简介：AnewReynolds-averagedNavier-Stokes(RANS)turbulencemodelisdevelopedinordertocorrectlypredictthemeanflowfieldinadrafttubeoperatingunderpartialloadusing2-Daxisymmetricsimulations.Itisshownthatalthough2-Daxisymmetricsimulationscannotmodelthe3-Dunsteadyfeaturesofthevortexrope,theycangivetheaveragelocationofthevortexropeinthedrafttube.Nevertheless,RANSsimulationsunderpredicttheturbulentkineticenergy(TKE)productionanddiffusionnearthecenterofthedrafttubewherethevortexropeforms,resultinginincorrectcalculationofTKEprofilesand,hence,poorpredictionoftheaxialvelocity.Basedonthisobservation,anewk-εturbulenceRANSmodeltakingintoaccounttheextraproductionanddiffusionofTKEduetocoherentstructuresassociatedwiththevortexropeformationisdeveloped.Thenewmodelcansuccessfullypredictthemeanflowvelocitywithsignificantimprovementsincomparisonwiththerealizablek-εmodel.ThisisattributedtobetterpredictionofTKEproductionanddiffusionbythenewmodelinthedrafttubeunderpartialload.Specifically,thenewmodelcalculates31%moreproductionand46%morediffusionrightattheshearlayerwhencomparedtothek-εmodel.

简介：这份报纸为不一致的自然沉积混合物的运输以中部的谷物尺寸和有效沉积尺寸评估代表性的沉积尺寸的适用性。来自Krasak河的自然沉积，Yogjakarta被使用。床样品从三不同的河节被收集，即在上游的(U)，中流(M)和下游的(D)。中部的直径，d50和沉积几何标准差，为节U，M和D的g是1.63公里，0.91公里和0.69公里，并且4.8，2.3和1.5分别地。特别注意对在阀值沉积运动上改变代表性的沉积尺寸的效果被给予，在四个阀值方程被采用的地方。当时，阀值价值变化g=4.8g=4.8并且与g<2.4g<2.4。分析用有或没有沉积运动的阀值标准说明两个的八个选择公式被扩大到水流带来的碎石运输的预言。到为床材料的不一致的报道，当时，在用d50的计算水流带来的碎石分泌物之间的比较与水流带来的碎石预言被做代表性的沉积直径被使用。当有效沉积尺寸为不一致的沉积混合物被采用时，统计分析的改进仅仅为预言被观察的分析表演计算了使用Brownlie(1981)和Camenen和Larson(2005)表情。采用有效沉积缩放de或d计算水流带来的碎石分泌物的他们未必确实改进水流带来的碎石预言，d50的使用被看作足够。

简介：Theharmonicdriveisakindofgeartransmissionthatuseswavegeneratortoproducecontrollablesoftroundelasticdeformationandengageswithrigidgeartotransmitmotionandpower.Theloaddistributiononthesurfaceoftheflexiblegearandwavegeneratorisanimportantparameterofstudyingthedeformationofflexiblegearandflexiblebearingoutsidethewavegeneratorandisalsoanecessaryconditionforstudyingthefatiguedamageofflexiblegearunderalternatingload.Inthispaper,a3Dmodelof32-type80:1harmonicdriveisbuild.BasedonthegeneralizedHookelaw,ahypothesisofloaddistributionwhichisprovedtobevaliditybyusingfiniteelementsimulationisproposedontheinterfaceofflexiblegearandwavegenerator.Onthisbase,themathematicmodelandthequantitativecalculationformulaoftheloaddistributiononthesurfaceoftheflexiblegearandwavegeneratorareproposedwhichprovideabasisforthedynamicanalysisandthefatiguedamageofharmonicgeardrive.

简介：这份报纸建议新方法论选择最佳的阀值水平在阀值(壶)上在山峰被过去常为负担极端的短期的分布的预言的方法近海风汽轮机。如此的最佳的阀值水平为山峰价值的出现基于variance-to-mean比率的评价被发现，它描绘泊松假设。概括Pareto分布然后在最佳的阀值水平上被适合到提取山峰，分发参数被最大的间距评价的方法估计。这方法论被使用估计把时刻和在支持monopile的5MW的mudline把时刻弄弯的塔底弄弯的片的负担极端的短期的分布近海风汽轮机作为一个例子。用最佳的阀值水平的POT方法的精确性被显示更好，以分发试穿，比用实验阀值层次的POT方法的。在短期的极端反应价值之中的比较由与最佳的阀值层次并且与实验阀值层次并且由直接使用使用POT方法预言模拟结果进一步证实建议新方法论的有效性。

简介：Basedontheloadmodelofauniformisotropicsemi-infiniteelasticmedium,wededucedacalculationofverticaldisplacementandtiltandproposedamethodofcalculationofverticaldisplacementsandtiltscausedbyirregularloadonthegroundorundergroundatacertainpointwithtwo-dimensionalandthree-dimensionalshapes.Wecomparedthedifferencebetweenthesimplifiedmodelandtheirregularmodel.Finally,theverticaldisplacementsneartheirregularloadandthedistributionofhorizontaltiltarepresented.Theresultsshowthat,comparedwiththepointsimplifiedmodel,theirregularloadmodelhascertainadvantagesfordescribingthenearfield.Theestablishmentofatwodimensionalirregularloadmodelcanhelpwiththecalculationofthemodalvectorsuperpositionafterloadscattering.Thethree-dimensionalirregularloadmodelcanredistributeloadthroughdifferentweightsgiventothescatteredpointsaftertheloadscattering,andthenobtaindisplacementwiththevectorcalculationmethod.Theresultsofvectorsuperpositioncalculationfromthescatteredirregularloadbothintwo-dimensionsandthree-dimensionsareallconvergentobviouslyasgridsbecomedenser,anditisshownthatthecalculationmethodiscorrectandfeasible.

