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简介：

简介：作为与不同焊接不规则通过一个磁道的车辆，磁道部件的动态性能被使用acoupled车辆鈥搕rack模型详细调查。在模型，车辆与自由的35个学位作为一个多身体系统被建模，并且一根Timoshenko横梁被用来为被睡眠者分离地支持的栏杆建模。在课程模型，睡眠者为他们的垂直、侧面、滚动的运动作为僵硬身体财务被建模并且假定以经常的速度向后移动模仿以一样的速度沿着课程跑的车辆。在联合车辆和课程动力学的学习，Hertizian接触理论和理论由沈鈥揌edrick鈥揈l建议分别地，家族被用来计算正常并且爬在车轮和栏杆之间的力量。在正常力量的计算，正常接触僵硬的系数被车轮和栏杆表面的短暂接触状况决定。在蠕动的计算，侧面，栏杆的连接运动和在在他们的普通正常方向的车轮和栏杆之间的相对速度等于零的事实同时被考虑。车辆和磁道的运动方程借助于一个明确的集成方法，栏杆焊接不规则作为垂直偏差由一些理想的余弦函数描述了的本地轨道在被建模被解决。不规则的火车速度，轴负担，波长和深度的效果，和在一个睡眠者的焊接中心位置在装载的车轮鈥搑ail影响上跨越被分析。获得的数字结果是极大地在引起由的焊接栏杆侧面不规则的忍耐设计有用在栏杆焊接和轨道维护以后磨手。关键词栏杆焊接-不规则-车辆鈥搕rack联合动力学这个工程被中国(2007CB714702)和中国(50821063，50675183和50875221)的国家自然科学基础的国家基本研究节目支持。

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简介：Inthispaper,FeBSiNbCrmetallicglasscoatingswerepreparedontoAISI1045steelsubstratebyusingwirearcsprayingprocess.Thephaseandstructureofthecoatingwerecharacterizedbytransmissionelectronmicroscopy(TEM),X-raydiffraction(XRD)andscanningelectionmicroscopy(SEM)equippedwithenergydispersiveX-rayanalysis(EDX).Themicrostructureofthecoatingconsistsoffullamorphousphase.Thecoatinghashighhardnessandlowporosity.Fulldensityandlittleoxidesaredetectedinthecoating.Themechanicalproperties,especiallywearresistance,wereinvestigated.Therelationshipbetweenwearbehaviorandstructureofthecoatingswereanalyzedindetail.Themainfailuremechanismofthemetallicglasscoatingisbrittlebreakingandfracture.TheresultsindicatethatFeBSiNbCrmetallicglasscoatinghasexcellentresistancetoabrasivewear.

简介：Effectsofstartingmaterialsandfourdispersants(STP,SHP,FDNandFS60)onZetapotentialandrheologicalbehaviorofaluminabasedULCcastablesmatrixwereinvestigated.Theresultsshowthat:characteristicsofsilicafumeandaluminacementsplayaveryimportantroleinZetapotentialandviscosityofsuspensionsofthecastablesmatrix;thedispersantsSTPandSHPcanchangeZetapotentialvaluesofthematrixsuspensionsremarkably;thefourdispersantscaneffectivelyimprovetherheologicalpropertiesofmatrixsuspensions.Forthepointoflowerviscosityofthematrixsuspensions,thesuitableadditionsofthethreedispersants(SHP,FDNandFS60)areabout0.2%whilethatofSTPisabout0.3%.

简介：Thestudyofthebehaviorofconcreteunderbiaxialstressesisessentialtothedesignofoffshoreconcreteplatforms.Usingthemultiaxialtestapparatusdevelopedbytheauthors,thedeformationandstrengthofconcreteunderbiaxialstressesarestudiedexperimentally.Basedonthetestdata,anendochronicdamageconstitutivemodelandafailurecriterionareproposed.Accordingtotheabovemodel,anincrementalnonlineariterativeprogrammeisdeveloped,andaplatesampleinplanestressstateisanalyzed.

