学科分类
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86 个结果
  • 简介:Alaboratoryexperimentwasconductedinsideawindwavetanktoinvestigatethewaveinducedturbulence.Inthisexperiment,thewavesurfaceelevationandvelocitybeneaththewatersurfaceweremeasuredsimultaneouslytoinvestigatetherelationbetweenthewavestatusandwaveinducedturbulence.TheprofileoftheturbulentdissipationrateandReynoldsstresswerecalculatedusingexperimentaldata.Theeffectofthewavestatusonturbulenceisinvestigatedwithregardtothewindwave,swell,andmixedwaveconditions.Itwasdepictedthattheturbulencedecreasedwithincreasingdepthfromthewatersurfaceandthattheturbulencethatwasinducedbyawavewithlargerwavelengthandwaveheightismuchstrongerforthesamewavestatus.Finally,weobservedthatthewindwaveismoreeffectiveinactivatingthewaveinducedturbulence.

  • 标签: WAVE induced TURBULENCE TURBULENT DISSIPATION RATE
  • 简介:大Wenchuan()地震导致了山崩的大数量。他们广泛地被散布并且引起巨大的损坏。这些导致地震的山崩的滑动机制和特征与常规严肃山崩的那些不同。他们的出现被强大的地震显然控制,并且他们被高势能滑动并且喷射滑动描绘。在这篇文章,导致地震的山崩被分类,滑动和这些山崩的破坏的特征被描述,并且在地震之间的关系和山崩被分析。Donghekou()山崩被用作一个例子描绘移动迅速的长途的导致地震的喷射滑动和山崩。这研究建议与导致地震的山崩有关的许多现象和问题在当前的识别和知识以外,并且新方法论应该被采用在山崩的发展把地震的效果看作首要的因素。而且,移动迅速的长途的导致地震的山崩的学习能也使旧、古老的山崩的形成清楚些。

  • 标签: 诱发滑坡 大地震 汶川 滑动机制 山体滑坡 特征描述
  • 简介:Theman-inducedsedimentdisasterincludesmaterialerosion,transportationandaccumula-tionbyhumanactivities.Itpossessesspecialattributeinsociologyanddisasterscience.Inaccordancewithhumanactivities,geomorphologiclocation,behaviorandparticular,theman-inducedsedimentdisastercanbedividedinto4types:thedrainagenetwork,slopeandgully,channelandplain-estu-au-coastline.Eachtypeincludeserosion,transportation,accumulation,complexityandcascading.Basedonhumanactivity,geomorphology,sedimentmechanicsandcatastrophology,theman-inducedsedimentdisasterischaracterizedasfollows:(1)acceleratingtendencywithgeographicalzoningback-ground;(2)non-ordercharactersbyblindactionwithoutspecialtechnicaltraining;(3)graduallyandsharplychangingwithhumanenvironmentvibration;and(4)complexityandnon-linearfigure,etc.Oneofthereasonsleadingtoman-inducedsedimentdisasterishumanenvironmentvibration.

  • 标签: man's DYNAMICS SEDIMENT DISASTER type CHARACTER
  • 简介:INTERHEMISPHERICEFFECTOFDIABATICALLYINDUCEDLINEARSTATIONARYWAVES¥PengTaoyong彭涛涌(GuangzhouinstituteofTropicalandOceanicMeteoro...

  • 标签: STATIONARY WAVES inter-hemispheric connection wavetrain PROPAGATION
  • 简介:Basedonthesphericalcavityexpansiontheoryintheelastichalfspace,thegroundsurfacemovementcharacteristicsofshallowlyburiedexplosionsareanalyzed.TheresultsshowthattheinducedseismicwaveisalongitudinalwaveinthenearzoneandaRayleighwaveinthefarzone.Themaximumdisplacement(velocity)ofthelongitudinalwaveandtheRayleighwaveareinverselyproportionaltothescaleddistance,andcanbedescribedbyexponentialfunctionwithexponentsequalto1.4and0.5,respectively.Thevibrationfrequenciesofthewaveshavealmostnochange.Thevibrationfrequencyofthelongitudinalwaveapproximatesthenaturalvibrationfrequencyofthecavityinthebrokenarea,andthevibrationfrequencyoftheRayleighwaveisabouthalfthatofthelongitudinalwave.Onthesamereducedburieddepthandreduceddistance,theparticledisplacementisdirectlyproportionaltotheproductoftheboundaryloadingandcavityradius,andisinverselyproportionaltothetransversalwavevelocity.Meanwhile,theparticlevelocityisdirectlyproportionaltotheboundaryloadingandinverselyproportionaltothewavevelocityratio.Inthefarzone,theburieddepthoftheexplosiveonlyhasaslighteffectonthelongitudinalwave,buthasalargereffectontheRayleighwave.

