简介：Advancesinmaterialscienceandmathematicsinconjunctionwithtechnologicalneedshavetriggeredtheuseofmaterialandelectriccomponentswithfractionalorderphysicalproperties.Thispaperconsidersthemathematicalmodelofapiezoelectricwindflowenergyharvestersystemforwhichthecapacitanceofthepiezoelectricmaterialhasfractionalordercurrent-voltagecharacteristics.Additionallythemechanicalelementisassumedtohavefractionalorderdamping.Theanalysisisfocusedontheeffectsoforderofderivativesontheappearanceandcharacteristicsoflimitcircleoscillations(LCO).Itisobtainedthat,theorderofderivativestoenhancetheamplitudeofLCOandlowerthethresholdconditionleadingtoLCO.Thedomainsofefficiencyofthesystemareillustratedinvariousparametersspaces.

简介：Gas-liquidcouplingoscillationisanovelapproachtoreducingtheresonantfrequencyandtoelevatingthepressureamplitudeofathermoacousticengine.Ifathermoacousticengineisusedtodrivelow-frequencypulsetuberefrigerators,thefrequencymatchingbetweenthethermoacousticengineandtherefrigeratorplaysanimportantrole.Basedonanacoustic-electricanalogy,alumpedparametermodelisproposedtoestimatetheresonantfrequencyofastanding-wavethermoacousticenginewithgas-liquidcouplingoscillation.Furthermore,asimplifiedlumpedparametermodelisalsodevelopedtoreducethecomputationcomplexity.Theresonantfrequencydependenceonthemeanpressure,thegasspacevolume,andthewatercolumnlengthiscomputedandanalyzed.Theimpactofdifferentworkinggasesontheresonantfrequencyisalsodiscussed.Theeffectivenessofthemodelsisvalidatedbycomparingthecomputedresultswiththeexperimentaldataofthegas-liquidcouplingoscillationsystem.Anincreaseinthemeanworkingpressurecanleadtoariseintheresonantfrequency,andalowerresonantfrequencycanbeachievedbyelongatingtheliquidcolumn.Incomparisonwithnitrogenandargon,carbondioxidecanrealizealowerfrequencyduetoasmallerspecificheatratio.

简介：根据强壮的ENSO处理的1982/1983的比较，象快速的开发，巨大的紧张和突然的撤退那样的关键特征在1997/1998关于温暖的事件被揭示，为这个过程在它海洋和空气的发作和进化期间为热带印度洋和西方的太平洋管理intraseasonal摆动的特征特征地详细被学习。

简介：Thispaperdiscussesnumericalresultsfromthree-dimensionallargeeddysimulationsofanoscillatingcylinderunderprescribedmovementsinuniformflow.Sixcases,namelypurein-line,purecross-flowandtwogroupsof'FigureofEight'oscillationpatternsareunderinvestigationatReynoldsnumberRe=24000.The'FigureofEight'patternineachgroupiswithidenticalshapebutoppositeorbitaldirections.Thenumericalresultsonhydrodynamicforces,higherorderforcecomponents,andvortexsheddingmodesareextensivelystudiedandcomparedwiththemeasuredexperimentaldata.Itisfoundthatthefluidforceinphasewiththevelocity,whichrepresentstheenergytransferbetweenthefluidandthecylinder,hasoppositesignanddifferentmagnitudeduetotheoppositeorbitaldirection.Higherorderforcecomponentsincross-flowdirectionarefoundtooccuratoddnumbertimesoftheoscillatingfrequency,whileevennumbersdominatethehigherorderforcecomponentsinin-linedirection.The2Cand2Tvortexsheddingmodesarewellreproducedduetotheoppositeorbitaldirectioneffect.Comparisonsbetweennumericalandexperimentalresultsindicatethatthepresentnumericalmodelcouldbearationaltoolfortheidentificationofhydrodynamiccoefficientswhicharenormallyappliedinempiricalmodelstopredictthevortex-inducedvibrationsofslendermarinestructures.

