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简介：Asanimportantmulti-functionalmaterialappliedinsurfaceacousticwavedevices,opticalcommunications,laserandoptoelectronicsduetoitsgoodphotoelectricandpiezoelectricproperties,lithiumtantalate(LiTaO3)hasdrawnextensiveinterests[1].NumerousphysicalpropertiesofLiTaO3,suchasacoustical,electronicstructures,opticalpropertiesandeffectivemass,thermodynamicproperties,havebeenreportedinseveralpapers.Pointdefectswillaffecttheelectronicstructurewhichshouldberesponsibleformanyphysicalproperties,especiallyopticalproperties.

简介：Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.

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简介：MP3风靡我们的时候，我们就开始患上MP3疯魔症——眼睛睁开的第一秒，便搜索最爱的MP3，低头走路，孤立进食，默默无语……自始至终，活在一个人的世界里，你说，这不是疯了是怎么了？

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简介：Poly(3-hydroxybutyrate-co-3-hydroxyvalerate)/Organophilicmontmorillonite(PHBV/OMMT)nanocompositeswerepreparedandthebiodegradabilityofthePHBV/OMMTnanocompositeswasstudiedbyacultivationdegradingmethodinsoilsuspension.TherelationshipbetweenstructureandbiodegradabilityofPHBV/OMMTnanocompositeswasinvestigated.TheresultsshowedthatthebiodegradabilityofPHBV/OMMTnanocompositesdecreasedwithincreasingamountofOMMTanditwasrelatedtothenumberofPHBVdegradingmicroorganismsindegradationenvironment,theanti-microbialpropertyofOMMTandthedegreeofcrystallinityofthenanocomposites.

简介：DrugsSPD-304(6,7-dimethyl-3-{[methyl-(2-{methyl-[1-(3-trifluoromethyl-phenyl)-1H-indol-3-ylmethyl]-amino}-ethyl)-amino]-methyl}-chromen-4-one)andzafirlukastcontainacommonstructuralelementof3-substitutedindolemoietywhichcloselyrelatestoadehydrogenatedreactioncatalyzedbycytochromeP450s(CYPs).ItwasreportedthatthedehydrogenationcanproduceareactiveelectrophilicintermediatewhichcausetoxicitiesandinactivateCYPs.DrugL-745,870(3-{[4-(4-chlorophenyl)piperazin-1-yl]-methyl}-1H-pyrrolo2,3-β-pyridine)mighthavesimilareffectsinceitcontainsthesamestructuralelement.Weusedmoleculardockingapproachcombinedwithmoleculardynamics(MD)simulationtomodelthree-dimensional(3D)complexstructuresofSPD-304,zafirlukastandL-745,870intoCYP3A4,respectively.Theresultsshowthatthesethreedrugscanstablybindintotheactivesiteandthe3-methylenecarbonsofthedrugskeepareasonablereactivedistancefromthehemeiron.ThecomplexstructureofSPD-304-CYP3A4isinagreementwithexperimentaldata.Forzafirlukast,thecalculationresultsindicatethat3-methylenecarbonmightbethedehydrogenationreactionsite.DockingmodelofL-745,870-CYP3A4showsapotentialpossibilityofL-745,870dehydrogenatedbyCYP3A4at3-methylenecarbonwhichisinagreementwithexperimentinvivo.Inaddition,residuesinthephenylalanineclusteraswellasS119andR212playacriticalroleintheligandsbindingbasedonourcalculations.ThedockingmodelscouldprovidesomecluestounderstandthemetabolicmechanismofthedrugsbyCYP3A4.

简介：以化学沉淀法制备单相的铕离子掺杂硼铝酸盐红色荧光粉YAl3（BO3）4：Eu3＋，考察了焙烧温度、掺铕量等因素对材料性能的影响，用X射线衍射、扫描电镜、激发光谱和发射光谱对荧光粉的结构、形貌和发光性能进行了表征．以尿素为沉淀剂，900℃焙烧沉淀前驱体可得到单相荧光粉YAl3（BO3）4：Eu3＋，反应温度比传统高温固相法降低了300℃；沉淀法制备的荧光粉粒径分布范围小，无团聚现象，粒径约300nm．掺铕量为10％（物质的量比）时发光强度最大．在260nIn的紫外光激发下，Eu3＋的5D0→F72的电偶极跃迁最强，发射光为618nm的红光．

简介：Takingadvantageofthelargeγ-detectorarrayGammasphereandtherecoilmassseparatorFMA,highspinstatesin117Bawereinvestigatedthroughtherecoil-β-delayedprotondecaytaggingtechniqueviatheheavy-ioninducedfusion-evaporationreaction64Zn(58Ni,2p3n)117Ba,atabeamenergyof305MeV.Promptγraysbelongingto117Bahavebeenidentifiedfurthermore,arotationalbandhasbeenidentifiedforthefirsttimeandpresentedasbandAinFig.1.

