简介：TheequationofmotionofsandwichbeamwithpyramidallatticecoreinthesupersonicflowconsideringgeometricnonlinearityisformulatedusingHamilton’sprinciple.Thepistontheoryisusedtoevaluateaerodynamicpressure.Thestructuralaeroelasticpropertiesareanalyzedusingfrequency-andtime-domainmethods,andsomeinterestingphenomenaareobserved.Itisnotedthattheflutterofsandwichbeamoccursunderthecouplingeffectoflowordermodes.Thecriticalflutteraerodynamicpressureofthesandwichbeamishigherthanthatoftheisotropicbeamwiththesameweight,lengthandwidth.Theinfluenceofinclinationangleofcoretrussonfluttercharacteristicisanalyzed.

简介：

简介：Thestraindifferenceofsteelandconcreteunderverticalconcentratedloadwasanalyzedonthebasisofelastictheory,andwascomparedwithidealsolutionofsteelandconcreteunderverticaluniformload.Theresultsindicatethatthecomputingformulaconcludedfromthepaperisbelievable.Thepracticalstructureusuallybearsconcentratedload,soitcanbeusedinthepracticalengineering.

简介：Tosatisfytheinterfacialshearforcecontinuityconditions,anewmodelisproposedforthetwo-layercompositebeamwithpartialinteractionbymodifyingReddy’shigherorderbeamtheory.ThegoverningdifferentialequationsforfreevibrationandbucklingareformulatedusingtheHamilton’sprinciple,thenaturalfrequenciesandaxialforcesarethusanalyticallyobtainedbyLaplacetransformtechnique.Theanalyticalresultsareverifiedthroughthecomparisonwiththoseofseveralothermodelscommoninuse;andthepresentedmodelisfoundtobeafineronethantheReddy’s.Aparametricstudyisalsoperformedtoinvestigatetheeffectsofgeometryandmaterialparameters.

简介：一根双横梁在红外线附近的分光计被开发在紧张补偿水吸收和仪器的飘移。分光计可以被用于单个、双的横梁大小，并且二个操作模式被比较。结果证明双横梁技术在单个横梁测量消除仪器的飘移，因此，系统的稳定性增加超过20%。水吸收上的双横梁系统的赔偿被胖内容的测量在牛奶验证。结果证明光谱数据比传统的单个横梁模式基于两倍横梁模式得到更好的刻度模型和更低的预言错误。CLC数字TH744.1-TN219-O433.1这个工作被中国(号码2004BA706B12)和天津(No.023800411)的自然科学关键基础的第10五个年计划支持。

简介：Inindirectdrive,reducingpeakintensityofasinglebeamandcontrollingoverlapofmulti-beamsaretwooppositerequirementsforlaserfocalspotdesign.Inthispaper,animprovedlaserspotdesigntechniqueforindirectdrivebuiltuponthegeometricstructuresoflaserpropagationintohohlraumhasbeenintroduced.Theproposedtechniqueisabletogenerateappropriatecontinuousphaseplate(CPP)producingaspecialshapedspotthatcanbalancetheoppositerequirements.ThecorrespondingCPPdoesnotbringdifficultiestothedesignandfabrication.Phaseaberrationsaremoresensitivetothespecialshapedspot;however,itcanbetolerableforthecurrentbeamcontrollevel.

简介：Aprocesssuitableforproductiononalargescaleofcoldlightmirrorforfilmprojectorisintroduced.DepositionparametersrequiredforproducingTiO2/SiO2opticalmultialyersystemsbyelectronbeamevaporationofTiO2andSiO2startingmaterialsareinvestigated.Manufactureandtechniquesofcoldmirrorandtheadhesion,stability,wearandcorrosionresistanceofcoldmirrorbythisprocessarediscussed.Theresultshowsthatcoldmirrorproducedhasgoodopticalpropertiesandbetteradhesion.

简介：

简介：HighZandlowZmaterialsareboththecandidateplasmafacingmaterials(PFM),uptonow,thetypicalrepresentativeofhighZmaterialsistungsten,andtherepresentativesoflowZmaterialsarecarbonmaterials(suchasgraphite,C/Ccomposite)andberyllium.MostofthesematerialshavebeenusedasPFMlimitersanddiverterarmortilesoftokamakmachines,tungsten,molybdenumandC/Ccompositearealwaysusedashighheatfluxcomponents.

