简介：利用室温液相还原、晶种生长的方法,成功的制备了大小形貌均一、性能稳定且具有磁性的Fe3O4@Cu2O复合纳米粒子,并且对制备的Fe3O4@Cu2O纳米粒子进行了光催化性能的研究.在以紫外光为光源的照射下,合成的Fe3O4@Cu2O纳米粒子对有机染料甲基蓝溶液起到很好的降解作用.更重要的是,在外加磁场的作用下,Fe3O4@Cu2O纳米粒子容易回收,具有良好的可循环利用性能.
简介：Thenatureofresistivetransitionofhigh-qualitycrystallinethinfilmsofYBa2Cu3O7-δhasbeenstudiedundermagneticfields(H)appliedalongthecdirectionoverawiderangeofdopedholes,p,intheCuO2planes.Thefield-andtemperature-dependentin-planeresistivity,ρab(T,H),hasbeenanalyzedwithinthethermallyassistedflux-flow(TAFF)formalism.Thefluxactivationenergy,U(T,H),hasbeenextractedfromthisanalysis.Thelow-Tpartoftheρab(T,H)datacanbedescribedbyanactivationenergyhavingthefunctionalformofU(T,H)=(1-t)m(H-0/H)β,wheret=T/Tc(reducedtemperature),andH0isafieldscalethatprimarilydeterminesthemagnitudeofU(T,H).Thetemperatureexponent,m,showsasystematicvariationwithp,whereasthefieldexponent,β,isinsensitivetothepvaluesandisclosetounity.TheH0,ontheotherhand,changesrapidlyaspisvaried.U(T,H)islinkedtothepinningpotentialandconsequentlyonthesuperconductingcondensationenergy.Sincethenormalstatepseudogapdirectlyaffectssuperconductingcondensationenergy,aclearcorrespondencebetweenH0andthePGenergyscale,εg,isfound.Possibleimplicationsoftheseresultsarediscussed.
简介：测量了ZnO-TiO2-Bi2O3-CuO-Co2O3,ZnO-TiO2-Bi2O3-CuO-Cr2O3,ZnO-TiO2-Bi2O3-CuO-MnO2和ZnOTiO2-Bi2O3-CuO-MnO2-Co2O3-Cr2O3压敏陶瓷的正电子寿命谱及其电性能参数。研究了MnO2、Co2O3和Cr2O3掺杂对ZnO-TiO2-Bi2O3-CuO压敏陶瓷电子密度和电性能的影响。实验发现：ZnO-TiO2-Bi2O3-CuOCr2O3压敏陶瓷基体和晶界缺陷态的电子密度均最高,其压敏电压最低;ZnO-TiO2-Bi2O3-CuO-MnO2压敏陶瓷晶界缺陷态的电子密度最低,其压敏电压比前者高;ZnO-TiO2-Bi2O3-CuO-Co2O3压敏陶瓷基体（晶粒内）的电子密度最低,其压敏电压较高;而ZnO-TiO2-Bi2O3-CuO-MnO2-Co2O3-Cr2O3压敏陶瓷基体和晶界缺陷态的电子密度均较低,其压敏电压VT和非线性系数ɑ最高,漏电流IL最小。
简介：利用水热技术合成了一个以Keggin型多金属氧酸盐和柔性有机配体为建筑块的三维超分子化合物[H2bbi]3[α-PMo12O40]2（1）（bbi=1,4-双-（咪唑-1-基）丁烷）,用X-射线单晶衍射、元素分析、红外光谱和X-射线粉末衍射对晶体结构进行了表征.X-射线单晶衍射显示,该晶体属于三斜晶系,P-1空间群,a=1.18360（9）nm,b=1.20932（10）nm,c=1.77728（15）nm,α=74.0890（10）°,β=70.9490（10）°,γ=71.8160（10）°,V=2.2421（3）nm3,Z=2,Dc=3.109g/cm3,F（000）=2300,μ=3.39mm-1,S=1.047,R1=0.0350,wR2=0.0776[I〉2σ（I）].
