简介:研究了YBaCu3O6~7超导催化剂上CO2的加氢制醇反应。考察了温度、压力和空速等条件对催化剂反应性能的影响。反应的主要产物是甲醇、CO和少量甲醚。利用XPS、XRD和AFM等技术对催化剂的结构、铜的存在状态和反应活性位进行表征发现,在反应过程中,YBa2Cu3O6~7由orthombic相转变为tetragonal相。反应活性位可能是Cu(I)物种。反应后催化剂颗粒的分散程度明显提高
简介:在1935,迪拉克证实在de保姆空格而是两个精力动量操作员也不他们的保守法律的物理波浪方程被给。在它在在那里的de保姆组被证明那的这篇文章是对海森堡组和组们是的这的生成器同形的一个亚群组遵守一条保守法律的精力动量操作符。
简介:Hightimeresolutionmeasurementsoftheelectrostaticfluctuations,radialelectricfieldErandturbulence-inducedelectronfluxΓehavebeenperformedacrossthetransitionoflowerhybridcurrentdriveimprovedconfinementwithagraphiteLangmuirprobearrayatthelastclosedfluxsurfaceoftheHT-7tokamak.ThedecreaseofΓeisdominatedbythesuppressionoffluctuationlevels,whichfollowsthechangeofEr.AreversalofthepoloidalpropagationdirectionofturbulencedemonstratesthatthepoloidalpropagationisdominatedbyEr×Bφdrift.Theenhancementofpoloidalcoherenceaccompaniesthefluctuationsuppression,whichsuggeststhesubtlevariationofturbulencefeatures.
简介:InsituhighpressureenergydispersiveX-raydiffractionmeasurementsonlayeredperovskite-likemanganateCa3Mn2O7underpressuresupto35GPahavebeenPerformedbyusingdiamondanvilcellwithsynchrotronradiation.Theresultsshowthatthestructureoflayeredperovskite-likemanganateCa3Mn2O7isunstableunderpressureduetotheeasycompressionofNaCl-typeblocks.ThestructureofCa3Mn2O7underwenttwophasetransitionsunderpressuresintherangeof0-35GPa.Onewasatabout1.3GPawiththecrystalstructurechangingfromtetragonaltgoorthorhombic.Theotherwasatabout9.5GPawiththecrystalstructurechangingformorthorhombicbacktoanothertetragonal.
简介:Wetrytoapplyaconstituentquarkmodel(avarietychiralconstituentquarkmodel)andtheresonatinggroupapproachforthemulti-quarkproblemstocomputetheeffectivepotentialbetweentheNN-inS-wave(thequarksinthenucleonsNandN-,andthetwonucleonsrelativelyaswell,areinSwave)soastoseethepossibilityiftheremaybeatightboundstateofsixquarksasindicatedbyastrongenhancementatthresholdofpp-inJ/ψandBdecays.TheeffectivepotentialwhichweobtainintermsofthemodelandapproachshowsiftheexperimentalenhancementisreallycausedbyatightS-waveboundstateofsixquarks,thenthequantumnumberoftheboundstateisverylikelytobeI=1,JPC=0-+.
简介:PE3340芯片是Peregrine公司研制的一款低噪声、高性能整数分频锁相环,工作频率可高达3GHz,用20引脚TSSOP封装形式,芯片约6.5mm×6.4mm。PE3340内含一个双模前置分频器、R和M计数器以及鉴相器,可通过串行接口对芯片进行编程。遥测发射机设计是用Xilinx公司的CPLD芯片XC9536对PLL芯片PE3340进行预置数据编程。发射机设计用准两点注入式锁相调频技术,包括PE3340、XC9536、温补晶振(TCXO)、有源积分滤波器电路(LF)、VCO、缓冲放大器(Buffer)和S波段功放(PA)等电路模块。发射机电路原理框图如图1所示(虚线框内为PE3340)。
简介:YBa2Cu3Ox(YBCO)thinfilmsgrownondifferentsubstrateswithand/orwithoutEu2CuO4(ECO)bufferlayerwereinvestigatedbyX-raywideanglediffraction,reflection,diffusescatteringandtopography.TheresultsshowthatfortheyttriastabilizedZrO2(YSZ)substrate,thepresenceofanECObufferlayerimprovesthecrystallinequalityoftheYBCOfilm,whileanegativeeffectisobservedfortheSrTiO3(STO)substrate.ThelateralcorrelationlengthforasamplegrownonaYSZsubstratewithECObufferLayerismuchgreaterthangrownonanSTOsubetrate.TheSTOsubstrateusedhasmosaicstructure.2001ElsevierScienceB.V.Allrightsreserved.
简介:我们理论上由认为Rashba是纺纱轨道在一个极极的半导体的接口附近学习极化子的扎根的州的精力(那么)结合theLee-Low-Pines中间的联合方法。我们的数字结果证明在异种结构从倒置不对称现象发源的RashbaSOinteraction切开极化子的扎根的州的精力。到总数的SOinteraction的比率的真实密度和向量依赖扎根了的电子州的精力或另外的精力作文是明显的。一个人能看到甚至没有任何外部磁场,扎根的州的精力能被RashbaSOinteraction切开,并且这切开不是一个单身者但是复杂的。自从礼品声子,其精力把否定贡献给极化子的家,极化子的切开纺纱的状态比电子的家更稳定。
简介:Asimplemethodisappliedtocalculatingtheisotopeshifts(ISs)on5S1/2→4D3/2,5/2transitionsof87,88Sr+.FirstwehavecalculatedtheISsoflowertransitionsonaseriesofalkali-likesystemssuchasB2+,Ca+andBa+,whichareinagreementwithotherworks.ThentheISson5S1/2→4D3/2,5/2transitionsof87,88Sr+,whichareusefultostudytheSr+opticalfrequencystandard,areevaluated.
简介:ThephysicalmodeldescribingtheYin-Yangbalanceinthetai-chidiagramviathemeltingandfreezingprocessesinarotatingdevicepresentedinparts1and2isfurtherdevelopedforthecontemporarytai-chidiagramandintheyuan-chidiagram.Thecontemporarytai-chidiagramshowninFig.1isasimplificationformoftheancienttai-chidiagrampresentedinReference[2].Therearetwosemi-circlesformingtheinterfacecurvebetweentheyinandyanginthecontemporarytai-chidiagram.Byknowingthelocationoftheinterfacebetweentheyinandyanginthecontemporarytai-chidiagram,therequirementforthesimulationmodelistofindtheconditiontomatchtheinterfacelocation.Thesimplificationchangesnotonlythestructurebutalsothephysicalinsightoftheancienttai-chidiagram,whichwillbedescribedinthepresentstudy.Theyuan-chidiagramshowninFig.2isthecombinationoftheMasterChen’stai-chidiagrampresentedinReferences[1,2]andthecontemporarytai-chidiagram.Th