简介：Theformulaeusedtocalculatethefrictioninthenon-uniformflowchutewereexaminedwiththeexperimentaldata,andtheresultsshowthattheaccuracyoftheformulaisenoughforengineeringapplications.Acomparisonbetweentheresultsoffrictionrespectivelyfromtheuniformflowassumptionandthenon-uniformflowapproximationindicatesthattheformerisanorderofmagnitudelargerthanthelatterinthecaseofsteepchute.Thehydraulicdragonasteepchutewithaeratorswasmeasuredonthehydraulicmodeldirectlyandthecoefficientoftheaeratoreffectonthedragwasobtained.Thevariationpatternsofthewallshearjustdownstreamoftheaeratorswereinvestigatedandthemechanismoftheincreaseinthedragbyaeratorwereanalyzedqualitativelywiththemeasuredwater-depthsjustdownstreamtheaerators.

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简介：AmovablebedphysicalmodelwasconstructedtoinvestigatehydraulicdesiltationbyflushingandlateralerosionintheTapureservoir,Taiwan.Themodelscalingisbasedontherequirementfordynamicsimilarityofcohesivesedimentdepositinitiationinflushingprocesses.Formodelscaling,flumeexperimentsinvestigatingtheinitiationofcohesivesedimentdepositswerecarriedouttoestablishtherelationshipbetweencriticalshearstressoftheflowanddrydensityofthedeposit.Experimentsinthephysicalmodelwerethenperformedtomeasurethevariationsofthereservoirwaterlevel,theoutletdischargeandtheoutflowsedimentdischarge.Theprocessesofemptyingandflushingwereobservedandanalyzedinthemainflushingchannel.Oneoftheexperimentswasconductedtosimulatetheon-siteflushingoperationsonJune11,1997.Theresultsshowedthatthetotalcumulativeflushedsedimentvolumebyphysicalmodelingwasclosetothatbynumericalsimulation.Todealwiththefloodplaindeposits,experimentsoflateralerosionasanauxiliarymethodwerealsoconductedinthephysicalmodeltoinvestigatetheeffectivenessandapplicabilityfortheTapureservoir.

简介：FourgianthydraulicturbinesofYantanHydropowerSta-tionlocatedontheHongshuiRiver,GuangxiProvincearenowunderconstructionbytheHarbinElectricMachineryWorks(HEMW)ofChinaHarbinPower-PlantEquipmentCorporation(GROUP).TheturbinewillbecomethelargestindimensionforFrancistypeturbineevermadeinChina.Theexternaldiameteroftherunneris8.6m,whichissupposedtoberankedNo.3amongthelargestrunnersofthiscategoryintheworld.Eachturbineisrated

简介：Intherillerosionprocess,run-onwaterandsedimentfromupslopeareas,andrillflowhydraulicparametershavesignificanteffectsonsedimentdetachmentandtransport.However,thereisalackofdatatoquantifytheeffectsofrun-onwaterandsedimentandrillflowhydraulicparametersonrillerosionprocessatsteephillslopes,especiallyintheLoessPlateauofChina.Adual-boxsystem,consistingofa2-m-longfeederboxanda5-m-longtestboxwith26.8%slopegradientwasusedtoquantifytheeffectsofupsloperunoffandsediment,andofrillflowhydraulicparametersontherillerosionprocess.Theresultsshowedthatdetachment-transportwasdominatedinrillerosionprocesses;upsloperunoffalwayscausedthenetrilldetachmentatthedownsloperillflowchannel,andthenetrilldetachmentcausedbyupsloperunoffincreasedwithadecreaseofrunoffsedimentconcentrationfromthefeederboxoranincreaseofrainfallintensity.Upsloperunoffdischargingintotherillflowchanneloranincreaseofrainfallintensitycausedtherillflowtoshiftfromastratumflowintoaturbulentflow.Upsloperunoffhadanimportanteffectonrillflowhydraulicparameters,suchasrillflowvelocity,hydraulicradius,Reynoldsnumber,FroudenumberandtheDarcy-Weisbachresistancecoefficient.Thenetrilldetachmentcausedbyupsloperunoffincreasedastherelativeincrementsofrillflowvelocity,ReynoldsnumberandFroudenumbercausedbyupsloperunoffincreased.Incontrast,thenetrilldetachmentdecreasedwithanincreaseoftherelativedecrementoftheDarcy-Weisbachresistancecoefficientcausedbyupsloperunoff.Thesefindingswillhelptoimprovetheunderstandingoftheeffectsofrun-onwaterandsedimentontheerosionprocessandtofindcontrolstrategiestominimizetheimpactofrun-onwater.

