简介:综述了国内外快放电直线型变压器驱动源(fastlineartransformerdriver,FLTD)闪光照相加速器的研究进展,包括美国圣地亚国家实验室(SandiaNationalLaboratory,SNL)双轴7MVLTD型闪光照相装置、洛斯·阿拉莫斯国家实验室LANSCE装置C区与质子照相装置轴垂直的LTD型闪光照相装置、21级串联LTD-MinorURSA装置及32级串联正负极性可调的LTD装置的概念设计。同时,介绍了法国原子能部CEA/PAM8MVLTD型照相装置IDERIX和英国原子能武器中心为替代Mevex加速器拟研制的空气绝缘LTD的概念设计。最后,介绍了中国工程物理院和西北核技术研究所FLTD相关研究进展,结合西北核技术研究所现有技术条件和需求,提出了开展闪光LTD驱动源的初步设想。
简介:Bythemethodofdynamicalsystem,weconstructtheexacttravellingwavesolutionsofanewHamiltonianamplitudeequationandtheOstrovskyequation.Basedonthismethod,thenewexacttravellingwavesolutionsofthenewHamiltonianamplitudeequationandtheOstrovskyequation,suchassolitarywavesolutions,kinkandanti-kinkwavesolutionsandperiodictravellingwavesolutions,areobtained,respectively.
简介:Withanincreasingemphasisonrenewableenergyresources,wavepowertechnologyisbecomingoneoftherealisticsolutions.However,the2011tsunamiinJapanwasaharshreminderoftheferocityoftheocean.Itisknownthattsunamisarenearlyundetectableintheopenoceanbutasthewaveapproachestheshoreitsenergyiscompressed,creatinglargedestructivewaves.Thequestionposedhereiswhetheranoscillatingwavesurgeconverter(OWSC)couldwithstandtheforceofanincomingtsunami.Severaltoolsareusedtoprovideananswer:ananalytical3Dmodeldevelopedwithintheframeworkoflineartheory,anumericalmodelbasedonthenon-linearshallowwaterequationsandempiricalformulas.Numericalresultsshowthatrun-upanddraw-downcanbeamplifiedundersomecircumstances,leadingtoanOWSClyingondryground!
简介:Wavepropagationintwo-dimensionalhierarchicalhoneycombstructureswithtwoorderhierarchyisinvestigatedbyusingthesymplecticalgorithm.Byapplyingthevariationalprincipletothedualvariables,thewavepropagationproblemistransformedintoatwo-dimensionalsymplecticeigenvalueproblem.Thebandgapsandspatialfilteringphenomenaareexaminedtofindthestopbandsanddirectionalstopbands.Specialattentionisdirectedtotheeffectsoftherelativedensityandthelengthratioonthebandgapsandphaseconstantsurfaces.Thisworkprovidesnewopportunitiesfordesigninghierarchicalhoneycombstructuresinsoundinsulationapplications.
简介:Inthispaper,weuseamethodinordertofindexactexplicittravelingsolutionsinthesubspaceofthephasespaceforCH2equations.Thekeyideaisremovingacoupledrelationforthegivensystemsothatthenewsystemscanbesolved.Theexistenceofsolitarywavesolutionsisobtained.Itisshownthatbifurcationtheoryofdynamicalsystemsprovidesapowerfulmathematicaltoolforsolvingagreatmanynonlinearpartialdifferentialequationsinmathematicalphysics.
简介:Theassessmentofthewave-inducedsoilliquefactionplaysakeyroleinthegeotechnicaldesignforoffshorefoundations.Theunderlyingshortcomingsoftheexistingmomentaryliquefactioncriteriaareidentifiedandclarifiedbymechanismanalysesandtherecentfieldobservations.Amodifiedcriterionforthewave-inducedmomentaryliquefactionofasandyseabedisgiventodescribetheverticalporepressuredistributions.Animprovedapproximationofthemomentaryliquefactiondepthisfurtherpresented.Parametricstudyoftheeffectsofthesaturationdegreeofsoilsindicatesthatthismodificationissignificantfortheevaluationofwave-inducedmomentaryliquefaction.
