简介：InthispaperweextendthemethoddevelopedinforlimitingStokeswaveofinfinitewaterdepthtocoverthecaseoffinitedepth.Themethodhashighefficiencyandtheresultisaccurate.

简介：Stokesdriftisthemainsourceofverticalvorticityintheoceanmixedlayer.InthewaysofCoriolis-StokesforcingandLangmuircirculations,Stokesdriftcansubstantiallyaffectthewholemixedlayer.AmodifiedMellor-Yamada2.5levelturbulenceclosuremodelisusedtoparameterizeitseffectonupperoceanmixingconventionally.Resultsshowthatcomparingsurfaceheatingwithwavebreaking,Stokesdriftplaysthemostimportantroleintheentireoceanmixedlayer,especiallyinthesubsurfacelayer.Asexpected,Stokesdriftelevatesboththedissipationrateandtheturbulenceenergyintheupperoceanmixing.Also,influenceofthesurfaceheating,wavebreakingandwindspeedonStokesdriftisinvestigatedrespectively.ResearchshowsthatitissignificantandimportanttoassessingtheStokesdriftintooceanmixedlayerstudying.Thelaboratoryobservationsaresupportingnumericalexperimentsquantitatively.

简介：Inthispaper,weconsiderthefollowinginitialproblemofsemilinearStokesequationswiththeexistenceofglobalsolutionsobtained

简介：Inthispaper,weconsidertheso-called"inexactUzawa"algorithmappliedtotheunstableNavier-Stokesproblem.Weusestabilizationmatrixtostabilizetheunstablesystemandprovedtheoreticallythatundergivenproperpreconditioners,Uzawaalgorithmisconvergentforthestablizationsystem.Boundsfortheiterationerrorareprovided.WeshownumericallythatUzawaalgorithmisconvergentaswellforthestabilizationsystemswhenitisusedinthesteady-stateNavier-Stokesproblem(cf.[6]).

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简介：Inthispaper,weproposeamortarelementmethodwithLagrangemultiplierforincompressibleStokesproblem,i.e.,thematchingconstraintsofvelocityonmortaredgesareexpressedintermsofLagrangemultipliers.WealsopresentP_1noncon-formingelementattachedtothesubdomains.Byprovinginf-supcondition,wederiveoptimalerrorestimatesforvelocityandpressure.Moreover,weobtainsatisfactoryapproximationfornormalderivativesofthevelocityacrosstheinterfaces.

简介：Thispaperaddressesanonstationaryflowofheat-conductiveincompressibleNewtonianfluidwithtemperature-dependentviscositycoupledwithlinearheattransferwithadvectionandaviscousheatsourceterm,underNavier/Dirichletboundaryconditions.Thepartialregularityforthevelocityofthefluidisprovedforeachproperweaksolution,thatis,forsuchweaksolutionswhichsatisfysomelocalenergyestimatesinasimilarwaytothesuitableweaksolutionsoftheNavier-Stokessystem.Finally,westudythenatureofthesetofpointsinspaceandtimeuponwhichproperweaksolutionscouldbesingular.

简介：摘要目的系统比较复苏性主动脉球囊阻断术（REBOA）与复苏性剖胸术（RT）治疗不可压迫性躯干出血（NCTH）的预后。方法通过计算机检索MEDLINE、EMBASE、PubMed、万方数据库、中国知网、维普期刊数据库，收集REBOA与RT治疗NCTH患者预后比较的文献。检索时限为建库至2020年12月的相关文献。由2名研究者按照纳入与排除标准独立进行文献筛选、资料提取与质量评价后，采用Revman 5.3软件进行Meta分析。根据入院时对患者所采取的治疗方式将其分为REBOA组与RT组，并对各组的预后程度进行评价，观察REBOA与RT治疗NCTH患者的病死率、术后剖腹手术再发生率、术后栓塞手术发生率、手术区域病死率差异。采用Egger法检测发表偏倚。结果纳入2篇前瞻性研究和4篇回顾性研究，共2 588例研究对象，其中REBOA组1 591例，RT组997例。在病死率（I2=68%，OR=0.33，95%CI 0.26~0.42，P<0.01）、术后剖腹手术再发生率（I2=76%，OR=1.41，95%CI 1.11~1.77，P<0.01）和术后栓塞手术发生率（I2=84%，OR=0.76，95%CI 0.59~0.99，P<0.05）方面，REBOA组与RT组差异有统计学意义。亚组分析结果显示，ICU室REBOA组病死率与RT组差异无统计学意义（I2=83%，OR=0.69，95%CI 0.45~1.05，P>0.05），急诊室REBOA组病死率低于RT组（I2=94%，OR=0.52，95%CI 0.38~0.70，P<0.01）。Egger检验显示发表偏倚对结果影响较小。结论与RT治疗相比，REBOA治疗NCTH可降低患者病死率、术后栓塞手术发生率，但是增加了患者的剖腹手术再发生率，同时急诊室比ICU更适合作为REBOA常备的手术区域。

