简介:Inthispaper,acomparisonamongthesevenlargemeandersoftheKuroshioismadeinordertoprobeintotheirsimilarityanddifferences.Themajorresultsaredescribedasfollows.1.Althoughthethreephasesforthesevenlargemeanderssuchastheirformations,maturity,aswellasdeclineareverysimilartooneanother,eachmeanderhasitsowntrivialdifferenceindetail.2.Thepathsofthefirstsixlargemeandersinthematurephasemaybeclassifiedintotentypes:U1,V1,U2,V2,U1’,V1’,U2’,V2’,φandW.3.Thesevenlargemeandersmaybegroupedintotwopatterns,i.e.,patternⅠandpatternⅡ.PatternⅠincludesthefirstandthefourthlargemeanders,andpatternⅡincludestherestoftheabovemeanders.4.FourstandardsforidentifyingthelargemeandersoftheKuroshioareputforward.
简介:Thelarge-diametercylinderstructure,whichismadeoflargesuccessivebottomlesscylindersplacedonfoundationbedorpartlydrivenintosoil,isarecentlydevelopedretainingstructureinChina.Itcanbeusedinport,coastalandoff-shoreworks.Themethodforstabilityanalysisofthelarge-diametercylinderstructure,especiallyforstabilityanalysisoftheembeddedlarge-diametercylinderstructure,isanimportantissue.Inthispaper,anideaispresentedthatis,em-beddedlarge-diametercylinderquayscanbedividedintotwotypes,i.e.thegravitywalltypeandthecylinderpilewalltype.Amethodforstabilityanalysisofthelarge-diametercylinderquayofthecylinderpilewalltypeisdevelopedandamethodforstabilityanalysisofthelarge-diametercylinderquayofthegravitywalltypeisalsoproposed.Theeffectofsig-nificantparametersonthestabilityofthelarge-dianetercylinderquayofthecylinderpilewalltypeisinvestigatedthroughnumericalcalculation.
简介:Theeffectsofwaterdepthonthewave-inducedverticalbendingmomentandshearingforceonaverylargeFPSOarestudiedbyexperimentsandcomputationsforregularandirregularwaves.TherestrictedwaterdepthcompositeGreenfunctionisemployedtodevelopaprogramforthecomputationofthehydrodynamiccoefficientsoftheverylargeFPSOatshallowwater.Athree-segmentmodelwith1:100scaleistestedintheStateKeyLaboratoryofOceanEngineeringatShanghaiJiaoTongUniversityfortheverificationofthenumericalmethod.Theexperimentalandcomputationalresultsshowthatthewaterdepthhasasubstantialeffectonwave-inducedloads.Thewave-inducedverticalloadsincreasewiththedecreaseofwaterdepthforshallowwater.Especially,forultra-shallowwatertheseloadsincreaseveryevidentlywiththedecreaseofwaterdepth.Thelong-termpredictionvaluesofwave-inducedverticalloadsincreasewiththedecreaseoftheratioofwaterdepthtodraught.Thelong-termpredictionvaluesofwave-inducedverticalloadsareabout8%largerthanthosefordeepwaterwhentheratioofwaterdepthtodraughtis3.0.However,waterdepthhardlyaffectsthelongtermpredictionvaluesofwave-inducedloadswhentheratioofwaterdepthtodraughtislargerthan5.0.
简介:Lethaltemperaturetolerancewasdeterminedforabout8cm,age0Pseudosciaenacroceausingbothslowheatingandrapidtransferprotocol.Theacclimatizationtemperaturewas28℃withsummerseason,lethaltemperature(LT50value)ofslowheatingprotocol(CTMax)was35.0℃,andtheupperandlowerincipientlethaltemperaturesofrapidtransferprotocolwere34.2℃and17.5℃respectively.
简介:AmethodofcoupledBEM-FEManalysisfortheelasticspatialstructuresystemispresented.Itcanbeappliedtothecalculationofthestressanddeformationofthelarge-diamatercylinderstructuresystemanditissuitableforsymmetricornon-symmetricstructuresunderthedistributedorconcentratedload.NumericalexamplesshowthattheproposedmethodandcomputerprogramBEFEMarequiteefficientintheanalysisofthelarge-diametercylinderstructureproblemsinoceanengineering.
简介:AnalysisofArgofloattrajectoriesat1000mandtemperatureat950mintheNorthAtlanticbetweenNovember2003andJanuary2005demonstratestheexistenceoftwodifferentcirculationmodeswithfasttransitionbetweenthem.Eachmodehasapairofcyclonic-anticyclonicgyres.Thedifferenceisthelocationofthecyclonicgyre.Thecyclonicgyrestretchesfromsoutheasttonorthwestinthefirstmodeandfromthesouthwesttothenortheastinthesecondmode.TheobservedmodesstronglyaffecttheheatandsalttransportintheNorthAtlantic.Inparticular,thesecondmodeslowsdownthewestwardtransportofthewarmandsalinewaterfromtheMediterraneanSea.
