简介:Thedesignofternaryedge-triggeredJKL-typeflip-flopisproposed.ThecomputersimulationandthetestinexperimentalcircuitmadeupwithTTLgateshowthisflip-flophastheexpectedlogicfunctions.
简介:Developinganelectrostaticdischarge(ESD)protectiondevicewithabetterlatch-upimmunityhasbeenachallengingissueforthenanometercomplementarymetal-oxidesemiconductor(CMOS)technology.Inthiswork,animprovedgrounded-gateN-channelmetal-oxidesemiconductor(GGNMOS)transistortriggeredsilicon-controlledrectifier(SCR)structure,namedGGSCR,isproposedforhighholdingvoltageESDprotectionapplications.TheGGSCRdemonstratesadoublesnapbackbehaviorasaresultofprogressivetrigger-onoftheGGNMOSandSCR.Thedoublesnapbackmakestheholdingvoltageincreasefrom3.43Vto6.25Vascomparedwiththeconventionallow-voltageSCR.TheTCADsimulationsarecarriedouttoverifythemodesofoperationofthedevice.
简介:Wenchuan()地震在2008年5月12日沿着Longmenshan导致了很多山崩,倒塌,和大量的落石()差错。在Niujuan的山崩()近到震中,山谷(命名Niujuan山崩)是传的有损坏后果的长距离。用QuickBird卫星图象和GIS工具,seismogenic团运动被分析,并且运动分阶段执行旅行路径,和catastrophic以后Niujuan山崩的进程被描述并且讨论。图象解释和GPS调查证明集体运动剥光37%研究区域。Niujuan山崩沿着Lianhuaxingou移动了1950m()溪流,转变了到碎片雪崩,并且在Niujuan山谷的下游的床上积累了,在他们形成了一个水坝的地方在高度的30m,堵住Niujuan溪流并且与11万个m3存储能力创造障碍湖盆。对Niujuan山崩随后,因为碎片的积累的团,碎片流动在Lianhuaxingou和Niujuan山谷是更活跃的。
简介:OnApril14,2010at07:49(Beijingtime),acatastrophicearthquakewithMS7.1occurredatthecentralQinghai-TibetanPlateau.TheepicenterwaslocatedatYushucounty,QinghaiProvince,China.Atotalof2036landslidesweredeterminedfromvisualinterpretationofaerialphotographsandhighresolutionremotesensingimages,andverifiedbyselectedfieldinvestigations.Theselandslidescoveredatotalareaofabout1.194km2.Characteristicsandfailuremechanismsoftheselandslidesarelistedinthispaper,includingthefactthatthespatialdistributionoftheselandslidesiscontrolledbyco-seismicmainsurfacefaultruptures.Mostofthelandslidesweresmallscale,causingratherlesshazards,andoftenoccurringclosetoeachother.Thelandslideswereofvarioustypes,includingmainlydisruptedlandslidesandrockfallsinshallowsandalsodeep-seatedlandslides,liquefactioninducedlandslides,andcompoundlandslides.Inadditiontostronggroundshaking,whichisthedirectlandslidetriggeringfactor,geological,topographical,andhumanactivityalsohaveimpactontheoccurrenceofearthquaketriggeredlandslides.Inthispaper,fivetypesoffailuremechanismsrelatedtothelandslidesarepresented,namely,theexcavatedtoesofslopesaccompaniedbystronggroundshaking;surfacewaterinfiltrationaccompaniedbystronggroundshaking;co-seismicfaultslippingaccompaniedbystronggroundshaking;onlystronggroundshaking;anddelayedoccurrenceoflandslidesduetosnowmeltorrainfallinfiltrationatsiteswhereslopeswereweakenedbyco-seismicgroundshaking.Besidesthemainco-seismicsurfaceruptures,slopefissureswerealsodelineatedfromvisualinterpretationofaerialphotographsinhighresolution.Atotalof4814slopefissures,withatotallengthupto77.1km,werefinallymapped.Theseslopefissuresaremainlydistributedontheslopeslocatedatthesoutheasternendofthemainco-seismicsurfacerupturezone,anareasubjecttostrongcompressionduringtheeart
简介:AstatisticalanalysisontheWenchuanaftershockactivitytriggeredbytidalforcesissystematicallystudiedbasedonSchusterstest,includingearthquakestriggeredbytidalforce,tidalstressandtidalcoulombfailurestress.TheresultsshowthatagroupofstrongaftershockswhichoccurredattheendofJulytoearlyAugustin2008atthenorthofWenchuanwereobviouslytriggeredbyearthtide,thesameconclusionisdrawnbySchusterssmoothtestofthetidalforce,tidalstressandtidalcoulombfailurestress.Inaddition,theWenchuanaftershockactivityisobviouslytriggeredbyfortnighttide.Inthenorth,theaftershockshappenedmorefrequentlyinthefirstandlastquartersofthemoon,andinthesouth,theaftershockshappenedmorefrequentlyinthefirstandlastquartersofthemoonandduringthefullmoon.
