简介：Theacousticemission(AE)featuresinrockfracturearesimulatednumericallywithdiscreteelementmodel(DEM).Thespecimenisconstructedbyusingsphericalparticlesbondedviatheparallelbondmodel.Asaresultoftheheterogeneityinrockspecimen,thefailurecriterionofbondedparticleiscoupledbytheshearandtensilestrengths,whichfollowanormalprobabilitydistribution.TheKaisereffectissimulatedinthefractureprocess,foracubicrockspecimenunderuniaxialcompressionwithaconstantrate.TheAEnumberisestimatedwithbreakagesofbondedparticlesusingapairofparameters,inthetemporalandspatialscale,respectively.ItisfoundthattheAEnumbersandtheelasticenergyreleasecurvescoincide.TherangefortheKaisereffectfromtheAEnumberandtheelasticenergyreleasearethesame.Furthermore,thefrequency-magnituderelationoftheAEnumbershowsthatthevalueofBdeterminedwithDEMisconsistentwiththeexperimentaldata.

简介：Thepurposeofthisworkistoinvestigatethedynamicfracturepropertiesofglassypolycarbonate(PC)withdiferentagingtimes.Theopticalmethodofcausticsisadoptedinwhichtheshadowspotpatternsarerecordedbyahighspeedcameraduringthedynamicfractureprocess.Then,thedynamiccrackpropagation,thestressintensityfactor(SIF)andthedynamicfracturetoughnessofagedPCareobtainedthroughananalysisofthecharacteristicsizeofcausticpattern.Moreover,bycombiningwiththeinvestigationofthefracturesurfaceandtheenergyreleaserateanalysis,theinfluenceofagingtimeonthedynamicfracturebehaviorisdiscussed.ResultsshowthatthedynamicfracturetoughnessandcriticalenergyreleaserateofPCdecreaseswithagingtimeforshortagingtimes,whereastheyhavelittlechangeorevenincreaseforlongeragingtimes.Therefore,agingmodifiesthemechanicalpropertiesespeciallythedynamicfracturepropertiesofPCnonlinearly,notlinearlyasgenerallythoughtof.

简介：Theresultsofatheoreticalstudyontheinfluenceofstrengthofinterphaseboundariesinmetal—ceramiccompositeonmacroscopicalcharacteristicsofcompositeresponsesuchasstrength,deformationcapacity,fractureenergyandfracturepatternarepresented.Thestudywasconductedbymeansofcomputer-aidedsimulationbymeansofmovablecellularautomatonmethodtakingaccountofadeveloped'mesoscopical'structuralmodelofparticle-reinforcedcomposite.Thestrengthofinterphaseboundariesisfoundtobeakeystructuralfactordeterminingnotonlythestrengthpropertiesofmetal—ceramiccomposite,butalsothepatternandrateoffracture.Theprinciplesforachievementofthehigh-strengthvaluesofparticle/binderinterfacesinthemetal—ceramiccompositionduetotheformationofthewidetransitionzones(areasofvariablechemicalcomposition)attheinterphaseboundariesarediscussed.Simulationresultsconfirmthatsuchtransitionzonesprovideachangeinfracturemechanismandmaketheachievementofahigh-strengthandahighdeformationcapacityofmetal—ceramiccompositepossible.

简介：骨头骨折愈合的起始的煽动性的阶段为愈合的过程的结果代表关键步。然而，开始这个煽动性的阶段的机制和在破裂地点在场的有免疫力的房间的功能糟糕被理解。以便在破裂hematoma以内学习早事件，我们建立了一在里面vitro破裂hematoma模型：我们有教养的hematomas在bioenergetically控制的条件下面在vitro在全部的新潮的关节造形术(THA)期间在腿节的截骨术(人工的骨头破裂)期间形成。这个模型允许我们在跟随破裂的早阶段期间监视有免疫力的房间人口，房间幸存和cytokine表示。而且，这个模型使我们能改变bioenergetical条件以便模仿在里面vivo状况，它被假定被组织缺氧描绘并且限制了营养素的数量。用这个模型，我们发现有免疫力的房间经由angiogenic因素，chemoattractants和支持inflammatory分子的表示适应组织缺氧。另外，联合了氧的限制，滋养的供应与myeloid的比较提高了淋巴细胞的选择幸存导出的房间(即，neutrophils)。笔记，非限制的bioenergetical条件没关于cytokine表示或有免疫力的房间子集的不同幸存率显示出任何类似的效果。在结论，我们发现bioenergetical条件在导致骨折愈合的起始的煽动性的阶段的关键因素之中并且因此是为在早破裂hematoma影响有免疫力的房间的幸存和功能的一个关键步骤。