简介:Thispaperdiscussesnumericalresultsfromthree-dimensionallargeeddysimulationsofanoscillatingcylinderunderprescribedmovementsinuniformflow.Sixcases,namelypurein-line,purecross-flowandtwogroupsof'FigureofEight'oscillationpatternsareunderinvestigationatReynoldsnumberRe=24000.The'FigureofEight'patternineachgroupiswithidenticalshapebutoppositeorbitaldirections.Thenumericalresultsonhydrodynamicforces,higherorderforcecomponents,andvortexsheddingmodesareextensivelystudiedandcomparedwiththemeasuredexperimentaldata.Itisfoundthatthefluidforceinphasewiththevelocity,whichrepresentstheenergytransferbetweenthefluidandthecylinder,hasoppositesignanddifferentmagnitudeduetotheoppositeorbitaldirection.Higherorderforcecomponentsincross-flowdirectionarefoundtooccuratoddnumbertimesoftheoscillatingfrequency,whileevennumbersdominatethehigherorderforcecomponentsinin-linedirection.The2Cand2Tvortexsheddingmodesarewellreproducedduetotheoppositeorbitaldirectioneffect.Comparisonsbetweennumericalandexperimentalresultsindicatethatthepresentnumericalmodelcouldbearationaltoolfortheidentificationofhydrodynamiccoefficientswhicharenormallyappliedinempiricalmodelstopredictthevortex-inducedvibrationsofslendermarinestructures.
简介:Weinvestigatedtheeffectofthereplacementofdietaryfishoilwithvegetableoilsonthegrowthandfleshqualityoflargeyellowcroaker(Larmichthyscrocea).Thebasaldiet(FO)wasformulatedtocontain66.5%fishmealand6.4%menhadenfishoil;whereastheother3experimentaldietswereformulatedbyreplacingthefishoilwith50%soybeanoil(SO50),100%soybeanoil(SO100)and100%palmoil(PO100),respectively.The4dietswererandomlyassignedto4floatingseacages(3.0m×3.0m×3.0m),andeachwasstockedwith250fishindividualswithaninitialaverageweightof245.29g±7.45g.Thefishwerefedtoapparentsatiationtwiceadayat5:00and17:00,respectively,for12weeks.ExperimentalanalysisshowedthatthespecificgrowthrateoffishfedSO50orPO100weresignificantlyhigherthanthatoffishfedFOorSO100(P<0.05),andcrudelipidcontentsofventralmuscleandvisceraweresignificantlylowerinfishfedFOthaninthosefedtheother3diets(P<0.05).Nosignificantdifferencesinconditionfactor,viscerosomaticindex,hepatosomaticindex,guttedyieldandcolorimetricvaluesoffishamongthedietarytreatmentswereobserved(P>0.05).ComparedtoFOdiet,SO50,SO100andPO100dietsledtosubstantialdecreasesintheliquidlossandwaterlossfromfreshfillets(1d,4℃)(P<0.05).Similarly,thiobarbituricacidreactivesubstance(TBARS)valuesoffilletsunderdifferentstorageconditions(1d,4℃;7d,4℃;4weeks,-20℃;8weeks,-20℃)decreasedsignificantlyafterpartialorcompletereplacementoffishoilwithvegetableoils.Thesefindingsindicatedthatthegrowthperformanceandselectedfleshqualityproperties(liquidholdingcapacityandTBARSvalue)oflargeyellowcroakerweresubstantiallyimprovedbyreplacingdietaryfishoilwithvegetableoils.
简介:Toexploretheeffectofenvironmentconditionsonimmuneactivityoffish,eightimmune-associatedgenesresponsibleforinnateimmunitywereselectedfromtheGenBank,i.e.Pgrn-a,Ifit2,P-hepcidin,Lect2,β2m,Irf1,Il25andHsp96,andthemRNAexpressionsoftheminthekidneyofculturedlargeyellowcroakerLarimichthyscroceaindifferentseaareasintheEastChinaSeawereexaminedwithqPCRtechniques.Inthecontrastsofimmune-associatedgeneexpressionbetweenareasandpopulations,significantdifferenceswerefound,expressionlevelsoftheseimmune-associatedgeneswerelowerintheclearwaterareathaninthepoorwaterquantityarea,andlowerinMaythaninOctober.MYwasmoresensitivetoenvironmentalfactorsthanDQ,whichwascoincidentwiththewaterqualityintheculturingareas.Differentialanalysesoftheexpressionlevelsoftheseimmune-associatedgenesshowedthatsignificantup-regulationcouldbetriggeredbypoorenvironmentalfactors.Theexpressionpatternsindicatedthattheexpressionlevelsofthesegenesweresensitivetoecologicalchanges,therebytheimmune-associatedgenes,especiallyPgrn-a,Ifit2,β2m,Il25andHsp96,mightserveasimmediateandsensitiveindicatorsofpopulationimmunologicvigorandecosystemhealth.Buttheexpressionofimmunity-associatedgenesatthelevelofgenetranscriptionishighlyinfluencedbymultiplefactors,andtheexactcausesorinfluencingfactorsoftheup-regulationordown-regulationofthesegenesstillneedfurtherthoroughinvestigation.
简介:MicrostructureandsubmicrostructureofLeydigcellandSertolicellinthetestisofgonadalprecocityandimmaturationinculturedlargeyellowcroaker,Pseudosciaenacrocea,arestudiedusinghistologyandelectronmicroscopictechnique.Theresultsindicatethatthefinestructureofthetwokindsofcellsindifferentdevelopmentstagespresentsanobviousdifference.ThesmoothendoplasmicreticularandtubularmitochondriaofLeydigcellandSertolicellarewelldevelopedinthetestisofgonadalprecocity,butpoorlydevelopedinthetestisofimmaturation.WesuggestthatthereasonforgonadalprecocityinthelargeyellowcroakermayberelatedtotheearlierdevelopmentandmaturationofLeydigcellandSertolicell.