简介:Differentrareearth(RE)ionsdopantswereaddedintotheSrAl2SiO7:Eu2+phosphorsinordertoenhancethephosphorescenceproperties,andtheeffectoftheREionsincludingYb3+,Ce3+,Nd3+,Dy3+andTm3+,wascomparativelyinvestigated.ItwasfoundthatNd3+additionimprovedthephosphorescencepropertiesobviouslyamongallthestudiedREions.Therefore,Sr1.96–xAl2SiO7:xEu2+,yNd3+phosphorswerestudiedindetail,andtheoptimumEu2+andNd3+concentrationsweredeterminedwiththeafterglowtimeofabout20min.Thephasestructures,photoluminescence(PL)properties,long-lastingphosphorescence(LLP)properties,afterglowdecaycurvesandthermo-luminescence(TL)fortheselectedphosphorsduringthecorrespondingstudywereinvestigated.AllthephosphorsexhibitedgreenPLemissionandLLPemission.ThereweretwoTLbandslocatedatabout325and380Kforthestudiedsamples,andtherelationshipbetweenREadditionandphosphorescencepropertieswasdiscussed.
简介:Sr1.995–1.5xGdxSiO4:0.005Eu2+phosphorserieswithx=0–0.08molfornear-ultravioletwhitelight-emittingdiodes(NUVw-LEDs)weresynthesizedviasolid-statereactionmethod.XRDprofilepatternandrefinementresultsdemonstratedthatdopingGd3+ionsresultedinthephasetransformation(β-Sr2SiO4→α’-Sr2SiO4).Thephotoluminescencespectrumofthesamplewithx=0moldisplayedtwoemissionpeakscenteredat470and525nm.Thetwo-peakspectrabecameone-peakspectrawiththeGd3+concentrationincreasing.Actually,thefittingresultsdemonstratedthattheone-peakspectrawerestillcomposedoftwosingleemissionspectra.ThephotoluminescenceintensitywasimprovedandtheCIEchromaticitycoordinateswereadjustedviadopingGd3+.
简介:与许多在细胞浆内复制的RNA病毒不同,流感病毒的复制及转录都在细胞核内进行。流感病毒感染细胞进入细胞浆后,经病毒脱壳将病毒核糖核蛋白体复合物(vRNP)释放到细胞浆。vRNP含有病毒的RNA基因和碱性聚合酶1(PB1)、碱性聚合酶2(PB2)、酸性聚合酶(PA)及核蛋白(NP)。vRNP被主动运送到细胞核内,开始病毒基因组的复制和转录。流感病毒感染细胞的晚期,在细胞浆中新合成的PB1、PB2、PA及NP蛋白也需要进入细胞核,参与新的vRNP的装配。我们简要介绍有关流感病毒vRNP和新合成的PB1、PB2、PA及NP蛋白进入细胞核的机制。
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:采用水热法合成了一个新的分子式为[Pb(phen)2(NO3)]·NO3的金属-有机配合物(phen=1,10-邻啡啰啉),并对其进行了元素分析、红外光谱表征和X射线单晶衍射的结构解析.该配合物(C24H16N6O6Pb)属于单斜晶系,空间群为P21/n,晶体学数据:a=16.7035(12),b=7.7341(5),c=18.1198(13),β=98.1860(10),V=2317.0(3)3,Mr=691.62,Dc=1.983g/cm3,μ(MoKα)=7.337mm-1,F(000)=1328,Z=4.直接法解析原子位置的结果显示:R=0.0269,wR=0.0533.该配合物具有零维网状结构.
简介:在沥滤的Pb之间的关系当在它的团结的形式的水泥在酸媒介被沥滤时,有时间的集中和答案pH被分析。团结的形式,增加方法的水泥,和Pb团结上的水和度的粒子尺寸的效果也被调查。试验性的结果显示水泥快速被溶解,形成有好吸附的C-S-H胶化或硅的酸大音阶的第五音并且在酸媒介含水。当cement-Pb团结了时,形式在一个醋酸盐答案被沥滤,含水的产品与时间侵蚀,Pb集中因此在开始稍微增加。然后,一些Pb离子被最新产生的硅的酸大音阶的第五音吸收,C-S-H。其它生产Pb(哦)为第二等的团结的2降水,在超过二个小时的一沥滤的时间在Pb集中导致渐渐的减少。而且,团结的形式的粒子尺寸在Pb溶解上有重要效果。当增加的水泥的数量是低的时,与不到9.5的pH,团结影响原来的水泥粉末的顺序,水泥含水的粉末,和cement-Pb团结了形式。当水泥的增加的数量与超过11的pH增加时,在团结上增加方法的效果减少,并且团结的形式比其它好一些。
简介:建立了非线性热力学模型,定性分析了外加应力和外加温度对外延生长在正交基底上的Pb(Zr1-xTix)O3(PZT)薄膜相变的影响。在外力场下,固定其中一个方向失配应变e1=0.005,模拟得到了不同组分的PZT薄膜的失配应变一外加应力的相图。研究发现,随着Ti组分的减少,出现了新相正交a1c相和四方相a1相,且新相区域也会随Ti组分的不同而变化。在外加拉应力下,c相是薄膜较易出现的相,而在外加压应力下薄膜易处于a1a2相。在不同温度场下,模拟非等轴失配应变的PZT薄膜得到不同组分的PZT薄膜的失配应变一外加温度相图。当组分x≤0.7时,相图中出现了正交a1c相,由于非等轴失配应变的存在,使得从顺电相向r相发生相变的过程中,多出了正交a1a2相;同时另一新的四方a1相也出现在沿失配应变正方向e2被拉伸的区域。随着Ti组分的增加,单斜r相的面积缩小且位置下移。之前存在的四相点也变为了三相点,而正交相a1a2相则向相图的中心位置移动。模拟结果对研究外场下铁电薄膜微器件的性能变化具有一定的指导意义。
简介:Newvisibletransparent,UVabsorption,andhighinfraredreflectionpropertieshavebeenrealizedbydepositingmultilayerSiO2/ZnO:Al/CeO2-TiO2/SiO2filmsontoglasssubstratesatlowtemperaturebyradiofrequencymagnetronsputtering.OptimumthicknessofSiO2,ZnO:Al(ZAO)andCeO2-TiO2(CTO)filmsweredesignedwiththeaidofthinfilmdesignsoftware.Thedegreeofantireflectioncanbecontrolledbyadjustingthethicknessandrefractiveindex.TheouterSiO2filmcandiminishtheinterferencecoloringandincreasethetransparency;theinnerSiO2filmimprovestheadhesionofthecoatingontheglasssubstrateandpreventsCa2+,Na+intheglasssubstratefromenteringtheZAOfilm.Theaveragetransmittanceinthevisiblelightrangeincreasesbynearly18%-20%,ascomparedtodoublelayerZAO/CTOfilms.Andthefilmsdisplayhighinfraredreflectionrateofabove75%inthewavelengthrangeof10-25μmandgoodUVabsorption(〉98%)properties.Thesesystemsareeasytoproduceonalargescaleatlowcostandexhibithighmechanicalandchemicaldurability.ThetriplefunctionalfilmswithhighUVabsorption,antireflectiveandhighinfraredreflectionratewilladapttoapplicationinflatpaneldisplayandarchitecturalcoatingglass,automotiveglass,withdiminishinglightpollutionaswellasdecreasingeyefatigueandincreasingcomfort.