简介：AngulardistributionsoffragmentsB,C,N,O,F,Ne,Na,MgandAlinducedbythecollisionof^19F+^27Alat114MeVhavebeenmeasured.Angulardispersionparametersareextractedfromtheexperimentaldataandcomparedwiththetheoreticalones.ThedynamicdispersionsfordissipativeproductsdependstronglyonthechargenumberZofthefragments.

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简介：研究了钙钛矿太阳能电池材料CH3NH3PbI3（CH3NH3=MA,MAPbI3）的输运特性,理论分析了有机分子MA对晶格结构的影响。发现：MA沿[110]方向排布且近邻MA分子相互垂直的构型最稳定,将此构型作为MAPbI3的标准结构,使用第一性原理方法,通过分析晶格的振动散射或声子散射,计算了MAPbI3材料中形变势散射主导的载流子迁移率,分析了材料的输运特性,讨论了载流子迁移率理论计算值和实验值之间的差异。

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简介：ＥＬＥＣＴＲＯＮ　ＴＲＡＮＳＦＥＲ　ＢＥＴＷＥＥＮ　Ｅｕ３＋　ＡＮＤ　Ｃｅ３＋　ＩＮ　ＳｒＭｇＦ４　ＭＡＴＲＩＸＥＬＥＣＴＲＯＮＴＲＡＮＳＦＥＲＢＥＴＷＥＥＮＥｕ３＋ＡＮＤＣｅ３＋ＩＮＳｒＭｇＦ４ＭＡＴＲＩＸ￥ＹｉｎｇＷＵ；Ｃｈ...

简介：YbxY1-xAl3(BO3)4(x=0.1,0.07and0)crystalshavebeengrownbythefluxmethod.ThegrowthdefectsofYbxY1-xAl3(BO3)4crystalsweredetectedbyX-raytopography.ItisfoundthattheperfcetionofYbYABcrystalwithlowYbdopantisbetterthanthatwithhighYbdopant.InYb0.1Y0.9Al3(BO3)4crystal,growhtbands,growthboundaries,grown-indislocationsandinclusionswereobserved.Howver,thedensitiesofgrowthdefectsforYb0.07Y0.93Al3(BO3)4andYAl3(BO3)4arelowandnoobviousinclusionsareobservedinthesecrytals.Inaddition,growthtwinswrerdetectedinYbxY1-xAl3(BO3)4crystalbyusingthechemicaletchingmethod.ItisfoundthatthegrowthtwinsoccurfrequentlyinYb0.01Y0.9Al3(BO3)4crystalwhereasnogrowthtwinappearsinYAl3(BO3)4crystal.Basedontheexperimentalobservations,theformationmechanismofgrowthtwinsisdiscussed.Inthemeantime,theeffectivemeasuresforreducingthegrowthtwinsanddefectsareproposed.2001ElsevierScienceB.V.Allrightsreserved.

简介：Inthispaper,wereportedamultiwavelengthpassivelyQ-switchedYb3+:GdAl3（BO3）4solid-statelaserwithtopologicalinsulatorBi2Te3asasaturableabsorber（SA）forthefirsttime,tothebestofourknowledge.Bi2Te3nanosheetswerepreparedbythefacilesolvothermalmethod.TheinfluenceofthreeBi2Te3densitiesonthelaseroperationwascompared.Themaximumaverageoutputpowerwasupto57mWwithapulseenergyof511.7nJ.Theshortestpulsewidthwasmeasuredtobe370nswith110kHzpulserepetitionrateand40mWaveragepower.Thelaseroperatedatthreewavelengthssimultaneouslyat1043.7,1045.3,and1046.2nm,ofwhichthefrequencydifferenceswerewithintheterahertzwaveband.OurworksuggeststhatsolvothermalsynthesizedBi2Te3isapromisingSAforsimultaneouslymultiwavelengthlaseroperation.

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简介：Abstract.Inthispaper,weintroduceanewapproachtocharacterizetheisomor-phismsofcirculantdigraphs.Intermsofthismethod,wecompletelydeterminetheisomorphicclassesofcirculantdigraphsofdegree3.Inpsrticular,wecharacterizethosecirculantdigraphsofdegree3whichdon''tsatisfyJkdAm''sconjectttre.

简介：让f：M→R~3是有非退化的秒的面向的表面基本形式。我们由H和K表示它的吝啬的弯曲和高斯弯曲。然后f的Laguerre体积，由L(f)=∫(H~2定义-K)/KdM，一在Laguerre转变下面不变。功能的L的批评表面被称为Laguerre最小的表面。在这篇论文，我们学习在由使用拉久雷·高斯的R~3的最小的表面印射的theLaguerre。这被知道最小的表面有的genericLaguerre有一样的高斯地图的双Laguerre最小的表面。在这篇论文，我们证明不是Laguerre的任何表面最小被它的LaguerreGaussmap特别地决定。我们也证明圆范围是在R~3的唯一的紧缩的Laguerre最小的表面。并且我们与消失的Laguerre形式在R~3给表面的一条分类定理。