简介：Vanadiumalloyisoneofthemostimportantcandidatestructuralmaterialsforafusionreactor.Itsmainadvantagesoverothercandidatesareitslowactivityfeatureandfeasiblepropertiesathightemperature.However,vanadiumiseasilyoxidizedathightemperaturetoformanon-protectivesurfacefilmofV2O5.Oxygenconcentrationwouldthusgethighandthepropertiesgetworseinnotonlythelossoftheductilitybutalsotheenhancedhydrogenembrittlementbytheoxidation.

简介：受到动人的负担的一座带子浮桥桥的一个数学模型用简单地支持的横梁的理论被提出。动人的负担模型的二种类型被使用，第一个一moving-constant-force模型和第二个一动人团的模型。用负担的两种类型，当使遭到了到单个移动负担然后多重移动负担时，一座带子浮桥桥的动态行为被模仿。当模特儿在MATLAB软件用完了Simulink包裹。结果显示模型是正确的。当负担在桥上移动了时，动人的负担模型的二种类型对反应范围有小差别，但是对反应阶段有某差别。当负担离开了时，moving-constant-force模型负担导致的动态回答的振幅比动人团的模型导致的那些大。有很多更多的差别当有更多的负担时。

简介：ThefracturebehaviorofSiCp/A356compositeatroomandhightemperatureswasstudied.Undertensilestressconditionatroomtemperature,thefractureismostlyacombinationofthebrittlefractureofSiCparticlesandductilefractureofA356matrix.Asthetensiletemperatureincreases,thecompositechangesthemainfracturebehaviortotheseparationfractureofthebondingsurfacebetweenSiCparticlesandA356matrix.Whenthetensiletemperaturereaches573K,thefracturebehaviorofthecompositesisalmostthewholeseparationfractureofthebondingsurface,whichisthemainstrengtheningmechanismathightemperature.Underthecyclestressconditionatroomandhightemperatures,themainfracturebehaviorofthecompositesisalwaysacombinationofthebrittlefractureofSiCparticlesandductilefractureofA356matrix.However,underthecyclestressathightemperature,cyclebehaviorofthecompositeschangesfromcyclehardeningatroomtemperaturetothecyclesofteningathightemperature.

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简介：Anon-autonomousLogistictypeequationwithinfinitedelayisinvestigated.Forgeneralnonau-tonomouscase,sufficientconditionswhichguaranteetheuniformpersistenceandgloballyattractivityofthesystemareobtained;Foralmostperiodiccase,bymeansofasuitableLyapunovfunctional,sufficientconditionsarederivedfortheexistenceanduniquenessofalmostperiodicsolutionofthesystem.Somenewresultsareobtained.

简介：Aneigenvaluemethodconsideringthemembranevibrationofwrinklingout-of-planedeformationisintroduced,andthestressdistributingruleinmembranewrinkledareaisanalyzed.Adynamicanalyticalmodelofrectangularshearwrinkledmembraneanditsnumericalanalysisapproacharealsodeveloped.Resultsindicatethatthestressinwrinkledareaisnotuniform,i.e.itislargerinwrinklingwavepeaksalongwrinklesandtwoendsofwrinkleinverticaldirection.Vibrationmodesofwrinkledmembranearestronglycorrelatedwiththewrinklingconfigurations.Therigidityislargerduetotheheavierstressinthepartofwrinklingwavepeaks.Therefore,wavepeaksarealwayslocatedatthenodelinesofvibrationmode.Thevibrationfrequencyobviouslyincreaseswiththevibrationofwavepeaks.

