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简介：Thispaperpresentstheexperimentalresultsonthedistributionofsedimentsatchannelbifurcation.Theexperimentshavebeenconductedinaphysicalmodelofchannelbifurcation.Itconsistsofastraightmainchannelwhichbifurcatesintotwobranchchannelsofdifferentwidths.Thetestrigisamobilebedwithfixedbank.Fourdifferentnoseshavebeenusedtostudythephenomenon.Foreachnose,threeupstreamdischargesviz.20l/s,30l/sand40l/shavebeenemployed.Fromthemeasureddata,dischargesandsedimenttransportratiosperunitwidtharecalculatedinthedownstreambranches.Thesedatahavebeensettothegeneralnodalpointrelationandasetofequationshasbeendevelopedtodescribethedistributionofsedimentstothedownstreambranchesfordifferentnoseangles.

简介：Insteady,solid-liquidtwo-phaseturbulentflows,thereexisttwotypicalpatternsoftheverticaldistributionofparticleconcentration.ThepatternIshowsamaximumconcentrationatanelevationabovethebed.ThepatternIIshowsanincreaseoftheparticleconcentrationdownwardoverthewholevertical,withthemaximumatthebed.MostofthetheoriesonparticleconcentrationdistributionhavebeendonewiththepatternII,anditislackofasuccessfultheorycovetingbothofthetwopatterns.Thispaperreviewstheparticledistributiontheories,includingthediffusiontheory,themixturetheory,theenergytheory,thesimilaritytheory,thestochastictheoryandthekinetictheory.Thekinetictheoryisalsoappliedtodescribetheverticaldistributionofparticleconcentrationinbothdiluteanddenseflows.

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简介：地震信号的变细经常用力量光谱的统计措施在频率领域被描绘。然而，常规Fourier基于变换的力量光谱评价方法受不了时间频率决定问题。Wigner-Ville分发，是科恩班时间频率分布的一个成员，拥有许多呼吁的性质，例如时间频率边缘的分发，时间频率本地化，等等。因此，Wigner-Ville分发为估计地震信号的变细提供一个新方法。这篇论文开始把简短介绍给Wigner-Ville分发和在减少跨术语的效果是有效的弄平的Wigner-Ville分发，然后基于Wigner-Ville分发的即时精力光谱为地震变细评价介绍一个方法。从在西方的中国的中央Tarim盆的一个真实数据例子被举说明建议方法的有效性。结果证明Wigner-Ville基于分发的地震变细评价方法罐头有效地检测礁石之间的差别，浅并且由他们的变细性质的泻湖外形，显示估计的地震变细能被用于礁石和浅碳酸盐水库描述。

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简介：水流动和沉积运输方程在伪平衡条件的假设下面被线性化，经分解解决了。这个解决方案允许重建从planimetric数据的河深测术，从为大多数世界的大河的卫星图象可得到的唯一一个。线性化的伪平衡答案提供一个标准评估精确性近似(一致流动)模型，与相比常规(稳定流动)模型。为非平衡条件，进一步的限制准时，分辨率应该被增加，它是不管多么通常为长期的词法模拟满足了。一致流动的答案介绍变得关键的许多优点因为在分水岭的长期的数字计算可伸缩。文章提供精确性的详细数字比较和稳定流动、一致流动的模型的分辨率，用到更低的Zambezi河的进化的应用，它证实理论标准。一致流动的解决方案的精确性看起来当河与一个粗糙的计算格子被扼要表示时，尽管，改善，当然与空间分辨率的相应损失。

