleration of protons in a plasma slab produced in a gas jet by the collision of two laser-driven hydrodynamic shockwaves

在线全文

维普期刊数据库

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 12-25页

作者： J.-R.Marquès L.Lancia P.Loiseau P.forestier-Colleoni M.Tarisien E.Atukpor V.Bagnoud C.Brabetz f.Consoli J.Domange f.Hannachi P.Nicolaï M.salvadori B.Zielbauer LULI CNRSÉcole PolytechniqueCEASorbonne UniversitéInstitut Polytechnique de Paris91128 Palaiseau CedexFrance CEA DAMDIF91297 Arpajon CedexFrance UniversitéParis-saclay CEALMCE91680 Bruyères-le-ChatelFrance CENBG CNRS-IN2P3Universitéde Bordeaux33175 Gradignan CedexFrance GsI Helmholtzzentrum für schwerionenforschung GmbH Planckstraße 164291 DarmstadtGermany University of Darmstadt Schloßgartenstr.764289 DarmstadtGermany ENEA fusion and Technologies for Nuclear safety Department C.R.FrascatiVia Enrico Fermi 45FrascatiRomeItaly CELIA Universitéde Bordeaux–CNRS–CEA33405 TalenceFrance UniversitéParis-saclay CEALIDYL91191 Gif-sur-YvetteFrance

We have recently proposed a new technique of plasma tailoring by laser-driven hydrodynamic shockwaves generated on both sides of a gas jet[Marquès et al.,*** 28,023103(2021)].In a continuation of this numerical work,we study experimentally the influence of the tailoring on proton acceleration driven by a high-intensity picosecond laser in three cases:without tailoring,by tailoring only the entrance side of the picosecond laser,and by tailoring both sides of the gas *** tailoring,the acceleration is transverse to the laser axis,with a low-energy exponential spectrum,produced by Coulomb *** the front side of the gas jet is tailored,a forward acceleration appears,which is significantly enhanced when both the front and back sides of the plasma are *** forward acceleration produces higher-energy protons,with a peaked spectrum,and is in good agreement with the mechanism of collisionless shock acceleration(CsA).The spatiotemporal evolution of the plasma profile is characterized by optical shadowgraphy of a probe *** refraction and absorption of this beam are simulated by post-processing 3D hydrodynamic simulations of the plasma *** with the experimental results allows estimation of the thickness and near-critical density of the plasma slab produced by tailoring both sides of the gas *** parameters are in good agreement with those required for CsA.

关键词： acceleration hydrodynamic collision

Heat and mass transfer of a circular porous moist object located in a triangular shaped vented cavity

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 Central south University 2024年第6期31卷 1956-1972页

作者： sELIMEfENDIGIL fatih OZCAN COBAN seda OZTOP Hakan f Department of Mechanical Engineering College of EngineeringKing Faisal UniversityAl Ahsa 31982Saudi Arabia Department of Mechanical Engineering Manisa Celal Bayar UniversityManisa 45140Turkey Department of Mechanical Engineering Technology FacultyFırat UniversityElazığTurkey

Heat and mass transfer of a circular-shaped porous moist object inside a two-dimensional triangle cavity is investigated by using finite element *** porous object is considered to be a moist food sample,located in the middle of the cavity with inlet and outlet ports with different configurations of inlet/outlet *** drying performance is numerically assessed for different values of Reynolds numbers(between 50 and 250),dry air inlet temperature(between 40 and 80℃)and different locations of the *** is observed that changing the port locations has significant impacts on the flow recirculaitons inside the triangular chamber while convective drying performance is highly *** moisture content reduces with longer time and for higher Reynolds number(Re)*** P4 where inlet and outlet ports are in the middle of the walls provides the most effective configuration in terms of convective drying performance while the worst case is seen for P1 case where inlet and outlet are closer to the corners of the *** is a 192% difference between the moisture reduction of these two cases at Re=250,T=80℃ and t=120 min.

关键词： convective drying porous domain cavity flow inlet/exit port finite element method

first evidence for chiral wobbling of triaxial nuclei

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear science and Techniques 2024年第7期35卷 4-7页

作者： s.frauendorf Department of Physics and Astronomy University of Notre DameNotre DameIN 46556USA

Chirality(Greek“handiness”)is a property of many com-plex *** molecules exist in two forms,one being the mirror image of the *** for our hands,it is impossible to make the images identical by a suitable *** two forms are called left-handed and *** have the same binding energy,because the electro-magnetic interaction,which holds the molecule together,does not change under a *** properties that are insensitive to the geometry are also the *** different geometry is the reason why the left-handed form turns the polarization plane of transmitted light in one direction by some angle while the right-handed form turns it in the oppo-site direction by the same ***,the geometrical differences between the two species may have other *** two species of the carvon molecule shown in fig.1 taste quite differently.

