简介：目的：探讨超声e-flow技术结合梯形成像在下肢交通支静脉功能不全诊断中的作用。方法回顾性分析23例行交通静脉结扎手术患者的超声图像，术前利用超声e-flow技术结合梯形成像检出交通支静脉，将其定位结果与手术结果比较，以检验其准确率。结果下肢交通支静脉功能不全表现为朝向体表的条状或网状血流，超声检出功能不全的交通支静脉47条，手术发现交通支静脉56条，以手术结果为金标准，诊断准确率为83.9%。结论超声e-flow技术结合梯形成像能准确诊断和定位功能不全的交通支静脉，有助于术中寻找需结扎的交通支静脉。

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简介：存在抵抗公式为石子床溪流生产大量磨擦因素估计。这份报纸的目的是以Darcy-Weisbach磨擦因素f开发一个可靠抵抗公式。出版数据被屏蔽并且过去常建立公式。存在公式认为f仅仅是相对粗糙D84/R的功能，在R是水力的半径，D84是指的粒子尺寸的地方等于或超过84%床沉积的中间的直径。在这份报纸，f除了相对粗糙被看作弗鲁德数字的功能。为D84/R的f>1为D84/R比那显示一个不同趋势<1也许由于为D84/R的对数的速度分布的无效假设>1。为D84/R的一个f公式<1被建立了。

简介：Withtheincreaseofpetroleumandgasproductionindeepocean,marinerisersofcircularcylindershapearewidelyusedintheoffshoreoilandgasplatform.Inordertoresearchthehydrodynamicperformanceofmarinerisers,thedynamicmeshtechniqueandUser-DefinedFunction(UDF)areusedtosimulatethecircularcylindermotion.Themotionofatransverselyoscillatingcircularcylinderincombinationofuniformflowandoscillatingflowissimulated.Theuniformflowandoscillatingflowbothareinxdirection.SIMPLEalgorithmisusedtosolvetheNavier-Stokesequations.TheUser-DefinedFunctionisusedtocontrolthecylindertransversevibrationandtheinletflow.Theliftanddragcoefficientchangingwithtimeandthemapofvorticityisolinesatdifferentphaseangleareobtained.ForcetimehistoriesareshownforuniformflowatReynoldsnumber(Re)of200andforthecombinationofuniformandoscillatingflows.Withtheincreaseofamplitudeofoscillatingflowincombinedflow,thechangeofliftamplitudeisnotsensitivetothethechangeofcylinderoscillatingfrequency.Liftamplitudeincreaseswiththeincreaseofoscillatingflowamplitudeinthecombinedflow,butthereisnodefiniteperiodicityoftheliftcoefficient.Thedragandinertiaforcecoefficientschangewhenthemaximumvelocityoftheoscillatingflowincreasesinthecombinedflow.Thevortexsheddingnearthecircularcylindershowsdifferentcharacteristics.

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简介：Themechanicalenergyequationisafundamentalequationofa1-DmathematicalmodelinHydraulicsandEngineeringFluidMechanics.ThisequationforthetotalflowusedtobededucedbyextendingtheBernoulli’sequationfortheidealfluidinthestreamlinetoastreamtube,andthenrevisedbyconsideringtheviscouseffectandintegratedonthecrosssection.Thisderivationisnotrigorousandtheeffectofturbulenceisnotconsidered.Inthispaper,theenergyequationforthetotalflowisderivedbyusingtheNavier-StokesequationsinFluidMechanics,theresultsareasfollows:(1)Anewenergyequationforsteadychannelflowsofincompressiblehomogeneousliquidisobtained,whichincludesthevariationoftheturbulentkineticenergyalongthechannel,theformulaforthemechanicalenergylossofthetotalflowcanbedetermineddirectlyinthedeductionprocess.(2)Thetheoreticalsolutionofthevelocityfieldforlaminarflowsinarectangularopenchannelisobtainedandthemechanicalenergylossintheenergyequationiscalculated.ThevariationsofthecoefficientofthemechanicalenergylossagainsttheReynoldsnumberandthewidth-depthratioareobtained.(3)Theturbulentflowinarectangularopenchannelissimulatedusing3-DReynoldsaveragedequationsclosedbytheReynoldsstressmodel(RSM),andthevariationsofthecoefficientofthemechanicalenergylossagainsttheReynoldsnumberandthewidth-depthratioarediscussed.

