学科分类
/ 12
227 个结果
  • 简介:有分叉的烃链的酚衍生物的聚集和deaggregation行为在CH3OH和缓冲区答案被学习了。有聚集数字测量和房间粘附实验的联合,目标分子的deaggregating能力上的结构效果被讨论。结果显示2-phytyl-4-methoxylphenol(11)是在学习的系统的最有效的deaggregator。

  • 标签: 苯酚 衍生物 聚合反应 碳氢化合物
  • 简介:在激光,微波和类似的技术的进展导致了包含皮组织的热治疗的最近的开发。这些处理的有效性被管理由联合了影响织物的热、机械、生物、神经的回答:一个有利相互作用相对小的疼痛和没有持续副作用地导致一个过程。当前,尽管每个行为的方面到建立并且理解的某个程度,任何一个都不在学科交差的区域存在到日期。一条高度学科交差的途径为学习皮肤的biothermomechanical行为被要求,包含简历热转移,简历力学和生理学。对这个题目恰当的全面文学评论在这篇论文被介绍,盖住四个题目区域:(a)皮肤结构,(b)皮肤简历热转移和热损坏,(c)皮肤简历力学,和(d)皮肤biothermomechanics。为进一步的研究的主要问题,问题,和话题也被构画出。这评论发现在每这些方面的重要进展在最近的年里被完成了。尽管焦点被放在皮肤织物的biothermomechanical行为之上,在这篇论文考察的基本概念和方法论可能也为学习另外的软纸巾是适用的。

  • 标签: 皮肤组织 生物热交换 生物力学 生物热机械学
  • 简介:Thephotoelectrochemicalbehaviorofpolyaniline(PAn)filmwasstudiedinaqueouselectrolytesolutioncontainingFe(CN)63-/Fe(CN)+4-redoxcouple.ItwasfoundthatPAnfilmspossessthepropertiesofp-typesemiconducterandacathodicphotocurrentashighas700μA/cm2wasobservedwhenirradiatedunderpolychromaticlightof100mW/cm2.

  • 标签: cathodic ELECTROLYTE redox IRRADIATED irradiation DOPING
  • 简介:Basedonaseriesofnumericalcalculations,thebehaviorofflowfieldinobstructedsquarebuoyantverticaljetissummarizedandanalyzed.Basedontheaxiallinevelocitydistribution,theflowafterthedisccanbedividedintothreeregions,i.e.,recirculationregion,transitionalregionandself-similarregionThecharacteristicofself-similarityofuprightvelocitywasvalidated.Thethreeregionscanalsobedistinguishedbasedontheaxialvelocity.Theaxialvelocityinself-similarregionwasfoundtoobeythesamelawandtheformulapresentedbyintroducingthevelocityexpressionusedbyChenandRodi.Theisolinesofpressureoncross-sectionsofdifferentheightsweredisplayedandtheproduction,expansion,breakinganddisappearingofnegativepressureregionswerefound.

  • 标签: 浮力射流 分离区域 速率场 压力场 轴向速率
  • 简介:Thedynamicresponseofthenon-linearelasticsimplysupportedbeamsubjectedtoaxialforcesandtransverseperiodicloadisstudied.Melnikovmethodisusedtoconsiderthedynamicbehav-iorofthesystemwhosepost-bucklingpathissteady.Theeffectofthehigherordertermsinthecon-trollingequationistakenintoaccount.Itisfoundthatthefifth-ordertermshaveagreatinfluenceonthedynamicbehaviorofthesystem.Theresultshowsthatthereexisteitherhomoclinicorbitsorhete-roclinicorbitsinthesystem.Inthispaper,thecriticalvaluesofthesystementeringchaoticstatesaregiven.Thediagramofanexampleisshown.

  • 标签: CHAOS HOMOCLINIC ORBIT HETEROCLINIC ORBIT MELNIKOV
  • 简介:Grapheneisthestrongestmaterialbutitsperformanceissignificantlyweakenedbyvacancydefects.Weusemoleculardynamicssimulationstoinvestigatethetensilebehaviorofagraphenewhichcontainsasinglevacancydefect.Ourresultssuggestthatbecauseofthesinglevacancy,thefracturestrengthofgraphenelossesabout17.7%.Thestressconcentrationaroundthevacancydefectleadstothedestructionofnearbysix-memberringsstructure,whichformstheinitialcrack.Thepropagationdirectionofthiscrackindefectivegrapheneisatanangleof60°tothetensiledirectioninitially,butthenbecomesperpendiculartothetensiledirection.

