简介:Anewcompositioncontentquaternary-alloy-basedphasechangethinfilm,Sb-richAglnSbTe,hasbeenpreparedbyDC-magnetronsputteringonaK9glasssubstrate.Afterthefilmhasbeensubsequentlyannealedat200℃for30min,itbecomesacrystallinethinfilm.Thediffractionpeakofantimony(Sb)areobservedbyshallow(0.5degree)x-raydiffractioninthequaternaryalloythinfilm.Theanalysesofthemeasurementfromdifferentialscanningcalorimetry(DSC)showthatthecrystallizationtemperatureofthephasechangethinfilmisabout190℃andincreaseswiththeheatingrate.ByKissingerplot,theactivationenergyforcrystallizationisdeterminedtobe3.05eV.Thereflectivity,refractiveindexandextinctioncoefficientofthecrystallineandamorphousphasechangethinfilmsarepresented.Theopticalabsorptioncoefficientofthephasechangethinfilmsasafunctionofphotonenergyisobtainedfromtheextinctioncoefficient.Theopticalbandgapsoftheamorphousandcrystallizationphasechangethinfilmsare0.265eVand1.127eV,respectively.
简介:合金(SMA)电线增强了的形状存储器的机械行为疼痛有损坏的结构通过变化原则被分析,为中央排水量域的为结构的一个管理方程被导出的、数学表达式,有损坏的典型元素的压力紧张地被介绍,并且为在SMA电线和矩阵之间的接口失败的一个失败标准在死了负担的二种使活动和温度下面被建立,在温度在有效免费恢复被包括的地方,拉紧。另外,在象接口性质那样的失败标准有一些另外的创作因素,SMA的动态性质,起始的debonding长度L-l等等。结果是重要的理解自我改编的控制和SMA电线的失败机制增强了的结构的力量有损坏的聪明的结构。
简介:Mechanicalcharacterizationofsteelframestructureafterfireareanalyzedbasedonfiredynamics,heattransfertheory,structuralmechanics,andfiniteelementtheory.Westudythetemperaturecharacteristicsandmechanicalpropertiesofsteelframestructureunderdifferentfirelocationsandproposeasafetyevaluationmethod.Wealsoanalyzedamagelevelofmainframecomponents,maximumtemperatureoffire,thermalcharacteristicsofframecomponents,firingduration,etc.toprovideusefulinformationforfireresistancedesignofthesteelframestructureandpost-disastersafetyevaluation.
简介:ThefluorescenceemissionandX-raydiffractionofmagenesium8-hydroxyquinolinecomplex(Mgq2)havebeenmeasuredathighpressureupto14GPa.Ithasbeenfoundthatpressurecaninfluencetheemissiondramatically.Atrelativelowerpressure(lessthan2.5GPa)thefluorescenceofMgq2changesslightly,buttheemissiondropsquicklywithincreaseofthepressurewhenthepressuregetshigherthan2.5GPa.TheresultsofinsituenergydispersiveX-raydiffractionathighpressurewithsynchrotronradiationindicatethatthereisaphasetransitionatabout2.5-3GPaforMgq2crystal.2001ElsevierScienceB.V.Allrightsreserved.
简介:
简介:Aseriesofsisalbasedactivatedcarbonfiberswerepreparedwithsteamactivationattemperaturefrom750℃to900℃.Theirporestructureswerecharacterizedthroughtheirnitrogenadsorptionisothermsat77Kusingdifferenttheories.Theresultsshowedthatt-plotmethodandDR-plotmethodcouldsuitablybeusedtocharacterizethemesoporestructureandthemulti-stagedistributionofporesizeofactivatedcarbonfibers.Italsoshowedthattheporesizewidenswiththeincreaseofactivationtemperature.
