简介：PureAl2O3-2SiO2powderswerepreparedbysol-gelandcoprecipitationmethods,andtheiralkaliactivationreactivitieswerecompared.Thealkali-activationreactivityofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbythecoprecipitationmethod.Thepowderswereinvestigatedby27AIand29Simagic-anglespinningnuclearmagneticresonancespectroscopy（MASNMR）tounderstandtherelationshipbetweentheirstructureandalkali-activationreactivity.The27AlMASNMRdatashowedthatthefive-coordinateAIcontentofthepowderpreparedbythesol-gelmethodwashigherthanthatofthepowderpreparedbycoprecipitation.Thehighercontentoffive-coordinateAlcorrespondedtohigheralkali-activationreactivity.The29SiMASNMRdatashowedthatforthepowderpreparedbythesol-gelmethod,siliconwasreplacedbyaluminumatsecondarycoordinationsitesofthecentralSiatomsduringcalcination.However,forthepowderpreparedbysingle-batchcoprecipitation,themainchangewasfromalowdegreeofpolycondensationtoahighdegreeofpolycondensation.

简介：AnFEanalysisprocedurewaspresentedtopredictthebehaviorofsoilogeogridinterctionunderautomobileloading.Thedynamicinteractionsbetweenthetransversebars,thelongitudinalribsandthesoilweresimulatedbyasystemconsistingofnonlinearsprings,dashpotsandmasses,tostudythedeformationpropertiesofthereinforcedsoil.Theequivalentstiffnessanddampingratioscouldbedeterminedwiththeshakingtable.Thedynamicresponsesofareinforcedsubgradewereanalyzedwiththe3Dfiniteelementapproach.Thisapproachisprogrammedandappliedtoanalyzethesoilogeogridinteractionunderdynamicloading.Thecomparativeanalysisoftheresponseofthereinforcedsubgradeandthatofthesubgradewithoutreinforcementshowsthatthegeogridplacedatthebottomofthebaselayermayeffectivelyreducetheaccumulativeplasticdeformationduetothecyclicautomobileloading.

简介：Uniformlysizedα-Fe2O3hexagonalplateletsweresynthesizedbyahydrothermalprocessusingFe(OH)3suspensionandlargeamountofNaOH.ThereactionproductswerecharacterizedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM),selectedareaelectrondiffraction(SAED),andavibratingsamplemagnetometer(VSM).Theresultsshowthatthehexagonalplateletsarefine,monodisperseandconsistingofsingle-crystals.Themagnetichysteresis(M-H)curveofthesamplesmeasuredatroomtemperatureindicatesthattheα-Fe2O3micro-plateletsexhibitferromagneticbehaviorswithrelativelylowcoercivity.

简介：Inthealloywithsolutecontenthigherthanthelimitingsolubility,thesoluteatomsthathavefailedtodissolvewillprecipitatefromthesolidsolutionandformprecipitations.Inthisstudy,thePortevin-LeChatelier(PLC)effectsinannealed5456and5052aluminumalloyswithdifferentprecipitationcontentshavebeeninvestigatedunderdifferentappliedstrainrates.TheresultssuggestthatprecipitationshavesignificanteffectonthePLCeffectandthemoretheprecipitationsare,thegreaterthe...

简介：

简介：Acleanmethodforpreparinglayereddoublehydroxides(LDHs)hasbeendeveloped,featuredbyusingthehydroxidesoftwodifferentmetalsasstartingmaterialsbyatom-economicreactions.Thereactionswerecarriedoutunderhydrothermalconditionsineitherahighpressureautoclaveoramicrowavedigester.Thecompositions,structuralparametersandthermalbehavioroftheresultingLDHsareverysimilartothoseofmaterialsproducedbyusingtheseparatenucleationandagingsteps(SNAS)method.Themajoradvantageofthenewmethodisthatnoby-productisproduced,sothatfiltrationandwashingprocessesareunnecessary.Theconsequentreductioninwaterconsumptionisbeneficialtotheenvironment.

简介：

简介：平台漂移误差测试和标定是保证惯性系统精度最基本的措施之一,应用于武器载体特别是战术弹时,要求尽量延长标定周期.在长期存储过程中,陀螺、加速度计等惯性元件测量轴的安装精度会因安装应力和自重应力作用而有损失,使平台漂移模型失真.理论分析表明,复合材料技术可大大减小此类误差,从而可通过长期保持惯导系统机械零位精度来延长平台标定周期.

