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500 个结果
  • 简介:高分辨率的浅地震方法是在近的表面描述的最广泛地使用的地球物理的方法。然而,在许多情况中,解释地震图象能是似是而非的。在这篇文章,我们在场因为不适当的限制,源于表面波浪(MASW)的地震思考,嘘波浪地震思考,和多信道的分析调查的P波浪的三案例研究不正确地在调查地点表面或表面下的条件上被解释。一个P波浪思考调查特征首先作为一个浅差错地区被解释,但是当获得通过了道路交叉,它以后决心源于背景噪音的高水平。一个嘘波浪地震思考调查特征被解释是一个反向的蘸滑倒差错,但是指向钻证明它是进基岩表面的深本地的侵蚀。在MASW调查,最后,一个陡峭地蘸的特征首先作为一条基岩山谷被解释。然而,以后探索的钻显示了特征是严重地抑制了大多数应用表面波浪频率乐队的很软的湖沉积的浅层。尽管起始的解释是不正确的,他们在地球物理学者和地质学家之中刺激了讨论并且以前为在科学家之间的有意义的合作和讲话强调了需要,在期间,并且在地球物理的数据获得以后。

  • 标签: 地震资料解释 浅层 地球物理方法 陷阱 地震反射 地球物理学家
  • 简介:—Inthispaper,anonlinearmodelispresentedtodescribewavetransformationinshallowwat-erwiththezero-vorticityequationofwave-numbervectorandenergyconservationequation.Thenonlineareffectduetoanempiricaldispersionrelation(byHedges)iscomparedwiththatofDalrymple'sdispersionrelation.Themodelistestedagainstthelaboratorymeasurementsforthecaseofasubmergedellipticalshoalonaslopebeach,wherebothrefractionanddiffractionaresignificant.Thecomputationre-sults,comparedwiththoseobtainedthroughlineardispersionrelation.showthatthenonlineareffectofwavetransformationinshallowwaterisimportant.Andtheempiricaldispersionrelationissuitableforre-searchingthenonlinearityofwaveinshallowwater.

  • 标签: wave propagation: SHALLOW water non/inearity REFRACTION
  • 简介:Basedonthehydrodynamicalfeatureandthetheoreticalvelocityprofilesoftidalflowandwind-inducedflowinshal-lowsea,acomputationalmodelisestablishedforthefirsttime,whichcanseparateobservedvelocityintotidalvelocityandwind-inducedvelocitybyuseoftheleastsquaremethod.Withthemodel,notonlythesurfacevelocitiesoftidalflowandwind-inducedflowareobtained,butalsothebedroughnessheightisdeterminedandthewindvelocityabovethewa-tersurfaceisestimated.Forverificationofthemodel,theobservedvelocityintheYellowRiverEstuaryandthelaborato-rytestisseparated,thenitisappliedtotheYangtzeRiverEstuary.Alltheresultsaresatisfactory.Theresearchresultsshowthatthemodelissimpleinmethod,feasibleinprocessandreasonableinresult.Themodelisavalidapproachtoanalysisandcomputationoffielddata,andcanbeappliedtoseparatetheobservedvelocityinshallowsea;atthesametime,reasonableboundaryconditionsofthesurfaceandbottomcanbeobtainedfortwo-andthree-dimensionalnumericalsimulation.

  • 标签: SHALLOW SEA VELOCITY profile TIDAL fiow
  • 简介:这份报纸为盲目评价建议了一个方法在水下在由使用的浅水环境的隧道在一个单个水中听音器或从单个beam.First收到了数据,收到的信号借助于信号依赖者TF(时间频率)分发被用于来源信号重建,与即时频率评价和TF倒置联合。然后,浅水的隧道评价被收到的信号和估计的来源信号的使用经由WRELAX技术完成。最后,数字模拟的结果和从在华南海试用拿的真实数据的试验性的测试证明了令人满意。建议方法是有用的为,这被显示出在水下隧道评价。