简介:Stent-graftimplantationisanimportantmeansofclinicaltreatmentforaorticdissectinganeurysm(ADA).However,researchesonfluiddynamicseffectsofstentwererare.ComputersimulationwasusedtoinvestigatetheinteractionsbetweenbloodstreamandvascularstructureinastentedADA,whichendurestheperiodicpulsevelocityandpressure.Weobtainedandanalyzedtheflowvelocitydistribution,thewalldisplacementandwallstressintheADA.Bycomparingthedifferentresultsbetweenanon-stentedandastentedADA,wefoundthattheinsertionofavasculargraftcanmakethelocationofmaximumstressanddisplacementmovefromtheaneurysmlumenwalltothearterywall,accompaniedwithagreatlydecreaseinvalue.Theseresultsimplythattheplacementofastent-graftofanykindtooc-cludeADAwillresultinadecreasedchanceofrupture.
简介:Shapememoryalloy(SMA)reinforcedsmartstructurecanbeusedtomakestructuralshapeandstrengthselfadaptedandstructuraldamageself-restrained.AlthoughSMAsmartstructureswithoutdamageswereextensivelystudied,researchesonSMAsmartstructureswithdamageshaverarelybeenreportedthusfar.Inthispaper,thermo-mechanicalbehaviorsofSMAfiberreinforcedsmartstructureswithdamagesareanalyzedthroughashearlagmodelandthevariationalprinciple.Mathematicalexpressionsofthemeso-displacementfieldandthestress-strainfieldofatypicalelementwithdamagesareobtained,andafailurecriterionforinterfacefailurebetweenSMAfibersandmatrixisestablished,whichisappliedtoanexample.ResultspresentedhereinmayprovideatheoreticalfoundationforfurtherstudiesonintegrityofSMAsmartstructures.
简介:Basedonthemathematicalmodelofakindofcomplicatedfinancialsystem,allpossiblethingsthatthemodelshowsintheoperationofourcountry'smacro-financialsystemwereanalyzed,suchasbalance,stableperiodic,fractal,Hopf-bifurcation,therelationshipbetweenparametersandHopf-bifurcations,andchaoticmotionetc.Bythechangesofparametersofalleconomicmeanings,theconditionsonwhichthecomplicatedbehaviorsoccurinsuchafinancialsystem,andtheinfluenceoftheadjustmentofthemacro-economicpoliciesandadjustmentofsomeparameteronthewholefinancialsystembehaviorwereanalyzed.Thisstudywilldeepenpeople'sunderstandingoftheleverfunctionofallkindsoffinancialpolicies.
简介:(连续)为电子结构的答案的计算的不同订单的有限元素近似在一些报纸被建议,这些途径的表演正在变得可估计并且现在很好被理解。在这份出版物,作者建议由联合有限元素网孔的精炼为完整潜力的电子结构计算扩大这discretization,在溶液随溶液主要是常规的区域的多项式近似的度的增加是很单个的的地方。近似性质的增加的这联合,做在一priori或一种posteriori方式,甚至当答案是单个的时,是著名的通常关于自由的度的数字生产最佳的指数的类型集中率。这里执行的分析在Hartree-Fock和Kohn假冒的问题的情况中支撑这个性质。
简介:Highspinstatesintheneutron-rich^108Runucleushavebeenstudiedthroughmeasuringpromptγ-raycoincidencesfollowingthespontaneousfissionof^252CfwiththeGammaspheredetectorarray.Theyrastbandhasbeenconfirmed.Theone-phononγ-vibrationalbandandthetwo-quasiparticlebandbasedonthe5^-levelhavebeenextendedupto13^+and15^-,respectively.Inaddition,twolevelsat1644.8keVand1826.5keVexcitationenergiesarenewlyidentifiedandproposedtobethemembersofatwo-phononγ-vibrationalband.Itisshownthatthe^108Runucleushastriaxialdeformationwithparametersβ2~0.29andγ=-22°fromthetotalRouthiansurfacecalculations.Theobservedbandcrossingintheyrastbandisduetothealignmentofapairofh11/2neutronsaccordingtothecrankedshellmodelcalculations.Thepossibleconfigurationforthetwo-quasiparticlebandhasbeendiscussed.