简介:Inthisstudy,factorsaffectingthecrystalstructureofflame-synthesizedY2O3:Euparticleswereinves-tigated,especiallytheparticlesizeeffectanditsinteractionwithEudopingconcentration.PolydisperseY2O3:Eu(sizerange200nmto3m)powdersampleswithEudopingconcentrationsfrom2.5mol%to25mol%weregeneratedineitherH2/airorH2/O2substrate-freeflames.ThecrystalstructureofthepowdersampleswasdeterminedbypowderX-raydiffraction(XRD),whichwascomplementedbypho-toluminescence(PL)measurements.Singleparticlecrystalstructurewasdeterminedbysingleparticleselectedareaelectrondiffraction(SAED),andforthefirsttime,byelectronbackscatterdiffraction(EBSD).H2/airflamesresultedincubicphaseY2O3:Euparticleswithhollowmorphologyandirregularshapes.ParticlesfromH2/O2flameshaddenseandsphericalmorphology;sampleswithlowerEudopingconcen-trationshadmixedcubic/monoclinicphases;sampleswiththehighestEudopingconcentrationswerephase-puremonoclinic.ForsamplesgeneratedfromH2/O2flames,aparticlesizeeffectanditsinteractionwithEudopingconcentrationwerefound:particlessmallerthanacriticaldiameterhadthemonoclinicphase,andthiscriticaldiameterincreasedwithincreasingEudopingconcentration.Thesefindingssug-gestthattheformationofmonoclinicY2O3:Euisinevitablewhenextremelyhotsubstrate-freeflamesareused,becausetypicalflame-synthesizedY2O3:Euparticlesizesarewellbelowthecriticaldiameter.However,itmaybepossibletogenerateparticleswithdense,sphericalmorphologyandthedesiredcubicstructurebyusingamoderatelyhighflametemperaturethatenablesfastsinteringwithoutmeltingtheparticles.
简介:Weinvestigatetheeffectsofspontaneouslygeneratedcoherence(SGC)onboththesteadyandtransientgainpropertiesinafour-levelinverted-Y-typeatomicsysteminthepresenceofaweakprobe,twostrongcoherentfields,andanincoherentpump.Forthesteadyprocess,wefindthattheinversionlessgainmainlyoriginsfromSGC.Inparticular,wecanmodulatetheinversionlessgainbychangingtherelativephasebetweenthetwofields.Moreover,theamplitudeofthegainpeakcanbeenhancedandtheadditionalgainpeakcanappearbychangingthedetuningofthecouplingfield.Asforthetransientprocess,thetransientgainpropertiescanalsobedramaticallyaffectedbytheSGC.ComparedtothecasewithoutSGC,thetransientgaincanbegreatlyenhancedwithcompletelyeliminatedtransientabsorptionbychoosingtheproperrelativephasebetweenthetwofields.Andtheinverted-Y-typesystemwithSGCcanbesimulatedinbothatomicandsemiconductorquantumwellsystemsavoidingtheconditionsofSGC.
