简介：

简介：

简介：

简介：采用2步水热法合成了LaPO4∶Eu3＋-Fe3O4复合材料.在LaPO4∶Eu3＋-Fe3O4复合材料中,LaPO4∶Eu3＋为单斜晶相,呈纳米棒状,纳米棒的直径和长度分别为20-100nm和0.2-1μm;Fe3O4为正交晶相、呈20-30nm的颗粒状,Fe3O4粒子紧紧附着在LaPO4∶Eu3＋纳米棒的表面;样品的磁性和发光性质研究表明所合成的LaPO4∶Eu3＋—Fe3O4复合材料既具有发光性质又具有磁性.

简介：研究目的：研究新型磁性回热填料Gd2O2S对液氦温区高频脉管制冷机多级回热器损失特性的影响。创新要点：确定了不同回热填料以及运行参数（频率、平均压力）下液氦温区多级脉管制冷机的制冷温度和各级预冷量，进一步明确了4K高频回热损失机理。研究方法：采用理论研究与实验验证相结合的方法，基于一台两级G-M型低频脉管制冷机预冷的单极斯特林型高频脉管制冷机，研究多级回热器在高频以及4K温区下的损失特性。选取新型回热填料Gd2O2S替代部分回热填料HoCu2，比较回热器采用两种填料时在不吲运行频率及平均压力下的冷端制冷温度（图10）、各级预冷量和预冷温度（图1112）。重要结论：采用孔隙率较小的新型磁性回热填料Gd2O2S可显著改善第一级回热器内压力波与质量流的相位关系，从而减小该级回热损失。减小平均压力可以降低制冷机无负荷制冷温度并减小第二级预冷量，但制冷工质氦的体积比热容会急剧增大，从而使低温级回热器的换热对频率非常敏感。此外，频率对高温级回热器的回热特性影响不明显。该方法可以为三级斯特林型4K多级脉管制冷机提供设计依据。

简介：InthispaperweusedMOF-5andCu3(BTC)2toseparateCO2/CH4andCH4/N2mixturesunderdynamicconditions.Bothmaterialsweresynthesizedandpelletized,thusallowingforameaningfulcharacterizationinviewofprocessscale-up.ThematerialswerecharacterizedbyX-raydiffraction(XRD)andscanningelectronmicroscopy(SEM).Byperformingbreakthroughexperiments,wefoundthatCu3(BTC)2separatedCO2/CH4slightlybetterthanMOF-5.BecausethecrystalstructureofCu3(BTC)2includesunsaturatedaccessiblemetalsitesformedviadehydration,itpredominantlyinteractedwithCO2moleculesandmoreeasilycapturedthem.Conversely,MOF-5withasuitableporesizeseparatedCH4/N2moreefficientlyinourbreakthroughtest.

简介：Inthisreport,wepresentasimulatedresultontheion-massindependenceoftheguidedtransmission,whichisinagreementwiththepreviousexperimentalresults[1].Inordertosearchtheinuenceoftheionmassonguidedtransmission,variousspeciesofionsusedasprojectilesinsimulations.Fig.1showsthetransmissionfractionsforNe7+,Ar7+,Kr7+,andXe7+ions.Thesedatawereacquiredfortiltangleof2inenergyof7keV.Itisseenthatallofionfractionsgraduallyrisesafteratimedelay,andnallyreachstable.

简介：

简介：Morelocalizedenergydepositionisabletobeproducedinantiproton-nucleuscollisionsincomparisonwithheavy-ioncollisionsduetoannihilationreactions.Searchingforthecoldquark-gluonplasma(QGP)withantiprotonbeamshasbeenconsideredasahottopicbothinexperimentsandinthereticalcalculationsoverthepastseveraldecades.Strangenessproductionandhypernucleusformationinantiproton-inducednuclearreactionsareimportanceinexploringthehyperon(antihyperon)-nucleon(HN)potentialandtheantinucleon-nucleoninteraction,whichhavebeenhottopicsintheforthcomingexperimentsatPANDAinGermany.

