学科分类
/ 7
134 个结果
  • 简介:TheRichtmyer–Meshkovinstabilityofa‘V'shapedair/heliumgaseousinterfacesubjectedtoaweakshockwaveisexperimentallystudied.Asoapfilmtechniqueisadoptedtocreatea‘V'shapedinterfacewithaccurateinitialconditions.Fivekindsof‘V'shapedinterfaceswithdifferentvertexanglesareformedtohighlighttheeffectsofinitialconditionsontheflowcharacteristics.Theresultsshowthataspikeisgeneratedaftertheshockimpact,andgrowsconstantlywithtime.Asthevertexangleincreases,vorticesgeneratedontheinterfacebecomelessnoticeable,andthespikedevelopslesspronouncedly.Thelineargrowthrateofinterfacewidthaftercompressionphaseisestimatedbyalinearmodelandarevisedlinearmodel,andthelatterisproventobemoreeffectivefortheinterfacewithhighinitialamplitudes.Thelineargrowthrateofinterfacewidthis,forthefirsttimeinaheavy/lightinterfaceconfiguration,foundtobeanon-monotonousfunctionoftheinitialperturbationamplitude–wavelengthratio.

  • 标签:
  • 简介:ESD(electrosparkdeposition)isapromisingprocesstoproducehardandwear-resistingcoatingsonmetallicsubstrates.InthispapermicrostructureandinterfacialcharacteristicsoftheWC92-Co8coatedontitaniumandcarbonsteelarepresented.Ametallurgicalbondingbetweenthecoatingandsubstrateisobtained.TheTielementwasfoundtodistributeinWC92-Co8atthemetalpool,aswellastheinterfacebydiffusion.SomenewphaseswereproducedinthecoatinglayerduetothechemicalreactionduringtheESDprocess.ExperimentalobservationandthermodynamicanalysiswereutilizedtostudythemechanismofESD.

  • 标签: WC92-Co8 硬质合金 电火花沉积 涂层 界面 ESD
  • 简介:为了认识到钨和CuCrZr合金的有效连接,为血浆面对生产了部件(陆军),爆炸焊接为它的一些被采用唯一的优点。不同焊接特征在这研究被调查。周期性地改变从的焊接盘子的界面的波形对一个大波浪并且最后扁平小浪指向一个稳定的波浪,它以爆炸开始了。标本的结合的力量比32.9MPa高。焊接变硬并且microcracks的形成发生在接口地区。结果证明加入的可靠性需要被改善以便满足包含制作基于钨的陆军的爆炸焊接的使用的应用的需要。

  • 标签: 爆炸焊接 爆炸复合板 粘接界面 等离子体 部件 铬锆铜
  • 简介:Byusingthefinite-partintegralconceptsandlimittechnique,thehypersingularinte-grodifferentialequationsofthree-dimensional(3D)planarinterfacecrackwereobtained;thenthedominant-partanalysisof2Dhypersingularintegralwasfurtherusedtoinvestigatethestressfieldsnearthecrackfronttheoretically,andtheaccurateformulaewereobtainedforthesingularstressfieldsandthecomplexstressintensityfactors.Afterthat,anumericalmethodisproposedtosolvethehyper-singularintegrodifferentialequationsof3Dplanarinterfacecrack,andtheproblemofellipticalplanarcrackisthenconsideredtoshowtheapplicationofthemethod.Thenumericalresultsobtainedaresat-isfactory.

  • 标签: THREE-DIMENSIONAL PLANAR interface CRACK hypersingular intesrodifferential
  • 简介:ThestatisticalpropertiesofthemodeconvertedSVwavespecklesinthebackscatteringspacewerestudiedasultrasonicPwaveswereincidentonastronglyscatteringinterface.BasedontheFrensel-Huygenstheoryandthecorrelationprinciple,theRayleighdistributionoftheSVwavespeckleamplitudeandtheformulaforcalculatingtheaveragelateralsizeoftheSVwavespeckleswereobtained.Besides,theprobabilitydensityfunctionofthenormalizedintensityoftheSVwavespecklesreceivedbyatransversewaveprobewithanapertureofsomesizewasdeduced.Theprobabilitydensityfunctionwasrelatedtotheaveragenumberofthespecklesreceivedbytheprobe.TwotransversewaveprobeswithaperturesindifferentsizewereemployedtomeasurethesoundintensityoftheSVwavespecklesintheexperiment.Aftertheexperimentaldataofthespeckleintensitywereanalyzedstatistically,itwasshownthattheexperimentalresultswereingoodagreementwiththetheoreticalones.Thus,thepresentedtheoreticalconclusionswereprovedtobecorrect.

