简介：为实现2×5GW级双路输出超宽谱高功率微波驱动源的小型化,研制了一种初级脉冲功率源——与双筒脉冲形成线(Blumlein线)相配一体化的带有开路磁芯的Tesla变压器.通过对Tesla变压器的理论分析,并根据简化的磁路模型得出了Tesla变压器初、次级线圈电感等电参数的估算方法,给出了Tesla变压器磁芯截面的估算和磁芯制作方法.实验结果表明,Tesla变压器最大输出电压为880kV,充电时间约为20μts,耦合系数约为0.95,与理论值吻合较好.

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简介：Anacceleratedmicro-foilisusedtoigniteapre-compressedcylindricalshellcontainingdeuterium–tritiumfuel.Thewell-knownshockwaveignitioncriterionandanovelcriterionbasedonheatwaveignitionaredevelopedinthiswork.Itisshownthatforheatignitionveryhighimpactvelocitiesarerequired.Itissuggestedthatamulti-petawattlasercanaccelerateamicro-foiltorelativisticvelocitiesinaveryshorttimeduration(picosecond)ofthelaserpulse.Thecylindricalgeometrysuggestedhereforthefastignitionapproachhastheadvantageofgeometricallyseparatingthenanosecondlasersthatcompressthetargetfromthepicosecondlaserthatacceleratesthefoil.Thepresentmodelsuggeststhatnuclearfusionbymicro-foilimpactignitioncouldbeattainedwithcurrentlyexistingtechnology.

简介：Manynonlinearquantumopticalphysicsphenomenaneedmoreaccuratewavefunctionsandcorrespondingenergyorquasienergylevelstoaccountfor.AnanalyticexpressionofwavefunctionswithcorrespondingenergylevelsforanatomicelectroninteractingwithaphotonfieldispresentedasanexactsolutiontotheSchrSdinger-likeequationinvolvedwithbothatomicCoulombinteractionandelectron-photoninteraction.Thesolutionisanaturalgeneralizationofthequantum-fieldVolkovstatesforanotherwisefreeelectroninteractingwithaphotonfield.ThesolutionshowsthatanN-levelatominlightformstationarystateswithoutextraenergysplittinginadditiontotheFloquetmechanism.Thetreatmentdevelopedherewithcomputingcodescanbeconvenientlytransferredtoquantumopticsinclassical-fieldversionasresearchtoolstobenefitthewholephysicscommunity.

简介：Thisletterpresentsanewanalyticalapproximationforwave(current)-induceddynamicsoilresponseinmarinesediments.Inthemodel,thethird-orderapproximationforwave-currentinteractionsisemployedfortheflowmodel,whileBiot’sdynamicporo-elasticmodelisusedtosimulatetheporousflowinaseabed.Thenewlyanalyticalsolutionisvalidatedwiththefieldobservations.Basedonthesolution,effectsofcurrentsandwave-nonlinearityonsoilresponseareexaminedandaparametricstudywillbecarriedouttoexaminetheinfluenceofcurrentsontheliquefactionpotential.

简介：Inthisarticle,weconsidertheglobalexistenceanddecayratesofsolutionsforthetransmissionproblemofKirchhofftypewaveequationsconsistingoftwophysicallydifferenttypesofmaterials,onecomponentbeingaKirchhofftypewaveequationwithtimedependentlocalizeddissipationwhichiseffectiveonlyonaneighborhoodofcertainpartofboundary,whiletheotherbeingaKirchhofftypeviscoelasticwaveequationwithnonlinearmemory.

简介：Theauthorshaveinventedtheuniqueoceanwavepowerstation,whichiscomposedofthefloatingtypeplatformwithapairofthefloatsliningupattheintervalofonewavepitchandthecounter-rotatingtypewavepowerunit,itsrunnersaresubmergedintheseawateratthemiddlepositionoftheplatform.Suchprofilesmaketheflowvelocityattherunneristwicefasterthanthatofthetraditionalfixed/caissontypeOWC,ontheidealflowconditions.Besides,therunnerscounter-rotatetheinnerandtheouterarmaturesofthepeculiargenerator,respectively,andtherelativerotationalspeedisalsotwicefasterthanthespeedofthesinglerunner/armature.Suchcharacteristicsmaketherunnerdiameterlarge,namelytheoutputhigher,asrequested,becausethetorqueofthepowerunitneveractonthefloatingtypeplatform.Atthepreliminaryreseach,thispaperverifiestogetthepowerusingaWellstypesinglerunnerinstalledinthemodelstation.Therunnertakestheoutputwhichisaffectedbytheoscillatingamplitudeoftheplatform,therotationalspeedandtheinertiaforceoftherunner,etc.