  • 标签: 听觉通道 浅水 实验 评估
  • 简介:Athree-dimensionalnumericalmodel,EFDC(environmentalfluiddynamicscode)isappliedtothePamlicoRiverEstuary(PRE)ineasternNorthCarolinaoftheUnitedStatestoexaminethewindimpactonpollutantagedistributionsandresidencetime.Aseriesofmodelexperimentsrepresentingbasecase,remote-wind-inducedwaterlevelset-upandlocalwindscasesareconducted.ModelresultsindicatethatthepollutantmeanageandthesystemresidencetimearefunctionsofgravitationalcirculationinthePRE.Thesystemresponsestoremote-wind-inducedwaterlevelset-uparedifferentindifferentportionsofthePRE.Undersuchcondition,dissolvedsubstancesintheupstreamportionofthePREhaveayoungerageandshorterresidencetime(comparedwiththebasecase),bycontrast,theyhaveaolderageandlongerresidencetimeinthedownstreamportionofthePRE.Upriveranddownriverlocalwindsappeartohaveoppositeimpactsonpollutantagedistributions.ThesubstancesareretainedmuchlongerwithinthePREunderupriverwindthanthoseunderdownriverwind.Themodelresultsalsosuggestthatacross-riverwindsmayleadtolongerresidencetimethroughenhancedturbulencemixing,whichslowsdownthegravitationalcirculationinthePRE.

  • 标签: 帕姆利科湾 浅湾 重力循环 盐量
  • 简介:BasedonKármán’snonlinearfundamentaldifferentialequations,thenewapproach,whichcombinesmodifiediterationmethodwithGalerkin’sone,hasbeenputforwardtosolvenonlinearbendingofshallowsphericalshellwithconcavebaseandclampededgesonthePasternakfoundationunderuniformloadsinthispaper.Mathematicalexpressionofload-deflectionhasbeengiven;furthermore,resultsobtainedareingoodagreementwithexistentones.

  • 标签: SHALLOW sphericall/pasternak FOUNDATION modified ITERATION METHOD
  • 简介:TheexistingestimatesofthevolumetransportfromthePacificOceantotheSouthChinaSeaaresummarized,showinganannualmeanwestwardtransport,withtheTaiwanStraitoutflowsubtracted,of3.5±2.0Sv(1Sv=106m3s-1).Resultsofaglobaloceancirculationmodelshowanannualmeantransportof3.9SvfromthePacifictotheIndianOceanthroughtheSouthChinaSea.TheborealwintertransportislargerandexhibitsaSouthChinaSeabranchofthePacific-to-IndianOceanthroughflow,whichoriginatesfromthewesternPhilippineSeatowardtheIndonesianSeasthroughtheSouthChinaSea,aswellasthroughtheKarimataandMindoroStraits.ThesouthwestwardcurrentnearthecontinentalslopeofthenorthernSouthChinaSeaisshowntobeacombinationofthisbranchandtheinteriorcirculationgyre.Thiswinterbranchcanbeconfirmedbytrajectoriesofsatellite-trackeddrifters,whichclearlyshowaflowfromtheLuz6nStraittotheKarimataStraitinwinter.Insummer,theflowintheKarimataStraitisreversed.NumericalmodelresultsindicatethatthePacificwatercanentertheSouthChinaSeaandexittowardtheSuluSea,butnoobservationalevidenceisavailable.Therolesofthethroughflowbranchinthecirculation,waterpropertiesandair-seaexchangeoftheSouthChinaSea,andinenhancingandregulatingthevolumetransportandreducingtheheattransportoftheIndonesianThroughflow,arediscussed.

