简介：

简介：

简介：BSTOdielectricceramicwaspreparedfromSrTiO3andBaTiO3powderssynthesizedbyhydrothermalmethod,aswellasfromBa0.6Sr0.4TiO3powdersynthesizedbyconventionalsolid-statereaction.Theformercanbesinteredatarelativelylowtemperatureof1120℃.CharacterizationbySEMshowedthatthegrainshapesofbothceramicsarecubical,thoughthegrainsizeoftheformerismuchsmaller.Dielectricconstantsmeasuredat20℃wereshowntovarywithfrequencyintherangefrom1kHzto2MHzanddcbiasfield,andfurtherthatthedielectriclossoftheformertobelessthan2×10-3inthefrequencyrangeof20kHzto1MHz,muchsmallerthanthatofthelattersample.Fortheformer,temperaturedependenceofdielectricconstantismuchflatterandthereexistsanextendedphasetransitiondiffusioncoveringawidetemperaturerangeofCurietemperatureTc.Thesmallergrainsizeoftheformerdepressesthedcbiaselectricalfielddependenceofdielectricconstant.Thetunabilityis7%underabiasfieldof0.6kV/mmdc.

简介：Dispersionofmulti-walledcarbonnanotubesinpoly(p-phenylene)compositeexposedtotoluenewasexperimentallyinvestigated.3mgofmulti-walledcarbonnanotubeswithnominalsizeof20nmwascompoundedwith30mgofpoly(p-phenylene)withthepresenceofterpineolasbindinginitiator.Toinvestigateanoptimalconditionforhomogenizingallconstituents,ultrasonicationwithanoutputpowerof750Wwasemployedwithcompoundingtimeof3,10,20and30min.WithFTIRanalyses,itcouldbeconfirmedthathomogeneouscompositeofmulti-walledcarbonnanotubesandpoly(p-phenylene)couldbeprepared.SEManalyseswerealsoconductedtoexaminethedispersionofmulti-walledcarbonnanotubesinthepolymermatrix.Thenintrinsicelectricalresistanceofthecompositesafterbeingexposedtotoluenewasalsoinvestigated.Itwasfoundthatthecompositefilmpreparedwithultrasonicationfor20mincouldprovidesufficientlysensitiveresponsewithrespecttovariedconcentrationoftoluene.

简介：TiO2@ZrO2@Y2O3:有coremultishell结构的Eu3+合成粒子通过layer-by-layer(LBL)的联合被综合自己组装方法和一个solgel过程。获得的样品与扫描电子被描绘显微镜学(SEM)，传播电子显微镜学(TEM)，X光检查光电子光谱学(XPS)，X光检查衍射(XRD)，和荧光spectrophotometry。结果证明合成粒子有coremultishell结构，球形的形态学，和狭窄的尺寸分布。TiO2核心上的ZrO2层的存在能有效地阻止在TiO2核心和Y2O3壳之间的反应；为在在TiO2@ZrO2@Y2O3的TiO2核心和Y2O3壳之间的反应的温度:Eucoremultishell黄磷能被300提高

简介：

简介：3阶段的水动力学反的使流体化的床为不同液体和煤气的速度用低密度粒子试验性地被学习。水动力学特征学习了包括压力落下，最小的液体和气体使液化速度和阶段劫盗。用床压力坡度决定的最小的液体使液化速度，随气体的增加减少速度。液体劫盗沿着床高度增加的阶段劫盗表演的轴的侧面，而稳固的劫盗减少，击倒床。然而，煤气的劫盗在床上是几乎一致的。

简介：A3-DnonlinearproblemofsupercavitatingflowpastanaxisymmetricbodyatasmallangleofattackisinvestigatedbymeansoftheperturbationmethodandFourier-cosine-expansionmethod.Thefirstthreeorderperturbationequationsarederivedindetailandsolvednumericallyusingtheboundaryintegralequationmethodanditerativetechniques.Computationalresultsofthehydrodynamiccharacteristicsandcavityshapesofeachorderarepresentedfornonaxisymmetricsupercavitatingflowpastconeswithvariousapex-anglesatdiffer-entcavitationnumbers.Thenumericalresultsarefoundingoodagreementwithexperimentaldata.

简介：Soilconsolidationwouldinducevariationsofitstransportcoefficientssuchashydraulicconductivityanddiffusioncoefficient.Thispaperpresentsastudyoftheinfluenceofbarrierconsolidationontransportcoefficients,anda3Dtransportmodelbasedonmixturetheoryisproposedfordescribingthelinersthatinvolvecirculardefectsinthegeomembrane.TheelastoplasticALPHAmodelisrevisedbyusingthespatiallymobilizedplane(SMP)criterionforsimulatingthedeformationofthesoils.Then,the3Dmodelcouplingthenonlinearconsolidationandcontaminantadvection-diffusionissolvedusingthefiniteelementsoftwareABAQUS.Theresultsshowthattheimportanceofreducingthedefectsizeinthegeomembraneandthelinerporositytocontrolthecontaminantconcentrationincrease.

简介：TheIsodynetechniquebasedonthescatteredlightscanningfromathinlaserbeamcanbeusedtoobtaintheinformationinsidetheloadedobjectintheroomtemperaturenondestructively,soitisaverypowerfultechniquein3Dstressanalysis.Theproblemsarehowtointerprettheinformationandhowtogetsufficientinformationfromthefewinterferencefringe.Birefringencephaseshifttechniquecandistinguishthefringeordersautomaticallyandenrichtheinformationin256graylevelsbetweenmaximandminimlightintensity.InthepapertheIsodynebirefringencephaseshiftmethodwithanobliqueincidenceandequilibriumequationispresented,bywhichthe3DstressesinthemiddleplaneofaplatewithUshapenotchareseparatedsuccessfully.

