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500 个结果
  • 简介:ResultsofinelasticneutronscatteringexperinientsandabinitiomoleculardynamicssimulationsforGeTe一theparentcompoundofphase-changematerialsarereported.TheinelasticneutronspectraofGeTepowdersampleshavebeendeterminedinthetemperaturerangeextendingfrom300to700K.Thephononpeaksundergothermalshiftsresultingfromanharmoniceffectsbeingweakerforacousticthanopticmodes.AsmallconcentrationoffreechargecarriesarisingfromthepresenceofGe-vacancieswasfoundnottoaffectsignificantlytheneutronweightedphonondensitiesofstatesofGeTe.Thespectralpatternchangesqualitativelyacrossthestructuralphasetransition,butthelocalstructureofGeTeremainshardlyaffected,asconfirmedbytheanalysisoftemperaturedependenceofthepairdistributionfunctionobtainedfromabinitiomoleculardynamicsinvestigations.Thepresenttheoreticalstudiessupportinawideextentourexperimentalobservationsandalsothoseprovidedbylocalprobemethods.

  • 标签: PHASE-CHANGE MAT erials INELASTIC neutron scattering
  • 简介:Basedoncontinuummechanics,wehavedevelopedamodelforsemi-quantitativeestimatingeffectsofphasecontinuityonflowstrengthoftwo-phaserocksincludingpartiallymeltedorcrystallizedrocks.Calculationsofthebulkflowstrengthofcompositerocksasfunctionsofthevolumefraction,geometricalshapeandcontinuityoftheconstitutivephasesinvolveinnumericallysolvingtwonon-linearequationsandthusareeasytobeperformed.Themodelhasbeenjustifiedbyagoodagreementbetweenthepredictedandmeasuredresultsondiabase(64%clinopyroxeneand36%plagioclase)intherangeofexperimentaltemperaturesandstrain-rates.Itisbelievedthatthepresentmodelcouldprovideanapproximateestimatefortherheologicalevolutionofmagmaticrocksduringtheirlifecycleofmelting-crystallization-deformation.

  • 标签: PHASE CONTINUITY TWO-PHASE ROCKS RHEOLOGY CONTINUUM
  • 简介:Phase Transitions in Sodium ClustersPhaseTransitionsinSodiumClusters¥ZhangFengshou;E.SuraudandR.GlowinskiMostofthetheoretical...

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  • 简介:Thesolid-phasesynthesisofisoxazolineson2-polystyrylsulfonamidoethanolresinisreported.2-Polystyrylsuifonamidoethanolresin1wasreactedwithacryloylchloridetoafford2-polystyrylsulfonylamidoethylacrylateresin2,whichwasfurtherreactedwithbrominatedaldoximesby[3+2]cycioadditiontogiveisoxazolineresin4.Resin4wastreatedwithaqueous6mol/LHCIsolutiontoobtainisoxazolinesingoodyieldandpurity.

  • 标签: 固相合成 异唑酮 2-聚苯乙烯基亚磺酰氨基乙醇
  • 简介:Anovelmethodforconvertinganarrayofout-of-phaselasersintooneofin-phaselasersthatcanbetightlyfocusedispresented.Themethodexploitssecond-harmonicgenerationandcanbeadaptedfordifferentlaserarraysgeometries.Experimentalandcalculatedresults,presentedfornegativelycoupledlasersformedinasquare,honeycomb,andtriangulargeometriesareingoodagreement.

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  • 简介:Wesynthesized(Pb,Cd)Sr2(Y,Ca)Cu2O7+x,phasesuperconductor.AftersubstitutionofPbwithBi,theBiCd1212phaseshowsnosuperconductivity.AlthoughpreviousEXAFSstudyhasshownthelocalstructureenvironmentoftheCuissimilarinbothcompounds,EXAFSresultsofBiandPbheredemonstratethatσ2ofPb-Oin-planeislargerthanthatofBi-Oinplane,whereasσ^2ofPb-OapicalissmallerthanthatofBi-O,wheraseσ^2ofPb-OapicalissmallerthanthatofBi-Oapical.TheSrshellfeaturesarealsodiffernet,itappearedthatsuperconductivityneedssomedisorder.incarrierreservoirlayer,whichisduetothesubstitutionaldefectcausedbydifferentionicradii.

  • 标签: 超导体相 (Pd Cd)1212 化合物相 (Bi Cd)1212
  • 简介:我们理论上学习光参量的扩大(OPA)或二根弄歪阶段的激光横梁抽的啁啾的脉搏OPA(OPCPA)的阶段特征。由于空间走离开,在two-beam-pumped,光参量的扩大(TBOPA)将两个都泵阶段失真是部分转了在单个晶体发信号以便降级信号横梁质量,它将在高精力的OPCPA更严肃。有补偿walkoff的水晶对的一种OPA配置为减少在第一个阶段经验丰富的信号阶段失真并且通过第二晶体保证二泵阶段失真的信号阶段独立人士被表明,因此维持信号横梁质量。如此的TBOPA类似于借助于消除它的敏感到泵横梁的阶段和数字的常规量激光放大器。[从作者抽象]