简介：Thispaperreviewssomeoftheprincipaluses,overalmostsevendecades,ofcorrelations,inbothEulerianandLagrangianframesofreference,ofpropertiesofturbulentflowsatvariablespatiallocationsandvariabletimeinstants.Commonlycalledspace–timecorrelations,theyhavebeenfundamentaltotheoriesandmodelsofturbulenceaswellasfortheanalysesofexperimentalanddirectnumericalsimulationturbulencedata.

简介：数字建模具有在理解地区性的地下水系统的行为的关键重要性。然而，当在长时间跨度上执行高分辨率的模拟时，为能力建模上的需求是集中的。这份报纸论述一个平行程序的应用程序加快在诺思中国平原地下水流动系统当模特儿详细说明。平行程序被在我们的并行计算的框架上重建著名MODFLOW程序实现，它被设计基于补丁的平行数据结构和算法，但是维持compute流动和MODFLOW的功能完成。有超过100万个格子和时间的一十年的详细模型被解决了。平行模拟结果对观察数据和这二个数据通常在好同意的地被检验。为在答案时间的比较，在32个核心上跑的平行程序比最快的基于MICCG的MODFLOW程序快6倍、比基于GMG的MODFLOW程序快11倍。因此，当使用平行程序时，显著计算时间能被节省，它便于在北方中国平原的快速的建模和地下水流动系统的预言。

简介：Inthiswork,westudiedthedimensionsofstreamtubeintheverticalaswellasinclinedbankconditions.Datawerecollectedfrombothaphysicalmodelanda3-Dnumericalmodel(SSIIM2).Equationsforpredictingstreamtubedimensionswerepresentedandcomparedwithexistingformulae.Incomparisonwithverticalbank,itisfoundthatincliningbankcausesthebottomstreamtubewidthtobegreaterthanatthesurface.Thestrengthofsecondarycurrentformedattheentranceofbranchchannelisreduced.Thesechangesinflowpatterncanreducetheamountofsedimentdeliveryintotheintake.

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简介：智能手机是个好东西，用得好那就是一个小型的移动终端，给咱们提供了不少方便。但是智能手机也不方便，除开一些病毒之类的闹心事儿，常常电量不足也很麻烦。有个同事就抱怨说，早上才给苹果充满电，还不到中午就只剩下75％了，要是有事儿出门，那充电器啊移动电源啊更是必不可少——那些东西都不轻呢!

简介：Thefullydevelopedslipflowinanannularsectorductissolvedbyexpansionsofeigenfunctionsintheradialdirectionandboundarycollocationonthestraightsides.Themethodisefficientandaccurate.Theflowfieldforslipflowdiffersmuchfromthatofno-slipflow.ThePoiseuillenumberincreaseswithincreasedinnerradius,openingangle,anddecreaseswithslip.

简介：NumericalsimulationsoftheflowinthedrafttubeofaFrancisturbinearecarriedoutinordertoelucidatetheeffectsoftangentialvelocityonflowstability.Influenceofthelocationofthemaximumtangentialvelocityisexploredconsideringtheequalityofthetotalenergyattheinletofthedrafttube.Itisfoundthattheamplitudeofthepressurefluctuationdecreaseswhenthelocationofthemaximumofthetangentialvelocitymovesfromthecentretothewallonthecrosssection.Thus,thestabilityoftheflowinthedrafttubeincreaseswiththemovingofthelocationofthemaximumtangentialvelocity.However,therelativehydrauliclossincreasesandtherecoverycoefficientofthedrafttubedecreasesslightly.

