简介：Theanalysisofthedataofmodeltestsoftwolargedeepwharvesandmonographicexperimentalstudiesshowthattwoaspectsaretobeimprovedsoastopredictthewaveupliftforcesonthebottomofacircularcylinder.Thefirstaspectistheupliftpressuredistributiononthebottom,andthesecondisthecorrectdeterminationofthephaseformaximumhorizontalwaveforces.Thesecondproblemhasbeensolved.Synthesizingtheresultsoftheoreticalanalysisandexperiments,wesuggestadiagramforthedeterminationofthephasewhenthemaximumhorizontalwaveforceappears.Onthebasis-efthediagramthesimultaneouswaveupliftforcescanbeobtainedforthestructuralstabilityanalysis.

简介：ThebiomassesoffishesatthebottomlayeroftheBohaiSeaareextimatedbyanalysingthedataonsamples(447hauls,morethan0.2millioninnumberor20tinweightoffishes)collectedmonthlybyourinstitutefromApril,1982toMay,1983byapairofbottomtrawlsthroughtheBohaiSea.Theexploitationproblemsarealsodiscussedinthispaper.

简介：ThispaperpresentsabriefreviewoftheresultsontheinteractionbetweenwavesandmuddybottomobtainedduringthelastdecadeincludingtheresultsobtainedbytheauthorattheCoastalEngineeringLaboratoryofTianjinUniversity.

简介：NanxiaohongandNangangmainsouthchannelarechosenasthetypicalfloodandebbchannels.HydrodynamicsanalysisbasedonfieldhydrologicalandsedimentdataisconductedwithGao-Collinsmodeltoanalysesedimenttransporttrends.Also,thegrainsizedistributionanalysisofthebottomsedimentsampledinSep.2001isusedasthebaseoftheanalysis.TheresultshowsthatthesedimentinNanxiaohongisfromtherivemoutharea.Thesedimenttransportsupwardswiththefloodflowwhichisstrongerthantheebbflow,i.e.,inthedirectionofSE-WN.Thesedimentinmainsouthchannelcomesfromupward.Theytransportdownwardswiththeebbflow,whichisstrongerthanthefloodflow,i.e.,inthedirectionofWN-SE.Thedirections,sourcesandmechanismofsedimenttransportareidentifiedaccordingtocomprehensiveanalysesoftheobserveddataonhydrodynamicsandsediment.

简介：AstudyoftsunamieventsintheEast(Japan)SeausingcontinuousGalerkinfiniteelementmodel,aimingatreproducingtsunamiwavesgeneratedbyunderwaterearthquakesin1983and1993respectivelyhasbeenperformedfocusingonthegeographicextentofatopographicfeatureintheEast(Japan)Sea.Numericalmodelscanbethepropertoolstostudythecombinedeffectsofrealistictopography.Subsequently,usingtheFEMbasedtwo-dimensionalmodelwehavesimulatedthesmoothedandflattenedtopographiceffectsbyremovalofYamatoRiseandseamountsforthecasesoftthe1983Centralregionearthquaketsunamiandthe1993southwesternHokkaidoearthquaketsunami.TheresultshaveshownthattherewillbehighertsunamisalongtheeasterncoastsofKoreaingeneralexceptsomeareas,likeSokchowithremovaloftopographichighs,thusprovidingcomplicatedbottomtopographyoftheEast(Japan)Seaaseffectivetsunamienergyscattering.

简介：Asoneofthekeysafetyproblems,themotionperformanceandtouchingseabottomofaFPSOarepaidmuchattentionbytheoceanoilcompanieswhentheFPSOisexposedtosurvivalstormsintheshallow-waterworkingareas.Inthispaper,timedomainnumericalsimulationsarecarriedoutona160kDWTFPSOwithaYokemootingsystemmooredintheBZ25-1oilfieldwithawaterdepthof16.7m.Theresultsarecomparedwiththoseofthecorrespondingmodeltests.Goodagreementshowsthatthetime-domainsimulationscanbeusedtopredicttheperformanceoftheFPSOinshallow-waterreasonably.ItisfoundthatthetouchofseabedbyafullyloadedFPSOoccurredfewtimesundersurvivalstormconditions.Therefore,theFPSOshouldbelessloadedthanthatinthefullyloadedconditionunderthesurvivalstorms.