简介:Basedonthetheoryofcomplexfunctionandtheprincipleofhomogenization,harmonicdynamicsstressofaradiallyinfiniteinhomogeneousmediumwithacircularcavityisinvestigated.Duetothesymmetry,wavevelocityisassumedtohavepower-lawvariationintheradialdirectiononly,andtheshearmodulusisconstant.TheHelmholtzequationwithavariablecoefficientisequivalentlytransformedintoastandardHelmholtzequationwithageneralconformaltransformationmethod(GCTM).Thedisplacementsandstressfieldsareproposed.Numericalresultsshowthatthewavenumberandtheinhomogeneityparameterofthemediumhavesignificanteffectsonthedynamicstressconcentrationaroundthecircularcavity.Thedynamicstressconcentrationfactor(DSCF)becomessingularwhentheinhomogeneityparameterofmediumisclosetozero.
简介:Agraphene-coatedmicrofiber(GCM)-basedhybridwaveguidestructureformedbywrappingmonolayergraphenearoundamicrofiberwithlengthofseveralmillimetersispumpedbyananosecondlaserat~1550nm,andmultiordercascadedfour-wave-mixing(FWM)iseffectivelygenerated.Byoptimizingboththedetuningandthepumppower,suchaGCMdevicewithhighnonlinearityandcompactsizewouldhavepotentialforawiderangeofFWMapplications,suchasphase-sensitiveamplification,multi-wavelengthfilter,all-opticalregenerationandfrequencyconversion,andsoon.
简介:我们学习二维(2D)在吝啬地的模型的事波浪solitons在2D空间与远程的quadrupolequadrupole相互作用(QQI)由电的四极粒子形成了。在空间的2D事波浪solitons的存在用2DGrossPitaevskii方程(GPE)被预言。我们发现QQIsolitons比dipoledipole相互作用(DDI)有一个更高的团(更小的尺寸和更高的紧张)和更强壮的anisotropy在一样的环境参数下面的solitons。在在2D空间的二相同QQIsolitons之间的各向异性的solitonsoliton相互作用被学习。而且,稳定的各向异性的偶极子solitons被观察到我们的知识,第一次在在各向异性的非局部的立方的非线性下面的2D空间。
简介:Theinteractionofanti-planeelasticSHwaveswithaperiodicarrayofinterfacecracksinamulti-layeredperiodicmediumisanalyzedinthispaper.AperfectperiodicstructurewithoutinterfacecracksisfirststudiedandthetransmissiondisplacementcoefficientisobtainedbasedonthetransfermatrixmethodinconjunctionwiththeBloch-Floquettheorem.Thisisthengeneralizedtoasingleandperiodicdistributionofcracksatthecenterinterfaceandtheresultiscomparedwiththatofperfectperiodiccaseswithoutinterfacecracks.Thedependenceofthetransmissiondisplacementcoefficientonthefrequencyoftheincidentwave,theinfluencesofmaterialcombination,crackconfigurationandincidentanglearediscussedindetail.Comparedwiththecorrespondingperfectperiodicstructurewithoutinterfacecracks,anewphenomenonisfoundintheperiodiclayeredsystemwithasingleandperiodicarrayofinterfacecracks.
简介:All-opticalcanonicallogicunitsat40Gb/susingbidirectionalfour-wavemixing(FWM)inhighlynonlinearfiberareproposedandexperimentallydemonstrated.Cleartemporalwaveformsandcorrectpatternstreamsaresuccessfullyobservedintheexperiment.Thisschemecanreducetheamountofnonlineardevicesandenlargethecomputingcapacitycomparedwithgeneralones.ThenumericalsimulationsaremadetoanalyzetherelationshipbetweentheFWMefficiencyandthepositionoftwointeractionalsignals.
简介:UsingthestandardtruncatedPainlevexpansion,theresidualsymmetryofthe(2+1)-dimensionalmodifieddispersivewater-wavesystemislocalizedintheproperlyprolongedsystemwiththeLiepointsymmetryvector.Somedifferenttransformationinvariancesarederivedbyutilizingtheobtainedsymmetries.ThesymmetriesofthesystemarealsoderivedthroughtheClarkson-Kruskaldirectmethod,andseveraltypesofexplicitreductionsolutionsrelatetothetrigonometricorthehyperbolicfunctionsareobtained.Finally,somespecialsolitonsaredepictedfromoneofthesolutions.