  • 标签: shallowly BURIED explosions GROUND SURFACE RESPONSE
  • 简介:Thispaperpresentsreal-timemonitoringdataandanalysisresultsofthenon-stationaryvibrationsofanoperationalwindturbine.Theadvancedtime-frequencyspectrumanalysisrevealsvariednon-stationaryvibrationswithtimevaryingfrequencies,whicharecorrelatedwithcertainsystemnaturalmodescharacterizedbyfiniteelementanalysis.Undertheeffectsofstrongwindload,thewindturbinesystemexhibitscertainresonancesduetobladepassingexcitations.Thesystemalsoexhibitscertaininstabilitiesduetothecouplingofthetowerbendingmodesandbladeflapwisemodewithbladepassingexcitationsunderthevariationofwindspeed.Ananalyticalmodelisusedtoelaboratethenon-stationaryandinstabilityphenomenaobservedinexperimentalresults.ThepropertiesofthenonlinearinstabilitiesareevaluatedbyusingLyapunovexponentestimation.

  • 标签: wind turbine condition MONITORING NON-STATIONARY vibrations
  • 简介:震荡器刺激在不同频率的表面下的接口而且电磁波上产生波浪领域的不仅思考和折射。在这篇论文,我们在自发的潜在的地上探讨导致颤动的效果。自发的潜在的领域上的可控制的颤动的效果在真实的地下面被学习地质的条件。试验性的数据证实自发的潜在的领域上的导致颤动的效果确实在领域条件下面存在。在很长时间间隔上监视记录在那里显示出那存在在自发的潜力上的导致颤动的效果的三个信息地区回答。这些是变化信号的地区,极端马厩的地区,和松驰恢复地区。与不同好地点的数据结合了,这被结束在信息地区的异例的变化时间的特征仔细与表面下的液体(油和水)的性质有关。

  • 标签: 震电效应 振动激励 时间特性 流体性质
  • 简介:在现在的学习,旋涡在开的隧道流动被产生,跨流动的柱体在床附近水平地安装了。沉积拾起率然后下游地在隧道床上被测量用一部沉积电梯的柱体。拾起率面对旋涡指数地增加的试验性的数据表演。二种不同关系能清楚地为没有障碍的流动在拾起率和streamwise速度变化,为妨碍柱体的流动的变化和其它的最大的root-mean-square(rms)价值之间被观察。结果暗示导致旋涡的沉积拾起不能基于传统的边界层理论被解释。

  • 标签: 实验室测量 沉积物 拾取 涡流 速率 明渠流量
  • 简介:Thispaperdealswiththepredictionofpotentiallymaximummagnitudeandorigintimeforreservoirinducedseismicity(RIS).ThefactorandsignofseismologyandgeologyofRIShasbeenstudied,andtheinformationquantityformagnitudeofinducedseismicityprovidedbythemhasbeencalculated.Intermsofinformationquan-titythebiggestpossiblemagnitudeofRISisdetermined.Thechangesofseismicfrequencywithtimearestudiedusinggreymodelmethod,andthetimeofthebiggestchangerateistakenasoriginaltimeofthemainshock.ThefeasibilityofmethodsforpredictingmagnitudeandtimehasbeentestedforthereservoirinducedseismicityintheXinfengjiangreservoir,ChinaandtheKoynareservoir,India.

  • 标签:
  • 简介:QBO-likeOscillationsInducedbyLocalThermalForcingZhangDaizhou;(张代洲),andQinin(秦瑜)(DepartmentofGeophysics,PekingUniversity,Beiji...