简介：Twocalix[4]arenederivativescontaining1,2,3-triazolemoietyweresynthesizedviaK2CO3-catalyzed1,3-dipolarcycloadditionreactionbetweencalix[4]arene-basedazideandactivemethylenecompoundsingoodyields.Thestructuresofthetwocompoundssynthesizedhereinwerefullyconfirmedby1HNMR,,13CNMR,andMS（ESI）.Thethermalanalysisshowedthatthemasslossesofthesynthesizedcompounds4and5containing1,2,3-triazolegroupsaresimilartoeachother.
简介：合成了2个N-（2-乙胺）-9,10-二氢蒽-9,10-桥-α,β-琥珀酰亚胺希夫碱衍生物,利用单晶X-射线衍射法测定了它们的晶体结构.化合物1为正交晶系,Pca21空间群,晶胞参数a=1.13259（15）nm,b=2.5356（4）nm,c=0.83582（12）nm;α=90.00°,β=90.00°,γ=90.00°,V=2.4003（6）nm3,Z=4;化合物2为三斜晶系,P-1空间群,晶胞参数a=1.0129（15）nm,b=1.1901（16）nm,c=1.3075（18）nm;α=67.17（3）°,β=72.88（3）°,γ=75.41（3）°,V=1.371（3）nm3,Z=2.
简介：<正>Foranyintegersa1,a2,a3,a4andcwitha1a2a3a40（modp）,thispapershowsthatthereexistsasolutionX=（x1,x2,x3,x4）∈Z4ofthecongruencea1x12+a2x22+a3x32+a4x42≡c（modp）suchthat‖X‖=max{|x1|,|x2|,|x3|,|x4|}《p1/2logp.
简介：Theefficiencyofthepoly（3-hexylthiophene）（P3HT）and[6,6]-phenylC61-butyricacidmethylester(PC61BM)basedorganicsolarcellswasenhancedbyusing1,2,4-trichlorobenzene（TCB）asaprocessingadditivetocontroltheblendmorphology.TheadditionofTCBimprovedthearrangementofP3HTwhichresultedingoodphaseseparatedblendfilms.Correspondingly,theoptimizedsolarcellsshowedapowerconversionefficiency（PCE）of4.17%withafillfactor（FF）of0.69,whichwerehigherthanthoseofcommonthermalannealingdevices（PCE3.84%,FF0.67）.Theefficiencywasfurtherimprovedto4.74%bythermalannealingat150°Cfor10minwithahigherFFof0.74.
简介：AseriesofmesoporousCu-Mn-Al2O3(CMA)materialswassynthesizedatmoderatetemperatureandtheirstructureswerecharacterizedbyXRD,N2physicaladsorptionandTPRtechniques.Itwasfoundthatusingmetalcomplexion[Cu(NH3)42+-Mn(NH3)62+]asrawmaterialsiseasiertoformgood-structuremesoporousCu-Mn-Al2O3materialsthanusingitsnitratesalt[Cu(NO3)2-Mn(NO3)2].TheTPRtestsresultsindicatethatCuOandMnOxwerehomogeneouslydispersedinthemesoporousmaterials.TheircatalyticapplicationtopreferentialcatalyticoxidationofCOinahydrogen-richstreamwasstudied.TheactivityvariesintheorderofCMA(1:1,molarratio)>CMA(1:2)>CMA(2:1)>CMA(CP)>CMA(1:0)≈CMA(0:1).TheCMA(1:0)andCMA(0:1)haveloweractivitycomparedtoothersamples,implyingthatthereexistedcoordinationeffectbetweenCu-Mninthesamples.TheselectivityvariedintheorderofCMA(0:1)≥CMA(1:2)>CMA(1:1)>CMA(2:1)>CMA(1:0)athighertemperature(≥120°C),indicatingthatincreasingtheCucontentenhancedtheconversionofH2.ThesampleCMA(CP)madebycoprecipitationmethodhasalowerCOoxidationactivityandselectivitythanitscounter-partsofmesoporousCu-Mn-Al2O3materials[CMA(1:2)],thisattributedtothelowersurfaceareaoftheformerandpoorinteractionofCuOwithMnOx.