简介：Basedonthegeneralconservationlawsincontinuummechanics,theEulerianandLagrangiandescriptionsofthejumpconditionsofshockwavesin3-dimensionalsolidswerepresentedrespectively.Theimplicationofthejumpconditionsandtheirrelationsbetweeneachother,particularlytherelationbetweenthemassconservationandthedisplacementcontinuity,werediscussed.Meanwhiletheshockwaveresponsecurvesin3-dimensionalsolids,i.e.theHugoniotcurveswereanalysed,whichprovidethefoundationforstudyingthecouplingeffectsofshockwavesin3-dimensionalsolids.

简介：The1/3subharmonicsolutionfortheDuffing'sequationisinvestigatedbyusingthemethodsofharmonicbalanceandnumericalintegration.Thesensitivityofparametervariationforthetransientprocessandthetransientprocessfortheperturbanceinitialconditionsarestudied.Overandabove,theprecisionofnumericalintegrationmethodisdiscussedandthenumericalintegrationmethodiscomparedwiththeharmonicbalancemethod.Finally,asymptoticalstabilityofthepuresubharmonicoscillationselementisinspected.

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：Becausemostpiezoelectricdeviceshaveinterfaceswithfluidinengineering,itisvaluabletostudythecoupledfieldbetweenfluidandpiezoelectricmedia.Asthefundamentalproblem,the3DGreen'sfunctionsforpointforcesandpointchargeloadedinthefluidandpiezoelectricbimaterialsarestudiedinthispaper.Basedonthe3Dgeneralsolutionsexpressedbyharmonicfunctions,weconstructedthesuitableharmonicfunctionswithundeterminedconstantsatfirst.Then,thecouplefieldinthefluidandpiezoelectricbimaterialscanbederivedbysubstitutionofharmonicfunctionsintogeneralsolutions.Theseconstantscanbeobtainedbyvirtueofthecompatibility,boundary,andequilibriumconditions.Atlast,thecharacteristicsoftheelectromechanicalcoupledfieldsareshownbynumericalresults.

简介：Thisletterobtainsatyphoon-likevortexsolutionbysolvingtheBragg-Hawthorneequation.ThesolutiondescribesspiralpathsoffluidmaterialelementontheBernoullisurface,whereassomenewexactsolutionsareobtainedwhichareboundedinthewholeregion.Thefirstoneisacontinuedumbrellavortexsolution,whichisatyphoon-likevortex.Thesecondoneisamulti-planarsolution,whichisperiodicinz-coordinate.Withineachlayer,thereisanumbrellavortexsolutionsimilartothefirstone.Theabove...

简介：

简介：ThisstudypresentsanovelprocessofinsitusurfacemodificationofCaCChnanoparticlesusingamultipleorificedispersionmicroreactor.CO2/Ca（OH）2precipitationreactionwasemployedtoprepareCaCO3nanoparticleswithsodiumstearatesurfactant.SynthesizedCaCChproductswerecharacterizedbythermogravimetricanalysis（TGA）,infra-red（IR）,X-raydiffraction（XRD）,transmissionelectronmicroscopy（TEM）andBrunauer-Emmet-Telleranalysis（BET）.Theeffectofvariousoperationparametersonnanoparticlesandthedosageofsodiumstearateweredetermined.Theresultsshowedthatthepreparationprocesscouldbepreciselycontrolledwithefficientmasstransferprocess.Theparticleswerehighlyhydrophobicwithacontactangleof117andmonodispersewithanaveragesizeof30nm.Theadsorptionsofsodiumstearateandcalciumiononsolidparticlesduringtheinsitusurfacemodificationprocesswereinvestigated.

简介：AnovelmethodformodelingcellularmaterialsisproposedbasedonMATLABimageprocessingandsynchrotronX-raycomputedtomographyscanningtoobtainanaccuratecalculationresultofaluminumfoambasedonfiniteelementmodel.Themaximumentropyalgorithmisemployedtoobtainthebinarizationimage,andthemedianfilteringalgorithmisusedtoreducethenoiseafterbinarization.Theexternalcontourandinternalporesboundaryisextractedbythe"edge"functioninMATLAB,andthegeometricalmodelisreconstructed.Atwo-stepmeshalgorithmisadoptedtomeshthereconstructedgeometricalmodel.Accordingly,thefiniteelementmodelofaluminumfoamisestablishedbytheproposedmethodbasedonreconstructiongeometricalmodel.Thecompressionbehaviorofaluminumfoamisobtainedat25℃,100℃,200℃byABAQUS,andgoodagreementswithexperimentsareachievedbyapplyingthepresentreconstructionalgorithmandmodelingmethod.

简介：

简介：3-degree-of-freedom(3-DOF)的一个新分析模型旋转罗盘加速表系统由一个1-DOF驱动器和2-DOF感觉模式组成被介绍。模型构造微分方程由向量分析与系统的每DOF联系了的lumped。因此建立的联合微分方程是为他们在时间和频率领域的回答的解决的经分解。就这些频率反应方程而言，新奇设备设计概念被强迫感觉阶段到零导出，它导致在结构的频率之间的某个关系，从而在系统的表演上引起抑制效果的最小化。而且，现在的旋转罗盘加速表结构的可行性在他们的事件为旋转罗盘行动和线性加速的察觉用一个唯一的差别对待的计划被学习。这个计划把旋转罗盘加速表的提出的解决的短暂解决方案与同步解调和过滤的进程相结合，它导致同相并且系统输出的照部件发信号。这二个部件能在尖运动和线性加速的察觉被利用。获得的分析结果被模拟在MATLAB/Simulink环境验证，并且结果在对对方的优秀同意，这被发现。