简介：Number1GlobalSeaLevelChangeandThermalContributionZUOJuncheng,ZHANGJianli,DULing,LIPeiliang,andLILei

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

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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：Usingstatisticallydownscaledatmosphericforcing,weperformedanumericalinvestigationtoevaluatefutureclimate’simpactonstormsurgesalongtheGulfofMexicoandU.S.eastcoast.Thefocusisontheimpactofclimaticchangesinwindpatternandsurfacepressurewhileneglectingsealevelriseandotherfactors.Weadaptedtheregionaloceanmodelsystem(ROMS)tothestudyregionwithameshgridsizeof7-10kminhorizontaland18verticallayers.Themodelwasvalidatedbyahindcastofthecoastalsealevelsinthewinterof2008.Model’srobustnesswasconfirmedbythegoodagreementbetweenmodel-simulatedandobservedsealevelsat37tidalgages.Two10-yearforecasts,onefortheIPCCPre-Industry(PI)andtheotherfortheA1FIscenario,wereconducted.Thedifferencesinmodel-simulatedsurgeheightsunderthetwoclimatescenarioswereanalyzed.Weidentifiedthreetypesofresponsesinextremesurgeheightstofutureclimate:acleardecreaseinMiddleAtlanticBight,anincreaseinthewesternGulfofMexico,andnon-significantresponsefortheremainingarea.Suchspatialpatternisalsoconsistentwithpreviousprojectionsofseasurfacewindsandoceanwaveheights.

简介：AdetailedsurveyofthereefsintheNanshaIslands’seathatareofstrategicimportanceisconducivetotheirfuturedevelopment.Inthisstudy,atotalof50Landsat8operationallandimager(OLI)imageswereusedtoanalyzethegeologicalfeaturesandspectralcharacteristicsoftheNanshareefs.Theexposedislands/sandbanks,reefflatsandsub-tidalreefswereidentifiedwiththenear-infraredband,theredandgreenbands,andtheblueband,respectively.BasedontherelationshipsamongvariouscharacteristicsandbandsillustratedintheOLIimages,themaximumbetween-clustervariancethresholdalgorithm(OTSUmethod)andthemathematicalmorphologywereemployedtoextractcharacteristicparametersofthespatialgeometryofthereefsfromtoptobottom,whichweresubsequentlyoperatedbyaseriesofpost-processingmethodssuchasvectorization,simplificationandtopologicalanalysis.Amongthe132standalonereefsand16atollsthatareidentifiedinthestudy,fourreefshaveyettobenamedintheStandardNamesofVariousIslandsintheSouthChinaSeaandthewebsiteNanshaIslandsOnline(http://www.nansha.org/).Another24onesareexposedtotheatmosphereevenduringhightides.TaipingIslandwithanareaof0.57km~2representsthelargestexposedgeologicalfeature.Thisstudydemonstratedtheapplicabilityofmedium-resolutionsatelliteimagestoderivethecoralreefinformationeffectivelyandthusprovidedinformationfortherelateddepartmentsthatareresponsibletomanagethecoast.Animprovedresolutionofmultispectralbandswiththepanchromaticbandinhigherspatialresolution(15mforOLIimage)isexpectedtoprovideanoptimumsatellitebasedapproachtomapmarinehabitats.