关键词： turns Chiral mirror

维普期刊数据库

Tribological behavior of lubricant-impregnated porous polyimide

在线全文

学校读者我要写书评

暂无评论

friction 2024年第4期12卷 711-725页

作者： Jinbang LI Ningning ZHOU Janet s.s.WONG school of Mechanical Engineering and Mechanics Ningbo UniversityNingbo 315211China Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms Beijing Institute of Control EngineeringBeijing 100029China Department of Mechanical Engineering Imperial College LondonLondon SW72AZUK

Porous materials impregnated with lubricants can be used in conditions where limited lubricant is *** this work,three porous polyimides(PPI)with different densities were ***(PAO)impregnated PPI(iPPI)discs were rubbed against steel and sapphire *** operando observations of the iPPI-sapphire contacts show that oil is released under an applied load,forming a meniscus around *** at the outlet is created at high sliding *** amount of released oil increases with increasing PPI *** moduli,E*,estimated based on the actual contact size show that trapped oil in iPPIs contributes to load *** higher speeds,tribological rehydration of the contact occurs in low density iPPI,with that E*rises with *** high density PPIs,high speeds give a constantly high E*which is limited by the viscoelastic properties of the PPI network and possibly the rate of oil *** of iPPI-steel contacts is governed by the mechanical properties of the PPI,the flow of the lubricant,and the roughness of the PPI *** low-and medium-density(highly porous,high roughness)PPIs,large amount of oil is released,and lubrication is mainly via lubricant restricted in the contact in the pores and possibly tribological *** high density(low porosity)PPI,with lower roughness,hydrodynamic lubrication is achieved which gives the lowest *** results show that polymeric porous materials for effective lubrication require the optimization of its surface roughness,stiffness,oil flow,and oil retentions.

关键词： polyimide porous material friction mechanism polymer limited lubrication

Biomass gasification,catalytic technologies and energy integration for production of circular methanol:New horizons for industry decarbonisation

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 Environmental sciences 2024年第6期140卷 306-318页

作者： Luis f.Bobadilla Lola Azancot Miriam González-Castañ Estela Ruíz-López Laura Pastor-Pérez francisco J.Durán-Olivencia Runping Ye Katie Chong Paula HBlanco-sánchez Zenthao Wu Tomás R.Reina JoséA.Odriozola Departamento de Química Inorgánica e Instituto de Ciencia de Materiales de sevilla Centro Mixto CSIC-Universidad de SevillaAvda.Américo Vespucio 49Sevilla 41092Spain Departamento de Ingeniería Universidad Loyola AndalucíaAvda.de Las Universidades s/nSevilla 41704Spain Key Laboratory of Jiangxi Province for Environment and Energy Catalysis School of Chemistry and Chemical EngineeringNanchang UniversityNanchang330031China Energy and Bioproducts Research Institute(EBRI) Aston UniversityBirminghamB47ETUnited Kingdom Department of Chemical and Process Engineering University of SurreyGuildfordGU27XHUnited Kingdom

The Intergovernmental Panel on Climate Change(IPCC)recognises the pivotal role of renewable energies in the future energy system and the achievement of the zero-emission *** implementation of renewables should provide major opportunities and enable a more secure and decentralised energy supply *** fuels provide long-term solutions for the transport sector,particularly for applications where fuels with high energy density are *** addition,it helps reducing the carbon footprint of these sectors in the *** on biomass characteristics feedstock is essential for scaling-up gasification from the laboratory to *** review deals with the transformation biogenic residues into a valuable bioenergy carrier like biomethanol as the liquid sunshine based on the combination of modified mature technologies such as gasification with other innovative solutions such as membranes and microchannel *** abatement is a critical process in product gas upgrading since tars compromise downstream processes and equipment,for this,membrane technology for upgrading syngas quality is discussed in this *** reactor technology with the design of state-of-the-art multifunctional catalysts provides a path to develop decentralised biomethanol synthesis from biogenic ***,the development of a process chain for the production of(i)methanol as an intermediate energy carrier,(ii)electricity and(iii)heat for decentralised applications based on biomass feedstock flexible gasification,gas upgrading and methanol synthesis is analysed.

关键词： Biogenic residues Gasification Biomethanol Circular Economy Microreactors

维普期刊数据库

Linking IL-10 signaling with lipid metabolic programs in macrophages:dysregulated ceramide homeostasis drives colitis

在线全文

学校读者我要写书评

暂无评论

signal Transduction and Targeted Therapy 2024年第7期9卷 2835-2836页

作者： Imke Atreya Markus f.Neurath Department of Medicine 1 University Hospital of ErlangenFriedrich-Alexander University Erlangen-NürnbergErlangenGermany Deutsches Zentrum Immuntherapie(DZI) ErlangenGermany

In a recent study published in Nature,York and coworkers identified the immunometabolic regulation of mono-unsaturated fatty acid(MUfA)pools and the subsequent increase in sphingolipid biosynthesis in TLR2-activated macrophages as an important link between impaired IL-10 signaling and the development of intestinal inflammation.1 Thus,targeted interference with the newly identified IL-10/MUfA/sphingolipid axis appears as a promising strategy to restore immunometabolic homeostasis in the intestine of patients with inflammatory bowel diseases(IBD).

关键词： homeostasis impaired intestine

Comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable Mg-3Y alloy prepared by selective laser melting and spark plasma sintering

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 Magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： P.Minárik M.Zemková s.Šašek J.Dittrich M.Knapek f.Lukáˇc D.Koutný J.Jaroš R.Král faculty of Mathematics and Physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of Plasma Physics of the Czech Academy of sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of Machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable magnesium alloy Mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(sPs)and selective laser melting(sLM).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the sLM material and unmeasurably low porosity in the sPs *** main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion *** materials showed comparable strength of∼110 MPa in tension and compression and relatively good deformability of∼9%and∼21%for the sLM and sPs materials,*** corrosion resistance of the sPs material in 0.1 M NaCl solution was superior to the sLM one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the sLM *** the other hand,one of the primary outcomes of this study is that the sPs consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

关键词： Magnesium Yttrium Powder metallurgy Microstructure Mechanical strength Corrosion resistance

维普期刊数据库