简介：摘要：随着油气田开发进度的深入，储层压裂效果直接影响到后期储层产量及增产措施。本文应用气田应用较多的偶极子声波测井，构建一套储层可压性评价方法，在评价压裂效果的同时，为后期压裂提供指导参数，为油气公司的工程压裂施工提供测井技术支撑。

简介：摘要：页岩油可压性是评价储层能否作为工程“甜点”关键参数之一。可压性用于表征储层体积压裂改造的难易程度，主要分析地质因素对形成复杂裂缝的影响程度，可压性的好坏直接关系到储层体积改造形成缝网的效果。储层可压性越好，体积改造效果越好；储层可压性越差，体积改造效果越差。通过初步的探索与研究，英雄岭干柴沟区块页岩油可压性可用“脆性、地应力差异”两个因素进行表征。

简介：有一个智者即将经过一个经商为主的小镇,他还没到来之前,已经在小镇引起了广泛的议论,大家都觉得这么一个伟大的人物来了,一定要他对我们好好地说些什么。这一天,智者经过了小镇,他被镇民请了过去,央求他对大家说些话。智者说:"我和你们一样平凡,没有什么特

简介：以一个空气压缩机的油气分离器为研究对象，以雷诺平均NS方程为控制方程，以Realizablek-ε模型为湍流模型（DPM）对油气分离器内气液两相流流场进行了数值模拟。最近将数值模拟结果与工程试验数据进行了对比，验证了计算模型的准确性。

简介：摘要：本文针对压缩机转子中窄流道二元流叶轮的一种制造方法，避开了小流量压缩机中窄流道二元叶轮采用纯铆接或“钎+铆”接的传统制造方式，提出了新的制造技术，即“半开＋半闭”式相结合的叶轮铣制技术及“钎＋环”焊的焊接技术 , 使制造出的叶轮更加符合原始设计。

简介：APLU-SGSmethodbasedonatime-derivativepreconditioningalgorithmandLUSGSmethodisdevelopedinordertocalculatetheNavier-Stokesequationsatallspeeds.TheequationswerediscretizedusingAUSMPWschemeinconjunctionwiththethird-orderMUSCLschemewithVanLeerlimiter.ThepresentmethodwasappliedtosolvethemultidimensionalcompressibleNavier-Stokesequationsincurvilinearcoordinates.Characteristicboundaryconditionsbasedontheeigensystemofthepreconditionedequationswereemployed.Inordertoexaminetheperformanceofpresentmethod,driven-cavityflowatvariousReynoldsnumbersandviscousflowthroughaconvergent-divergentnozzleatsupersonicwereselectedtotestthismethod.Thecomputedresultswerecomparedwiththeexperimentaldataortheothernumericalresultsavailableinliteratureandgoodagreementsbetweenthemareobtained.Theresultsshowthatthepresentmethodisaccurate,self-adaptiveandstableforawiderangeofflowconditionsfromlowspeedtosupersonicflows.

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简介：这份报纸与可变粘性为分离Oseen问题的反复的答案处理preconditioners。这个工作的动机从多相的流动的数字模拟发源，由联合Cahn-Hilliard和不可压缩的海军司烧方程管理了。某已知的preconditioning技术上的可变粘性的影响被分析。理论考虑和数字实验证明一些广泛地使用了preconditioning技术因为当粘性正在变化时，有经常的粘性的Oseen问题也是有效的。

简介：Thevelocitiesofboundarylayerflowsbetweentwoparalleloscillatingplatesseparatedbysmalldistance,i.e.,insocallednarrowchannel,weretheoreticallyandexperimentallystudied.ThefocuswasonthelaminarcasewheretheReynoldsnumberReAismuchsmallerthanthetransitionvalue.ThetheoreticalanalysisoftheStokeslayerinoscillatingflowoveranarrowchannelwasmadefirst.ThenLaserDopplerVelocimeter(LDV)wasemployedtomeasuretheStokesboundarylayeraboveanoscillatingflatplateandinsidetheoscillatingnarrowchannelatvariousReHnumbers.Atthesametime,thephaseangledifferencealongtheverticaldirectioninbothanalysisandexperimentwereprovided.Thegoodagreementsareshownbetweenthemeasuredresultsandthetheoreticalsolution.

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