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简介：Inthispaper,amathematicalmodelforLovewavepropagationinaporouselasticlayerunderarigidboundaryrestingoveraporo-elastichalf-spacehasbeendeveloped.ThestudyshowsthatsuchamediumtransmitstwotypesofLovewaves.ThefirstfrontdependsonthechangeinvolumefractionoftheporeswhereasthesecondfrontdependsuponthemodulusofrigidityoftheelasticmatrixofthemediumandisthesameastheLovewaveinanelasticlayeroveranelastichalf-space.Itisobservedthatthefirstfrontismanytimesfasterthantheshearwaveinthemediumwithvoidporesduetothechangeinthevolumefractionoftheporesandissignificant.

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简介：在一个二维的方形的数组的螺线波浪的开发由于部分离子隧道块(钾，钠)被调查，节点的动力学被HodgkinHuxley神经原描述，这些神经原最近被结合邻居连接。参数比率xNa(并且xK)，它定义钠(钾)的工作离子隧道数字的比率到钠的全部的离子隧道数字(并且钾)，被用来测量隧道块导致的移动传导力。在二参数的阶段空间(参数比率对毒害的区域)的统计可变R的分发广泛地被计算为部分离子隧道块导致的螺线波浪的转变标记参数区域，有同步R的更小的因素的区域被联系那个螺线波浪使明白毒害的隧道、柔韧的参数区域。当毒害的区域(钾或钠)和沉醉的度是小的时，螺线波浪保持活着，不同转变(死亡，几个螺线波浪共存或多手臂螺线波浪出现)发生在中等比率xNa下面(并且xK)当堵住的区域的尺寸超过某些阀值时。螺线波浪的决裂发生，螺线的多手臂飘动当隧道噪音被考虑时，被观察。

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简介：这份报纸涉及多域光谱方法，基于内部惩罚不连续的Galerkin(IPDG)明确的表达，为经由一个准确通报或球形的Dirichlet-to-Neumann(DtN)边界截断的外面的Helmholtz问题调节。一条有效反复的途径被建议本地化全球DtN边界条件，它为scatterers的复杂几何学便于多域方法，和处理的实现。在不连续的Galerkin明确的表达下面，建议方法允许在不同子域上使用不同的度的多项式基础功能，并且更重要地，明确的波浪数字依赖估计光谱计划能被导出，它为多域是以某种方式难以置信的连续Galerkin明确的表达。[从作者抽象]

简介：Theelasticwavepropagationphenomenaintwo-dimensionalperiodicbeamlatticesarestudiedbyusingtheBlochwavetransform.Thenumericalmodelingisappliedtothehexagonalandtherectangularbeamlattices,inwhich,boththein-plane(withrespecttothelatticeplane)andout-of-planewavesareconsidered.ThedispersionrelationsareobtainedbycalculatingtheBlocheigenfrequenciesandeigenmodes.Thefrequencybandgapsareobservedandtheinfluenceoftheelasticandgeometricpropertiesoftheprimitivecellonthebandgapsisstudied.ByanalyzingthephaseandthegroupvelocitiesoftheBlochwavemodes,theanisotropicbehaviorsandthedispersivecharacteristicsofthehexagonalbeamlatticewithrespecttothewavepropagationarehighlightedinhighfrequencydomains.OneimportantresultpresentedhereinisthecomparisonbetweenthefirstBlochwavemodestothemembraneandbending/transverseshearwavemodesoftheclassicalequivalenthomogenizedorthotropicplatemodelofthehexagonalbeamlattice.Itisshownthat,inlowfrequencyranges,thehomogenizedplatemodelcancorrectlyrepresentboththein-planeandout-of-planedynamicbehaviorsofthebeamlattice,itsfrequencyvaliditydomaincanbepreciselyevaluatedthankstotheBlochmodalanalysis.Asanotherimportantandoriginalresult,wehavehighlightedtheexistenceoftheretropropagatingBlochwavemodeswithanegativegroupvelocity,andofthecorresponding'retro-propagating'frequencybands.