  • 标签: 光参量放大器 激光束 泵浦 扭曲 OPCPA 相控
  • 简介:Phasecontrastimagingtechniquehasbeenimprovedpromptlyinrecentyears.Amongthesetechniquesin-linephase-contrastimagingiswidelyused.Variousalgorithmsforin-linephaseretrievalhavebeenproposedsofarsuchasTIE(transportofintensityequation),CTF(contrasttransferfunction),firstborn-approximations,GSF(Gerchberg-Saxton-Fienup),etc.Bronnikov'salgorithm(BA)isatypeoflinearalgorithmthatissimpleandefficient.Butitcanonlybeusedwithoutabsorptionsituations.Inthispaper,animprovedalgorithmbasedonBAwaspresented.TheapproachaddsΔφ(x,y)tothephasemapφ_b(x,y)retrievedbyBAtomakethereconstructedphasemapmoreprecise.Further,theapproachwasevaluatedonsimulatedimagesandconfirmedtobeaccurateathigherabsorptionrates.

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  • 简介:分阶段执行多样的点缀是成像技术的一种新奇类型并且能被用来从未知阶段错误克服图象降级,例如大气的骚乱。在Zernike多项式上扩展的波前阶段从一双图象被估计(在里面焦点并且从焦点飞机)。在这份报纸,PDS的原则被分析,并且基因算法被用作反复的算法模仿一些特征,例如Zernike多项式鈥?模式的影响,阶段评价上的骚乱的振幅。因此,为图象的恢复的一个新方法被探索。CLC数字TN911.74

  • 标签: 斑点 相位变化 修正 光学信号处理
  • 简介:AnewmethodofphasespectralanalysisofEEGisproposedforthecomparativeanalysisofphasespectrabetweennormalEEGandepilepticEEGsignalsbasedonthewaveletdecompositiontechnique.Byusingmultiscalewaveletdecomposition,theoriginalEEGsaremappedtoanorthogonalwaveletspace,suchthatthevariationsofphasecanbeobservedatmultiscale.Itisfoundthatthephase(andphasedifference)spectraofnormalEEGsaredistinctfromthatofepilepticEEGs.Thatisthevariationsofphase(andphasedifference)ofnormalEEGshaveadistinctperiodicpatternwiththeelectricalactivityproceedsinthebrain,butdonottheepilepticEEGs.ForepilepticEEGs,onlyatthosetransientpoints,thephasevariationsareobvious.Inordertoverifytheseresultswiththeobservationaldata,thephasevariationsofEEGsinprincipalcomponentspaceareobservedandfoundthat,thefeaturesofphasespectraisincorrespondencewiththatthewaveletspace.TheseresultsmakeitpossibletoviewthebehaviorofEEGrhythmsasadynamicspectrum.

  • 标签: 定相光谱分析 脑电图 波谱信号 动态光谱 癫痫
  • 简介:Africa,whichcomprisesasignificantnumberofdevelopingcountries,isanimportantforceworkingforworldpeaceandstabilityandglobaleconomicdevelopment.TheAfricancontinentisrichinnaturalandhumanresourcesandpotentialsfordevelopment.Foryears,however,Africagavepeopletheimpressionthatitwasapoverty-stricken,backwardlandravagedbysuccessivewarsandepidemicdiseases.Sincethebeginningofthe21stcentury,therehavebeensome

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  • 简介:阶段差别方法(PDM)为到达(DOA)的方向被介绍narrowband来源的评价。它由测量估计DOA在兴趣频率箱的传感器产量系列的阶段范围相互。PDM的山峰宽度和变化被介绍。只要他们用至少一频率箱被分开,PDM能仔细与不同、未知的中心频率区分spaced来源。模拟结果证明PDM比常规beamforming的有一个更好的决定。

  • 标签: DOA估计 差分法 测量频率 PDM 方向估计 相位差法
  • 简介:ImprovementofPhaseMeasurementSystemforHIRFL¥ZhangJianhua;LiJiandHuangZhengrongPhasemeasurementisveryimportantforacceleratorop...

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  • 简介:提炼伴随转变从的变化对在蝗虫的独居的阶段状态群居是那么激烈的很长时间,这些阶段被看作不同种类。是鲍里斯·乌瓦罗夫介绍了polyphenism的概念。研究的十年表明阶段转变在morphometry,表皮的颜色,行为和生理学的几个方面暗示变化。在最近的十年,特别地,相当很多分子的研究被承担了揭开阶段相关的差别。他们导致了新奇卓见进corazonin的角色,neuroparsins,一些朊酶禁止者,phenylacetonitrile等等。蝗虫的EST数据库的来临(例如坑等,2004)是在生理、行为的蝗虫研究的很令人鼓舞的新奇开发。然而,最吸引人的问题的答案,也就是是否有阶段转变的初发的分子的inducer,在不久的将来可能不在活动范围以内。

  • 标签: 分子标记 相位转移 蝗虫 昆虫学
  • 简介:Cahn-Hilliard阶段地的数字近似当模特儿因为二阶段的不可压缩的流动在这份报纸被考虑。几有效并且为联合非线性的Cahn-Hilliard阶段地的精力马厩时间discretization计划为匹配的密度盒子和变量的系统密度大小写被构造,并且被显示满足类似于连续精力法律的分离精力法律。

  • 标签: 不可压缩流 能源计划 流动模型 稳定 位场 d相