  • 标签: 空位缺陷 拉伸性能 石墨 分子动力学模拟 拉伸方向 断裂强度
  • 简介:Abriefreviewwithdiscussionsisconductedforsomepertinentworks,doneandongoingintheLaboratoryofPhase-ChangeandInterfacialPhenomenaatTsinghuaUniversity,oninterfacialbehaviorofvaporbubblesandinterfacialtransportphenomenaduringliquidnucleationboiling.Fromasequenceofexperimentalinvestigations,somenewphenomena,particularly,thevisuallyobservedinterfacialtransportphenomenaorprocessesincludingjet-likeflows,bubbleinteractionandspatialscaleeffect,weredescribedinthisarticle.Theinterfacialeffectsandtransportphenomenaassociatedwithsurfacetensiongradientscausedbytemperatureandconcentrationvariationsweretheoreticallyanalyzedtorevealthemarkedinfluenceonbubbleinterfacialshapeanddynamicbehavior,thebubbledynamicsincludingnucleation,bubblemotionandcoalescence.Severaltheoreticalmodelsandmethodswereproposedtodescribethedynamiccharacteristicsandexplainthephysicsofinterfacialphenomena/processes.Thespe

  • 标签: BOILING INTERFACIAL PHENOMENA transport process phase
  • 简介:Phosphatidylcholines(Ln’s)andtheirneutralanalogs1,2-diacyl-sn-glycerol-3-phospho-ricacidbromoethylesters(Pn’s)havebeenfoundtoexhibitdifferentaggregationbehaviorsbroughtaboutbyhydrophobic-lipophilicinteractions(HLI)bymeansofkineticprobeinMeOH-H2Obinaryaquiorganicsystems.Theeffectsofthestructureandtheenvironmentontheinterestingaggregationoftheamphiphilicmoleculesarediscussed.

  • 标签: Kinetic probe PHOSPHATIDYLCHOLINE hydrophobic-lipophilic interactions aggregating
  • 简介:ThepaperconsiderstheKrylov-LanczosandtheEckhoffapproximationsforrecoveringabivariatefunctionusinglimitednumberofitsFouriercoefficients.Theseapproximationsarebasedoncertaincorrectionsassociatedwithjumpsinthepartialderivativesoftheapproximatedfunction.ApproximationoftheexactjumpsisaccomplishedbysolutionofsystemsoflinearequationsalongtheideaofEckhoff.AsymptoticbehaviorsoftheapproximatejumpsandtheEckhoffapproximationarestudied.Exactconstantsoftheasymptoticerrorsarecomputed.Numericalexperimentsvalidatetheoreticalinvestigations.

  • 标签: 二元函数 逼近 傅里叶系数 线性方程组 近似函数 精确常数
  • 简介:这份报纸报导巨浪的试验性、理论的学习发生在原型一台极端微离心的压缩机。作为第一步,10次缩放有40公里的一台极端微离心的压缩机的模型外部直径被设计并且生产。为有B参数的几不同价值的巨浪的短暂行为的详细试验性的调查被执行。试验性的结果在巨浪期间与非线性的lumped参数理论获得以便为微离心的压缩机验证理论巨浪模型的有效性的那些相比。作为结果,巨浪的相当不同的行为在实验并且在分析为B的不同价值出现了。关键词微离心的压缩机-澎湃-lumped参数模型CLC数字TK474.8+2

  • 标签: 微离心压缩机 汹涌 集中参量模型 外直径
  • 简介:金属性的multilayers(NMM)很吸引了的nanoscale的机械行为从科学、实际的看法的注意。与他们的整体的对应物相比,在NMM存在的接口的大数字支配结构的合成材料的这个特殊的班的唯一的行为。当microlaminates的机械机制上有很多评论时,纳米技术的快速的开发为专门集中于NMM的一个基于性质的定义的概述带了紧迫的需要,他们的特别尺寸依赖者微观结构和机械性能。这篇文章试图在微观结构,机械性质和NMM的塑料变丑物理上提供全面、新的评论。我们希望这评论能完成二个目的:(1)介绍可伸缩和维的分析到研究NMM系统的科学家和工程师的基本概念,并且(2)提供接口行为和在NMM的接口在原子规模显示的非凡的质量的更好的理解。