简介：Thepropagationofshockwavesinacellularbarissystematicallystudiedintheframeworkofcontinuumsolidsbyadoptingtwoidealizedmaterialmodels,viz.thedynamicrigid,perfectlyplastic,locking(D-R-PP-L)modelandthedynamicrigid,linearhardeningplastic,locking(D-R-LHP-L)model,bothconsideringtheeffectsofstrain-rateonthematerialproperties.Theshockwavespeedrelevanttothesetwomodelsisderived.ConsiderthecaseofabarmadeofoneofsuchmaterialwithinitiallengthL0andinitialvelocityviimpingingontoarigidtarget.Thevariationsofthestress,strain,particlevelocity,specificinternalenergyacrosstheshockwaveandtheceasedistanceofshockwavearealldeterminedanalytically.Inparticularthe'energyconservationcondition'andthe'kinematicexistencecondition'asproposedbyTanetal.(2005)isre-examined,showingthatthe'energyconservationcondition'andtheconsequent'criticalvelocity',i.e.theshockcanonlybegeneratedandsustainedinR-PP-Lbarswhentheimpactvelocityisabovethiscriticalvelocity,isincorrect.Instead,withelasticdeformation,strain-hardeningandstrain-ratesensitivityofthecellularmaterialsbeingconsidered,itisappropriatetoredefineafirstandasecondcriticalimpactvelocityfortheexistenceandpropagationofshockwavesincellularsolids.StartingfromthebasicrelationsforshockwavepropagatinginD-R-LHP-Lcellularmaterials,anewmethodforinverselydeterminingthedynamicstress-straincurveforcellularmaterialsisproposed.Byusinge.g.acombinationofTaylorbarandHopkinsonpressurebarimpactexperimentaltechnique,thedynamicstress-straincurveofaluminumfoamcouldbedetermined.Finally,itisdemonstratedthatthisnewformulationofshocktheoryinthisone-dimensionalstressstatecanbegeneralizedtoshocksinaone-dimensionalstrainstate,i.e.forthecaseofplateimpactoncellularmaterials,bysimplymakingproperreplacementsoftheelasticandplasticconstant

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简介：Controlofthespatiotemporalpatternsnearthecodimension-threeTuring–Hopf–Wavebifurcationsisstudiedbyusingtime-delayedfeedbackinathree-variableBrusselatormodel.LinearstabilityanalysisofthesystemshowsthatthecompetitionamongtheTuring-,Hopf-andWave-modes,thewavenumber,andtheoscillationfrequencyofpatternscanbecontrolledbychangingthefeedbackparameters.TheroleofthefeedbackintensityPuplayedoncontrollingthepatterncompetitionisequivalenttothatofPw,butoppositetothatofPv.TheroleofthefeedbackintensityPuplayedoncontrollingthewavenumberandoscillationfrequencyofpatternsisequivalenttothatofPv,butoppositetothatofPw.Whentheintensitiesoffeedbackareappliedequally,changingthedelayedtimecouldnotalterthecompetitionamongthesemodes,however,itcancontroltheoscillationfrequencyofpatterns.Theanalyticalresultsareverifiedbytwo-dimensional(2D)numericalsimulations.

简介：Analyticalsolutionsfortheflexural-gravitywaveresistancesduetoalinesourcesteadilymovingonthesurfaceofaninfinitelydeepfluidareinvestigatedwithintheframeworkofthelinearpotentialtheory.Thehomogenousfluid,coveredbyathinelasticplate,isassumedtobeincompressibleandinviscid,andthemotiontobeirrotational.ThesolutioninintegralformforthewaveresistanceisobtainedbymeansoftheFouriertransformandtheexplicitlyanalyticalsolutionsarederivedwiththeaidoftheresiduetheorem.Thedispersionrelationshowsthatthereisaminimalphasespeedcmin,athresholdfortheexistenceofthewaveresistance.NowaveisgeneratedwhenthemovingspeedofthesourceVislessthancminwhilethewaveresistancesfirstlyincreasetotheirpeakvaluesandthendecreasewhenVcmin.Theeffectsoftheflexuralrigidityandtheinertiaoftheplatearestudied.

简介：基于功率MOSFET器件研制了一种能产生高压高速脉冲的发生装置.设计了由超高速运算放大器构成的宽频带放大器和MOSFET互补推挽驱动电路,分析了功率MOSFET器件的开关特性,并讨论了影响其工作速度及工作频率的因素.脉冲发生器输出脉冲幅值最高可达-500V,前后沿时间均小于5ns.脉冲宽度和频率根据输入触发信号进行调节,触发延迟小于30ns,触发抖动小于500ps.