简介：TheliftforcesonhorizontalcylindernearbottomisexperimentallyinvestigatdeatReynolds(Re)intherangelf2500~10000andKeulegan~CARPENTERNUMBERS(kc)intheintervalof5~20,andgapratio(e/D)isfrom(a0)areanalyzdebyusingtheFourieranalysesmethod.ItisfoundthatfoundthatbothCl&a0arethefunctionslftheKcnumber.

简介：Amethodofobtainingbottombackscatteringstrengthbyemployinganomnidirectionalprojectorandomnidirectionalhydrophoneisproposed.Thebackscatteringstrengthisextractedfrommonostaticbackscatteringdata.ThemethodwasadoptedinanexperimentconductedintheSouthYellowSeaofChina.Theseafloorsurfacewasrelativelysmoothandcoveredbyasmallquantityofshellfragments,asobservedthroughadigitalcamerasystem.Samplingdatashowedthatthemaincomponentofthesedimentatthisexperimentalsitewasfinesand.Inthispaper,wedetailthecalculationmethod.Preliminaryresultsofbackscatteringstrengthasafunctionofgrazingangle(20°–70°)inthefrequencyrangeof6–24kHzarepresented.Themeasuredbackscatteringstrengthincreasedwiththegrazingangleandchangedmorerapidlyatlargegrazingangles(60°–70°).Acomparisonofthedataatdifferentfrequenciesrevealsthatthemeasuredbackscatteringstrengthsubstantiallyriseswiththeincreaseofacousticfrequency.AfittingcurveofLambert’slawagainstthemeasureddatashowsthatthebackscatteringstrengthdeviatesfromLambert’slawatlargegrazingangles.

简介：AnanalyticalmethodisdevelopedforthestudyofthewavedefendingeffectsoftheV-typebottom-mountedbreakwater.Thebreakwaterisassumedtoberigid,thin,impermeableandverticallylocatedinwaterofconstantdepth.Thefluiddomainisdividedintothreesub-regionsbyanimaginaryinterface.Thevelocitypotentialineachregionisexpandedbyeigenfunctions.Bysatisfyingthecorrespondingboundaryconditionsandnatchingconditionsinandbetweensub-regions,asetoflinearalgebraicequationscanbeobtainedtodeterminetheunknowncoefficientsfortheeigenfunctionexpansionsforeachsub-region.Theaccuracyofthepresentmodelisverifiedbyacomparisonwithexistingresultsforthecaseofanisolatedbreakwater.Numericalresults,intheformofcontourmapsoftherelativewaveamplitudearoundthebreakwater,arepresentedforarangeofwaveandbreakwaterparameters.TheresultsshowthattheV-typebottommountedbreakwaterisgenerallyeffectiveindefendingagainstwaves.Ingeneral,thewaveheightintheprotectedareaisabout20～50percentoftheincidentwaveheight.

简介：PCR-DGGEapproachwasusedtoanalyzebacterialdiversityinthebottomsectionofsevenarcticseaicesamplescolletedfromtheCanadaBasin.Thirty-two16SrDNAsequenceswereobtainedfromprominentDGGEbands.Theclosestrelativesofthesesequencesarefoundtobethoseofcultivatedorunculturedbacteriafromantarcticorarcticseaice.Phylogeneticanalysisclusteredthesesequencesorphylotypeswithinα-proteobacteria,γ-proteobacteriaandCFB(cytophaga-flexibacter-bacteroides)group.Sequencesbelongingtoγ-proteobacteriaweredominantandmembersoftheCFBgroupwerehighlyabundant.ItwassuggestedthattheCFBgroupwastherepresentativeofthebottomsectionofseaicesamples.

简介：Astructurefunctionapproachisappliedtoestimatetheturbulentkineticenergy(TKE)dissipationrateinthebottomboundarylayerofthePearlRiverEstuary(PRE).SimultaneousmeasurementswithanacousticDopplervelocimeter(ADV)suppliedindependentdatafortheverificationofthestructurefunctionmethod.Theresultsshowthat,1)thestructurefunctionapproachisreliableandsuccessfullyappliedmethodtoestimatetheTKEdissipationrate.Theobserveddissipationratesrangebetween8.3×104W/kgand4.9×106W/kginYM01andbetween3.4×104W/kgand4.8×107W/kginYM03,respectively,whileexhibitingastrongquarter-diurnalvariation.2)Thebalancebetweentheshearproductionandviscousdissipationisbetterachievedinthestraightriver.Thisfirst-orderbalanceissignificantlybrokenintheestuarybynon-shearproduction/dissipationduetowave-inducedfluctuations.