简介：有从30～80nm的尺寸的Fe3O4nanoparticles被湿milling铁粉末在一家行星的球工厂综合。阶段作文和同样综合的产品的形态学被X光检查衍射(XRD)测量，扫描电子显微镜学(SEM)和传播电子显微镜学(TEM)。NanosizedFe3O4粒子被湿milling准备金属性的铁粉末(?200网孔，99%)在与不锈钢装备的一家行星的球工厂，使用的小瓶与50:1并且以300rpm的旋转速度的ball-to-powder团比率在提取的水下面熨球。在这个方法的铁球的使用在Fe3O4formation起了一个关键作用。现在的技术简单，这个过程是容易的执行。

简介：Nanostructuredtransitionmetaloxidesarepromisingalternativeanodesforlithiumionbatteries.Li-ionstorageperformanceisexpectedtoimproveifhighpackingdensityenergyparticlesareavailable.Herein,Mn2O3microsphereswithaca.18μmdiameterandatappeddensityof1.33g/cm3weresynthesizedbyafacilesolvothermal-thermalcoversionroute.SphericalMnCO3precursorswereobtainedthroughsolvothermaltreatmentandtheydecomposedandconvertedintoMn2O3microspheresatanannealingtemperatureof700C.TheMn2O3microspheresconsistedofMn2O3nanoparticleswithanaverage40nmdiameter.TheseporousMn2O3microspheresallowgoodelectrolytepenetrationandprovideanionbufferreservoirtoensureaconstantelectrolytesupply.TheMn2O3microsphereshavereversiblecapacitiesof590and320mAh/gat50and400mA/g,respectively.Wethusreportanefficientrouteforthefabricationofenergyparticlesforadvancedenergystorage.

简介：密度功能的理论(DFT)学习被执行了为[Znn?1Al(OH2)n+6(哦)2n?2]3+(n=36)并且[Znn?1Al(OH2)2n?2(哦)2n?2]3+(n=7)簇，它包括象brucite一样格子的基本结构的信息在范围与Zn/Al臼齿的比率(R)Zn/Al分层的双氢氧化物(LDH)组织26，以便在二进制Zn/AlLDH的结构和稳定性上理解Zn/Al比率的效果。基于几何参数的系统的计算和簇模型的形成精力，Zn2+和Al3+阳离子用不同R价值在象brucite一样结构同态地代替Mg2+是可能的，这被发现，在簇和单位房间参数的微观结构导致差别一ofZn/AlLDH。几何学的分析并且在三价的Al3+或二价的Zn2+阳离子附近结合表明Al3+在当时，决定微观结构性质，形成和相应ZnRAl簇的结合的稳定性比Zn2+起一个更重要的作用R<5，当Zn2+的影响在R5的情况中成为主导的因素时。这些调查结果在对实验的好同意。这个工作提供阳离子的作文怎么影响包含Zn二进制LDH层的微观结构和稳定性的详细电子水平的理解。

简介：Multi-walledcarbonnanotubes(MWNTs)with20nmouterdiameterwerepreparedbychemicalvapordepositionofethyleneusingultrafinesurface-modifiedacicularα-Fecatalystparticles.ThegrowthmechanismofMWNTsonthelargercatalystparticlesareattributedtotheinteractionbetweentheFenanoparticleswiththesurface-modifiedsilicalayer.Thisinteraction-mediatedgrowthmechanismisillustratedbystudyingtheelectronic,atomicandcrystalpropertiesofsurface-modifiedcatalystsandMWNTsproductsbycharacterizationwithX-raydiffraction(XRD),transmissionelectronmicroscopy(TEM),highresolutiontransmissionelectronmicroscopy(HRTEM),thermalgravimetricanalysis(TGA)andRamanspectra.

简介：Carbonnanotube（CNTs）/Fe-Ni/TiO2nanocompositephotocatalystshavebeensynthesizedbyaninsitufluidizedbedchemicalvapordeposition（FBCVD）method.ThecompositephotocatalystswerecharacterizedbyXRD,Ramanspectroscopy,BET,FESEM,TEM,UV-visspectroscopy,andXPS.TheresultsshowedthattheCNTsweregrowninsituonthesurfaceofTiO2.Fe（lll）inTiO2showednochemicalchangesinthegrowthofCNTs.Ni（Ⅱ）waspartlyreducedtometalNiintheFBCVDprocess,andthemetalNiactedasacatalystforthegrowthofCNTs.ThephotocatalyticactivitiesofCNTs/Fe-Ni/TiO2decreasedwiththeriseoftheFBCVDreactiontemperature.ForthesamplesynthesizedatlowFBCVDtemperature（500℃）,morethan90%andnearly50%ofmethylenebluewereremovedunderUVirradiationin180minandundervisiblelightirradiationin300min,respectively.TheprobablemechanismofsynergisticenhancementofphotocatalysisontheCNTs/Fe-Ni/TiO2nanocompositeisproposed.

简介：