简介:AheavyrainfalleventthatoccurredinShandongProvincein26-28August2004wascausedmainlybyTyphoonAereandcoldairactivitiesrelatedtoawesterlytrough.Theeventwastriggeredbyaninvertedtyphoontrough,whichwascloselyassociatedwiththeintensificationofthelow-levelsoutheasterlyflowandthenorthwardtransportofheatandmomentumintheperipheryofthetyphoonlow.AnumericalsimulationofthiseventisperformedusingthenonhydrostaticmesoscalemodelMM5withtwo-wayinteractiveandtriply-nestedgrids,andthestructureoftheinvertedtyphoontroughisstudied.Furthermore,theformationanddevelopmentmechanismoftheinvertedtyphoontroughandamesoscalevortexarediscussedthroughavorticitybudgetanalysis.Theresultsshowthattheheavyrainfallwasinducedbythestrongconvergencebetweenthestrongandweakwindswithintheinvertedtyphoontrough.Dynamiceffectsofthelow-leveljetandthediabaticheatingofprecipitationplayedanimportantroleinthedevelopmentoftheinvertedtyphoontroughandtheformationofthemesoscalevortex.Thevorticitybudgetanalysissuggeststhatthedivergenceterminthelowtroposphere,thehorizontaladvectionterm,andtheconvectionterminthemiddletroposphereweremaincontributorstopositivevorticity.Nonetheless,atthesamepressurelevel,theeffectofthedivergencetermandthatoftheadvectiontermwereoppositetoeachother.Inthemiddletroposphere,theverticaltransporttermmadeapositivecontributionwhilethetiltingtermmadeanegativecontribution,andthetotalvorticitytendencywasthenetresultoftheircounteractions.Itisfoundthatthechangetendencyoftherelativevorticitywasnotuniformhorizontally.Astrongpositivevorticitytendencyoccurredinthesoutheastofthemesoscalevortex,whichiswhytheheavyrainfallwasconcentratedthere.Theincreaseofpositivevorticityinthelow(upper)tropospherewascausedbyhorizontalconvergence(upwardtransportofvorticityfrom
简介:FourparallelGaAsphotoconductivesemiconductorswitches(PCSSs)weretriggeredsimultaneouslybyfour1064nmlaserbeams.Thetransientcharacteristicsoffourlinearelectricalpulseswereinvestigated.Whentheenergyoffourlaserbeamswere16.4mJ,15.6mJ,15.3m.J,and13.7mJ,respectively,fourstableelectricalpulsesofabout25nswidthand10nsrisetimewereobtainedatthesamebiasvoltageof8kV.Themaximumswitchingvoltageamplitudewas3.8kV.Withthetriggeringpulseenergyandbiasvoltagekeptconstant,thethreeGaAsPCSSsweretriggeredat10Hzlaserpulse.Themethodofsynchronizationcalculationwasgiven,andthesynchronizationoffourparallelGaAsPCSSswascalculatedtobe79ps.Theinfluenceofbiasvoltageandlaserenergyonthevoltageamplitudeofelectricalpulsewasanalyzed.Furthermore,relationshipbetweenthesynchronizationandthejittertimewasalsodiscussed.