简介：

简介：MoleculardynamicssimulationsareperformedtostudythegrowthmechanismofCH4-CO2mixedhydrateinxCO2=75%,xCO2=50%,andxCO2=25%systemsatT=250K,255Kand260K,respectively.OursimulationresultsshowthatthegrowthrateofCH4-CO2mixedhydrateincreasesastheCO2concentrationintheinitialsolutionphaseincreasesandthetemperaturedecreases.Viahydrateformation,thecompositionofCO2inhydratephaseishigherthanthatininitialsolutionphaseandtheencagingcapacityofCO2inhydratesincreaseswiththedecreaseintemperature.ByanalysisofthecageoccupancyratioofCH4moleculesandCO2moleculesinlargecagestosmallcages,wefindthatCO2moleculesarepreferablyencagedintothelargecagesofthehydratecrystalascomparedwithCH4molecules.Interestingly,CH4moleculesandCO2moleculesfrequentlyreplacewitheachotherinsomeparticularcagesitesadjacenttohydrate/solutioninterfaceduringthecrystalgrowthprocess.Thesetwospeciesofguestmoleculeseventuallyacttostabilizethenewlyformedhydrates,withCO2moleculesoccupyinglargecagesandCH4moleculesoccupyingsmallcagesinhydrate.

简介：利用水热合成方法合成了2个新的双核稀土-异烟酸配合物修饰的Dawson型有机-无机杂化化合物[Ln2（HINC）4（H2O）8（P2W18O62）]·nH2O（Ln=Ce（1）,Eu（2）;n=16（1）,9（2）;INC=4-吡啶羧酸/异烟酸）.化合物1与2同构,并通过红外光谱、元素分析和X-射线单晶衍射方法确定了该化合物的晶体结构.单晶结构分析表明化合物1属于三斜晶系,P-1空间群,晶胞参数a=1.3236（3）nm,b=1.8650（4）nm,c=2.2872（5）nm,α=67.26（3）°,β=78.01（3）°,γ=70.34（3）°,V=4.8838（17）nm3,Z=2.化合物2也属于三斜晶系,P-1空间群,晶胞参数a=1.3201（2）nm,b=1.8569（3）nm,c=2.2856（4）nm,α=67.378（2）°,β=77.745（3）°,γ=70.039（3）°,V=4.8398（13）nm3,Z=2.

简介：<正>一、中考内容要求"整式与分式"这部分内容,主要涉及的考点有:整式与分式的概念和运算,因式分解和分式的基本性质.试题难度为低、中档,题型多为选择题、填空题、计算题的形式出现,着重考查基础知识、基本技能和基本方法.近年来中考的热点是化简、求值的考查,旨在让学

简介：Highenergyprotonbeamhasthelongpenetrationlengthinsolidmatteranditcouldproducetheradiographsandindicatethetomographyandmaterialpropertiesinsideofthespecimen.Consideringtheexpensivecoststoconstructahighenergyprotonaccelerator,theothercandidateofhighenergyelectronbeambecomesmoreacceptable[1??3].Duetothehighspatialandtemperalresolutionofhighenergyelectronbeam.Itisapowertooltodiagnosetheinnerstructurechangeduringthehighenergydensitymatterproductionandtheinertialconfinementfusionprocess.Inordertostudythedensityresolutionofthehighenergyelectronbeamradiography,astep-targetwasdesignedandproduced.ThestructureandthetargetpicturesareshowninFig.1andtheSitargetswithdifferentslot-widthwereproducedbyusingthemicroetchtechnics.

简介：TemperatureisoneofthekeythermodynamicparametersofHEDmatter.Asapopulartechnique,thepyrometerofnarrow-bandlterstogetherwithphotodiodes(namelymulti-channelpyrometer)hasbeenapplied.However,thepyrometercanonlymeasureone-positiontemperatureinsingleshot[1;2].Actually,itisveryimportanttoknowtemperatureevolutionofmultiplepositionsinsingleshot,especiallyforthetargetinducedbyheavyionbeam,wherealargevolumeofHEDmattercanbegenerated.Consequently,afastnew-typepyrometerhasbeendesigned.