简介：Theeffectsoftwopost-weldheattreatmentprocessesonthemicrostructureandfatiguepropertiesoftheelectronbeamweldedjointsof30CrMnSiNi2Asteelwerestudied.Electronbeamlocalpost-weldheattreatment(EBLPWHT),inavacuumchamber,immediatelyafterweldingandatraditionalfurnacewholepost-weldheattreatment(FWPWHT)wereaccepted.Theexperimentalresultsshowthat,afterEBLPWHT,themainmicrostructureofweldischangedfromcoarseacicularmartensiteintolathmartensite,andbasemetalischangedfromferriteandperliteintoupperbainiteandresidualaustenite,howeverthemicrostructuresofdifferentzonesofjointsinFWPWHTconditionsaretemperedsorbite.Thefatiguecrackgrowthrateda/dNofweldsandbasemetalarenotobviouslychangedamongEBLPWHT,FWPWHTtestandas-welded(AW)test,asthemechanicalpropertiesofmaterialshaveacertainbutnotlargeeffectontheda/dNofweldedjoints.TheresistancetonearthresholdfatiguecrackgrowthdataofweldedjointscanbelargelyimprovedbyEBLPWHTanditisrelatedtomicrostructureandcrackclosureeffect.

简介：TransportationofoxygenfromAI203shelltotheencapsulatedAIcoreundertheelectronbeamirradiationwasachievedbyfieldemissionguntransmissionelectronmicroscope.

简介：Beam-columnorbeam-wallconnectionsareanimportantprobleminhigh-risebuildings.Inthisstudy,basedontheanalysisofanexamplestructure,ananalyticalmodelfordesignofthesemi-rigidconnectionsbetweensteelbeamsandRCwallsinhigh-risehybridbuildingsisproposed.Also,themechanicalcharacteristicsoftheseconnectionssubjectedtolowreversedcyclicloadingareinvestigatedthroughcomparisonofexperimentalresultsfromthreesemi-rigidconnectionsandtworigidconnections.Moreover,somelatentproblemsfordesignoftheseconnectionsaswellasthecorrespondingsolutionsarediscussed.Theresultsfromtheexperimentsandanalysesindicatethatsemi-rigidconnectionsexhibitsatisfactorycapacityandseismicperformance,andtheproposeddesigncanbeusedinpractice.

简介：Cracksmayeasilyoccurinthefusionweldbetweenvanadiumalloysandstainlesssteelduetothebrittleintermetallicsandweldingstress.Thehighvacuumelectronbeambraze-weldinghasbeensuccessfullyusedtojoinvanadiumalloy(V-5Cr-5Ti)tostainlesssteel(HR-2)withelectroplatedCuandAgcoating.Toinvestigatetheeffectsofelectroplatedcoatingontheweldability,thejointappearance,themicrostructureandthemechanicalpropertiesofthejointshavebeenthoroughlyanalyzed.Theresultsshowthatthejointsurfaceconfigurationwasgoodandrootreinforcementwasfullandsmooth.Areactionzone(RZ)wasgainedontheinterfacebetweentheVSCrSTialloyandHR-2stainlesssteelbasemetals.Thewidthofreactionzoneatthetopofthejointwasupto0.65mm,widerthanthatinthebottomofthejoint(0.46mm).Thereactionzoneconsistedofconsiderablysmallerdendriticstructureswithanaveragegrainsizeoflessthan10μm.ElementAgandCualmostenrichedtheinterfacebetweenV-5Cr-5TialloysubstrateandRZ,servingasaphysicalbarrierwhichdecreasesoravoidstheformationofintermetallics.Themaximumtensilestrengthofvanadiumalloy/stainlesssteeldissimilaralloyjointwasmorethan300MPa.Thejointwasdefectsfree.

简介：Asuccessfulbeamcleanupofa5-mJ/200-μspulsedsolid-statelasersystemoperatingat532-nmwavelengthisdemonstrated.Inthisbeamcleanupsystem,awave-frontsensor-lessadaptiveoptics(AO)systemissetupwitha20-elementbimorphmirror(BM),ahigh-voltageamplifier,acharge-coupleddevicecamera,andacontrolsoftwareimplementingthestochasticparallelgradientdescent(SPGD)algorithm.Thebrightnessofthelaserfocalspotisimprovedbecausethewave-frontdistortionshavebeencompensated.Theperformanceofthissystemispresentedandtheexperimentalresultsareanalyzed.