  • 标签: 统计特性 界面反射 超声波斑纹 离散相位
  • 简介:到空气的从水的健全传播由于在空气和水阻抗之间的一个大对比是很弱的,这是传统的信仰。最近,提高的健全传播和空气水接口的异常透明性被介绍了。声音由在深度局部性的沉没浅深度单极点来源产生了的空气水接口状态的异常透明性不到1/10声音波长,能与全向的模式被播送进空气。产生声音与古典光线理论预言相比有高35倍的力量。在这份报纸,通过空气水接口鸣传播为一局部性在水下浅深度来源被检查。完成这,在空气水的二阶段的媒介的二阶段的联合Helmholtz波浪方程被商业有限元素解决基于的COMSOLMultiphysics软件。不同健全来源在的压力振幅的比率二不同在水下并且空气坐标对来源深度(D)的非维的比率被计算并且分析到健全波长()。获得的结果与试验性的数据相比,好同意被显示。

  • 标签: 空气-水界面 声音传输 数值研究 低频声 平滑 异常声音
  • 简介:Inthispaper,wecombinethedirect-forcingfictitiousdomain(DF/FD)methodandthesharpinterfacemethodtoresolvetheproblemofparticledielectrophoresisintwodimensions.TheflowfieldandthemotionofparticlesaresolvedwiththeDF/FDmethod,theelectricfieldissolvedwiththesharpinterfacemethod,andtheelectrostaticforceontheparticlesiscomputedusingtheMaxwellstresstensormethod.Theproposedmethodisvalidatedviathreeproblems:effectiveconductivityofparticlecompositebetweentwoplanarplates,celltrappinginachannel,andmotionofparticlesduetobothconventionalandtravelingwavedielectrophoreticforces.

  • 标签: 接口方法 颗粒 夏普 虚拟 导电粒子 应力张量
  • 简介:Thenucleationoforderedphasewassimulatedbasedonmicroscopicdiffusionequationandtheassumptionsoftheclassicalnucleationtheorywereexamined.Thequantitativecalculationsofinterfacethicknessevolutionwereaccomplishedforthefirsttime.Itwasfoundthattheinterfacesbetweenorderedphaseanddisorderedmatrixwerediffuse.Theinterfacethicknessdecreasedwithtime,fromtheinitial1.2nmtoanequilibriumvalue0.6nm.Theratiosoftheradiusoforderedparticlesandtheinterfacethicknessmonotonouslyincreased,buttheywereofthesameorderofmagnitudeallthetime.Thesharpinterfaceassumptionshouldnotbeadoptedinthisstage.FortheAl-10%Li(atomfraction)alloyagedat192℃,theassumptionsoftheclassicalnucleationtheorydisagreedwiththefacts.Thephasetransformationfollowedthenon-classicalnucleationmechanismandtheapplicablescopeoftheclassicalnucleationshouldbeconfined.

  • 标签: 计算机模拟 铝锂合金 晶核形成理论 界面扩散 相变
  • 简介:AbstractThe maternal-fetal interface is a key barrier to protect the fetus from infection. Toll-like receptors (TLRs) at the maternal-fetal interface are involved in antiviral responses. TLRs are expressed in both maternal decidua and fetal trophoblasts. Virus-induced activation of TLR signaling pathways triggers the release of interferon-related antiviral molecules and other inflammatory cytokines and/or chemokines by the host innate immune system, which may disrupt immune tolerance at the maternal-fetal interface and lead to pregnancy complications. In this review, we summarize the state of knowledge on the most common viral infections during pregnancy, antiviral TLR responses at the maternal-fetal interface, and TLR-associated pregnancy complications.