  • 标签: 中国 南海 太平洋 印度洋 海洋气象 循环模型
  • 简介:Basedonthe1stordercnoidalwavetheory,thewavediffractionaroundthepiergroupinshallowwaterisstudiedinthispaper.Theformulasforcalculatingthenonlinearwaveforcesarealsopresentedhere.Inordertoverifythetheoreticalresults,modeltestsareconductedinthewaveflumeinTheStateKeyLaboratoryofCoastalandOffshoreEngineeringlocatedinDalianUniversityofTechnology.TherangeofthewaveparametersintheexperimentsischaracteristicwaveperiodTg/d1/2=8.08-22.86,characteristicwaveheightH/d=0.10.45.Theresultsobtainedfromtheexperimentsagreewiththetheoreticalresultsquitewell.Itisshownthat,inshallowwaterthenonlinearwaveforcesactingonapiergrouparegreaterthanthosecalculatedbylinearwavetheory,thevalueofincrementinwaveforceincreaseswiththeincreasesofthenonlinearityofthewave.Inthewaverangestudiedinthispaper,thenonlinearwaveforcecanreachover4timestheforcecalculatecdbylinearwavetheory.Thus,itissuggestedthat,whenTg/d1/2>8,thewaveforceonthepiersinthepiergroupinshallowwatershouldbecalculatedbyusingthecnoidalwavetheory.

  • 标签: CYLINDER PIER GROUP WAVE FORCE SHALLOW
  • 简介:Basedonthesphericalcavityexpansiontheoryintheelastichalfspace,thegroundsurfacemovementcharacteristicsofshallowlyburiedexplosionsareanalyzed.TheresultsshowthattheinducedseismicwaveisalongitudinalwaveinthenearzoneandaRayleighwaveinthefarzone.Themaximumdisplacement(velocity)ofthelongitudinalwaveandtheRayleighwaveareinverselyproportionaltothescaleddistance,andcanbedescribedbyexponentialfunctionwithexponentsequalto1.4and0.5,respectively.Thevibrationfrequenciesofthewaveshavealmostnochange.Thevibrationfrequencyofthelongitudinalwaveapproximatesthenaturalvibrationfrequencyofthecavityinthebrokenarea,andthevibrationfrequencyoftheRayleighwaveisabouthalfthatofthelongitudinalwave.Onthesamereducedburieddepthandreduceddistance,theparticledisplacementisdirectlyproportionaltotheproductoftheboundaryloadingandcavityradius,andisinverselyproportionaltothetransversalwavevelocity.Meanwhile,theparticlevelocityisdirectlyproportionaltotheboundaryloadingandinverselyproportionaltothewavevelocityratio.Inthefarzone,theburieddepthoftheexplosiveonlyhasaslighteffectonthelongitudinalwave,buthasalargereffectontheRayleighwave.

  • 标签: shallowly BURIED explosions GROUND SURFACE RESPONSE
  • 简介:Basedonthe1stordercnoidalwavetheory,thenonlinearwavediffractionaroundacircularcylinderinshallowwaterisstudiedinthispaper.Theequationofthewavesurfacearoundthecylinderisformulatedandbyusingthisformulathewavesurfaceelevationonthecylindersurfacecanbeobtained.Inthispaper,theformulaforcalculatingthecnoidalwaveforceonacircularcylinderisalsoderived.Forthewaveconditionswhichareoftenencounteredinpracticalengineeringdesigns,theratiosofthenonlinearwaveforcestothelinearwaveforcesarecalculated,andtheresultsareplottedinthispaperfordesignpurposes.Inordertoverifythetheoreticalresults,modeltestsareconducted.Aftercomparingthetestresultswiththetheoreticalones,itisconcludedthat,inshallowwater,forthecaseofTg/d1/2>8-10andH/d>0.3,thecnoidalwavetheoryshouldbeusedtocalculatethewaveactiononacylindricalpier.