简介：与Zebiak藤条模型和parameterized一起强迫的intraseasonal的随机的表示，为ElNi的春天可预测性障碍(SPB)上的Madden-Jullian摆动(MJO)的无常的影响?o南部的摆动(ENSO)预言被学习。强迫的MJO的parameterized形式身体上被加到Zebiak藤条模型在与ElNi联系的SPB上获得所谓的Zebiak-Cane-MJO模型然后起始的错误，随机的模型错误，和他们的联合错误模式的效果?o预言被估计。当起始的错误能做时，结果证明强迫的随机的MJO引起的模型错误几乎不能导致重要SPB；而且，起始的错误的联合错误模式和与随机的MJO强迫联系的模型错误能也导致重要SPB。这些证明起始的错误可能是SPB的主要错误来源，它可以为ENSO预报提供数据吸收的一个理论基础。

简介：我们在东亚(EA)上在夏天intraseasonal摆动(ISO)的27年的强迫的模拟评估GAMIL1.1.1的表演西方的诺思太平洋(WNP)。评价基于二项措施：climatologicalISO(CISO)和短暂ISO(TISO)。CISO是对年度周期锁阶段并且描述季节的行军的ISO部件。TISO是逐年变化的ISO部件。模型相当捕获ISO的许多观察特征，包括逐步向北方CISO的雨带进展，在华南海菲律宾的海(SCS-PS)和长江盆(YRB)的TISO的主导的频率，向北方3050天的TISO的繁殖并且向西在SCS-PS上的1225天的TISO模式的繁殖，和在YRB上的三个主要TISO模式的带的宣传特征。然而，模型有著名缺乏。这些包括与CISO联系的华南海季风的早发作，太快向北方到40°N和10°N的CISO信号南方的缺席的从20°N的CISO的繁殖，3050天的TISO模式的缺乏的东方繁殖和在YRBTISO模式的向南方的繁殖的缺席。作者发现在ISO模拟的缺乏是仔细与模型在平均数的偏爱有关说，建议模型的改进意味着状态为intraseasonal变化的现实主义的模拟是关键的。

简介：否定阶段的诺思大西洋摆动(NAO)事件通常比积极阶段的强壮，即，有NAO的阶段力量不对称现象。在这个工作，我们用有条件的非线性的最佳的不安(CNOP)探索NAO的这不对称现象方法与一三水平全球伪因地球自转而引起光谱模型。与冬季climatological流动强迫，CNOP方法识别在给定的起始的限制下面触发最强壮的NAO事件的不安，这被显示出。同时，NAO的阶段力量不对称现象特征能被揭示。由与线性结果作比较，我们发现不安自我相互作用的过程支持否定NAO事件的发作，它比在积极NAO发作期间强壮得多。结果在北方的冬季(DecemberFebruary)用climatological和带平均数的流动独立被获得19792006作为起始的基本状态。我们得出结论，基于NAO发作是一个非线性的起始值的问题的事实，那阶段力量不对称现象是NAO的一个内在的特征。

简介：Inthispaper,five-yearsimulateddatafromalow-resolutionglobalspectralmodelwithtriangulartrunca-lionatwavenumber10areanalyzedinordertostudydynamicalfeaturesandpropagationcharacteristicsofintraseasonaloxillationsoverthemid-latitudesandthetropicalatmosphere.Thesimulationsshowthatthereisthe30-50dayperiodicoscillationinthelow-resolutionspectralmodelwithoutnon-seasonalexternalforcing,andspatialscaleoftheintraseasonaloscihationsisoftheglobe.Furtheranalysisfindsthatpropagationcharac-tersofintraseasonaloscillationsoverthemid-latitudesandthetropicsaredifferent.The30-50dayoscillationoverthetropicsexhibitsstructureofthevelocitypotentialwavewithwavenumber1inthelatitudinalandthecharacterofthetravelingwaveeastwardatspeedof8longitudes/day.However,the30-50dayoscillationsinmid-latitudeatmosphereexhibitphaseandamplitudeoscillationofthestandingplanetarywavesandtheyarerelatedtotransformofteleconnectionpatternsoverthemid-latitudes.Theenergyisnotonlytransferredbetweenthetropicsandthemiddle-highlatitudes,butalsobetweendifferentregionsoverthetropics.Basedontheanalysisof5-yearbandpassfiltereddatafroma5-layerglobalspectralmodelofJow-ordetwithtruncatedwavenumberl0,investigationisdoneofthesourceofintraseasonaloscillationsintheextratropicalmodelatmosphereanditsmechanism.Resultsshowthat(1)theconvectiveheattransferredeastwardalongtheequatorservesasthesourceoftheintraseasonaloxillationbothinthetropicalandtheextratropicalatmos--phere;(2)thevelocity-potentialwaveofazonalstructureofwavenumber1givesrisetooxillationindivergentandconvergentwindfieldsofadipole-formasseenfromtheequatorialIndianOceantothewesternPacificduringitseastwardpropagation,thusindicatingtheoscillationinthedipole-formheatsoure:e/sinkpattertl;(3)thetropicalheat-sourceoscillationisresponsibleforthe

