学科分类
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13 个结果
  • 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.

  • 标签: MATURE formations MATURITY identifying classified similarity
  • 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.

  • 标签: large-diameter CYLINDER quay CYLINDER PILE WALL
  • 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.

  • 标签: FPSO 水深限制 波动负荷 海洋工程 数学模型
  • 简介:Lethaltemperaturetolerancewasdeterminedforabout8cm,age0Pseudosciaenacroceausingbothslowheatingandrapidtransferprotocol.Theacclimatizationtemperaturewas28℃withsummerseason,lethaltemperature(LT50value)ofslowheatingprotocol(CTMax)was35.0℃,andtheupperandlowerincipientlethaltemperaturesofrapidtransferprotocolwere34.2℃and17.5℃respectively.

  • 标签: 大黄花鱼 温度公差 生长环境 临界热量 海洋水温
  • 简介:在这篇论文大,偏转Euler横梁的动态问题reinvestigated。颤动控制方程被导出基于多身体系统方法。为解决结果的Anumerical过程微分代数学的方程根据与Newton-Raphson反复的方法相结合的Newmark直接集成方法被介绍。潜水艇横梁在对流传热的坐标系统被当作小变丑,它能极大地简化变丑描述。潜水艇横梁的僵硬运动通过对流传热的坐标系统的运动被考虑。数字例子被执行,在结果显示出建议方法的有效性的地方。

  • 标签: 船体 柔性梁 大变形动力响应分析 多柔体系统法 非线性
  • 简介:AmethodofcoupledBEM-FEManalysisfortheelasticspatialstructuresystemispresented.Itcanbeappliedtothecalculationofthestressanddeformationofthelarge-diamatercylinderstructuresystemanditissuitableforsymmetricornon-symmetricstructuresunderthedistributedorconcentratedload.NumericalexamplesshowthattheproposedmethodandcomputerprogramBEFEMarequiteefficientintheanalysisofthelarge-diametercylinderstructureproblemsinoceanengineering.

  • 标签: COUPLED BEM-FEM large-diameter CYLINDER structure finite
  • 简介:AnalysisofArgofloattrajectoriesat1000mandtemperatureat950mintheNorthAtlanticbetweenNovember2003andJanuary2005demonstratestheexistenceoftwodifferentcirculationmodeswithfasttransitionbetweenthem.Eachmodehasapairofcyclonic-anticyclonicgyres.Thedifferenceisthelocationofthecyclonicgyre.Thecyclonicgyrestretchesfromsoutheasttonorthwestinthefirstmodeandfromthesouthwesttothenortheastinthesecondmode.TheobservedmodesstronglyaffecttheheatandsalttransportintheNorthAtlantic.Inparticular,thesecondmodeslowsdownthewestwardtransportofthewarmandsalinewaterfromtheMediterraneanSea.

  • 标签: 大西洋 中尺度环流 生物特征 光谱分析
  • 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.

  • 标签: 大涡模拟 涡激振动 相互作用 横流 水动力系数 圆柱
  • 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.

  • 标签: 特定生长率 大黄鱼 肉质特性 植物油 鱼油 膳食
  • 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.

  • 标签: immune-associated gene expression profile large yellow
  • 简介:MicrostructureandsubmicrostructureofLeydigcellandSertolicellinthetestisofgonadalprecocityandimmaturationinculturedlargeyellowcroaker,Pseudosciaenacrocea,arestudiedusinghistologyandelectronmicroscopictechnique.Theresultsindicatethatthefinestructureofthetwokindsofcellsindifferentdevelopmentstagespresentsanobviousdifference.ThesmoothendoplasmicreticularandtubularmitochondriaofLeydigcellandSertolicellarewelldevelopedinthetestisofgonadalprecocity,butpoorlydevelopedinthetestisofimmaturation.WesuggestthatthereasonforgonadalprecocityinthelargeyellowcroakermayberelatedtotheearlierdevelopmentandmaturationofLeydigcellandSertolicell.

  • 标签: Pseudosciaena crocea testis LEYDIG cell SERTOLI