简介：ObjectiveToexplorethevalueofcomputedtomographyvirtualendoscopy(VE)inassessingossicularchaindisruptionintemporalbonefractureandeartraumawithintacttympanum.MethodsHighresolutionspiralcomputerizedtomography(CT)wascompletedin35casesoftemporalbonefractureand5casesoftympanumtrauma,allwithintactorhealedtympanum.Three-dimensionalreconstructionwascompletedus-ingavirtualendoscopysoftware.Audiologicaltestswereconductedinallpatientsandevaluationoffacialnerveinjuryinpatientswithfacialparalysis.Patientswithmildconductivedeafness,ossicularchainsublux-ationonVE,andnofacialparalysisweretreatedconservativelyfor4-12weekswithrepeatedhearingevalu-ation;thosewithfacialparalysisunderwentsurgeryifnorecoveryafter4-8weeksofconservativetreat-ment.Patientswithmoderatetosevereconductivehearinglossormixedhearingloss,incuslongprocessfractureordislocationonVEandfacialparalysis,underwentossicularchainreconstructionandfacialnervedecompressionafterconservativetreatmentfor4-8weeks,orexploratorytympanotomyonlyifnofacialpa-ralysis.VE,audiologicaltestsandfacialnervefunctiontestswererepeatedin3-6monthsaftersurgery.Re-sultsOfthe6caseswithmildconductivehearingloss,ossicularchainsubluxationandnofacialparalysis,3recoveredtonormalhearingspontaneouslyand3showednosignificantimprovement,after4-12weeksofconservativetreatment.Afterconservativetreatmentfor4-8weeks,3ofthe12caseswithmildconductivedeafness,ossicularchaindislocationonVEandfacialparalysisrecoveredtonormalhearingandHouse-Brackmann(HB)gradeIfacialfunctionfromHBgradeII,4showedfacialfunctionrecoverytoHBgradeI(n=2)orII(n=2)fromHBgradeIIIbutnohearingrecovery,and5gainednorecoveryandwentontoreceiveexploratorytympanotomyandfacialnervedecompression.The11caseswithmoderatetosevereconductivedeafness,incuslongprocessfr

简介：ObjectiveToexplorethevalueofcomputedtomographyvirtualendoscopy(VE)inassessingossicularchaindisruptionintemporalbonefractureandeartraumawithintacttympanum.MethodsHighresolutionspiralcomputerizedtomography(CT)wascompletedin35casesoftemporalbonefractureand5casesoftympanumtrauma,allwithintactorhealedtympanum.Three-dimensionalreconstructionwascompletedusingavirtualendoscopysoftware.Audiologicaltestswereconductedinallpatientsandevaluationoffacialnerveinjuryinpatientswithfacialparalysis.Patientswithmildconductivedeafness,ossicularchainsubluxationonVE,andnofacialparalysisweretreatedconservativelyfor4-12weekswithrepeatedhearingevaluation;thosewithfacialparalysisunderwentsurgeryifnorecoveryafter4-8weeksofconservativetreatment.Patientswithmoderatetosevereconductivehearinglossormixedhearingloss,incuslongprocessfractureordislocationonVEandfacialparalysis,underwentossicularchainreconstructionandfacialnervedecompressionafterconservativetreatmentfor4-8weeks,orexploratorytympanotomyonlyifnofacialparalysis.VE,audiologicaltestsandfacialnervefunctiontestswererepeatedin3-6monthsaftersurgery.ResultsOfthe6caseswithmildconductivehearingloss,ossicularchainsubluxationandnofacialparalysis,3recoveredtonormalhearingspontaneouslyand3showednosignificantimprovement,after4-12weeksofconservativetreatment.Afterconservativetreatmentfor4-8weeks,3ofthe12caseswithmildconductivedeafness,ossicularchaindislocationonVEandfacialparalysisrecoveredtonormalhearingandHouseBrackmann(HB)gradeIfacialfunctionfromHBgradeII,4showedfacialfunctionrecoverytoHBgradeI(n=2)orII(n=2)fromHBgradeIIIbutnohearingrecovery,and5gainednorecoveryandwentontoreceiveexploratorytympanotomyandfacialnervedecompression.The11caseswithmoderatetosevereconductivedeafness,incuslongprocessfractureordis