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简介:Alaboratoryexperimentwasconductedinsideawindwavetanktoinvestigatethewaveinducedturbulence.Inthisexperiment,thewavesurfaceelevationandvelocitybeneaththewatersurfaceweremeasuredsimultaneouslytoinvestigatetherelationbetweenthewavestatusandwaveinducedturbulence.TheprofileoftheturbulentdissipationrateandReynoldsstresswerecalculatedusingexperimentaldata.Theeffectofthewavestatusonturbulenceisinvestigatedwithregardtothewindwave,swell,andmixedwaveconditions.Itwasdepictedthattheturbulencedecreasedwithincreasingdepthfromthewatersurfaceandthattheturbulencethatwasinducedbyawavewithlargerwavelengthandwaveheightismuchstrongerforthesamewavestatus.Finally,weobservedthatthewindwaveismoreeffectiveinactivatingthewaveinducedturbulence.
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。
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.
简介:INTERHEMISPHERICEFFECTOFDIABATICALLYINDUCEDLINEARSTATIONARYWAVES¥PengTaoyong彭涛涌(GuangzhouinstituteofTropicalandOceanicMeteoro...
简介:Basedonthesphericalcavityexpansiontheoryintheelastichalfspace,thegroundsurfacemovementcharacteristicsofshallowlyburiedexplosionsareanalyzed.TheresultsshowthattheinducedseismicwaveisalongitudinalwaveinthenearzoneandaRayleighwaveinthefarzone.Themaximumdisplacement(velocity)ofthelongitudinalwaveandtheRayleighwaveareinverselyproportionaltothescaleddistance,andcanbedescribedbyexponentialfunctionwithexponentsequalto1.4and0.5,respectively.Thevibrationfrequenciesofthewaveshavealmostnochange.Thevibrationfrequencyofthelongitudinalwaveapproximatesthenaturalvibrationfrequencyofthecavityinthebrokenarea,andthevibrationfrequencyoftheRayleighwaveisabouthalfthatofthelongitudinalwave.Onthesamereducedburieddepthandreduceddistance,theparticledisplacementisdirectlyproportionaltotheproductoftheboundaryloadingandcavityradius,andisinverselyproportionaltothetransversalwavevelocity.Meanwhile,theparticlevelocityisdirectlyproportionaltotheboundaryloadingandinverselyproportionaltothewavevelocityratio.Inthefarzone,theburieddepthoftheexplosiveonlyhasaslighteffectonthelongitudinalwave,buthasalargereffectontheRayleighwave.
简介:Thispaperpresentsreal-timemonitoringdataandanalysisresultsofthenon-stationaryvibrationsofanoperationalwindturbine.Theadvancedtime-frequencyspectrumanalysisrevealsvariednon-stationaryvibrationswithtimevaryingfrequencies,whicharecorrelatedwithcertainsystemnaturalmodescharacterizedbyfiniteelementanalysis.Undertheeffectsofstrongwindload,thewindturbinesystemexhibitscertainresonancesduetobladepassingexcitations.Thesystemalsoexhibitscertaininstabilitiesduetothecouplingofthetowerbendingmodesandbladeflapwisemodewithbladepassingexcitationsunderthevariationofwindspeed.Ananalyticalmodelisusedtoelaboratethenon-stationaryandinstabilityphenomenaobservedinexperimentalresults.ThepropertiesofthenonlinearinstabilitiesareevaluatedbyusingLyapunovexponentestimation.
简介:Thispaperdealswiththepredictionofpotentiallymaximummagnitudeandorigintimeforreservoirinducedseismicity(RIS).ThefactorandsignofseismologyandgeologyofRIShasbeenstudied,andtheinformationquantityformagnitudeofinducedseismicityprovidedbythemhasbeencalculated.Intermsofinformationquan-titythebiggestpossiblemagnitudeofRISisdetermined.Thechangesofseismicfrequencywithtimearestudiedusinggreymodelmethod,andthetimeofthebiggestchangerateistakenasoriginaltimeofthemainshock.ThefeasibilityofmethodsforpredictingmagnitudeandtimehasbeentestedforthereservoirinducedseismicityintheXinfengjiangreservoir,ChinaandtheKoynareservoir,India.
简介:QBO-likeOscillationsInducedbyLocalThermalForcingZhangDaizhou;(张代洲),andQinin(秦瑜)(DepartmentofGeophysics,PekingUniversity,Beiji...
简介:Ahybridcontrolplatformisinvestigatedinthispapertomitigatemicrovibrationstoagroupofvibrationsensitiveequipmentinstalledinamicroelectronicsfacilitysubjecttonearbyroadvehicle-inducedhorizontalandverticalgroundmotions.Thehybridcontrolplatform,onwhichmicroelectronicsequipmentisinstalled,ismountedonabuildingfloorthroughaseriesofpassivemountsandcontrolledbyhydraulicactuatorsinbothhorizontalandverticaldirections.Thecontrolplatformisanelasticbodywithsignificantbendingmodesofvibration,andasub-optimalcontrolalgorithmisusedtomanipulatethehydraulicactuatorswithactuatordynamicsincluded.Thefiniteelementmodelandtheequationsofmotionofthecoupledplatform-buildingsystemarethenestablishedintheabsolutecoordinatetofacilitatethefeedbackcontrolandperformanceevaluationoftheplatform.Thehorizontalandverticalgroundvibrationsatthebaseofthebuildinginducedbynearbymovingroadvehiclesareassumedtobestationaryrandomprocesses.Atypicalthree-storymicroelectronicsbuildingisselectedasacasestudy.Thecasestudyshowsthattheverticalvibrationofthemicroelectronicsbuildingishigherthanthehorizontal.TheuseofahybridcontrolplatformcaneffectivelyreducebothhorizontalandverticalmicrovibrationsofthemicroelectronicsequipmenttothelevelwhichsatisfiesthestringentmicroscalevelocityrequirementspecifiedintheBoltBeranek&Newman(BBN)criteria.