简介：Thepaperstudiestheproblemoffluidflowandfluidshearstressincanaliculiwhentheosteonissubjecttoexternalmechanicalloadingandbloodpressureoscillation.Thesingleosteonismodeledasasaturatedporoelasticcylinder.Solidskeletonisregardedasaporoelastictransverselyisotropicmaterial.Togetnear-realisticresults,boththeinterstitialfluidandthesolidmatrixareregardedascompressible.BloodpressureoscillationintheHaveriancanalisconsidered.Usingtheporoelasticitytheory,ananalyticalsolutionoftheporefluidpressureisobtained.Assumingthefluidincanaliculiisincompressible,analyticalsolutionsoffluidflowvelocityandfluidshearstresswiththeNavier-Stokesequationsofincompressiblefluidareobtained.Theeffectofvariousparametersonthefluidflowvelocityandfluidshearstressisstudied.更多还原

简介：Underharmonicwaveexcitation,thedynamicresponseofabilinearSDOFsystemcanbeexpressedbytheHilbertspectrum.TheHilbertspectrumcanbeformulatedby(1)theinter-wavecombinationmechanismbetweenthesteadyresponseandthetransientresponsewhenthesystembehaveslinearly,or(2)theintra-wavemodulationmechanismembeddedinoneintrinsicmodefunction(IMF)componentwhenthesystembehavesnonlinearly.ThetemporalvariationoftheinstantaneousfrequencyoftheIMFcomponentisconsistentwiththesystemnonlinearbehaviorofyieldingandunloading.Asathoroughstudyofthisfundamentalstructuraldynamicsproblem,thisarticleinvestigatestheinfluenceoftheamplitudeoftheharmonicwaveexcitationontheHilbertspectrumandtheintrinsicoscillatorymodeofthedynamicresponseofabilinearSDOFsystem.

简介：

简介：Theintraseasonaloscillation(ISO)isstudiedduringtheseverefloodanddroughtyearsoftheChangjiang-HuaiheRiverBasinwiththeNCEP/NCARreanalysisdataandtheprecipitationdatainChina.Theresultsshowthattheupper-level(200hPa)ISOpatternforsevereflood(drought)ischarac-terizedbyananticyclonic(cyclonic)circulationoverthesouthernTibetanPlateauandacyclonic(anti-cyclonic)circulationoverthenorthernTibetanPlateau.Thelower-level(850hPa)ISOpatternischar-acterizedbyananticyclonic(cyclonic)circulationovertheareasouthoftheChangjiangRiver,theSouthChinaSea,andtheWesternPacific,andacyclonic(anticyclonic)circulationfromtheareanorthoftheChangjiangRivertoJapan.Theselow-levelISOcirculationpatternsarethefirstmodesoftheISOwindfieldaccordingtothevectorEOFexpansionwithstrongeramplitudeoftheEOF1timecoefficientinse-verefloodyearsthaninseveredroughtyears.Theanalysesalsorevealthatat500hPaand200hPa,theatmosphericISOactivityovertheChangjiang-HuaiheRiverbasin,NorthChina,andthemiddle-highlatitudesnorthofChinaisstrongerforseverefloodthanforseveredrought.TheISOmeridionalwindoverthemiddle-highlatituderegionscanpropagatesouthwardsandmeetwiththenorthwardpropagatingISOmeridionalwindfromlowerlatituderegionsovertheChangjiang-HuaiheRiverBasinduringseverefloodyears,butnotduringseveredroughtyears.

简介：TheElNino-SouthernOscillation(ENSO)ismodulatedbymanyfactors;mostpreviousstudieshaveemphasizedtherolesofwindstressandheatfluxinthetropicalPacific.Freshwaterflux(FWF)isanotherenvironmentalforcingtotheocean;itseffectandtherelatedoceansalinityvariabilityintheENSOregionhavebeenofincreasedinterestrecently.Currently,accuratequantificationsoftheFWFrolesintheclimateremainchallenging;therelatedobservationsandcoupledocean-atmospheremodelinginvolvelargeelementsofuncertainty.Inthisstudy,weutilizedsatellite-baseddatatorepresentFWF-inducedfeedbackinthetropicalPacificclimatesystem;wethenincorporatedthesedataintoahybridcoupledocean-atmospheremodel(HCM)toquantifyitseffectsonENSO.AnewmechanismwasrevealedbywhichinterannualFWFforcingmodulatesENSOinasignificantway.Asadirectforcing,FWFexertsasignificantinfluenceontheoceanthroughseasurfacesalinity(SSS)andbuoyancyflux(QB)inthewestern-centraltropicalPacific.TheSSSperturbationsdirectlyinducedbyENSO-relatedinterannualFWFvariabilityaffectthestabilityandmixingintheupperocean.Atthesametime,theENSO-inducedFWFhasacompensatingeffectonheatflux,actingtoreduceinterannualQBvariabilityduringENSOcycles.TheseFWF-inducedprocessesintheoceantendtomodulatetheverticalmixingandentrainmentintheupperocean,enhancingcoolingduringLaNinaandenhancingwarmingduringElNino,respectively.TheinterannualFWFforcing-inducedpositivefeedbackactstoenhanceENSOamplitudeandlengthenitstimescalesinthetropicalPacificcoupledclimatesystem.

