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简介：Constitutiverelationsaregivenforthedescriptionofthedeformationbehaviorofshapememorymaterials.Thedeformationisthesuperpositionoftheelastic,thethermalandthephasetransformationdeformationcausedbythetransformationfromonetotheotheramongthehightemperaturephase,thelowtemperaturephaseandthestressinducedphase.Thephasetransformationiscontrolledbythedrivingforce,i.e.,theGibbsenergydifferencebetweenthephases.

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简介：Thedynamicalequationsforainertialreciprocatingmachineexcitedbytworotatingeccentricweightswerebuiltbythematrixmethodologyforestablishingdynamicalequationsofdiscretesystems.Amathematicalmodelofelectromechanicalcouplingsystemforthemachinewasformedbycombiningthedynamicalequationswiththestateequationsofthetwomotors.Thecomputersimulationtothemodelwasperformedforseveralvaluesofthedampingcoefficientorthemotorpower,respectively.Thesubstanceoftransientbehaviorofthemachineisunveiledbyanalyzingtheresultsofthecomputersimulation,andnewmethodsarepresentedfordiminishingthetransientamplitudeofthevibratingmachineandimprovingthetransientbehavior.Thereliablemathematicalmodelisprovidedforintelligentcontrolofthetransientbehaviorandengineeringdesignoftheequipment.

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简介：Theinterrelationofvariousfactorsaffectingthemechanicalstrength,thethermalshockresistivityandcreepdeformationofslabinasimplesettingconditionofthefiringoftablewarearediscussed,Theconrolofparametersinfavourofthedesiredperformanceoftheslabispropsed.

简介：Metalgrainsinstonymeteoritesarerelativelymovableduringthermalnetamorphism(Wood,1967;XieandWang,1979;Xie,1986).InviewofthefactthattheJilinmeteoriteisthelargestintheworldknownuptonow,itsmainbodyweighing1770kganditstotalvolumeamountingto117×93×84cm^3,ade-tailedinvestigationintosuchahugemeteoritebodywouldundoubtedlyprovideuswithalotofcluesandinformationvaluableinthestudyofthebehaviorofFe-Nimetalduringthermalmetamorphismofmeteorites.OurrecentinvestigationhasrevealedthatduringthermalmetamorphismoftheJilinchondirtefineFe-Nimetalparticlesmigratedeasilybydiffusioninsolidstate,andsubsequentlyaggregatedintometalnodulesabout5-10mminlength,andthelargestnodulewefoundis30mminsize(Photo1).Inthispaperwepresentsomenewresultsofourstudyconcerningthemigra-tionandconcentrationofFe-NimetalintheJilinchondriteonthebasisofop-tical,SEMobservationsandhigh-temperature-highpressureaswellasshockloadingexperiments.

简介：Theinfluenceofthegrainboundaryonthefatiguebehaviorwasstuiedbytwothree-point-bending(TPB)specimens.OneTPBspecimenwasnamedBicrystal1,whosepre-crackwasalongthegrainboundaryandtheappliedloadparalleledtopre-crackdirection,whiletheotherTPBspecimenwasnamedBicrystal2,whosethepre-crackwasperpendiculartothegrainboundaryandtheappliedloadparalleledalsotothepre-crack.ItwasfoundthattherateofthefatiguecrackgrowthofBicrystal1wasaboutatenfoldhigherthanthatofBicrystal2.ThefatiguebehaviorofBicrystal2specimenswasdependentonthedistancebetweenthecracktipandgrainboundary.Thecrackgrowthratewashighestwhenthecracktipwasatacriticaldistancetothegrainboundary,whiletheratewasthelowestwhenthecracktipreachedgrainboundary.Afterthecrackwasoverthegrainboundary,thecrackgrowthrateincreased.Thecrystallographicfiniteelementmethodwasappliedtoanalyzethestressandstrainstructureaheadofthecrack,inordertorevealtheabovecharacteristicsofthefatiguebehavior.Itisthegrainboundary-inducedredistributionofstressesnearthecracktipthatinducesthedifferenceoffatiguebehavior.

简介：Closed-celltypebarrierribssuchasmeander,honeycomb,SDR,andwaffletypeswereproducedusingcapillarymoldingprocess.SinteringoftheribsrevealedthattheribswithasymmetricgeometrysuchasmeanderandSDRtypebecamedistortedseverelybythesinteringprocess,buttheribswithsymmetricgeometrysuchashoneycombandwaffletypemaintainedtheirgreenstatemorphology.Aftersintering,theribswerecoatedwithgreenphosphorusingosmosiscoatingprocessanditsluminancecharacteristicswereevaluated.Theresultsindicatedthattheluminanceanditsefficiencyisimprovedbyusingclosed-celltyperibswiththenewphosphorformingtechnology.