  • 标签: 金属多层膜 力学性能 纳米级 结构复合材料 系统工程师 ITIES
  • 简介:Inperiodiccellularstructures,novelpatterntransformationsaretriggeredbyareversibleelasticinstabilityundertheaxialcompression.Basedonthedeformation-triggerednewpattern,periodiccellularstructurescanachievespecialmechanicalproperties.Inthispaper,thedesignedarchitecturematerialswhichincludeelastomermatrixescontainingemptyholesorfilledholeswithhydrogelmaterialaremodeledandsimulatedtoinvestigatethemechanicalpropertyoftheperiodicmaterials.Byanalyzingtherelationshipbetweennominalstressandnominalstrainofperiodicmaterial,andthecorrespondingdeformedpatterns,theinfluenceofgeometryandshapesoftheholesonthemechanicalpropertyofarchitecturematerialisstudiedinmoredetails.Wehopethisstudycanprovidefutureperspectivesforthedeformation-triggeredperiodicstructures.

  • 标签: 力学行为 周期结构 周期性结构 凝胶材料 型模 变形模式
  • 简介:Theinterfacialbehaviorofpipejointsisstudiedinthispaper.Firstly,throughnonlinearfracturemechanics,theanalyticalexpressionsofinterfacialshearstressandtheloaddisplacementrelationshipatloadedendofpipejointsundertorsionloadsareobtained.Thustheshearstresspropagationandthedebondingprocessofthewholeinterfacefordifferentbondlengthscanbepredicted.Secondly,throughtheanalyticalsolutions,theinfluencesofdifferentbondlengthsontheload-displacementcurveandtheultimateloadarestudied.Thestresstransfermechanism,theinterfacecrackpropagationandtheductilitybehaviorofthejointscanbeexplained.

  • 标签: 界面行为 载荷作用 管接头 扭转 荷载-位移曲线 极限荷载
  • 简介:electrospunpolyacrylonitrile(平底锅)的听觉的抑制性质有不同厚度和孔的nanofibrous膜被调查。健全吸收系数基于ISO10534-2:1998(E)用阻抗试管仪器被测量。结果显示nanofibrous膜的第一回声吸收频率随背洞的增加或膜的厚度变到更低的频率。而且,穿孔面板的健全吸收性能能被联合极大地与平底锅nanofibrous的薄层改进膜。传统的听觉的抑制材料(泡沫,纤维)与nanofibrous膜涂独自比听觉的材料的在低、中等的频率范围有更好听觉的性能。所有结果证明PANnanofibrous膜是噪音减小的一个合适的候选人。

  • 标签: 纳米纤维膜 聚丙烯腈 静电 声行为 声学材料 吸收频率
  • 简介:Weproposeacatalysis-selectmigrationdrivenevolutionmodeloftwo-species(A-andB-species)aggregates,whereoneunitofspeciesAmigratestospeciesBunderthecatalystsofspeciesC,whileunderthecatalystsofspeciesDthereactionwillbecomeoneunitofspeciesBmigratingtospeciesA.MeanwhilethecatalystaggregatesofspeciesCperformself-coagulation,asdothespeciesDaggregates.Westudythiscatalysis-selectmigrationdrivenkineticaggregationphenomenausingthegeneralizedSmoluchowskirateequationapproachwithCspeciescatalysis-selectmigrationratekernelK(k;i,j)=KkijandDspeciescatalysis-selectmigrationratekernelJ(k;i,j)=Jkij.Thekineticevolutionbehaviourisfoundtobedominatedbythecompetitionbetweenthecatalysis-selectimmigrationandemigration,inwhichthecompetitionisbetweenJD0andKC0(D0andC0aretheinitialnumbersofthemonomersofspeciesDandC,respectively).WhenJD0KC0>0,theaggregatesizedistributionofspeciesAsatisfiestheconventionalscalingformandthatofspeciesBsatisfiesamodifiedscalingform.AndinthecaseofJD0KC0<0,speciesAandBexchangetheiraggregatesizedistributionsasintheaboveJD0KC0>0case.

  • 标签: 动力学演化 催化剂 迁移率 行为 尺寸分布 聚集体