简介：Correspondingtotheslidingandtheoverturningfailure,theelementarymotionmodesofcaissonbreakwaterincludethehorizontal-rotationaloscillationcoupledmotion,thehorizontalsliding-rotationaloscillationcoupledmotion,thehorizontalvibrating-upliftrockingcoupledmotion,andthehorizontalsliding-upliftrockingcoupledmotion.Themotionmodeofacaissonwilltransformfromonetoanotherdependingonthewaveforcesandthemotionbehaviorsofthecaisson.Thenumericalmodelsoffourmotionmodesofcaissonaredeveloped,andthenumericalsimulationprocedureforjointmotionprocessofvariousmodesofcaissonbreakwaterunderwaveexcitationispresentedandtestedbyaphysicalmodelexperiment.Itisconcludedthatthesimulationprocedureisreliableandcanbeappliedtothedynamicstabilityanalysisofcaissonbreakwaters.

简介：PossiblerelationshipsbetweenMJOandthesevererain-snowweatherinEasternChinaduringNovemberof2009areanalyzedandresultsshowthatastrongMJOprocessisoneofthestrongimpactfactors.MJOisveryactiveovertheIndianOceaninNovember2009.Especially,itmaintains9daysinMJOphase3,justcorrespondingtothetwostrongestrain-snowprocesses.CompositesofMJOeventsshowthatwhentheMJOconvectivecenterislocatedovertheIndianOcean,theprobabilityofrainfallissignificantlyincreasedandthetemperatureislowerthannormalineasternChina,whichisconsistentwiththesituationinNovemberof2009.Atmosphericcirculationanomaliesofmid-andhigher-latitudescanbeinfluencedbythetropicalMJOconvectionforcingandthisinfluencecouldberealizedbyteleconnection.WhentheMJOisovertheIndianOcean,itisfavorableforthemaintenanceofacirculationpatternoftworidgesversusonetroughatmid-andhigher-latitudes.Meanwhile,thewesternPacificsubtropicalhighisstrongerandmorewestwardthannormal,andasignificantconvectivebeltappearsovereasternEastAsia.AllthesecirculationanomaliesshowninthecompositeresultalsoappearedintheobservationsinNovember2009,whichindicatesthegeneralfeaturesofrelationshipsbetweentheMJOandthecirculationanomaliesovertheextratropics.Besidesthezonalcirculationanomalies,theMJOconvectioncanalsoleadtomeridionalcirculationanomalies.WhentheMJOconvectionislocatedovertheIndianOcean,thewesternPacificisdominatedbyanomalousdescendingmotion,andtheeasternEastAsiaiscontrolledbystrongconvergenceandascendingmotion.Therefore,ananomalousmeridionalcirculationisformedbetweenthetropicsandmiddlelatitudes,enhancingthenorthwardtransportationoflow-levelmoisture.Itispotentiallyhelpfultounderstandingandevenforecastingsuchkindofrain-snowweatheranomaliesasthatinNovember2009usingMJO.

简介：Higher-bandself-trappingandoscillation(rotation)ofnonlinearquadruplebeamsintwo-dimensional(2D)squarephotoniclatticesarenumericallydemonstrated.Underappropriateconditionsofnonlinearity,aquadruple-likebeamcanself-trapintolocalizedmodesthatresideinthesecondBraggreflectiongapthroughsingle-siteexcitation.Bychangingtheinitialorientationoftheincidentquadruplebeamrelatedtothelattices,periodicoscillationsofthelocalizedquadruplemodemaybeobtained.Thelocalizedquadruplestatebecomesarotatingdoublychargedopticalvortex(DCV)duringrotationandshouldundergocharge-flippingwhentherotatingdirectionisreversed.