简介：Non-metallicinclusionisthemainreasonforthepresenceofsurfacedefectsincold-rolledsteelstrip.Inthisstudy,thecomposition,morphology,andsizeofthenon-metallicinclusioninhot-rolled304stainlesssteelstripsareanalyzed.Cold-rolled304stainlesssteelstripswithdifferentcold-rollingreductionhavebeenprepared,andthemorphologyandsizeofinclusioninthesecold-rolledstripsarealsoanalyzed.Furthermore,thedeformationbehaviorofanon-metallicinclusionduringthecold-rollingprocessisstudied.TheresultsshowthatCaO-SiO2-MgO-Al2O3,akindofbrittlecompoundoxide,isthemaintypeofinclusioninhot-rolled304stainlesssteelstrips.Duringthecold-rollingprocess,ductiledeformationofthistypeofinclusionisnotobvious,wherelargeinclusionsarecrushed,andtheaveragesizeofinclusionsincold-rolledstripsdecreasedwhilethecold-rollingreductionincreased.

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简介：Asaconvenientpassengertransitfacilitybetweenfloorswithdifferentheights,escalatorshavebeenextensivelyusedinshoppingmalls,metrostations,airportterminals,etc.Comparedwithotherverticaltransitfacilitiesincludingstairsandelevators,escalatorsusuallyhavelargetransitcapacity.Itisexpectedtoreducepedestriantravelingtimeandthusimprovethequalityofpedestrian'sexperiencesespeciallyinjammingconditions.However,itisnoticedthatpedestriansmaypresentdifferentmovementpatterns,e.g.,queuingoneachstepoftheescalator,walkingontheleft-sideandmeanwhilestandingontheright-sideoftheescalator.Thesedifferentpatternsaffecttheactualescalatortrafficvolumeandfinallythepassengerspatiotemporaldistributionindifferentbuiltenvironments.Thus,inthepresentstudy,amicroscopiccellularautomaton(CA)simulationmodelconsideringpedestrianmovementbehavioronescalatorsisbuilt.Simulationsareperformedconsid-eringdifferentpedestrianmovementspeeds,queuingmodes,andsegregationonescalatorswithdifferentescalatorspeeds.Theactualescalatorcapacitiesunderdifferentpedestrianmovementpatternsareinvestigated.Itisfoundthatwalkingonescalatorswillnotalwaysbenefitescalatortransitvolumeimprovement,especiallyinjammingconditions.

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简介：在现在的研究，一种湖泊的壳(Hyriopsiscumingii)的微观结构被使用扫描电子显微镜学，和壳珠母贝的机械行为实验观察并且测量被使用弯曲和张力的测试执行。它的微观结构上的壳珠母贝的机械性质的依赖被使用一个修改砍落后模型，和全面压力紧张关系分析被获得。试验性的结果表明壳珠母贝的机械性质强烈取决于湖泊的壳的水内容。干燥珠母贝显示出易碎的行为，而弄湿珠母贝显示强壮的韧性。比作张力的测试，弯曲测试过高估计力量并且低估幼仔的模量。修改砍落后模型能有效地描绘珠母贝的变丑特征。

简介：Inthispaper,someteststatisticsOfKolmogorovtypeandCramervonMisestypebasedonprojectionpursuittechniqueareproposedfortestingthesphericityproblemofahigh-dimensionaldistribution.Thelimitingdistributionsoftheteststatisticsarederivedunderthenullhypothesis.TheasymptoticpropertiesofBootstrapapproximationareinvestigatedandthetailbehaviorsofthestatisticsarestudied.

简介：Thecorrugatedpackingispronetobreakdowneasily,whichcanaffectthetowerefficiencysubstantially.Itistheinnerenvironmentofthevacuumdistillationtowerincludingthetemperatureandchemicalnatureoffluidthatleadtothepackingdamage.Thetheoreticalanalysisindicatesthatitistheinnermaterialflowofvacuumdistillationtowerthatleadstothevibrationofpacking,whichcanaffectthecorrosionfatigueofpackingsignificantly.Meanwhile,themodalshapeandinherentfrequencyofpackingunderprestresscanbeobtainedbymeansofmathematicalanalysis.Basedonthetwokindsofanalysis,theflowinducedvibrationandcorrosionfatigueareaccountableforthefailureofpacking.