简介：作者认为夸张几何流动是\(\tfrac{{\partial^2}}{{\partialt^2}}g(t)=-2Ric_{g(t)}\)由Kong和刘介绍了。用沿着Ricci的方程由Brendle流动处理进化的技术和想法，作者在夸张几何流动下面为Levi-Civita连接和弯曲张肌导出进化方程的全球形式。另外，同样流动到Ricci大小写，在有限时间开发奇特的夸张几何流动的任何答案有无界的Ricci，这被显示出弯曲。

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简介：Numericalsimulationsof10kWand110kWinductivelycoupledplasma(ICP)windtunnelswerecarriedouttostudyphysicalpropertiesoftheflowinsidetheICPtorchandvacuumchamberwithairastheworkinggas.Two-dimensionalcompressibleaxisymmetricNavierStokes(N-S)equationsthattookintoaccount11speciesand49chemicalreactionsofair,weresolved.Aheatsourcemodelwasusedtodescribetheheatingphenomenoninsteadofsolvingtheelectromagneticequations.Inthevacuumchamber,afour-temperaturemodelwascoupledwithN-Sequations.Numericalresultsforthe10kWICPwindtunnelarepresentedanddiscussedindetailasarepresentativecase.Itwasfoundthattheplasmaflowinthevacuumchambertendedtobeinlocalthermochemicalequilibrium.Tostudytheinfluenceofoperationconditionsontheflowfield,simulationswerecarriedoutfordifferentchamberpressuresand/orinputpowers.ThecomputationalresultsfortheabovetwoICPwindtunnelswerecomparedwithcorrespondingexperimentaldata.Thecomputationalandexperimentalresultsagreewell,thereforetheflowfieldsofICPwindtunnelscanbeclearlyunderstood.

简介：Theformationoflandslidedamsisofteninducedbyearthquakesinmountainousareas.Thefailureofalandslidedamtypicallyresultsincatastrophicflashfloodsordebrisflowsdownstream.Significantattentionhasbeengiventotheprocessesandmechanismsinvolvedinthefailureofindividuallandslidedams.However,theprocessesleadingtodominofailuresofmultiplelandslidedamsremainunclear.Inthisstudy,experimentaltestswerecarriedouttoinvestigatethedominofailureoflandslidedamsandtheconsequentenlargementofdownstreamdebrisflows.Differentblockageconditionswereconsidered,includingcompleteblockage,partialblockageanderodiblebed(noblockage).Themeanvelocityoftheflowfrontwasestimatedbyvideos.Totalstresstransducers(TSTs)andLaserrangefinders(LRFs)wereemployedtomeasurethetotalstressandthedepthoftheflowfront,respectively.Underacompleteblockagepattern,aportionofthedebrisflowwastrappedinfrontofeachretainedlandslidedambeforethelattercollapsedcompletely.Thiswasaccompaniedbyadramaticdecreaseinthemeanvelocityoftheflowfront.Conversely,underbothpartialblockageanderodiblebedconditions,themeanvelocityoftheflowfrontincreasedgraduallydownwardalongtheslopingchannel.Dominofailuresofthelandslidedamsweretriggeredwhenaseriesofdams(completeblockageandpartialblockage)weredistributedalongtheflume.However,notallofthesedominofailuresledtoenlargeddebrisflows.Themodesofdamfailureshavesignificantimpactsontheenlargementofdebrisflows.Therefore,furtherresearchisnecessarytounderstandthemechanismsofdominofailuresoflandslidedamsandtheireffectsontheenlargementofdebrisflows.

简介：作为在许多设计应用程序的一个基本问题，到骚乱的从laminar的转变在计算液体动力学(CFD)仍然是一个困难的问题。一过渡流动在的数字研究二维被雷纳兹进行在这份报纸的平均数字模拟(RANS)。骚乱模型戏在复杂流动模拟的一个重要角色，和四个先进骚乱模型被评估。摩擦抵抗系数的数字答案与在过渡地区的测量那个相比，它显示有修正的那个威尔科克斯(2006)k-模型是最好的候选人。平均无尺寸的速度介绍的streamwise的无尺寸的速度表演的数字、分析的解决方案的比较在过渡区域很快改正形状。而且，象骚乱动能，旋涡粘性，和雷纳兹应力那样的骚乱数量也被学习，它是有用的学习转变行为。

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