  • 标签: Quasi-biennial oscillation(QBO) LOCAL thermal FORCING FORCED
  • 简介:Ahybridcontrolplatformisinvestigatedinthispapertomitigatemicrovibrationstoagroupofvibrationsensitiveequipmentinstalledinamicroelectronicsfacilitysubjecttonearbyroadvehicle-inducedhorizontalandverticalgroundmotions.Thehybridcontrolplatform,onwhichmicroelectronicsequipmentisinstalled,ismountedonabuildingfloorthroughaseriesofpassivemountsandcontrolledbyhydraulicactuatorsinbothhorizontalandverticaldirections.Thecontrolplatformisanelasticbodywithsignificantbendingmodesofvibration,andasub-optimalcontrolalgorithmisusedtomanipulatethehydraulicactuatorswithactuatordynamicsincluded.Thefiniteelementmodelandtheequationsofmotionofthecoupledplatform-buildingsystemarethenestablishedintheabsolutecoordinatetofacilitatethefeedbackcontrolandperformanceevaluationoftheplatform.Thehorizontalandverticalgroundvibrationsatthebaseofthebuildinginducedbynearbymovingroadvehiclesareassumedtobestationaryrandomprocesses.Atypicalthree-storymicroelectronicsbuildingisselectedasacasestudy.Thecasestudyshowsthattheverticalvibrationofthemicroelectronicsbuildingishigherthanthehorizontal.TheuseofahybridcontrolplatformcaneffectivelyreducebothhorizontalandverticalmicrovibrationsofthemicroelectronicsequipmenttothelevelwhichsatisfiesthestringentmicroscalevelocityrequirementspecifiedintheBoltBeranek&Newman(BBN)criteria.

  • 标签: 微小振动 道路交通 微电子工程 有限元分析
  • 简介:Casestudiesarepresentedfortwoconcretelinedchannelsshakenbystronggroundmotionsduringthe1994Northridgeearthquake,thehighspeedchannel(HSC)andbypasschannel(BC),ontheLosAngelesDepartmentofWaterandPower'sVanNormanComplex.Performancesofthesetwochannelsastheypassthroughdifferentsubsurfacematerialsidentifyseveralimportantseismicaspectsandthecriticalroleofgeotechnicalearthquakeengineeringinassessingchannelbehaviors.Preliminaryevaluationsusingdetailedmappingofchannelcracks,permanentgroundmovements,subsurfaceprofiles,andnearbystronggroundmotionrecordingsfromthe1994earthquakeshowthatthechannellinersmayhavebeendamagedfrombothtransientmotionsandpermanentgroundmovements.Damagefrompermanentgrounddeformationsisobviousbyobservation;thereforesimplifiedanalysesarepresentedonlyfortransientmovements.SitespecifictransientresponseanalysesareperformedtoprovideaninitialassessmentofthedifferingeffectsfromtransientandpermanentgroundmovementsonHSCandBClinerdamage.Thesecasestudiesarehelpfulforintroducingthepotentialforlifelinedamagefromtransientmovementswithinzonesofpermanentgroundmovement,aconceptnotwellunderstoodintheearthquakeengineeringcommunity.

  • 标签: 混凝土渠道 北岭地震 案例 强地面运动 工程评估 高速通道
  • 简介:Thedynamicresponsesofoffshorefixedplatformsundericeloadsareanalysedinthispaper.Theresponsescalculatedincludethedisplacementandthehotspotstressesonthebasisofadynamicequationofice-inducedforcedvibrationforoffshorestructures.Theresultsobtainedcanbecitedandusedforthedesignandoperationofoffshorefixedplatformsagainsticeloading.

  • 标签: ice-induced vibration DISPLACEMENT hot SPOT stress
  • 简介:Wave-inducedtransientresponseofdisplacements,effectivestressesandporepressureinsaturateseabedaresalvedbyaconsolidationfiniteelementmethod.Theinfluenceoftheresponsestothestabilityofseabedandcoastalstructuresisshownbyanimprovedslicemethodwithcirculararcslipsurface.Dynamicelasticconsolidationtheoryandlinearpermeabilitytheoryareemployedinthesolutionofseabedresponse.Theseabedcanbeconsistedoflayeredsoilwitharbitraryboundaries.Theactingwavecanberegularorirregular.Irregularwavepressureactingonthesurfaceofseabediscalculatedbylinearsuperpositionmethod.Wave-inducedexcessstressontheslipsurfaceisconsideredinthestabilityanalysis.Thespatialandtemporalvariationsofporepressureinsandyseabedcomparewellwithexperiment.Calculationsforaverticalbreakwatershowthatthesafetyfactorofseabedandstructurewilldecreaseifwave-inducedseabedresponseisconsidered.Thescopeofdecreaseismainlyre

