简介:Theseaicecoverdisplaysvariousdynamicalcharacteristicssuchasbreakup,rafting,andridgingunderexternalforces.Tomodeltheicedynamicprocessaccurately,theeffectivenumericalmodelingmethodshouldbeestablished.Inthispaper,amodifiedparticle-in-cell(PIC)methodforseaicedynamicsisdevelopedcouplingthefinitedifference(FD)methodandsmoothedparticlehydrodynamics(SPH).Inthismethod,theicecoverisfirstdiscretizedintoaseriesofLagrangianiceparticleswhichhavetheirownsizes,thicknesses,concentrationsandvelocities.TheicethicknessandconcentrationatEuleriangridpositionsareobtainedbyinterpolationwiththeGaussianfunctionfromtheirsurroundingiceparticles.ThemomentumoficecoverissolvedwithFDapproachtoobtaintheEuleriancellvelocity,whichisusedtoestimatetheiceparticlevelocitywiththeGaussianfunctionalso.Thethicknessandconcentrationoficeparticlesareadjustedwithparticlemassdensityandsmoothlength,whichareadjustedwiththeredistributionoficeparticles.WiththeabovemodifiedPICmethod,numericalsimulationsforicemotioninanidealizedrectangularbasinandtheicedynamicsintheBohaiSeaarecarriedout.ThesesimulationsshowthatthismodifiedPICmethodisapplicabletoseaicedynamicssimulation.
简介:Anewmethodofcodinganddecodinginthesystemofunderwaterimagetransmissionisintroduced,includingtherapiddigitalfrequencysynthesizerinmultiplefrequencyshiftkeying,imagedatagenerator,imagegrayscaledecoderwithintelligentfuzzyalgorithm,imagerestorationanddisplayonmicrocomputer.
简介:Inthispaper,severalmathmaticalmodelsforthepile-soilinteractionareoutlined.TheBoundaryElementMethodisoneoftheveryeffectivemethodsforthereasonablemodelsofelasticityandelastoplasticity.ThemajorofthispaperisconcernedwiththeBoundaryElementMethodforthepile-soilinteraction,includinggeneralmethodsandcalculatingformulationofstaticanddynamicanalysisofthepileandpilegroups.Someresultsofanalysisarealsogiven.
简介:Adesignmethodofreinforcedconcrete(R.C.)offshoreplatformswithnonlinearfiniteelementanalysisisproposed.Accordingtothemethod,acomputerprogramisdeveloped.Inthisprogramnonlinearconstitutiverelationshipsandstrengthcriteriaofconcreteandsteelbarsareincluded,andtheprogressivecrackingandcrushingoftheconcretearetakenintoaccount.Basedonthestressdistributionobtainedbythenonlinearfiniteelementanalysis,theamountofreinforcementinthecontrolsectionscanbecomputedandadjustedautomaticallybytheprogramtosatisfytherequirementofthedesign.Theamountofreinforcementrequiredinthecontrolsections,whichareobtainedwiththenonlinearfiniteelementanalysis,isagreeabletothatobtainedintheexperiment.ThisshowsthatthedesignmethodofR.C.offshoreplatformwiththenonlinearfiniteelementmethodproposedbytheauthorsisreliableforpracticaluse.
简介:AnewmethodofNeutronActivationAnalysis(NAA)forsedimentmovementstudyispresentedinthispaper.Throughanalyzingthenaturalsediment,theinformationaboutnaturaltracingagentshasbeenobtained,whichcanshowthedirectionofsedimentmovementandrelativedischargeofsedimenttransportation.Testresultsinsomeareas,suchasShantouHarbourandHangzhouBay,areingoodagreementwiththosefromnormalhydrologicmeasurementsandsomeresultsarenotobtainablewiththelatter.TheNAAiseconomical,practicalandreliable,andshouldbewidelyusedinengineeringpractice.
简介:Throughnumericalmodeling,akindofsimplifiedcalculatingmethodforstandingwavepressureonverticalfacebreakwaterhavebeenputforward.Notonlytheformulasproposedinthispaperaresimpleinformandveryeasyinuse,butalsotheypossesscontinuityonthefullrangeofstandingwave.Andmore,theprecisionrequiremenntsofcalculationcanbesatisfiedtoacertainextentinengineeringpractice.
简介:Factoranalysisisusedtostudytheorganiccompoundsthathavehighdegreeofcorrelationwithbiomassinalgalblooming.Basedonthiscorrelation,theyarenamedcharacteristicorganiccompounds.Thecompoundsfoundaresequalene(SQU),cedrol(CED),2,5-cyclohexadiene-1,4-dione,2,6-bis(1,1-dimthylethyl)(PBQ),phenol,2,6-bis(1,1-dimethylethy-4-methyl)(BHT),3-t-butyl-4-hydroxyanisole(BHA),1,2-benzenedicarboxylieacid,bis-(2-methylpropyl)ester(DIBP),dibutylphthalate(DNBP),respectively.Monitoringthevariationsofconcentrationofthesecharacteristicorganiccompoundsinseawatermayprovidescientificbasisforstudyingandforecastingredtides.