简介：利用电介质的平均能带模型计算了PrBa2Cu3O7的化学键参数，得到Cu(1)-O键的人价性为0．41，Cu(2)－O键的平均共价性为0．28，应用由共价性和要化率定义的化学环境因子计算了^57Fe在PrBa2Cu3O7中的Mossbauer同质异能位移，确定了^57Fe在PrBa2Cu3O7中的价态和占位情况。
简介：Wereportthatβ’-Gd2(MoO4)3crystalshavebeengrownbytheCzochralski(CZ)method.Westudiedthegrowthconditionsfoβ’-Gd2(MoO4)3crystal.Acompatisonbetweentheresistance-heatedmethodandradiofrequencyinduction-heatedmethodisdescribed.Also,theinsituobservationofthedomainstructurebythemicroscopeandbysynchrotronradiationX-raytopographyundertheconditionsofDCpolarizationvoltageandtempertaturechangewerecarriedout.Experimentsshowedthatmultidomainstructureincludingferroelectricandferroelasticdomainsoccurredinβ’-Gd2(MoO4)3cystal.Usuallyferroeletiricdomainsappearedintheas-growncrystalandferroelasticdomainsappearedinthepolishedthinnerpiece.BothferroelectricandferroelasticdomainsdisappearedwhenthetemperatureofthecrystalpiecewashigherthantheCurietempperatureTcandtheycouldbereproducedwhenthetemperatureofthecrystalpiecewasloweredbelowTC.WhenaDCpolarizationvoltagerangingfrom150to500Vwasappliedonac-axisβ’-Gd2(MoO4)3piecehavingathicknessof0.5mm,themultidomainwouldgraduallytransformtoasingledomain.Thisresualmeansthatitispossibletomakeaperiodicallypoledβ’-Gd2(MoO4)3crystal.2001ElsevierScienceB.V.Allrightsreserved.
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：Onenovelorganic-inorganichybridsupramolecularassemblies|（NDPA）（18-crown-6）]2+（DMA）+·3ClO4-（1）,hasbeensuccessfullyconstructedthroughtheprominentstrategiesofcrystalengineering（NDPA=N,N-dimethyI-1,4-phenylenediamine,DMA=dimethylamine）,andcharacterizedbyIR,powderXRDandsinglecrystalX-raydiffraction.Inthestructure,thesupramolecularorganiccationsandinorganicClO4-anionsarearrangedalternatelyandlinkedbyN-O…Hhydrogenbonds.ItisworthytonotethattheClO4-arelinkedtoformone-dimensionalinorganicchainthroughstrongNH…Ohydrogenbondsalongb-axis.Thereisnodistinctdielectricanomalyinthetemperaturedependentandfrequency-dependentdielectricconstantcurves,suggestingthatnophasetransitionexistswithinthemeasuredtemperaturerange（120-420K）.Therelativedisplacementofcationsandanions,theturnedpolarizationofmolecularelectricmomentandmacrocyclicmoleculerotatorarethemainfactorstodeterminethetrendofdielectricconstant.
简介：P-typenitrogen-dopedZnOfilmsarepreparedsuccessfullybyin-situthermaloxidationofZn_3N_2films.Thepreparedfilmsarecharacterizedbyx-raydiffraction,non-Rutherfordbackscattering(non-RBS)spectroscopy,xrayphotoelectronspectroscopy,andphotoluminescencespectrum.TheresultsshowthattheZn_3N_2filmsstarttotransformtoZnOat400°Candthetotalnitrogencontentdecreaseswiththeincreasingannealingtemperature.Thep-typefilmsareachievedat500℃withalowresistivityof6.33Ω·cmandahighholeconcentrationof+8.82×10~(17)cm~(-3),aswellasalowlevelofcarboncontamination,indicatingthatthesubstitutionalnitrogen(N_O)isaneffectiveacceptorintheZnO:Nfilm.ThephotoluminescencespectrashowclearUVemissionsandalsoindicatethepresenceofoxygenvacancy(V_O)defectsintheZnO:Nfilms.Thep-typedopingmechanismisbrieflydiscussed.
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