  • 标签: wave SEABED RESPONSE PORE pressure dynamic
  • 简介:Maturationofthe4thphaseoocytesofmudskipperisinducedinvitrobysexpheromones,theextractofovary,testisandseminalvesicle,oxytocinianddeoxycorticosterone(DOC).Maturationratesofoocytesarerelatedtopheromonesandtheirdosages.ThesingleuseofprostaglandinE1(PGE1)isnoteffectiveintheinductionofmaturation,butthecombinationoIPGE1withHCGpromotesoocytematurationrates.Maturationisinducedbyinjectionsoftheextractoftheovaryatdosagesof0.01cm^3/afish,seminalvesicleextractatdosagesof0.1crn3/afish,testisextractatdosageof0.1cm^3/afish,orPGE1atdosageof10μg/fish,respectively.Amongthem,seminalvesicleextractisthemosteffectiveintheinductionofmaturation.Theartificialnests,withtheextractoftheovary,testisorseminalvesicleinside,attractmoreheterosexualmudskippersthanhomosexualmudskipperstoenter.Especially,theextractofseminalvesicleisthemosteffectiveinattractingfemales.Femalemudskipperscouldbeinducedtospawnbytheextractsofovary,testisandseminalvesicleplacedinsideboththeceramicandspongenests.Morespawnedeggsandhigherfertilizationratesareobservedintheceramicneststhaninthespongeones.

  • 标签: 性信息素 成熟 产卵 跳跳鱼 雌性
  • 简介:Recenthigh-resolutiondeepseismicreflectionprofileacrosstheKunlunfaultinnortheasternTibetshowsclearlythattheMohoiscutoffbyacomplexthrustfaultsystem.Mohooffsetisageneralphenomenon,butlittleisknownaboutthedynamicmechanism.Inthisstudy,contactmodelswithMaxwellmaterialsareusedtosimulatethemechanicalprocessofMohooffsetinducedbytheaseismicslipofdeeplyburiedfaults.Basedontheseismicreflectiondata,weprojectasinglefaultmodelandacomplexfaultsystemmodelwithtwofaultsintersecting.ThedeformationsoftheMoho,theaseismicslips,andcontactstressesonfaultsindifferentmodelsarediscussedindetail.ResultsshowthattheMohooffsetmightbeproducedbyaseismicslipofdeeplyburiedfaults,andthemagnitudeisinfluencedbythefrictioncoefficientoffaultsandtheviscosityofthelowercrust.ThemaximumslipoccursneartheMohoonthesinglefaultoratthecrossingpointoftwointersectingfaultssystem.StressconcentratesmainlyontheMoho,thedeependoffaults,orthecrossingpoint.ThisstudywillthrowlightonunderstandingthemechanismofMohooffsetandaseismicslipofdeeplyburiedfaults.Theresultsofcomplexfaultsystemwithtwofaultsintersectingarealsousefultounderstandtheshallowintersectingfaultsthatmaycauseearthquakes.

  • 标签: 逆冲断层 滑动机制 埋地 地震反射剖面 故障模型 失调
  • 简介:Theproblemoficeinducedvibrationiscommontooceanengineeringofcoldregioncountries.Tostudytheiceinducedvibrationofacompliantconicalstructure,aseriesofmodeltestshavebeenperformedandsomebreakthroughprogressesmade.Theicesheetbeforethecompliantconicalstructureisfoundtofailbytwo-timebreakinginthetests.Theprocessoftwo-timebreakingbehavesintwomodes,andthegeneralcontroloftheiceandstructuralconditionsdeterminethemodeinwhichtheiceforcewouldbehave.Twodynamiciceforcefunctionsareestablishedrespectivelyforthetwomodesoftwo-timebreakingprocessinthispaper.Thenumericalsimulationresultsareingoodagreementwiththemeasuredresults,indicatingthatthedynamiciceforcefunctionsgiveninthispapercanfullyreflecttherealsituationofthedynamiciceforceonacompliantconicalstructure.

  • 标签: 可靠性分析 海冰 模糊学 圆锥结构 海洋水文