简介:Thestudyofwaveguideinvariantinunderwateracousticsisoneofattractedtopicsinrecent30years.Theinterferencesofdirectwaveandreflectwavefromseasurfaceandseabottomofunderwatertargetradiatednoiseinherenttheinformationoftargetdistance.Extractionofthesedistanceinformationwillprovideapossiblenewwayinpassiverangingforunderwatertarget.ThetheoreticalanalysisandtheresultsofatseaexperimentsshowthattheLOFAR(LowFrequencyAnalysisRecord)figureinherentlycontainstherangeandmovinginformationofpassiveacousticsources,eveninthesituationthatthereceiverisonlyonesinglehydrophone.Thetheoreticalanalysisofextractionoftargetdistanceinformationbyusingwaveguideinvariantispresentedinthispaper.Itisshownthat,basedontheinterferencestriationpatternoftarget,thehydrophonearraysystemispossibletoextractthedistanceinformationwithquitehigharraygain.Althoughthemathematicalconstrainconditionsinforminginterferencestriationpatternaredifferentforindividualarrayelement,butitisprovedthatthedifferencesoftimedelaysbetweenarrayelementscanbeusedincompensationofbeamforming.Thetheoreticalanalysis,systemsimulationandsomeresultsofatseaexperimentshowanewwayinpassiverangingandtargetrecognition.
简介:Thefinite-dmerencetime-domam(FDTD)methodisproposedforanalyzingthesurfaceacousticwave(SAW)propagationintwo-dimensional(2D)piezoelectricphononiccrystals(PCs)atradiofrequency(RF),andalsoexperimentsareestabhshedtodemonstrateitsanalysisresultofthePCs’bandgaps.TheFDTDmethodtakesthepiezoelectriceffectofPCsintoaccount,inwhichperiodicboundaryconditionsareusedtodecreasememory/timeconsumptionandtheperfectlymatchedlayerboundaryconditionsareadoptedastheSAWabsorberstoattenuateartificialreflections.TwoSAWdelaylinesareestabhshedwith/withoutpiezoelectricPCslocatedbetweeninterdigitaltransducers.Byremovingseveralechoeswithwindowgatingfunctionintimedomain,delaylinestransmissionfunctionisachieved.ThePCs’transmissionfunctionsandbandgapsareobtainedbycomparingtheminthesetwodelaylines.WhenAluminum/128°YX-LiNbO3isadoptedasscatterandsubstratematerial,thePCs’bandgapiscalculatedbythisFDTDmethodandCOMSOLrespectively.ResultsshowthatcomputationalresultsofFDTDagreewellwithexperimentalresultsandarebetterthanthatofCOMSOL.
简介:Wedemonstratebinaryphaseshiftkeying(BPSK)modulationusingasiliconMach–Zehndermodulatorwithaπ-phase-shiftvoltage(Vπ)of-4.5V.Thesingle-drivepush–pulltravelingwaveelectrodehasbeenoptimizedusingnumericalsimulationswitha3dBelectro-opticbandwidthof35GHz.The32Gb/sBPSKconstellationdiagramismeasuredwithanerrorvectormagnitudeof18.9%.
简介:Inthispaper,weinvestigatethetravelingwavesolutionsforthenonlineardispersiveequation,Korteweg-deVriesZakharov–Kuznetsov(KdV-ZK)equationandcomplexcoupledKdVsystembyusingextendedsimplestequationmethod,andthenderivethehyperbolicfunctionsolutionsincludesolitonsolutions,trigonometricfunctionsolutionsincludeperiodicsolutionswithspecialvaluesfordoubleparametersandrationalsolutions.Thepropertiesofsuchsolutionsareshownbyfigures.Theresultsshowthatthismethodisaneffectiveandapowerfultoolforhandlingthesolutionsofnonlinearpartialdifferentialequations(NLEEs)inmathematicalphysics.