学科分类
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500 个结果
  • 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。

  • 标签: WIGNER-VILLE分布 时频分布 地震衰减 储层预测
  • 简介:Manyreal-worldsystemscanbemodeledbyweightedsmall-worldnetworkswithhighclusteringcoefficients.Recentstudiesforrigorouslyanalyzingtheweightedspectraldistribution(WSD)havefocusedonunweightednetworkswithlowclusteringcoefficients.Inthispaper,werigorouslyanalyzetheWSDinadeterministicweightedscale-freesmall-worldnetworkmodelandfindthattheWSDgrowssublinearlywithincreasingnetworkorder(i.e.,thenumberofnodes)andprovidesasensitivediscriminationforeachinputofthismodel.ThisstudydemonstratesthatthescalingfeatureoftheWSDexistsintheweightednetworkmodelwhichhashighandorder-independentclusteringcoefficientsandreasonablepower-lawexponents.

  • 标签: 小世界网络 加权网络 光谱分布 标度 聚类系数 网络模型
  • 简介:Anewtestmethodwasintroducedtomeasurefiberdistributioninsteelfiberreinforcedmortarbyusingimageanalysistechnique.Throughspecimenpreparation,imageacquisition,fiberextraction,andmeasurementofrelatedfiberparameters,quantitativeanalysisoffiberdistributioncouldbeobtainedbytwoparameters,namelydispersioncoefficientandorientationfactor.Effectofboundaries,sizeandsteelfibercontentonfiberdistributionwasdiscussed.Resultsshowedthat,steelfiberdistributionwasaffectedbyboundaryeffect,whichwouldbeweakenedwiththeincreaseofspecimensize.Ifthelengthandwidthremainedconstant,thespecimenheighthadasignificanteffectonorientationfactoroffiber,whileitsinfluenceondispersioncoefficientwasnotsoobvious.Withtheincreaseofsteelfibercontent,dispersioncoefficientdecreasedslightly,andorientationfactordeviatedfrom0.5.

  • 标签: 纤维分布 纤维砂浆 评估 行数 色散系数 技术测量
  • 简介:Heavymineralswithasizerangeof0.125~0.250mminthesurficialsedimentofMinjiangEstuaryarestudied.Thirty-fourheavymineralshavebeenidentified,withanaveragecontentof1.92%.Majormineralsincludemagnetite,epidote,hematite,hornblende,ilmenite,andzirconmica.Thesetypesarethesameasthoseinthe0.063~0.125mmrange;however,theaveragecontentislower,whichrevealsthattheheavymineralsinMinjiangEstuaryaremainlyenrichedinthevery-finesandfraction.Accordingtothecontentanddistributioncharacteristicsofthemajorheavyminerals,MinjiangEstuarycanbedividedinto4mineralassemblagezones.Ineachzonetheassemblageofheavymineralsisgreatlyaffectedbythehydrodynamicconditionandthesedimentaryenvironment.HeavymineraltypesalsoshowthatdetritalmattersinMinjiangEstuaryareoriginatedfromtheweatheringanderosionofthebedrockintheMinjiangRiverdrainagearea.

  • 标签: 海洋重矿 分布特征 有机物质 岷江河口 沉积地质
  • 简介:ParticlebasedmodelsofcompositeanodesareusefultoolsforexploringthebehaviorofSOFCsystems.Aspartofoureffortstodevelopmodelsforunderstandingfuelcells,wehavebeenbuildingmodelsofNi-YSZcompositeanodesusingexperimentallymeasuredparticlesizedistributions.Theobjectivesofthisstudyweretocharacterizethepercolationthresholdandconductivityofthesemodelsincomparisontosimplermonodispersedandbiphasicparticlesizedistributionsfromtheliterature.Wefoundthattheaveragevaluesfortheonsetofpercolationandthemeasuredconductivityofthemodelswithexperimentallymeasuredparticlesizedistributionsaresimilartothoseforthesimpledistributionsandtheexperimentallymeasureddistributions.Foralloftheconfigurationsevaluated,theonsetofpercolationintheNickelphaseoccurredatasolidfractionofNickelbetween20%and25%.ThiscorrespondedalmostexactlytothepointatwhichthecoordinationnumberbetweenNickelphaseparticlesreached2.2.Thesignificantfindingwasthatthevariationinthevaluefortheconductivity,asmeasuredbythestandarddeviationoftheresults,wasseveralordersofmagnitudehigherthanforthesimplersystems.Weexploredthevalidityofourassumptions,specificallytheassumptionofrandomparticleplacement,bybuildingaparticlemodeldirectlyfromFIB-SEMdata.Inthisreconstruction,itwasclearthatthelocationofparticleswasnotrandom.Particlesofthesametypeandsizehadmuchlikelihoodofcontacthigherthanwouldindicatedbyrandomlocation.