简介:Casestudiesarepresentedfortwoconcretelinedchannelsshakenbystronggroundmotionsduringthe1994Northridgeearthquake,thehighspeedchannel(HSC)andbypasschannel(BC),ontheLosAngelesDepartmentofWaterandPower'sVanNormanComplex.Performancesofthesetwochannelsastheypassthroughdifferentsubsurfacematerialsidentifyseveralimportantseismicaspectsandthecriticalroleofgeotechnicalearthquakeengineeringinassessingchannelbehaviors.Preliminaryevaluationsusingdetailedmappingofchannelcracks,permanentgroundmovements,subsurfaceprofiles,andnearbystronggroundmotionrecordingsfromthe1994earthquakeshowthatthechannellinersmayhavebeendamagedfrombothtransientmotionsandpermanentgroundmovements.Damagefrompermanentgrounddeformationsisobviousbyobservation;thereforesimplifiedanalysesarepresentedonlyfortransientmovements.SitespecifictransientresponseanalysesareperformedtoprovideaninitialassessmentofthedifferingeffectsfromtransientandpermanentgroundmovementsonHSCandBClinerdamage.Thesecasestudiesarehelpfulforintroducingthepotentialforlifelinedamagefromtransientmovementswithinzonesofpermanentgroundmovement,aconceptnotwellunderstoodintheearthquakeengineeringcommunity.
简介:Thedynamicresponsesofoffshorefixedplatformsundericeloadsareanalysedinthispaper.Theresponsescalculatedincludethedisplacementandthehotspotstressesonthebasisofadynamicequationofice-inducedforcedvibrationforoffshorestructures.Theresultsobtainedcanbecitedandusedforthedesignandoperationofoffshorefixedplatformsagainsticeloading.
简介:Wave-inducedtransientresponseofdisplacements,effectivestressesandporepressureinsaturateseabedaresalvedbyaconsolidationfiniteelementmethod.Theinfluenceoftheresponsestothestabilityofseabedandcoastalstructuresisshownbyanimprovedslicemethodwithcirculararcslipsurface.Dynamicelasticconsolidationtheoryandlinearpermeabilitytheoryareemployedinthesolutionofseabedresponse.Theseabedcanbeconsistedoflayeredsoilwitharbitraryboundaries.Theactingwavecanberegularorirregular.Irregularwavepressureactingonthesurfaceofseabediscalculatedbylinearsuperpositionmethod.Wave-inducedexcessstressontheslipsurfaceisconsideredinthestabilityanalysis.Thespatialandtemporalvariationsofporepressureinsandyseabedcomparewellwithexperiment.Calculationsforaverticalbreakwatershowthatthesafetyfactorofseabedandstructurewilldecreaseifwave-inducedseabedresponseisconsidered.Thescopeofdecreaseismainlyre
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.
简介:Recenthigh-resolutiondeepseismicreflectionprofileacrosstheKunlunfaultinnortheasternTibetshowsclearlythattheMohoiscutoffbyacomplexthrustfaultsystem.Mohooffsetisageneralphenomenon,butlittleisknownaboutthedynamicmechanism.Inthisstudy,contactmodelswithMaxwellmaterialsareusedtosimulatethemechanicalprocessofMohooffsetinducedbytheaseismicslipofdeeplyburiedfaults.Basedontheseismicreflectiondata,weprojectasinglefaultmodelandacomplexfaultsystemmodelwithtwofaultsintersecting.ThedeformationsoftheMoho,theaseismicslips,andcontactstressesonfaultsindifferentmodelsarediscussedindetail.ResultsshowthattheMohooffsetmightbeproducedbyaseismicslipofdeeplyburiedfaults,andthemagnitudeisinfluencedbythefrictioncoefficientoffaultsandtheviscosityofthelowercrust.ThemaximumslipoccursneartheMohoonthesinglefaultoratthecrossingpointoftwointersectingfaultssystem.StressconcentratesmainlyontheMoho,thedeependoffaults,orthecrossingpoint.ThisstudywillthrowlightonunderstandingthemechanismofMohooffsetandaseismicslipofdeeplyburiedfaults.Theresultsofcomplexfaultsystemwithtwofaultsintersectingarealsousefultounderstandtheshallowintersectingfaultsthatmaycauseearthquakes.
简介:Theproblemoficeinducedvibrationiscommontooceanengineeringofcoldregioncountries.Tostudytheiceinducedvibrationofacompliantconicalstructure,aseriesofmodeltestshavebeenperformedandsomebreakthroughprogressesmade.Theicesheetbeforethecompliantconicalstructureisfoundtofailbytwo-timebreakinginthetests.Theprocessoftwo-timebreakingbehavesintwomodes,andthegeneralcontroloftheiceandstructuralconditionsdeterminethemodeinwhichtheiceforcewouldbehave.Twodynamiciceforcefunctionsareestablishedrespectivelyforthetwomodesoftwo-timebreakingprocessinthispaper.Thenumericalsimulationresultsareingoodagreementwiththemeasuredresults,indicatingthatthedynamiciceforcefunctionsgiveninthispapercanfullyreflecttherealsituationofthedynamiciceforceonacompliantconicalstructure.