简介：Saturatedhydraulicconductivity(Ks)isanimportantsoilhydraulicparameterforcharacteringtherateofwaterflowacrossthesoilsandismainlyrelatedtoitshighspatialvariability.Inasmallwatershedwiththeareaof0.27km2intheLoessPlateau,Ksof197soilsamplesunderdifferentvegetationsandlandformsweremeasured.Kshadamoderatevariabilityfortotalsamples.TheforestlandhadhighKswithlowcoefficientofvariation(CV),butthegrasslandinthewatershedbottomhadlowKswit...

简介：Electro-hydraulicservovalveisatypicalcomplicatedmulti-domainsystemconstitutedbymechanical,electric,hydraulicandmagneticcomponents,whichiswidelyusedinelectro-hydraulicservosystemssuchasconstructionmachinery,heavyequipment,weaponandsoforth.Thetraditionalmethodofmodelingandsimulationofservovalveisbasedonblockdiagramorsignalflow,whichcannotdescribetheservovalvesystemfromcomponentslevelnorbeusedinmodelingandsimulationofoverallservosystems.Intheprocedureoftraditionalmethod,computationalcausalitymustbeinvolvedinmodelingofservovalve,whichisinconvenienttoexecutemodificationoncomponentsorparameters.Modelicaisanobject-orientedmodelinglanguagewhichissuitedforlarge,complex,heterogeneousandmulti-domainsystems.ThekeyfeaturesofModelicaaremulti-domain,object-orientedandnon-causal,whicharesuitableformodelingofservovalveandmakethemodelreadable,reusable,andeasytomodify.Thesimulationresultsshowsimilarcurveswithtraditionalmethod.Thisnewservovalvemodelingandsimulationmethodcanprovidetheengineersamoreefficientwaytodesignandoptimizeaservovalveandanoverallservosystem.

简介：PI控制策略为一个水力的起重机吊杆系统(HCBS)的活跃抑制控制基于模糊集合点weighting列在后面被建议。控制Twovalve的PI控制器，基于列在后面的fuzzyset点weighting和一个有限半综合者(大规模集成电路)包括一个比例的前馈控制控制器，分别地被设计。大规模集成电路习惯于限制输出信号并且在光谱的低频率结束阻止。由使用一个范围照相机和电子反馈控制，在HCBS上抑制的尖端能人工地被调整。HOPSAN和MATLAB/SIMULINK的一种合作控制模拟技术被用于控制器设计。模拟结果证明建议PI控制系统让更少象更快的反应一样射。在操作期间在HCBS上抑制的尖端被改进。

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简介：Takingaccountofturbulenceintensity,non-uniformityofvelocitydistributionattheinitialandsequentsec-tionofhydraulicjumpandfrictionaldragonthefloorwithinjumprange,thispaperderivesnewformulasforcal-culatingtheratioofconjugatedepthsandtheefficiencyofenergydissipationinthetwo-dimensionalfreehydraulicjump.Ithasbeenverifiedbytestdatathatthenewformulasarenotonlyexactintheorybutalsostillbetterinconformitywithpractice.

简介：Formulatedaresimplemodelsfortheflowinliquidfilm,formedbyimpingingjet,andatwo-phasedownwardflowinpipe.Themodelsarebasedonsimplifiedequationsofmass,momentumandenergy.thesolutionofsuchconservationequationsmayhaveregularpointsbelongingtooneintegralcurveonlyaswellasturningpointscanbefoundamongstthem.Whichrefertoextremevaluesintheappropriateco-ordinatesystem.Thesolutionscanalsohavesingularpointsbelongingtononeormorethanoneintegralcurve,Boththeturningandsingularpointshaveaclearphysicalmeaning.Theycouldbelinkedtocriticalflowconditionsinthepipeflowortotheso-calledhydraulicjump.Analogyexistingbetweencriticalconditionsinthepipeandtheflowofliquidfilmsformedbytheliquidjethavebeenshowninthepaper.

简介：Thewaterintakeheadinstalledwithinclinedboardingsiscalledlaminatesedimentprecipitation,whichseparatesliquidandsolidparticlesintwo-phaseflowbygravity.ThepaperpresentstheequationsforcalculatingthedistanceHbetweentwoincllinedboardings,indicatingthatHhasakeyeffectontheparticleprecipitationvelocityV2.Thepaperfocusesalsoonthecal-culationofhydraulicsimilarityofmodelwiththetheoreticmodel.