简介：Lowcement(LC)andultra-lowcement(ULC)bauxite-SiCcastablesareimportantandhighperformancemonolithicrefiactoriesandtheyhavebeenwidelyusediniron-makingandincineratorlinings.Inthiswork,rheo-logicalbehaviorofLCandULCbauxite-basedSiC-contain-ingcastableshasbeenstudied,includingtheeffectsofSiCcontentandcementcontentonrheologicalpropertiesofthecastables.TheresultsshowthatwithanincreaseofSiCandcementcontent,rheologicalpropertiesofthecastablesdeteriorate.Ontheotherhand,moderateamountsofSiC(4%～8%)andofcalciumaluminatecement(2%～4%)haveveryslightinfluenceonrheologicalproperties,(i.e.whenthecastablesareshearedtheirtorqueandyieldtorqueonlyslightlyincreasewiththeshearingspeed).Therheologicalcharacteristicsofthecastablesfol-lowBinghamfiuidandalwaysshowshearthinningbehav-ior.

简介：Thedynamicbehavioroftwoparallelsymmetriccracksinapiezoelectricstripunderharmonicanti-planeshearwavesisstudiedusingtheSchmidtmethodforpermeablecracksufaceconditions.Thecracksareparalleltotheedgeofthestrip.BymeansoftheFouriertransform,theproblemcanbesolvedwiththehelpoftwopairsofdualintegralequations.Theseequationsaresolvedusingtheschmidtmethod.Theresultsshowthatthestressandtheelectricdisplacementintensityfactorsdependonthegeometryofthecracks,thefrequencyofincidentwaves,thedistancebetweencracksandthethicknessofthestrip.Itisalsofoundthattheelectricdisplacementintensityfactorsforthepermeablecracksurfaceconditionsaremuchsmallerthanthosefortheimpermeablecracksurfaceconditions.

简介：SometribologicalbehaviorbetweenmatureGampsocleisgratiosafootpadsandverticalflatsofdifferentmaterialswerestudiedinthiswork.stereomieroscope(SMS)andscanningelectronmicroscope(SEM)wereusedtomeasurethemorphologyoftheGampsocleisgratiosafootpads.Anatomicforcemicroscope(AFM)wasusedtomeasurethemorphologiesofthesurfacesofglassandawalldopedwithcalciumcarbonatematerial.TheattachingbehaviorofGampsocleisgratiosafeetonthetwoverticalsurfaceswasobserved.Theattachingforce(perpendiculartotheverticalsurface)andthestaticfrictionalforce(alongthedirectionofgravitation)ofGampsocleisgratiosafootpadsonaverticalglassweremeasured.Itwasshownthattheaverageattachingforceis50.59mNandthestaticfrictionalforceis259.10mN.ThephysicalmodelsoftheattachinginterfacebetweenGampsocleisgratiosafootpadsandthetwoverticalsurfaceswereproposed.Itwasobservedthatthefootpadsaresmoothinmacroscale;however,thepadsurfaceiscomposedbyapproximatehexagonalunitswithsizesof3μmto7μminmicroscale;theadjacentunitsareseparatedbynanoscalegrooves.TheObservationsshowedthattheGampsocleisgratiosacannotclimbtheverticalcalciumcarbonatewall;incontrast,theycaneasilyclimbtheverticalglasssurface.Basedonthefeaturesofthegeometricalmorphologiesofthefootpadsandtheglasssurface,wespeculatethattheattachingforceandstrongstaticfrictionalforceareattributedtotheinterinlaysbetweenthedeformableGampsocleisgratiosafootpadsandthenanoscalesharptipsoftheglasssurface.

简介：ＭＡＳＳＣＯＮＳＥＲＶＡＴＩＯＮＢＥＨＡＶＩＯＲＯＦＷＡＶＥＥＱＵＡＴＩＯＮＭＯＤＥＬＦＯＲＳＯＬＶＩＮＧＳＨＡＬＬＯＷＷＡＴＥＲＥＱＵＡＴＩＯＮ￥ＷｕＪｉａｎ－ｋａｎｇ（ＨｕａｚｈｏｎｇＵｎｉｖｅｒｓｉｔｙｏｆＳｃｉｅｎｃｅａｎｄＴｅｃｈｎｏｌｏｇ...