  • 标签: cnoidal WAVE FORCE CYLINDER SHALLOW water
  • 简介:Tostudythecompactionlawandoverpressureevolutionindeepwatershallowsediments,alarge-straincompactionmodelthatconsidersmaterialnonlinearityandmovingboundaryisformulated.Themodelconsidersthedependenceofpermeabilityandmaterialpropertiesonvoidratio.ThemodifiedCam-Claymodelisselectedastheconstitutiverelationsofthesediments,andthedeactivation/reactivationmethodisusedtocapturethemovingtopsurfaceduringthedepositionprocess.Aone-dimensionalmodelisusedtostudythecompactionlawoftheshallowsediments.Resultsshowthatthesettlementoftheshallowsedimentsislargeundertheirownweightduringcompaction.Thevoidratiodecreasesstrictlywithburialdepthanddecreasesmorequicklyneartheseafloorthaninthedeeperlayers.Thegenerationofabnormalpressureintheshallowflowsandsiscloselyrelatedtothecompactionlawofshallowsediments.Thetwomainfactorsthataffectthegenerationofoverpressureinthesandsaredepositionrateandpermeabilityofoverlyingclaysediments.Overpressureincreaseswithanincreaseindepositionrateandadecreaseinthepermeabilityoftheoverlyingclaysediment.Moreover,anupperlimitfortheoverpressureexists.Atwo-dimensionalmodelisusedtostudythedifferentialcompactionoftheshallowsediments.Theporepressurewillstillincreaseduetotheinflowoftheporefluidfromtheneighboringclaysedimenteventhoughthedepositionprocessisinterrupted.

  • 标签: mechanical COMPACTION DEEPWATER SHALLOW SEDIMENTS COMPACTION
  • 简介:Inthisstudy,amulti-relaxationtimelatticeBoltzmannmodelforshallowwaterinacurvilinearcoordinategridisdevelopedusingthegeneralizedformoftheinterpolationsupplementedlatticeBoltzmannmethod.TheTaylor-Coletteflowtestsshowthattheproposedmodelenjoysasecondorderaccuracyinspace.Theproposedmodelisappliedtothreetypesofmeanderingchannelswith180°,90°and60°consecutivebends.Thenumericalresultsdemonstratethatthesimulatedresultsagreewellwithpreviouscomputationalandexperimentaldata.Inaddition,themodelcanachievetheacceptableaccuracyintermsofthewaterdepthandthedepth-averagedvelocitiesforshallowwaterflowsincurvedandmeanderingchannelsoverawiderangeofbendangles.

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  • 简介:如果他们一起被联合调查考古学的地点,渗透雷达,电磁的地面传导性,和电的断层摄影术的地面证明了是有效工具。我们在Akhmim考古学的地点进行了地球物理的调查,我们的调查的主要目的是定位另外的为进一步的挖掘的埋葬的结构。地球物理的数据用GEM-300多频率地面传导性剖析程序,SIR2000地面渗透雷达,和SyscalR2抵抗力米系统在区域被获得。综合解释的结果显示出很多个埋葬的特征和一个强壮的线性地区大约1m宽与一面埋葬的墙的怀疑的趋势与一致。看起来是任何一个方面上的猛烈思考的二条平行山脉,显示二面平行的墙扩大了东方西方,一个房间在底部被识别这个地点的左角落。而且,一些的解释结果选择了GPR和邻近的偶极子偶极子抵抗力侧面露天博物馆在能仍然在沙被埋葬的以前发现的塑像右边建议RamsesII的第二尊塑像的存在。

  • 标签: 考古学勘探 阿赫米姆 GPR GEM 电阻率
  • 简介:纸介绍2D浅水模型基于为快似地球形状的transients的分析的二阶段的明确的表达发生在河morphodynamics的上下文。质量和动量保存原则独立为两个阶段被强加。模型自然地说明非平衡固体运输,自从两个即时改编假设也不任何东西落后方程被采用代表沉积动力学。建议模型的夸张特性被显示在流动条件上独立地被保存。从1D和2D测试用例的数字模拟的结果与文学相比试验性的数据并且与可得到的数字解决方案。

  • 标签: 河流地貌 水模型 浅水流动 沉积动力学 动量守恒 固体输送
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