简介：Characteristicslipandcharacteristicearthquakemodelshavebeenproposedforseveraldecades.Suchmodelshavebeensupportedrecentlybyhigh-resolutionoffsetmeasurements.Thesemodelssuggestthatslipalongafaultrecursviasimilarlysized,largeearthquakes.Theinter-eventstrainaccumulationrate(ratioofearthquakeslipandprecedinginterseismictimeperiod)isusedheretotestthecharacteristicearthquakemodelbylinkingtheslipandtimingofpastearthquakesontheHaiyuanFault.Weaddresshowtheinter-eventstrainaccumulationratevariesovermultipleseismiccyclesbycombiningpaleoearthquakestudieswithhigh-resolutionairbornelightdetectionandranging(LiDAR)datatodocumentthetimingandsizeofpaleoearthquakedisplacementsalongthewesternandmiddlesegmentsoftheHaiyuanFault.Ourobservationsencompass5earthquakecycles.WefindsignificantvariationsovertimeandspacealongtheHaiyuanFault.WeobservethatonthemiddlesegmentoftheHaiyuanFaulttheratesslowdownorincreaseasananticorrelatedfunctionoftheratesofprecedingearthquakes.Here,weproposethattheinter-eventstrainaccumulationratesonthemiddlesegmentoftheHaiyuanFaultareoscillatingbothspatiallyandtemporally.However,alongthewesternsegment,theinter-eventstrainaccumulationrateisbothspatiallyandtemporallysteady,whichisinagreementwithquasi-periodicandslip-predictablemodels.Finally,weproposethatdifferentfaultsegmentswithinasinglefaultzonemaybehaveaccordingtodifferentearthquakemodels.

简介：1.ObjectivesSouthernQinghai-northemTibetpermafrostregionisaplacehavingthemostwidespreadandmostdevelopedpermafrostinChinawithgoodmineralizationconditionsandprospectingpotentialsforgashydrate(ZhuYHetal.,2011).In2011,ChinaGeologicalSurveyinitiatedaspecialnationalprogramentitled"Gashydrateresourceexplorationandtrialmining",whichsignaledapreludetoacomprehensivegashydratesurveyinsouthernQinghai-northernTibetpermafrostregion.Sofar,appreciableprogresshasbeenmadeinthegeological,geophysical,geochemicalanddrillingsurveyacrossanumberofkeyblocks.Thispaperisintendedtoexaminethefundamentalconditionsforgashydratemineralizationbasedonpreviousfindings,delineatefavorablezonesforgashydratemineralization,andtomakecontributionstotheonshoregashydrateresourceexplorationinChina.

简介：Pointabsorberwaveenergydevicewithmultipledegreesoffreedom(DOF)isassumedtohaveabetterabsorptionabilityofmechanicalenergyfromoceanwaves.Inthispaper,acoaxialsymmetricarticulatedpointabsorberwaveenergyconverterwithtwodegreesoffreedomispresented.Themechanicalequationsoftheoscillationbuoywithpowertake-offmechanism(PTO)inregularwavesareestablished.Thethree-dimensionalnumericalwavetankisbuiltinconsiderationofthebuoymotionbasedupontheCFDmethod.Theappropriatesimulationelementsareselectedforthebuoyandwaveparameters.ThefeasibilityoftheCFDmethodisverifiedthroughthecontrastbetweenthenumericalsimulationresultsoftypicalwaveconditionsandtestresults.Insuchcase,thebuoywithsingleDOFofheave,pitchandtheircouplingmotionconsideringfree(noPTOdamping)anddampedoscillationsinregularwavesaresimulatedbyusingtheverifiedCFDmethodrespectively.Thehydrodynamicandwaveenergyconversioncharacteristicswithtypicalwaveconditionsareanalyzed.Thenumericalresultsshowthattheheaveandpitchcanaffecteachotherinthebuoycouplingmotion,hydrodynamicloads,waveenergyabsorptionandflowfield.ThetotalcapturewidthratiowithtwocoupledDOFmotionishigherthanthatwithasingleDOFmotion.ThewaveenergyconversionofacertainDOFmotionmaybehigherthanthatofthesinglecertainDOFmotioneventhoughthewaveisattheresonanceperiod.Whenthewaveperiodsarehighenough,theinteractionbetweenthecoupledDOFmotionscanbeneglected.

简介：Thepenetrationdepthoftorpedoanchorintwo-layeredsoilbedwasexperimentallyinvestigated.Atotalof177experimentaldatawereobtainedinlaboratorybyvaryingtheundrainedshearstrengthofthetwo-layeredsoilandthethicknessofthetopsoillayer.Thegeometricparametersoftheanchorandthesoilproperties(theliquidlimit,plasticlimit,specificgravity,undrainedshearstrength,density,andwatercontent)weremeasured.Basedontheenergyanalysisandpresenttestdata,anempiricalformulatopredictthepenetrationdepthoftorpedoanchorintwo-layeredsoilbedwasproposed.Theproposedformulawasextensivelyvalidatedbylaboratoryandfielddataofpreviousresearchers.Theresultswereingoodagreementwiththoseobtainedfortwo-layeredandsingle-layeredsoilbed.Finally,asensitivityanalysisontheparametersintheformulawasperformed.

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简介：Tworedalgae,RhodymeniaantarcticaandIridaeacordata(Rhodophyta),wereemployedtoinvestigatethepollutionsituationalongFildesPeninsulacoastline,KingGeorgeIsland.Tensitesfromeastandwestcoastlineswereinvestigated,andtheconcentrationsofCu,Pb,Zn,Cd,Cr,AsandHgweredetermined.Themetalpollutionindex(MPI)wasusedtoevaluatetheoverallpollutionlevelrepresentedbytheinvestigatedsitesandforinterregionalcomparisons.Thetwoalgaeexhibiteddifferentpreferencetospecialtracemetal.R.antarcticacouldaccumulatemoreCd(0.63mgkg^-1)andHg(0.026mgkg^-1)thanI.cordata(Cd0.34mgkg^-1,Hg0.019mgkg^-1).I.cordatacouldaccumulatemoreAs(15.53mgkg^-1)thanR.antarctica(10.11mgkg^-1).TherewasnosignificantdifferenceinaccumulatingCu,Pb,ZnandCrbetweenthetwoalgae.R.antarcticacouldbeusedtomonitorCdandHg.I.cordatawouldbemoreappropriateformonitoringAs.MPImonitoredbythetwoalgaewerefrom1.02to2.26(R.antarctica),and1.03to1.25(I.cordata),respectively.PollutionsituationofFildesPeninsulawasbecomingserious,especiallyoftheeastcoastline.TheobjectiveofthisresearchwastogatherthebaselineinformationfortracemetalsinvestigationinAntarctic.

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