  • 标签: Toll-Like Receptor Antiviral Response Maternal-Fetal Interface
  • 简介:Fe-0.2C-l.5Si-l.67Mn钢受到熄灭并且划分(Q&P)进程,和在在提高的划分温度的马氏体和奥氏体之间的接口移植被观察。接口迁居在constrainedparaequilibrium(用户终端设备)被排除模型。基于“端点”由用户终端设备模型预言接口移植的热力学的条件被分析,也就是说,在在铁酸盐(martenisite)和奥氏体的铁的化学势的差别生产铁原子的驱动力从一个阶段移居到另外的阶段。另外,接口迁居罐头改变奥氏体部分;作为结果,在划分温度的奥氏体部分可能在通过接口移植熄灭温度比那高,但是这现象不能被用户终端设备模型解释。

  • 标签: 淬火分离过程 马氏体 奥氏体 界面移动
  • 简介:TheGreen’sfunctionisusedtosolvethescatteringfarfieldsolutionofSH-wavebyamov-ablerigidcylindricalinterfaceinclusioninalinearelasticbody.First,asuitableGreen’sfunctionisdevel-oped,whichisthefundamentaldisplacementsolutionofanelastichalfspacewithamovablerigidhalf-cylin-dricalinclusionimpactedbyout-of-planeharmoniclinesourceloadedatanypointofitshorizontalsurface.ByusingtheGreen’sfunction,aseriesofFredholmintegralequationsofthefirstkindwhichdeterminethescatteringfarfieldcanbesetup.Thenthepapergivestheexpressionsonthefarfieldincludingthedisplace-mentmodeofscatteringwaveandthesolutionofscatteringcross-section.Finally,someexamplesandnu-mericalresultsarediscussedtoanalyzetheinfluenceofthecombinationofdifferentmediaparametersontheansweroffarfield.

  • 标签: movable RIGID CYLINDRICAL INTERFACE INCLUSION Green’s
  • 简介:内在的hydrogenated非结晶的硅(a-Si:H)电影在n类型上被扔由到分析的热电线的化学蒸汽免职(HWCVD)的水晶的硅(c-Si)晶片非结晶/水晶的heterointerface钝化性质。对称的heterostructure的少数搬运人一生被使用请教WCT-120一生测试者系统,和决定从一生测量的接口状态密度被建议的一个简单方法的Sinton测量。接口状态密度测量被使用深水平的短暂光谱学(DLTS)证明简单方法的有效性也执行。微观结构和a-Si的氢结合配置:有不同的氢冲淡的H电影被使用分光镜的ellipsometry(SE)和Fourier变换调查红外线的光谱学(FTIR)分别地。接口状态密度的更低的值被使用a-Si获得:有水晶的硅上的更一致的、紧缩的微观结构和更少体积缺点的H电影由HWCVD扔了。

  • 标签: 氢化非晶硅 界面态密度 表面钝化 太阳电池 傅里叶变换红外光谱 少数载流子寿命
  • 简介:土壤结构接口的行为在土壤结构相互作用的定义起一个主要作用。在这糊双性人潜力表面为土壤结构接口的elasto塑料的模型被建议以便描述接口变丑行为,包括紧张弄软和正常膨胀性。模型在概括潜在的理论,土壤结构接口问题作为压力地里的一个二维的数学问题在是问候的框架被提出,并且塑料州的方程被用来代替传统的域表面。关系曲线砍应力和正切的紧张被明智的功能由夸张功能和夸张正割功能填写了的一片适合,当关系正常弯时,紧张和正切的紧张被明智的功能由二次的功能和夸张正割功能填写了的另一片适合。建议的途径有的优点导出elastoplastic没有要求的组成的矩阵塑料潜在的功能和收益表面。而且,数学原则是清楚的,并且全部模型参数能被试验性的测试识别。最后,模型的预言与获得从的试验性的结果相比简单砍在正常压力下面的测试,和结果证明模型讲理、实际。

  • 标签: 弹塑性本构模型 结构接触面 应变软化 土与结构相互作用 双曲函数 土壤结构
  • 简介:Fourdifferentstructuralmodelsofartificialjointsweredevelopedandthefiniteelementmethod(FEM)wasemployedtoinvestigatetheirmechanicalcharacteristicsunderstaticanddynamicconditions.ThematerialsusedintheFEMcalculationwereultra-highmolecularweightpolyethylene(UHMWPE),316Lstainlesssteel,CoCrMoalloyandTi6Al4Valloy.Thestressdistribution,strain,andelasticdeformationunderstaticanddynamicconditionswereobtained.Analysisandcomparisonofthecalculationresultsofdifferentmodelswereconducted.Itisshownthatwiththesameparametersthemodelofametallicfemurheadcoveredwithanartificialcartilagelayerismoresimilartothestructureofthenaturalhumanjointanditsmechanicalcharacteristicsarethebestofthefourmodels.