简介：WiththecontrolofpointsourcepollutioninDianchiLakebasin,andtheexpansionofKunmingcity,non-pointsourcepollutionhasbecomethemainsourcepollutionofurbanwaterenvironmentandDianchiLake.Torevealthenitrogenpollutioncharacteristicsinwatershed,thisresearchselectedkeymonitoringpointsandsectionsatBaoxiangriverbasininrainyseasonwhichisthepeaktransportedtimeofnon-pointsourcepollution,thenitrogenandhydrologicalindicatorsaremonitoredsystematically.Thedifferentformsofnitrogenareanalyzed,thepollutionloadofnitrogenarecalculatedandstudiedatcardinalsections;combinedwiththeliteraturedata,wecomparedthewaternitrogencharacteristicsofDianchibasinandTaihubasin,themainresultsareasfollows:(1)Insummer,waternitrogenformofBaoxiangriverintheCaoheareaisdominatedbynitratenitrogen,whileinotherareasitisdominatedbyammonianitrogenwhichisaccountedfor31%-50%oftotalnitrogen;(2)ThewaterpollutionloadsofBaoxiangrivertendedtoincreasefromupstreamtodownstream,fromJunetoAugustthetotalnitrogenpollutionmainlycomesfromurbanareasandthepollutionloadis166.408t;(3)InDianchiLakewatershedandTaihuLakewatershednitrogenconcentrationofinflowriverishigherthanthatofthelake,nitratenitrogenconcentrationbetweeninflowriverandlakeshowsalittledifference,whileammonianitrogenconcentrationofinflowriverishigherthanthatofthelake.TheresultscanprovidethetheoreticalbasisfornonpointsourcepollutioncontrolandurbanwaterenvironmentplanningandimprovementinDianchiLakeBasin.

简介：在有高地震的危险的地点的风汽轮机的宽推广导致了工程师考虑如此的结构的一个更全面的地震图案。汽轮机特定的指南通常使用简化方法并且认为许多假设把地震需求与完成这些结构的设计的另外的运作的负担相结合。当汽轮机在尺寸和能力增加，在地震负担和空气动力学的负担之间的相互作用变得甚至更重要。响应对能执行风和地震负担的联合模拟的一个计算工具的需要，一个地震模块为快代码被开发并且在这描述了研究。这个平台允许在这工业工作直接考虑在之间的相互作用的工程师地震并且为汽轮机的另外的环境负担。这篇论文详细说明这个平台的实际应用程序和理论并且为不同能力的使用提供例子。站台然后被用来与由估计适当负担因素的空气动力学的抑制的含蓄的考虑显示出合适的地震和运作的负担联合。

简介：Adesignofsemi-submersibleplatformismainlybasedontheextremeresponseanalysisduetotheforcesexperiencedbythecomponentsduringlifetime.Theexternalloadscaninducetheextremeairgapresponseandpotentialdeckimpacttothesemi-submersibleplatform.Itisimportanttopredictairgapresponseofplatformsaccuratelyinordertocheckthestrengthoflocalstructureswhichwithstandthewaveslammingduetonegativeairgap.Thewindloadcannotbesimulatedeasilybymodeltestintowingtankwhereasitcanbesimulatedaccuratelyinwindtunneltest.Furthermore,fullscalesimulationofthemooringsysteminmodeltestisstillatuffworkespeciallythestiffnessofthemooringsystem.Owingtotheabovementionedproblem,themodeltestresultsarenotaccurateenoughforairgapevaluation.Theaimofthispaperistopresentsensitivityanalysisresultsofairgapmotionwithrespecttothemooringsystemandwindloadforthedesignofsemi-submersibleplatform.Thoughthemodeltestresultsarenotsuitableforthedirectevaluationofairgap,theycanbeusedasagoodbasisfortuningtheradiationdampingandviscousdraginnumericalsimulation.Inthepresenteddesignexample,anumericalmodelistunedandvalidatedbyANSYSAQWAbasedonthemodeltestresultswithasimple4linesymmetricalhorizontalsoftmooringsystem.Accordingtothetunednumericalmodel,sensitivityanalysisstudiesofairgapmotionwithrespecttothemooringsystemandwindloadareperformedintimedomain.Threemooringsystemsandfivesimulationcasesaboutthepresentedplatformaresimulatedbasedontheresultsofwindtunneltestsandsea-keepingtests.Thesensitivityanalysisresultsarevaluableforthefloatingplatformdesign.

简介：目的探讨改良Load-sharing评分对胸腰段脊柱骨折手术治疗方法选择的指导价值。方法选取2012年9月至2014年9月我院收治的69例胸腰段脊柱骨折患者为研究对象,根据改良Load-sharing评分选择不同的手术方式,对于评分为4~6分的患者应用后路手术;对于评分≥7分且保留完整骨折椎后方结构、不伴有脱位的患者,应用前路手术＋骨折椎体次切＋前路植骨术;对于评分≥7分且骨折椎后方结构破坏或伴有脱位的患者,应用前后路联合手术＋骨折椎体次切＋前路植骨术。观察记录临床治疗效果。结果所有患者的后凸角、椎管占位及椎体压缩于手术后均得到恢复,与手术前比较差异具有统计学意义（P〈0.05）。40例不完全性神经功能损害患者中,3级神经功能恢复者2例,2级神经功能恢复者14例,1级神经功能恢复者24例。根据Denis分级对术后腰痛评价分级,P149例,P214例,P36例。术后31例恢复原来从事工作或体力劳动,32例更换较轻松工作或轻体力劳动,6例生活能自理但不能参加正常工作及劳动。结论改良Load-sharing评分对胸腰段脊柱骨折手术治疗方法的选择具有重要指导价值。