简介：-Thispapercarriesouttheanalysisofmechanicsofagripsystemofthree-key-boardhydraulictongsdevelopedforoffshoreoilpipelineswhichhasbeensuccessfullyusedinoilfieldsinChina.Themainimprovementofthissystemisthataleverframestructureisusedinthestructuraldesign,whichreducesgreatlythestressesofthemajorcomponentsoftheoilpipetongs.Theoreticalanalysisandnumericalcalcu-lationbasedonthirteenbasicequationsdevelopedshowthattheteethboardofthetongsisnoteasytoslipasfrequentlyhappenstoothersystemsandisofhigherreliability.

简介：Electro-hydraulicimpulsewater-airmixingjetbywhichthequalityofmetalmaterialscanbeimprovedisdescribedinthispaper.Theexperimentalresultsprovedthatthehardnessandthemicro-hardnessofthesurfacelayerofmetalmaterialscanbeimprovedwiththismethod,forexample,themicrohardnessofCrWMncanbeincreasedby35.62percent.

简介：为有在出现在所有团中的控制输入隧道和参数无常的时间延期的电镀物品水力的激活的结构的系统的一个类的柔韧的活跃颤动控制的问题，抑制并且僵硬矩阵在这份报纸被调查。由介绍一个线性变化参数，首先，非线性的系统被描述为变化的一个线性参数(LPV)模型。基于这个LPV模型，第二，为asymptotically要稳定的系统的一个基于LMI的条件被推出。由解决这些LMI，一个参数依赖者控制器为与骚乱变细的规定水平稳定的closedloop系统被建立。条件也被扩大到不明确的案例。最后，一些数字模拟表明建议控制器的令人满意的表演。

简介：Apotexperimentwasconductedtoinvestigatetheeffectsofnitrogencontent[N1(nofertilizer),N2(0.15g?kg–1),andN3(0.3g?kg–1)]onthegrowthandthehydrauliccharacteristicsofpeachseedlingsunderdifferentsoilmoistureconditions(W1,W2andW3,inwhichthesoilwatercontentwas45%to55%,60%to70%,and75%to80%ofthefieldwatercapacity,respectively)byusingaspecializedhighpressureflowmeterwitharootchamberandacoupling,whichwasconnectedtoplantorgans.Leafareaandleafhydraulicconductivity(KL)increasedsignificantlyintheseedlingsbecauseofincreasedsoilmoistureandNcontent.KLincreasedwithleafarea.AlinearcorrelationwasdocumentedbetweenKLandleafarea.KLwashigherinthemorningandbegantodeclinesharplyafter16:00,atwhichKLdeclinedafteraninitialincrease.SoilmoistureandNcontentenhancedshoot(Ks)androot(Kr)hydraulicconductivities,therebyimprovingthelowsoilmoistureconditiontoalargeextent.KsandKroftheseedlingswerereducedby32%and27%respectivelyinN1,andby14.7%and9.4%,respectivelyinN2,andbothinW1,comparedwiththecontroltreatment.N3hadnosignificanteffectonKsandKrundersimilarconditions.LinearnegativecorrelationswereobservedbetweenKrandtheexcisedrootdiameteraswellasbetweenKsandtheshootstemdiameter.Theshoot-to-rootratioincreasedwithincreaseinNcontent.Theshoot-to-rootratioinN3wasincreasedby14.37%,comparedwithN1inW1aswellasby12%and4.39%inW2andW3,respectively.KnowledgeoftheeffectsofsoilmoistureandNfertilizeronhydrauliccharacteristicsandgrowthisimportant.Ourresultsprovidebasicguidelinesfortheimplementationofwater-savingirrigationandfertilizationmanagementofnurserystock.

简介：摘 要：以咸宁市扩建给水管网系统为例，运用EPANET建立水力模型，模拟城市供水管网的现状运行工况，并对需要新建的管道管径及管材进行优化选择，从管道流量、管道流速和水头损失三个指标的比较来体现运用EPANET水力模型设计的管道设计方案相较于现状管道方案的安全可靠性和经济性，从而验证建立城市给水管网EPANET水力模型优化管道设计方案的可行性。

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