简介:丰富的山崩沉积物被Wenchuan地震触发,提供为在降雨条件下面的随后的碎片流动或斜坡失败的材料的富有的来源。山崩沉积物的物理、机械的性质的好理解对关于斜坡失败机制和碎片流动的开始的研究很重要。实验室biaxial压缩测试被用来在山崩存款,和一个分离元素方法(一个契约接触模型)的机械性质上学习材料作文和水内容影响被用来学习粒子僵硬,契约力量,磨擦系数和限制应力影响在数字、试验性的参数之间的机械行为和关系。试验性的结果证明山崩存款的失败压力与与增加的水内容增加好粒子并且也的内容被减少,特别在起始的增加阶段。浸透的山崩存款的结合被增加,但是磨擦角度随好粒子内容的增加被减少。砍力量参数(结合和磨擦角度)在起始的增加阶段与增加的水内容被减少,然后,他们慢慢地减少。有在5%-7%的水内容的批评的值(在重量)为失败强调并且砍山崩存款的力量参数。二次的方程被介绍描述在契约之间的关系力量和结合,和数字磨擦系数和试验性的磨擦角度。
简介:Techniquesofartificially-triggeredlightninghaveprovidedasignificantlyusefulmeanstodirectlymeasurevariousphysicalparametersoflightningdischargeandtoconductresearchonprotectionmethodsoflightningelectromagneticpulses.Inthisstudy,usingcapacitiveandresistivedividers,currentprobesandopticalfibertransmissiondevices,wemeasuredandanalyzedtheinducedovervoltageontheoverheadtransmissionlineandtheovercurrentthroughSurgeProtectiveDevices(SPD)whenalightningdischargewasartificiallytriggerednearbyonAugust12,2008atConghuaFieldLightningExperimentSite.Thetriggeredlightningdischargecontainedaninitialcurrentstageandeightreturnstrokeswhosepeakcurrentsrangedfrom6.6kAto26.4kA.WefoundthatovercurrentsthroughSPDwereinducedonthepowerlinebothduringtheinitialcontinuouscurrentstageandthereturnstrokeprocesses.Duringthereturnstrokes,theresidualvoltageandthecurrentthroughtheSPDlasteduptothems(millisecond)range,andtheovercurrentsexhibitedameanwaveformupto22/69μswithapeakvalueoflessthan2kA.Basedontheobserveddata,simplecalculationsshowthatthecorrespondingsingledischargeenergywasmuchgreaterthanthevaluesofthehighvoltagepulsegeneratorscommonlyusedintheexperimentsregulatedforSPD.TheSPDdischargecurrentpeakwasnotsynchronoustothatoftheresidualvoltagewiththeformerobviouslylaggingbehindthelatter.TheSPDdischargecurrentpeakwaswellcorrelatedwiththetriggeredlightningcurrentpeakandthewave-frontcurrentgradient.ThelongdurationoftheSPDcurrentisoneofthemajorreasonswhytheSPDwasdamagedevenwithabignominaldischargecurrent.
简介:Basedonintensiveautomaticweatherstationdata,satellitecloudimagery,NCEPreanalyzeddata,andthesimulationresultsfrommesoscalenumericalmodels,thisstudyanalyzesthecharacteristicsandformationmechanismsofthemesoscaleconvectionsystem(MCS)duringtheextremeprecipitationeventthatwastriggeredbyaweakenedlow-pressureinvertedtroughofTyphoonHaikuionAugust10/2012.Theresultsofthisstudyshowthatcoldairattherearofanortheasterncoldvortexcreatesthermodynamicconditionsfavorabletothedevelopmentofextremeprecipitation.Themainbodyofthecoldairisnorthwardlocatedsothatthecoldairinvadesonlythemiddlelayeroftheperipheryoftheinvertedtrough.Thus,thecoldairminimallyaffectsthelowerlayer,whichresultsinaverticallydistributedstructureofthetemperatureadvectionthataugmentstheformationanddevelopmentofconvectiveinstabilitystratification.Inthemiddletroposphere,thecoldairencounterstheconvergent,ascending,warmmoistairfromthelow-pressureinvertedtrough,leadingtofrontogenesis.Thefrontogenesisenhanceswindconvergencewhich,inturn,furtherenhancesthefrontogenesis,andthepositivefeedbackbetweenthesetwoforcesaugmentsthedevelopmentofmeso-andsmall-scaleconvectionsystemsintherainstormregionanditsvicinity,whichstrengthenstheupwardtransportationofwatervaporfromlowlayersandthickeningofwatervaporconvergenceandresultsinlocalheavyrains.