简介：

简介：WeproposeanddemonstrateexperimentallyamultimodeoscillationQ-switchederbium-dopedfiberlaserwithafew-modefibercavity.ThedifferentcouplingprocessesofreflectionpeaksoffiberBragggratings(FBGs)whichactascavitymirrorsallowthedifferentoscillatingstates.Weobtainmicrosecondlightpulseoutputstateswhoseoscillationandoutputbeamshavedifferentmodecompositions,includinghighordermode.Suchastructureenablesthehighordermodeoscillationinthewholecavitywithanall-fiberstructure,whichhaspotentialapplicationsinmode-divisionmultiplexedsystemsandresearchofmultimodenonlineareffect.

简介：AnupswinginhazeweatherduringautumnandwinterhasbeenobservedoverNorthandNortheastChinainrecentyears,imposingadverseimpactsuponlocalsocioeconomicdevelopmentandhumanhealth.However,suchanincreaseintheoccurrenceofhazeeventsanditsassociationwithnaturalclimatevariabilityandclimatechangearenotwellunderstood.Toinvestigatetheclimatologyofthemeteorologicalfactorsassociatedwithhazeeventsandtheirnaturalvariability,thisstudyusesameteorologicalpollutionindexcalledPLAM(ParameterLinkingAir-qualitytoMeteorologicalconditions)andERA-Interimreanalysisdata.TheresultssuggestthathighPLAMvaluestendtooccuroversouthernpartsofnorthernChina,implyingtheweatherconditionsoverthisareaarefavorablefortheoccurrenceofhazeweather.Fortheperiod1979–2014,theregionalmeanPLAMshowsanoverallincreaseacrossBeijing,Tianjin,andHebeiProvince,andpartsofShanxiProvince.Also,aperiodicityof28–34monthsisfoundinthetemporalvariationofPLAM,whichimpliesapotentialassociationofPLAMwiththestratosphericQuasi-BiannualOscillation(QBO).ByusingtheQBOindexduringtheautumnandwinterseasonsintheprecedingyear,anincreaseinPLAMisfoundforthewesterlyphasesoftheQBO,relativetotheeasterlyphases.Anupper-troposphericwarmingisalsofoundinthewesterlyphases,whichcaninduceastablestratificationthatfavorstheincreaseinPLAMacrossthemidlatitudes.Themodulationsoflarge-scaleenvironmentalfactors,includingmoiststaticstability,verticalvelocity,andtemperatureadvection,alsoacttoenhancePLAMinthewesterlyphases.However,thebaroclinictermofmoistpotentialvorticityat700hPatendstodecreaseoverthesouth,andanincreaseinlow-levelascentisfoundoverthenorth.ThesefactorscanreducePLAMandpossiblylimitthestatisticalsignificanceoftheincreasedPLAMinthewesterlyphasesoftheQBO.

简介：BasedontheNCEP/NCARreanalysisdataandtheobservedprecipitationdatainthesouthofChinafrom1958to2000,theimpactof30to60dayoscillationofatmosphericheatsourcesonthedroughtandfloodeventsinJuneinthesouthofChinaisdiscussed.Duringtheflood(drought)events,thereexistsananomalouslow-frequencyanticyclone(cyclone)atthelowlevelofthetroposphereovertheSouthChinaSeaandthenorthwesternPacific,accompaniedwithanomalouslow-frequencyheatsinks(heatsources),whilethereexistsananomalouslow-frequencycyclone(anticyclone)withanomalousheatsources(sinks)overtheareafromthesouthofChinatothesouthofJapan.Onaverage,thephaseevolutionofthelow-frequencyindroughteventsis7to11daysaheadofthatinfloodeventsinMaytoJuneinthesouthofChina.Infloodevents,low-frequencyheatsourcesandcyclonesarepropagatednorthwardfromthesouthernSouthChinaSea,northwestwardfromthewarmpoolofthewesternPacificandwestwardfromthenorthwesternPacificaround140°E,whichhaveveryimportantimpactontheabundantrainfallinJuneinthesouthofChina.However,indroughtevents,thenorthwardpropagationsofthelow-frequencyheatsourcesandcyclonesfromtheSouthChinaSeaanditsvicinityareratherlatecomparedwiththoseinfloodevents,andthereisnoobviouswestwardpropagationoftheheatsourcesfromthenorthwesternPacific.Thetimingofthelow-frequencyheatsourcepropagationhasremarkableimpactontheJunerainfallinthesouthofChina.