  • 标签: 静态力学 动态力学 仿生学 压力 关节运动
  • 简介:Thispaperdemonstratestheplanestressstateandthestressfreethermo-elasticdeformationofFGMthickplateunderthermalloading.First,theSneddon-LocketttheoremontheplanestressstateinanisotropicinfinitethickplateisgeneralizedforacaseofFGMprobleminwhichallthermo-mechanicalpropertiesareoptionalfunctionsofdepthco-ordinate.TheproofisbasedonapplicationoftheIljushinthermo-elasticpotentialtodisplacementtypesystemofequationsthatreducesittotheplanestressstateproblem.Thenanexistenceofthepurelythermaldeformationisprovedintwoways:first,itisshownthattheuniquesolutionfulfilsconditionsofsimultaneousconstanttemperatureandlineargradationofthermalexpansioncoefficient,second,proofisbaseddirectlyonstresstypesystemofequationswhichstraightforwardlyreducestocompatibilityequationsforpurelythermaldeformationifonlystressfieldishomogeneousindomainandatboundary.Finally,coupleexamplesofapplicationtoanengineeringproblemarepresented.

  • 标签: 平面应力状态 功能梯度材料 载荷作用 厚板 自由变形 热弹性方程
  • 简介:StraightandBentnano-cantileverspecimensarerespectivelyproposedtoinvestigatethesingle-modeandmixed-modecrackinitiationattheCu/Siinterfaceedgeinnanoscalecomponents.Withaminuteloadingapparatus,allnanoscalesamplesareinsituloadedandobserved.Numericalanalysisisemployedtoacquirethecriticalinterfacialstressdistributionsduringcrackinitiation.ThestressconcentrationregionsneartheedgeofCu/Siinterfaceinallspecimensarewithinthescaleof100nm,andthecriticalnormalandshearstresseshaveacircularrelationinnanoscalecomponents,whichrepresentsthefracturecriterionoftheinterfaceinnanoscalecomponents.

  • 标签: NANOSCALE 伸臂 接口 裂缝开始 混合模式 薄电影
  • 简介:Inthispaper,theequilibriumsurfacetensionandthedynamicsurfacetensionofaqueousTritonX100solutionattemperature25℃weremeasuredbymeansofWilhelmyplatemethodandmaximalbubblepressuremethodrespectively.Thedeterminedcriticalmicellarconcentration(cmc)ofTritonX-100at25℃is2.2×10^-4mol/dm^3.TheadsorptionmechanicsofTritonX-100atair/solutionwasdetermined.Forthesubmicellarconcentrationsitisdiffusion-controlled.Thediffusioncoefficientwascalculatedfromtheexperimentaldataintherangeofshortlimit.Intherangeoflongtimeadsorption,thesubsurfaceconcentrationisfittedfromthemeasureddynamicsurfacetensions.

  • 标签: 传播控制吸附动力学 动态表面张力 最大气泡压力方法 气液表面 表面活性剂
  • 简介:Thispaperdescribesanovelsharpinterfaceapproachformodelingthecavitationphenomenainincompressibleviscousflows.Aone-fieldformulationisadoptedforthevapor-liquidtwo-phaseflowandtheinterfaceistrackedusingavolumeoffluid(VOF)method.PhasechangeattheinterfaceismodeledusingasimplificationoftheRayleigh-Plessetequation.Interfacejumpconditionsinvelocityandpressurefieldaretreatedusingalevelsetbasedghostfluidmethod.Thelevelsetfunctionisconstructedfromthevolumefractionfunction.Amarchingcubesmethodisusedtocomputetheinterfaceareaattheinterfacegridcells.Aparallelfastmarchingmethodisemployedtopropagateinterfaceinformationintothefield.Adescriptionoftheequationsandnumericalmethodsispresented.Resultsforacavitatinghydrofoilarecomparedwithexperimentaldata.

  • 标签: 接口 液体 成穴 模特儿 集合函数 粘滞流动
  • 简介:3DstructuralreconstructionofMohointheTangshanearthquakeareabyusinginversionofcurvedinterfaceXIAOLINGLAI(赖晓玲)XIANKANGZHANG...

  • 标签: sectional INCOMPLETE POLYNOMIAL INTERFACE 3 D