简介:Theprofilingmethodisthefirstmethodtoselectinmeasuringtheremotesensingreflectance.InthelightofthecharacteristicsofChina'scoastalwaters,wedevelopanewmethodtocompensatetheenvironment'seffectswiththedownwellingirradiance'sprofileandtoestimatetheunderwaterremote-sensingreflectancerrs(λ).Theresultindicatesthattherelativedeviationofrepetitiousrrs(λ)inonestationisaround10%.
简介:Identificationofmodalparametersofalinearstructurewithoutput-onlymeasurementshasreceivedmuchattentionoverthepastdecades.Inthepaper,theNaturalExcitationTechnique(NExT)isusedforacquisitionoftheimpulsesignalsfromthestructuralresponses.ThenEigensystemRealizationAlgorithm(ERA)isutilizedformodalidentification.(SAMFM),isdevelopedtodistinguishthetruemodesfromnoisemodes,andtoimprovetheprecisionoftheidentifiedmodalfrequenciesofthestructure.Anoffshoreplatformismodeledwiththefiniteelementmethod.Thetheoreticalmodalparametersareobtainedforacomparisonwiththeidentifiedvalues.ThedynamicresponsesoftheplatformunderrandomwaveloadingarecomputedforprovidingtheoutputsignalsusedforidentificationwithERA.Resultsofsimulationdemonstratethattheproposedmethodcandeterminethesystemmodalfrequencywithhighprecision.
简介:Thefinitevolumemethod(FVM)hasmanyadvantagesin2-Dshallowwaternumericalsimulation.Inthisstudy,thefinitevolumemethodisusedwithunstructuredtriangulargridstosimulatethetidalcurrents.TheRoeschemeisappliedinthecalculationoftheintercellnumericalflux,andtheMUSCLmethodisintroducedtoimproveitsaccuracy.Thetimeintegralisatwo-stepschemeofforecastandrevision.Fortheverificationofthepresentmethod,theStoker'sproblemiscalculatedandtheresultiscomparedwiththemathematicallyanalyticsolutions.Thecomparisonindicatesthatthemethodisfeasible.Aseaareaofaportisusedasanexampletotestthemethodestablishedhere.Theresultshowsthatthepresentcomputationalmethodissatisfactory,anditcouldbeappliedtotheengineeringfields.
简介:Inthispaper,thecalculatingchartsandformulaeaboutwavepressureonthebreastwallarederivedwithsevenparametersonthebasisofphysicalmodelstudy.Theverificationshowsthatthechartsagreewiththeexample,andareadoptedintheSpecificationsofFisheryHarboursBreakwaterbytheMinistryofAgricultures.
简介:-Measuringmulti-directionalwaveswiththewavegaugearrayisoneofthefundamentalandeasilyrealisedmethods.Inthispaper,thewavegaugearrayisdescribedandtheeffectsofthegaugespacing,thearrayorientations,etc.ofthethreearrayarrangements,i.e.,lineararray,T-typearrayandpentagonarray,ontheresolutionofthedirectionalspreadingofwaves,areinvestigatedexperimentally.Thisstudycanbeusedasareferenceintheexperimentalstudyandthefieldmeasurementofdirectionalwaves.
简介:OnthebasisoftherandomamplifiedpolymorphicDNA-fingerprinting(RAPD)method,10morphospeciesofscuticociliatesfrom7genera,including15clonesof13strains,Uronemarnarinum,Uronemacfmarinum,Parauronernavirginianum,P.longurn,Metanophryssimilis,M.sinensis,Paralembusdigitiformis,Mesanophryscarcini,ParanophrysmagnaandCohnilembusverminuswereanalysedusing8oligonucleotideprimers.Thegeneticsimilarityamongtheclonesofthesamestrainmeasuredbyaband-sharingindexis0.97~0.98,while0.40~0.52amongstrains.Thisvaluemeasuredis0.39~0.46amongcongenersofthesamegenus,whereas0.16~0.47betweendifferentgenera.Adistancetreewasconstructedbasedon8-primeranalysis,inwhichthescuticociliatesinvestigatedwereseparatedintotwoclusters:oneconsistsof2genera,UronemaandParauronema,andtheotherwascomposedoffive,Metanophrys,Mesanophrys,Paranophrys,ParalembusandCohnilembus.ItisdemonstratedalsothatthemorphospeciesParauronemavirginianummaybeaspecies-complex,i.e.,itcontainsdifferentgenospecies.