  • 标签: 颗粒粒径分布 电池模型 复合阳极 燃料电池系统 固体氧化物 粒子模型
  • 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。

  • 标签: 粒度分布 模拟进化 非平衡条件 时间分辨率 河流 形象
  • 简介:TheFilteringGridScale(FGS)ofsub-gridscalemodelsdoesnotmatchwiththetheoreticalProperFGS(PFGS)becauseoftheimpropermesh.Therefore,properLargeEddySimulation(LES)Meshisverydecisiveforbetterresultsandmoreeconomicalcost.Inthiswork,thepurposeistoprovideanadaptivecontrolstrategyforproperLESmeshwithturbulencetheoryandCFDmethods.AnewexpressionofPFGSisproposedonthebasisof-5/3lawofinertialsub-rangeandthepropermeshofLEScanbebuiltdirectlyfromtheadjustmentofRANSmesh.Abenchmarkofthebackwardfacingstepflowatisprovidedforapplicationandverification.Therearethreekindsofmeshsizes,includingtheRANSmesh,LAM(LESofadaptive-controlmesh),LFM(LESoffinemesh),employedhere.ThegridnumberofLAMissmallerthanthoseofLFMevidently,andtheresultsofLAMareinagoodagreementwiththoseofDNSandexperiments.ItisrevealedthattheresultsofLAMareveryclosetothoseofLFM.Theconclusionsprovidepositiveevidencesforthenovelstrategy.

  • 标签: 自适应控制策略 网格分布 大涡模拟 植物功能群 计算流体力学 雷诺平均
  • 简介:潮汐的流动是一个周期的运动不稳定、不一致,它显然有加速和减速过程,特别在沿海的浅水里。潮汐的流动雷纳兹应力的垂直分发从线性分发背离了的许多研究表演。潮汐的流动雷纳兹压力的寓言的分发被歌等建议。(2009)。尽管模型更好充满领域观察和室内的试验性的数据,它有潮汐的流动雷纳兹应力的更低的截断的系列扩大,并且对分发的描述不是很全面的。由介绍潮汐的流动的运动方程并且改善,寓言的分发由歌等建立了。(2009),潮汐的流动雷纳兹压力的立方的分发被建议。立方的分发被领域数据验证很好(Bowden和Fairbairn,1952;Bowden等,1959;Rippeth等,2002)并且试验性的数据(Anwar和阿特金斯,1980),与Kuo等的数字模型结果一致。(1996),并且与潮汐的流动雷纳兹压力的寓言的分发相比。这立方的分布比寓言的分发,而且罐头不仅好,这更好被显示出反映与潮汐的流动减速与潮汐的流动加速并且向上向下从线性分发背离的雷纳兹应力的基本特征,为潮汐的流动的速度侧面上的进一步的学习的基础。

  • 标签: 潮汐流动 雷诺应力 垂直分布 抛物线分布 海域 减速过程
  • 简介:节省水的灌溉方法逐渐地在温室或塑料电影房子为蔬菜耕作被使用了。然而,有关土壤磷(P)行为上的节省水的灌溉方法的效果有有限信息。在这个实验,滴下并且表面下的灌溉方法被使用,与是的沟灌溉方法控制,在MollicGleysols。在整个深度的土壤P分发被灌溉方法显著地影响。全部,Olsen,器官、无机的P内容比在心土(20–30,30–40,40–50和50–60厘米)在表层土(0–10和10–20厘米)是更大的。在整个0–60厘米层在下面的OlsenP内容滴下并且表面下的灌溉处理在沟灌溉处理下面是比那低的。然而,全部、器官、无机的P从20~60厘米满足在下面滴灌溉处理比或近到在沟灌溉处理下面的那些高,但是比在沟灌溉处理下面在表面下的灌溉处理下面是更低的。在表面下的灌溉处理下面,在0–10厘米层的全部、器官、无机的P的内容是78.0%,1.3%和3.7%比那些大在10–20厘米层分别地。但是在10–20厘米层的OlsenP内容是5.7%比那大在0–10厘米层。这些建议那土壤P行为能被土壤水管理操作到某程度。