简介：Thiscontributionreportsethylenepolymerizationbehavioroftitaniumcomplexesincorporatingbis(phenoxyimine)ligands.Sixphenoxy-imineTi(IV)complexes{6-R1-2-[CH=N(2,6-difluoro-3,5-diR2-4-R3Ph)]C6H3O}2TiCl2(1:R1=H,R2=H,R3=H;2:R1=H,R2=H,R3=4-vinylphenyl;3:R1=CH3,R2=H,R3=H;4:R1=CH3,R2=H,R3=4-vinylphenyl;5:R1=CH3,R2=F,R3=H;6:R1=CH3,R2=F,R3=4-vinylphenyl)havebeensynthesizedandevaluatedforethylenepolymerizationusingdriedMAO(simplifiedasDMAO)ascocatalyst.AnobviouscatalyticheterogeneityofCat2(Complex2/DMAO)towardsethylenepolymerizationwasobserved,whichwasillustratedbydecreasedactivity,multimodalmolecularweightdistributionandpartiallyimprovedparticlemorphologycomparingwithCat1.Moreover,Cat3exhibits'living'characteristicsintheprocessundercertainconditions(25°C,lessthan20min).Otherwise,themoderatetohighethylenepolymerizationactivityofca.105-106gPE/(molTi·h)andhighmolecularweight(Mw=105-106)ofpolyethylenecanbeobtainedbychangingtheskeletonstructureofthesecomplexes.

简介：Grapheneistwodimensionalmaterialswhichismadeofhoneycombedcarbonatoms.Itattractsextensiveinterestsforitswonderfulcharacteristicsthatmakethegrapheneapotentialcandidateinfieldsofmicroelectronicsproduction,moleculedetection,desalinationandDNAsequencing.Highlychargedion(HCI)hashugepotentialenergyforpeelingoffelectrons.Wheninteractingwithsolidsurface,theHCIdistortedthesolidlatticeviapotentialdepositionandthenthenanostructureswereformedonthesolidsurface.TheHCIwasexpectedasatoolforsurfacemodification.Inthiswork,HOPGandgraphemewereirradiatedwithXeq+andArq+ions.ThetypicalRamanspectraofgrapheneandHOPGirradiatedwithhighlychargedionswereshowninFig.1.TheDpeakappearedat1335cm??1onthespectraofgrapheneirradiatedwithhighlychargedions.TheintensityofDpeakincreasedwithfluence.TheratioofintensityofDpeaktothatofGpeakvariedwithfluenceinFig.2.Theratioroselinearlywiththesquarerootoffluencewhenfluencewaslow.Theratiosaturatedwhentheirradiationfluencewashigh.Thecriticalfluencedependedonthechargestateofion.Thehigherchargestateitwas,thelowercriticalfluenceitwouldbe.

简介：Duetolowactivationcharacteristics,desirablehigh-temperaturestrength,goodresistancetoradiationdamageandusablefabricationproperties,vanadium(V)alloysareattractivecandidatestructuralmaterialsforfusionreactors[1].Irradiationinducedhardening/embrittlementatlowtemperatureisamajorproblemforthematerialsapplicationinfusionreactor[2].Inthisstudy,H/Heionswithvariousenergieswereusedtoirradiateapurevanadium(V)andaValloy(V-4Ti)toobtainadamageplateaufromsamplesurfacetothedepthof1.5m,asshowninFig.1[3].Thedetailsofirradiationparameters(energies,fluences)forHandHeionsareshowninTable1.NanoindentationwasperformedtoinvestigatethehardeningbehaviorofV-4TialloyandpureVunderirradiation.

简介：Thenanomaterialsoftenexhibitveryinterestingelectrical,optical,magnetic,andchemicalproperties,whichcannotbeachievedbytheirbulkcounterparts[1-7].Thedevelopmentofuniformnanometersizedparticleshasbeenintensivelypursuedbecauseoftheirtechnologicalandfundamentalscientificimportance[8-15].Itissignificantthatnanostructuredmaterialscanbecontrollablyassembledintotherequiredgeometryontosubstrates,becomingthebasisofthenextgenerationofcomponentsanddevices[16-31].Thedevelopmentofnewmethodsandstrategiesfororganizingthenanoparticlebasicbuildingblocksintothedesiredstructuresisrequired.Superlatticesmadefromthesebuildingblocksgiveustheopportunitytostudynotonlythepropertiesoftheindividualbuildingblocks,butalsocollectiveeffects.Thesuperparamagneticironoxidenanocrystals(NCs)havebeenusedinthefieldsofbio-medicine,ferrofluids,refrigerationsystem,catalysis,particularlyinmagneticresonanceimaging,tissueengineering,anddrugdeliveryapplications[32-42].

简介：