简介：Theparticlesizedistributionofbedmaterialsinthesandyriverbedofalluvialriversisimportantinthestudyoftopicssuchasfriction,riverbedevolution,erosion,andsiltation.Italsocanreflectthedependencyrelationbetweenriverbedsedimentandflowintensity.Inthispaper,thecriticalpatternofsedimentmovementinthenear-wallregionofasandyriverbedwasanalyzed.Accordingtotheprincipleofmomentumbalance,thecriticalsettling-risingconditionofbedmaterialinasandyriverbedwasfoundtobeinstantaneousturbulentvelocityequalto2.7timesthesedimentsettlingvelocityinquiescentwater.BasedonaverticalinstantaneousturbulentvelocitywithaGaussiandistribution,atheoreticalrelationforcalculatingtheparticlesizedistributionofbedmaterialsinasandyriverbedwithoutpre-knowncharacteristicgrainsizeswasdevelopedbysolvingastochasticequation.Theformulaisverifiedusingmeasureddata,andtheresultsshowthattheproposedformulawasinaccordancewiththemeasureddata.Thisstudyhastheoreticalsignificanceandpracticalvaluefordeterminingthebedmaterialparticlesizedistributionofthesandybedofalluvialrivers.

简介：Inthisstudy,accumulationanddistributionofPb,Cu,Zn,Co,Ni,MnandFeinwater,bottomsedimentsandfourplantspecies(Myriophyllumverticillatum,Hydrocharismorsus-ranae,NymphaeaalbaandTyphalatifolia)wereinvestigatedinCernekLakeofKizilirmakDelta.TheKizilirmakDeltaisoneofthelargestnaturalwetlandsofTurkeyanditisprotectedbytheRamsarconventionsince1993.Selectedphysico-chemicalparameterssuchaspH,conductivityanddissolvedoxygenandalsotracemetalconcentrationsweremonitoredinwater.Alltheparametersobtainedwerefoundhigherthanthatofthenationalstandardsfortheprotectedlakesandreserves.TheaccumulatedamountsofvarioustracemetalsinbottomsedimentsandwetlandplantswerefoundinthefollowingorderofFe>Mn>Zn>Ni>Co>Cu>PbandFe>Mn>Zn>Ni>Corespectively.ThehistoricaltracemetalintakeofMyriophyllumverticillatum,Hydrocharismorsus-ranae,TyphalatifoliaandNymphaeaalbawereobtainedhigherthanthatofthetoxicmetallevelsandtheseplantsmaybeacceptedasaccumulatorsforthedetectedtracemetalsandalsobioindicatorsinthehistoricallypollutednaturalareas.

简介：ThispaperdiscussestherelationshipbetweenthegrainsizedistributionofsedimentandcurrentsinthenorthernEastChinaSeaonthebasisofthegrainsizeanalysis.Theresultsshowthatgrainsizedistributionofsuspendedsedimentiscontrolledbythecurrents.Suspendedsedimentinthelittoralwaterisfinerthanthoseintheopenseacurrents.Grainsizedistributionofsurfacesedimentisaffectedbytheseacurrentstosomeextent.Andthegrainsizeofsuspendedsedimentandsurfacesedimentdonotagreewitheachotherinpositions.

简介：TostudythecharacteristicsofthedistributionofthepreferentialpathsandtheaffectingfactorsintheThreeGorgesarea,foursoilprofilesweredugtoobservethedistributionofpreferentialpathsintheQuxiwatershedintheYangtzeRiverbasin.TheMorisitaexponentialtestmethodwasusedtoexaminethedistributiontypeofpreferentialpaths.Thephysicalpropertiesandinfiltrationcharacteristicsofthesoilwerealsomeasuredtoevaluatetheirrelationshiptopreferentialpaths.Theresultsshowedthatinthisarea,preferentialpathsclusteredandmainlydistributedinthe80-100cmsoillayer,andalongtheinterfacebetweentheweatheredlayerandsemi-weatheredlayer.Thereweremorenon-capillaryporesinthe83-110cmlayerthanintheotherlayers.Itcanbederivedthatmostnon-capillaryporesinthislayerwerepreferentialpathscausedbygeologicalprocessesandrottenplantroots.Thepercentageofcoarsesoilparticlesincreasedwiththedepthofthesoillayer.Inthedeepersoillayer,thecoarsesoilparticleshelpedtheformationofpreferentialpaths.Thefasteststeadyinfiltrationratewasobservedintheof83-110cmlayer,whichisinferredtobeduetothegreaternumberofpreferentialpaths.

