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简介：

简介：这份报纸学习为在一个泼出的沙滩上宣传的表面水波浪打破波浪的连续进化。一个Lagrangianasymptotic答案被导出。根据结合的解决方案，打破标准和水粒子运动，波浪变丑和连续波浪的方程碎的波浪处理因为进步的水飘动在一个泼出的底部上宣传能被导出。一系列实验也被进行与理论答案作比较。结果证明现在的答案罐头相当描述打破现象的跳入或掉下的波浪。

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简介：Basedonthethermodynamictheory,anorthotropicdamageconstitutivemodelwasdevelopedtodescribethenonlinearmechanicalbehaviorofC/SiCcomposites.Thediferentnonlinearkinematicandisotropichardeningfunctionswereadoptedtodescribeaccuratelythedamageevolutionprocesses.Thedamagevariablesweredefinedwiththedamagedmodulusandtheinitialundamagedmodulusonenergyequivalenceprinciple.Theinitialorthotropyanddamagecouplingwerepresentedinthedamageyieldfunction.Tensileandin-planeshearloadingandunloadingtestswereperformed,andagoodagreementbetweenthemodelandtheexperimentalresultswasachieved.

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简介：Thecorrelationofthescaledenergy,e?=Es/M0,versusearthquakemagnitude,Ms,isstudiedbasedontwomodels:(1)Model1basedontheuseofthetimefunctionoftheaveragedisplacements,withax-2sourcespectrum,acrossafaultplane;and(2)Model2basedontheuseofthetimefunctionoftheaveragedisplacements,withax-3sourcespectrum,acrossafaultplane.Forthesecondmodel,therearetwocases:(a)Ass*T,wheresistherisetimeandTtherupturetime,lg(e?)*-Ms;and(b)AssT,lg(e?)*-(1/2)Ms.Thesecondmodelleadstoanegativevalueofe?.ThismeansthatModel2cannotworkforstudyingthepresentproblem.TheresultsobtainedfromModel1suggestthatthesourcemodelisafactor,yetnotauniqueone,incontrollingthecorrelationofe?versusMs.

简介：Duetothewideapplicationsofarchesinundergroundprotectivestructures,dynamicanalysisofcircu-lararchesincludingsoil-structureinteractionsisimportant.Inthispaper,anexactsolutionoftheforcedvibrationofcirculararchessubjectedtosubsurfacedenotationforcesisobtained.Thedynamicsoil-structureinteractionisconsideredwiththeintroductionofaninterfacialdampingbetweenthestructureelementandthesurroundingsoilintotheequationofmotion.Byneglectingtheinfluencesofshear,rotaryinertiaandtangentialforcesandassumingthearchincompressible,theequationsofmotionoftheburiedarchesweresetup.Analyticalsolutionsofthedynamicresponsesoftheprotectivearcheswerededucedbymeansofmodalsuperposition.Archeswithdifferentopeningangles,acousticimpedancesandrise-spanratioswereanalyzedtodiscusstheirinfluencesonanarch.Thetheoreticalanalysissuggestsblastloadsforelasticdesignsandpredictsthepotentialfailuremodesforburiedprotectivearches.

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：Anopticalbandpassfilter(OBF)isanimportantelementwhosepropertiesconsiderablyinfluencetheoutputperformanceofasinglesidebandmulticarriersourcebasedonare-circulatingfrequencyshifter.TheinfluenceoftheOBFintheloopontheoutputspectrumistheoreticallyanalyzed.Numericalsimulationsandexperimentsarealsocarriedout.Resultsshowthatthesteepnessanddeepnessofanonflat-topfilterinfluencethestabilityofthespectrumofanoutputmulticarrier.Toobtainmulticarrieroutputwithtonetonoiseratio(TNR)>26dBanderrorvectormagnitude(EVM)<0.25,thesteepnessratioofthefiltershouldbegreaterthan0.75anddeepnessshouldbelargerthan0.99.

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