简介：TheinfluencesofboththevolumeofPS/toluenesolutionintheUbbelohdeviscometerandtheprecisionofthetimemeasuringontheviscositybehaviorindiluteandextremelydiluteconcentrationregionareinvestigatedItwasfoundthattheinfluenceoftheformercanneglect,butthatofthelatterissoprominentthatthedatafluctuatebitterlyandlinearityofthecurveofthereducedviscosityvs.Concentration(ηsp/c～c)becomestoobadtoobeytheHugginsequationdowntotheextremelydiluteregion,despitetheerroroftheflowtimes△t≤0.2s,whichispermittedbytheconventionalmethodofviscositymeasurement.Throughstrictmathematicalanalyses,itwasfoundthatthcerror(E)ofthereducedviscosityisinproportionandinverseproportionto△tandconcentrationc,respectively.Sothelesstheconcentration,themoretheerroris.Consequently,alowestconcentrationlimitcLcorrespondingtogivenexperimentalerrormayexistanditwillbemeaninglessforfurtheroperationbelowcLbecauseofthegreatfluctuationofthedata.Therefore,itneedstoseriouslyreconsidertheapplicationoftheconventionalmethodofUbbelohdeviscositymeasurementintheextremelydilutepolymersolutionundertraditionalconditionsbecauseofthegreatinfluenceoftheexperimentalerror.

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简介：n种类的二个催化出生的模型(n≥2)驾驶withexchange的生长处理的总数被建议并且比较。在里面以前一个，交换反应与率核K_m发生在任何二总数A_k~m和一样的种类的A_j~m之间(k，j)=K_mkj(m=1，2，...，n，n≥2)，并且A~n种类的总数催化A~lspecies的单体出生(l=1，2，...，n-1)与催化作用率核J_l(k，j)=J_lkj~υ。运动行为借助于吝啬地的理论被调查。我们发现A~l种类的进化行为ofaggregate尺寸分发a_k~l(t)关键地取决于催化作用率参数υ的值：(ⅰ)a_k~l(t)在υ≤的情况中遵守常规可伸缩法律0，(ⅱ)a_k~l(t)在υ>的情况中满足一种修改可伸缩的形式0。在第二个模型，A~l种类催化的A~n种类的单体出生的机制根据第一个模型被增加，也就是说，A~l和A~n种类的总数催化对方到causemonomer出生。A~l和A~n种类的运动行为被发现为不同的υ掉进二个范畴：(与υ≤服从常规可伸缩的形式的ⅰ)生长0，(在有υ>的有限时间的ⅱ)gelling0。

简介：Atimeseriesx（t）,t≥1,issaidtobeanunstableARMAprocessifx（t）satisfiesanunstableARMAmodelsuchasx（t）=a1x（t-1）+a2x（t-2）+…+a8x（t-s）+w（t）wherew（t）isastationaryARMAprocess;andthecharacteristicpolynomialA（z）=1-a1z-a2z2-…-a3z3hasallrootsontheunitcircle.Asymptoticbehaviorofsumform1ton（x2（t））willbestudiedbyshowingsomeratesofdivergenceofsumform1ton（x2（t））.ThiskindofpropertiesWillbeusedforgettingtheratesofconvergenceofleastsquaresestimatesofparametersa1,a2,…,a?

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简介：Thisstudydescribestheseismicperformanceofanexistingfivestoreyreinforcedconcretebuildingwhichrepresentsthetypicalpropertiesoflow-risenon-ductilebuildingsinTurkey.Theeffectivenessofshearwallsandthesteelbracingsinretrofittingthebuildingwasexaminedthroughnonlinearstaticanddynamicanalyses.Byusingthenonlinearstaticanalysis,retrofittedbuildingsseismicperformancesunderlateralseismicloadwerecomparedwitheachother.Moreover,theperformancepointsandresponselevelsoftheexistingandretrofittingcasesweredeterminedbywayofthecapacity-spectrummethoddescribedinATC-40(1996).Forthenonlineardynamicanalysistherecordswereselectedtorepresentwiderangesofdurationandfrequencycontent.Consideringthechangeinthestiffnessandtheenergydissipationcapacities,theperformanceoftheexistingandretrofittedbuildingswereevaluatedintermsofstorydriftsanddamagestates.Itwasfoundthateachearthquakerecordexhibiteditsownpeculiarities,dictatedbyfrequencycontent,duration,sequenceofpeaksandtheiramplitude.Theseismicperformanceofretrofittedbuildingsresultedinlowerdisplacementsandhigherenergydissipationcapacitydependingmainlyonthepropertiesofthegroundmotionsandtheretrofittingstrategies.Moreover,severestructuraldamage(irreparableorcollapse)wasobservedfortheexistingbuilding.However,buildingswithretrofitalternativesexhibitedlowerdamagelevelschangingfromnodamagetoirreparabledamagestates.