简介:IntroductionUntilnow,manyobservationsandstudiesshowthatinacertainareasandduringacertainperiodmajorearthquakesfrequentlyocured...
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简介:Aco-designschemeofevent-triggeredsamplingmechanismandactivefaulttolerantcontrol(FTC)isdeveloped.Firstly,afaultdiagnosisobserverisdesignedtoestimateboththefaultandthestatesimultaneouslybyusingtheevent-triggeredsampledoutput.SomeH∞constraintsbetweentheestimationerrorsandtheevent-triggeredsamplingmechanismareestablishedtoensuretheestimationaccuracy.Then,basedontheconstraintsandtheobtainedfaultinformation,anevent-triggereddetectorandastaticfaulttolerantcontrollerareco-designedtoguaranteethestabilityofthefaultysystemandtoreducethesensorcommunicationcost.Furthermore,theproblemoftheeventdetectoranddynamicFTCco-designisalsoinvestigated.Simulationresultsofanunstablebatchreactorarefinallyprovidedtoillustratetheeffectivenessoftheproposedmethod.
简介:Thispaperinvestigatestheleader-followingconsensusproblemformulti-agentsystemswithevent-triggeredmechanismandcontrolpacketlosses.Basedonthelocalsynchronizationerror,event-triggeredmechanismsareproposedinordertoreducethenumberofcontrollerupdate.Thecontrolpacketmayloseduetounreliabilityofcommunicationchannel.Withtheassumptionthatoncethepacketlosshappensthecontrollerwillbesettozero,sufficientconsensuscriteriaformulti-agentsystemwithevent-triggeredmechanismandcontrolpacketlossesisobtained.Itisalsoshownthattheinterplayamongtheallowablepacketlossrate,event-triggeredmechanismandsamplingperiod.Anillustrativeexampleisgiventodemonstratetheeffectivenessofthetheoreticalresults.
简介:IntroductionRegionalseismicitytriggeredbybigearthquakesaswellasattershocksinsourcezonecouldbedetectedduetothehighseismicmonitoringcapabilitytoday(Anderson,etal,1994;Bodin,Gomberg,1994;Caskey,Wesnousky,1997;Deng,Sykes,1996;Hill,etal,1993;King,etal,19...
简介:TheKashmirearthquake2005(magnitudeMW7.6)triggeredthousandsofmassmove-mentsinnorthernPakistan.Thesemassmovementsweremainlyrockfalls,debrisfalls,rockslidesandrockavalanches.Themassmovementsvaryinsizefromafewhundredcubicmetersuptoabout100millioncubicmetersestimatedfortheHattianBalarockavalanche,thebiggestoneassociatedwiththisearthquake.Thismassmovement,whichmovedinsoutheasterndirection,createdtwonaturaldamsonthevalleybottomandblockedthewaterwaysoftheKarliandTungtributariesoftheJhelumRiver.Topographic,lithologicandstructuralinformationwereusedtoinvestigatetheHattianBalarockava-lanche.GeotechnicalandstructuralmapswerepreparedtounderstandrelationshipbetweengeologyandstructureofHattianBalarockavalanche.Thegeometryandfailuremodeofthisrockavalanchearecontrolledbysoutheastplungingsynclinalstructures,lithology,abeddingparallelslipsurfaceandapre-existingoldrockslide.ThestructuralmapshowsthatthemassmovementfailurewasduetoDannaandDandbehsynclinalstructuresplungingsoutheastonthehangingwallblockofthereacti-vatedMuzaffarabadfault.Theslipsurfaceofthemassmovementfollowedthebeddingplanesalongmudstone,claystoneandsandstonesurfaces.Themassmovementperfectlyfollowedthepre-existingsynclinalmorphologyoftheDannaandDandbehsynclines.