  • 标签: 灌溉方法 土壤磷素 塑料薄膜 无机磷含量 滴灌条件 土壤水分管理
  • 简介:这份报纸在人的真皮的部分处理散开的液体运输和分发的数学学习。它连续地通过皮肤流动的细胞内部的液体轰炸以便维持液体的帐号在身体以内平衡。一个数学模型为这个过程和有限元素方法被想象(女性)被采用在不同皮肤层计算液体的集中。这个评价与织物媒介和空气的另外的参数在关系被分析。

  • 标签: 人体皮肤 流体输送 数学研究 扩散 分配 有限元法
  • 简介:Theurbanelectricpowerdistributionnetworkrequireshighersupplyreliability,butthedecisionofinvestmentpolicyischieflydependentonthesecuritystandardsadoptedbythesupplyutilities.Thus,theformulationofreliabilitystandardsdeservesseriousconsiderationevenregardinginvestmentalone.Supplyreliabilitycanbeexpressedintermsofsupplyavail-ability,whichrelatestoannualdurationofinterruptionperconsumer.

  • 标签: FORMULATION avail CONSUMER ALONE SHORTAGE regarding
  • 简介:EnergyisthedeterminantfactorforthesurvivalofMobileSensorNetworks(MSN).Basedontheanalysisoftheenergydistributioninthispaper,atwo-phaserelocationalgorithmisproposedbasedonthebalancebetweentheenergyprovisionandenergyconsumptiondistribution.Ourmainobjectivesaretomaximizethecoveragepercentageandtominimizethetotaldistanceofnodemovements.Thisalgorithmisdesignedtomeettherequirementofnon-uniformdistributionnetworkapplications,toextendthelifetimeofMSNandtosimplifythedesignoftheroutingprotocol.Inad-dition,testresultsshowthefeasibilityofourproposedrelocationalgorithm.

  • 标签: 移动传感器网络 非均匀分布 定位算法 能源消耗 迁移算法 能量分布
  • 简介:ThisworkinvestigatesthedistributionofhighwindsaboveBeaufortscale6intheoffshorezonesofChinausinghigh-resolutionsatellitemeasurements.AnumericalexperimentiscarriedoutinordertofindouttheeffectsofTaiwanIslandontheformationofstrongwinds.Theanalysisindicatesthatthedistributionofhighwindoccurrenceissimilartothatoftheaveragewindvelocityinwinter.Highwindstendtobeanchoredinspecialtopographicalregions,suchastheTaiwanStrait,theBashiChannelandthesoutheastcoastofVietnam.HighwindsoccurmuchmorefrequentlyoverthewarmerthanthecolderflankofKuroshiofrontasitmeandersfromTaiwantoJapan.Thefrequencyofhighwindsdecreasesdrasticallyinspring.TheTaiwanStraitmaintainsthelargesthighwindoccurrence.Besides,highwindsremainfrequentintheBashiChannel,thesoutheasttipofTaiwanIslandandthewarmerflankofKuroshiofront.Insummer,highwindsgenerallyoccurinfrequentlyexceptoverabroadregionoffthesoutheastcoastofVietnamnear10°Nandthefrequencytheredecreasesfromsouthwesttonortheast.HighwindsaroundTaiwanIslandpresentnearaxisymmetricdistributionwithlargerfrequencyalongsoutheast-northwestdirectionandsmallerfrequencyalongsouthwest-northeastdirection.Thedominantdirectionofhighwindsexhibitsacounterclockwisecirculationsurroundingtheisland.Thefrequencyofhighwindsincreasesrapidlyinautumnandalmostrepeatsthedistributionthatappearsinwinter.ThesimulationresultssuggestthattheeffectsofTaiwanIslandtopographyonhighwindsvarywithseasons.Inwinter,topographyisthemajorcauseofhighwindsinthesurroundingoceaniczones.HighwindsinbothTaiwanStraitandthesoutheastcorneroftheislanddisappearandthefrequencydecreasesgraduallyfromsouthtonorthwhentheterrainisremoved.However,insummer,highwindfrequencyderivedfromtwosimulationswithandwithoutterrainisalmostidentical.Weattributethisphenomenontothefactorswhicharerespon

  • 标签: OFFSHORE HIGH winds in China COASTAL