简介：Arobustmethodforcharacterizingthemineralogyofsuspendedsedimentincontinentalriversisintroduced.Itencompasses3steps:thefiltrationofafewmillilitersofwater,measurementsofX-rayenergydispersivespectrausingScanningElectronMicroscopy(SEM),androbustmachinelearningtoolsofclassification.ThemethodisappliedtosuspendedparticlescollectedfromvariousAmazonianrivers.Atotalofmorethan204,000particleswereanalyzedbySEM-EDXS(EnergyDispersiveX-raySpectroscopy),i.e.about15,700particlespersamplingstation,whichleadtotheidentificationof15distinctgroupsofmineralogicalphases.ThesizedistributionofparticlescollectedonthefilterswasderivedfromtheSEMmicrographstakeninthebackscatteredelectronimagingmodeandanalyzedwithImageJfreeware.Thedeterminationofthemainmineralogicalgroupscomposingthebulksedimentassociatedwithphysicalparameterssuchasparticlesizedistributionoraspectratioallowsaprecisecharacterizationoftheloadoftheterrigenousparticlesinriversorlakes.InthecaseoftheAmazonianriversinvestigated,theresultsshowthattheidentifiedmineralogiesareconsistentwithpreviousstudiesaswellasbetweenthedifferentsamplescollected.Themethodenabledtheevolutionofgrainsizedistributionfromfinetocoarsematerialtobedescribedinthewatercolumn.Implicationsabouthydrodynamicsortingofmineralparticlesinthewatercolumnarealsobrieflydiscussed.Theproposedmethodappearswellsuitedforintensiveroutinemonitoringofsuspendedsedimentinriversystems.

简介：尽管高分辨率能被电的记载提供，测量电的木头范围是狭窄的并且被限制接近井。地上凿穿表面电的潜在的大小能检测一个足够宽的范围，但是它的分辨率是有限的，特别地为有复杂的油和水分发或复杂结构的水库。在这研究，我们试图精确地由联合地上凿穿表面和crosswell定位3-D水库水和油分发电的潜力。首先，在垂直、水平的方向的油和水的分布被地上凿穿表面和crosswell检测电的潜在的方法，分别地然后测量crosswell潜力结果被用来校准测量地上凿穿表面改进垂直分辨率以便剩余油分发在有三种尺寸的更低的一半空间是坚定的电的潜在的数据。剩余油分发的评估被水库的模拟结果之间的差别的调查有或没有水泛滥获得。有限差别数字模拟结果证明空间剩余油分发能被联合crosswell和地上凿穿表面有效地决定电的潜力。

简介：Cauchypriori基于分发的贝叶斯的AVO反射率倒置可以导致对大反射率敏感的稀少的估计。为倒置，协变性矩阵和调整条款的计算要求模型参数的优先的评价，它使反复的倒置弱非线性。同时，在模型参数之中的关系被假定线性。而且，反射率，倒置的结果，或有集成反射率恢复的累积错误的有弹性的参数很好不适合检测烃和液体。在贝叶斯的线性AVO倒置，相反，有弹性的参数能直接从prestack被提取没有为模型参数的线性假设的地震数据。就上述的方法的优点而言，贝叶斯的AVO反射率倒置过程被修改，当优先的概率分布和时间变体协变性也被考虑，Cauchy分发被探索。最后，我们为弱非线性的AVO波形倒置建议一个新方法。而且，线性假设被放弃，有弹性的参数例如P波浪速度，S波浪速度，和密度，能直接特别为大反射率的接口从地震数据被恢复。数字分析证明所有有弹性的参数能从prestack被估计地震数据甚至当地震数据的signal-to-noise比率是低的时。