简介：床负担的数量是在沉积运输研究的一个重要物理参数。在床负担测量瞄准困难，这篇论文开发一个装底部的监视器由采用沉积坑方法并且解决象称和desilting的如此的关键问题测量床负担运输率，它能完成长期，平凡的河，河口和海岸的床负担运输率的全天候、即时的telemeasurement。实验室和这个监视器是合理的在的领域测试表演设计，在性质稳定、方便在里面测量，和它能被用来在实际工程监视床负担运输率。

简介：

简介：象多重信号分类和经由旋转不变性技术(精神)的信号参数的评价那样的高分辨率的途径当前在multibeam回响声音(MBES)广泛地被采用为海地板深测术的系统，在一个一致的线数组也被要求的地方。然而，由于要求以系统范围/决定和安装空间限制，一个MBES系统通常与特殊形状采用一个收到的数组，它意味着高分辨率的算法不能直接被使用。另外，当在MBES系统使用高分辨率的算法时，短期的静止回响信号使估计高分辨率的途径要求的协变性矩阵困难，它进一步增加复杂性。有多重角度的subarraybeamforming的精神被采用以signal-to-noise比率，快照的数字，和计算努力减少要求。模拟证明新处理方法能提供更好好结构的分辨率。然后，一个highresolution底部察觉(HRBD)算法被把新处理方法与虚拟数组转变相结合开发。到一个U字形的数组的HRBD算法的应用程序是也讨论。计算机模拟和试验性的数据处理结果验证建议算法的有效性。

简介：柱体的垂直摆动与不同直径比率Dd/Dc和厚度比率td/Dc被3D学习(三维)在这份报纸开发的数字模型，并且通过2D与结果相比获得了(二维)数字模型。高顺序的迎风的计划被使用稳定计算，并且集中被多格子方法加速。2D和3D模拟结果之间的差别的质、量的分析与一个依附底部的磁盘在流动地特征和垂直地震荡的柱体的水动力学系数上揭示3D效果。液体领域上的3D效果主要在三个流旋涡的模式的意义被反映：x相对在2D模拟产生的旋涡在锋利的边附近在流动地上有更大的效果。在沿着轴的取向的片，沿着光线的轴的y比沿着环绕的方向的x，更在速度上显示光线的效果在磁盘的锋利的边附近比环绕的效果读了。旋转相互作用在水平飞机的液体的z在举运动期间是不足道的。基于2D和3D模拟结果，分开增加的集体系数和抑制比率的增加的政体的转弯的点被识别。直径比率Dd/Dc和厚度比率td/Dc详细被讨论。

简介：Ascientifichypothesisisproposedandpreliminarilyverifiedinthispaper:underthedrivingofseepageflows,theremightbeaverticalmigrationoffine-grainedsoilparticlesfrominteriortosurfaceofseabed,whichisdefinedas‘sub-bottomsedimentpumpaction’inthispaper.FieldexperimentswereperformedtwiceontheintertidalflatoftheYellowRiverdeltatostudythisprocessviabothtrappingthepumpedmaterialsandrecordingtheporepressuresinthesubstrate.Experimentalresultsarequiteinterestingaswedidobserveyellowslurrywhichismainlycomposedoffine-grainedsoilparticlesappearingontheseabedsurface;seepagegradientswerealsodetectedintheintertidalflat,undertheactionoftidesandsmallwindwaves.Preliminaryconclusionsarethat‘sedimentpump’occurswhenseepageforceexceedsacertainthreshold:firstly,itisbigenoughtodisconnectthesoilparticlesfromthesoilskeleton;secondly,thedegreeofseabedfluidizationorbioturbationisbigenoughtoprovidepreferredpathsforthedetachedmaterialstomigrateupwards.Thentheywouldbefirstlypumpedfrominteriortothesurfaceofseabedandtheneasilyre-suspendedintooverlyingwatercolumn.Influentialfactorsof‘sedimentpump’aredeterminedashydrodynamics(waveenergy),degreeofconsolidation,indexofbioturbation(permeability)andcontentoffine-grainedmaterials(sedimentaryage).Thisnewperspectiveof‘sedimentpump’mayprovidesomeimplicationsforthemechanisminterpretationofseveraluncleargeologicalphenomenaintheYellowRiverdeltaarea.