简介：Atwo-dimensionalhybridcodeisdevelopedtomodelthetransportofahigh-currentelectronbeaminadenseplasmatarget.Thebeamelectronsaretreatedasparticlesanddescribedbyparticle-in-cellsimulationincludingcollisionswiththetargetplasmaparticles.Thebackgroundtargetplasmaisassumedtobeastationaryfluidwithtemperaturevariations.Thereturncurrentandtheself-generatedelectricandmagneticfieldsareobtainedbycombiningAmpere’slawwithoutthedisplacementcurrent,theresistiveOhm’slawandFaraday’slaw.Theequationsaresolvedintwo-dimensionalcylindricalgeometrywithrotationalsymmetryonaregulargrid,withcenteredspatialdifferencingandfirst-orderimplicittimedifferencing.Thealgorithmsimplementedinthecodearedescribed,andanumericalexperimentisperformedforanelectronbeamwithMaxwelliandistributionejectedintoauniformdeuterium-tritiumplasmatarget.

简介：Intheterahertz(THz)band,theinherentshakeofthehumanbodymaystronglyimpairtheimagequalityofabeamscanningsinglefrequencyholographysystemforpersonnelscreening.Torealizeaccurateshakecompensationinimagingprocessing,itisquitenecessarytodevelopahigh-precisionmeasuresystem.However,inmanycases,differentpartsofahumanbodymayshaketodifferentextents,resultingingreatlyincreasingthedifficultyinconductingareasonablemeasurementofbodyshakeerrorsforimagereconstruction.Inthispaper,abodyshakeerrorcompensationalgorithmbasedontherawdataisproposed.Toanalyzetheeffectofthebodyshakeontherawdata,amodelofechoedsignalisrebuiltwithconsideringboththebeamscanningmodeandthebodyshake.Accordingtotherebuiltsignalmodel,wederivethebodyshakeerrorestimatedmethodtocompensateforthephaseerror.Simulationonthereconstructionofpointtargetswithshakeerrorsandproof-of-principleexperimentsonthehumanbodyinthe0.2-THzbandarebothperformedtoconfirmtheeffectivenessofthebodyshakecompensationalgorithmproposed.

简介：

简介：Anewspeciallycorrelatedpartiallycoherentbeamnamednonuniformmulti-Gaussiancorrelated(NMGC)partiallycoherentbeamisintroduced.Thecorrelationfunctionsofsuchbeaminxandydirectionsaredifferentfromeachother,i.e.,nonuniformcorrelationfunctioninonedirectionandmulti-GaussiancorrelatedSchell-modelfunctionintheotherdirection.ThepropagationpropertiesofanNMGCpartiallycoherentbeaminfreepacearedemonstrated,andwefindthattheintensitydistributionofsuchbeamexhibitsself-focusingandself-shiftingeffectinonedirectionandself-shapingeffectintheotherdirectiononpropagation.Thecorrelation-inducedself-focusingandself-shapingeffectwillbeusefulinsomeapplications,wherethehighpowerandshapedlaserisrequired,suchasmaterialthermalprocessingandlasercarving.

简介：因为紫外可见的吸收度察觉者不能避免的一般多波长源于光的紧张变化的噪音和飘移采购原料，双横梁多波长紫外可见的察觉者基于电荷耦合器件被设计。在它通过chopper以后，轻来源的光线被横梁splitter划分成一条信号光线和一条引用光线。信号光线照耀进样品房间。通过样品房间的信号光线失败到集中它到被一个凹面栅栏在电荷耦合器件的一部分上想象的槽上的一面凹面镜子上。参考光线被凹面栅栏在槽以后在电荷耦合器件的另外的部分上想象。信号光谱，引用光谱和电荷耦合器件的黑暗水流能在光系统的合作下面在一样的电荷耦合器件上被测量并且补助电路。为由使用参考光谱和电荷耦合器件的黑暗水流的信号光谱的即时赔偿能有效地压抑察觉者的噪音和飘移。短期的噪音是10?5AU和飘移是10?4AU/h。CLC数字TN366文件代码A

简介：