简介:Ca3Y2(BO3)(4):Eu3+黄磷被高温度solid-statereaction方法综合,并且光特征被调查。排放光谱在相应于电的dipoleD-5(0)的613和621nm展出二强壮的红排出物在365nm刺激下面的Eu3+的-F-7(2)转变,原因是Eu3+代替forY3+在Ca3Y2(BO3)(4)的水晶结构占据非中心对称的位置。为613nm的Theexcitation光谱显示黄磷能是有效地激动的由紫外(紫外)(254nm,365nm和400nm)并且蓝色(470nm)光。Ca3Y2(BO3)(4)的排放紧张上的Eu3+集中的效果:Eu3+黄磷被测量,排放紧张与增加Eu3+集中增加的结果表演,然后减少。Ca3Y2(BO3)(4)的CIE颜色坐标:Eu3+黄磷是(0.639,0.357)在15mol%Eu3+。
简介:阴极材料李[CoxNiyMn1?x?y]为锂的O2第二等的电池被一条新线路作为一位先锋用分层的双氢氧化物(LDH)准备了。结果有-NaFeO2结构的分层的阶段在菱形的系统结晶,与有到0.47nm的夹层间距结束的空格组R-3m。X光检查光电子光谱学(XPS)被用来测量公司,Ni和Mn的氧化状态。在结构和李的电气化学的性质上改变Co/Ni/Mn比率的效果[CoxNiyMn1?x?y]O2被X光检查衍射和电气化学的测试调查了。产品表明了相当稳定的骑车行为,与为有Co/Ni/Mn=1/1/1的分层的材料的118mAh/g的一个可逆能力。
简介:TiO2@ZrO2@Y2O3:有coremultishell结构的Eu3+合成粒子通过layer-by-layer(LBL)的联合被综合自己组装方法和一个solgel过程。获得的样品与扫描电子被描绘显微镜学(SEM),传播电子显微镜学(TEM),X光检查光电子光谱学(XPS),X光检查衍射(XRD),和荧光spectrophotometry。结果证明合成粒子有coremultishell结构,球形的形态学,和狭窄的尺寸分布。TiO2核心上的ZrO2层的存在能有效地阻止在TiO2核心和Y2O3壳之间的反应;为在在TiO2@ZrO2@Y2O3的TiO2核心和Y2O3壳之间的反应的温度:Eucoremultishell黄磷能被300提高
简介:theAlternatingSegmentCrank-Nicolsonschemeforone-dimensionaldiffusionequationhasbeendevelopedin[1],andtheAlternatingBlockCrank-Nicolsonmethodfortwo-dimensionalproblemin[2].Themethodshavetheadvantagesofparallelcomputing,stabilityandgoodaccuracy.Inthispaperforthetwo-dimensionaldiffusionequation,thenetregionisdividedintobands,aspecialkindofblock.ThismethodiscalledthealternatingBandCrank-Nicolsonmethod.
简介:Themassesofneutron-defcientnuclidesplayacriticalroleinthecalculationofastrophysicalrapidproton-captureprocesses[1].Neutron-defcientnuclideswithmassnumber∧around80arethelastsetofnuclideswithunknownmassesonthepathwayofvp-process[2].Themassmeasurementofnuclideswouldbeveryuseful.In2016,massesofneutron-defcientnuclides79Y,81Zr,82Zr,83Nband84Nbnucleiwerepreciselymeasureddirectlybytheexperimentalstorage-ringCSReatLanzhou.
简介:Poly(methylmetacrylate)(PMMA)/Y0.0025Si0.025Ba0.9725(Ti(0.9)Sn0.1)O3(YBTS)composites在YBTS的不同重量比率被准备(0wt%,5wt%,10wt%和20wt%YBTS)招待以便在PMMA的电、光的性质上调查YBTS增加的效果。电的性质(阻抗,绝缘的经常的绝缘的损失和交流电导率)在频率范围被学习10kHz-1MHz并且在温度范围20鈥?0掳C。在增加YBTS的内容之上陶器,我们在在绝缘的经常的、绝缘的损失和PMMA的交流电导率的阻抗和增加观察了减小主人。我们也发现在高YBTS内容的松驰过程由于在离子的传导性的松驰。吸收系数(伪)在波长范围被决定了230鈥?在为所有YBTS-PMMAcomposites的房间温度的00nm。而且,YBTS的增加陶器高度特别在300nm下面提高PMMA主人的紫外吸收。对PMMA主人陶器的20wt%YBTS的增加减少从5eV的光精力差距到3.41eV。关联在之间电,光并且SEM结果被报导。关键词电-光-PMMA,陶器-铁电体-Composites
简介:Bysimultaneouslyemployingbothanelectro-opticmodulatorandcarbonnanotubesaturableabsorber(CNT-SA)inadual-lossmodulator,asubnanosecondsinglemode-lockingpulseunderneathaQ-switchedenvelopewithhighpeakpowerwasgeneratedfromadoublyQ-switchedandmode-locked(QML)Nd:Lu0.15Y0.85VO4laserat1.06μmforthefirsttime,toourknowledge.CNTswithdifferentwallstructures—single-walledCNTs(SWCNTs),double-walledCNTs(DWCNTs),andmulti-walledCNTs(MWCNTs)—wereusedasSAsintheexperimenttoinvestigatethesinglemode-lockingpulsecharacteristics.Atpumppowerof10.72W,themaximumpeakpowerof1.312MWwasobtainedwiththeDWCNT.