简介：这研究的目的是估计在印度的东南的海岸在Tirumalairajan河河口在10表面沉积选择重金属(Fe，Mn，Cu，Zn，Pb，Cr，公司和Ni)划分的化学药品。一种五步的顺序的抽取技术被用来估计重金属的环境地位。大多数金属被认为由于在重金属的剩余部分的高可获得性不动。Tirumalairajan河河口的沉积没被重金属弄脏，并且他们没提出任何高生态的风险。重金属的季节的变化比在季风季节在夏天是稍微更高的。因素分析也被执行与沙，淤泥，泥土，有机物，pH，咸度和另外的金属在不同部分理解金属的协会。在Q模式和R模式簇分析之间的关系为在两个季节识别污染层次是有用的。重金属的丰富与地球表面形成学、人为的来源一起是相关的，这被证明。在沉积的全部的金属集中的信息不为在环境估计金属行为是足够的，但是顺序的抽取技术在估计污染沉积的环境影响是更有效的。

简介：ThispaperpresentsthenumericalinvestigationofthedistributionofinertialsedimentparticlesintheturbulentboundarylayerofanopenchannelflowwiththeparticleStokesnumberrangingfrom0.6to20.4.Themethodologyisacombinationofthreenumericalapproaches,i.e.directnumericalsimulationofturbulentflow,thepoint-particleimmersedboundarymethod,andthediscreteparticlemethod.ByapplyingtheVorono?analysis,thepreferentialconcentrationcharacteristicsofsedimentparticleswereinvestigatedquantitatively.ItwasfoundthatthenormalizedareaoftheVorono?cellsfollowsalognormalparticledistribution.Theinertialsedimentparticlesdistributedunevenlyintheturbulentboundarylayerandtheunevenness,governedbytheparticleStokesnumber,wasmoresignificantastheparticleStokesnumberapproachesunity.Theinertialsedimentparticlesintheturbulentboundarylayeraccumulatedpreferentiallyinstreamwise-alignedstreakystructuresandthispatternwaslesssignificantwithincreasingparticleStokesnumber.

简介：波形字符在分离数据在时间顺序安排了的地震数据结构特征工具把地震踪迹指向每2-D或3-D。用地震数据结构特征的烃预言是一种新水库预言技术。当主要薪水间隔与很强壮的不同类在碳酸盐骨折和裂缝大洞类型水库时，有烃预言的一些困难。因为Tahe油地里的第八个地区的特殊地质的条件，我们在这个地区为奥陶纪水库把地震数据结构特征用于烃预言。我们把区域油地区划分成有利、相反的块。十八个井地点在有利的油块被求婚，钻，并且恢复油和气体的更高的输出。

简介：Soilsusceptibilitytodetachmentandtransportsub-processesoferosionisgenerallycontroledbytheaggregatebreakdownmechanism.Measuringparticlesizeandaggregationtotheestimateerodibilitypotentialofsoilsisimportantundererosiverainfallconditions.TheAggregateSizeDistribution(ASD)isoneofthemostimportantdeterminantsofsoilstructurealongwithsoilorganicmattercontentfordescribingtheefficiencyofapplied,sustainablemanagementstrategies.Thisstudyaimedtocomparetheperformancesofthreedifferentaggregatesizedistributionmodelstopredictthecharacteristicaggregatesizeparameter(mediandiameter,D50)forerodedsedimentfrominterrillerosionprocessesofRain-SplashTransport(RST)andRaindropImpactedFlowTransport(RIFT).TheASDsof1143collectedsedimentsamplesfromtheRSTandRIFTprocessesweremeasuredandmodeledbytheLog-normal,Fractal,andWeibullapproaches.TheD50value,asacharacteristicparameterforaggregatesizedistributions,derivedfromthecumulativeASDcurvewascomparedforsoilsfromdifferentlandusetypesanddifferentslopeandrainfallintensityconditions.TheperformanceofeachmodelwasevaluatedusingtheMeanSquareError(MSE)andCoefficientofDetermination(R^2).TheWeibullapproachwasthemostaccuratemodelshowingthebestfitwiththelowestMSEvalues(0.0002≤MSE≤0.0048)andhavingthegreatestR2values(0.936≤R^2≤0.998)whencomparedwiththeLog-normalandFractalmodels.Herewith,forsemi-aridlanduseandsoil,specificshapeandscaleparametersfortheWeibulldistribution,therespectiveASDsweresuccessfullyre-generatedformodelingtheerodedsedimentofthesimulatedRSTandRIFTinterillprocesses.