简介：Hydraulicspinalcordandcaudaequinanerveinjuriesareveryuncommon.Since1996,wehavereceivedandtreated4patientswithhydraulicspinalcordandcaudaequinainjuries.Thisreportgivesadetaildescription.Fourpatientswithhydraulicspinalcordandcaudaequinanerveinjuries,male:3,female:1,aging13-56yearshavebeentreatedinourhospitalsince1996.Extraduralblockinginjurywasin1patient,extraduralanaesthesiainjuryin1patientandintraspinalcanalmyelographyinjuryin2patients;thesegmentsofintraspinalcanalwereL2-3andL3-4.Onepatientwasaccompaniedbyfemoralfracture,2patientsbyintraspinaltumorand1patienthadoperationbecauseofprolapseoflumbarintervertebraldisc.

简介：ThecurvedsurfaceofballmovementisaconnectingDentpipecommonlyusedinhydraulicengineering.Thecurvedsurfaceposesacomplicatedproblemwithcomputation.Themathematicmodelofthecircularcurvedsurfaceofballmovementinengineeringissetupbyadoptingtheconceptofenvelopecurvedsurface.

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简介：Asimplemethodwasdevelopedtorelatesoilsorptivitytohydraulicdiffusivityandwaterabsorptionexperimentswereconductedutilizingone-dimensionalhorizontalsoilcolumnstovalidatetherelationship.Inaddition,anestimationmethodforhydraulicdiffusivitywithdiscinfiltrometerwasdeveloped.Theresultsindicatedafavorablefitofthetheoreticalrelationtotheexperimentaldata.Also,theexperimentwithdiscinfiltrometerforestimatingthediffusivityshowedthatthenewmethodwasfeasible.

简介：１ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｅｘｐｅｒｔｓｙｓｔｅｍｓａｐｐｒｏａｃｈｉｓｃｕｒｅｎｔｌｙｂｅｉｎｇａｐｐｌｉｅｄｔｏｃｏｍｐｕｔｅｒ－ａｉｄｅｄｄｅｓｉｇｎ（ＣＡＤ）ｆｏｒｓｉｍｐｌｅｈｙｄｒａｕｌｉｃｃｉｒｃｕｉｔｓ．Ｍｏｓｔｏｆｔｈｅｅｘｐ...

简介：Inthispaper,tenwoodyplantsgrewonthecampusoftheBeijingForestryUniversitywereselectedformeasuringhydraulicarchitectureparametersandwaterpotentialofone-year-oldtwigs.Theresultsshowthatdayandnightchangeofwaterpotentialandhydraulicarchitectureparametersappeartobeobviouslyconvextrend.Therelationshipmodelsbetweenwaterpotentialandhydraulicconductivity,specialconductivityandleafspecialconductivitywererespectivelyestablished,whichweresimulatedb...

简介：Throughaseriesofmodeltestsoffivescalesfor2-Dfreehydraulicjump,theda-taoffluctuatingpressureactingonthefloorlevelwithinthehydraulicjumpwereobtained.Dur-ingtheexperiments,Froudenumbervariedfrom2.94to8.61,andReynoldsnumberrangedfrom2×10~4to6×10~5.Experimentresultsindicatethattheamplitudescaleoffluctuatingpres-sureisthelengthscaleofmodel,i.e.P’=L,whichagreeswithgravitysimilaritylaw:Thefrequencyscaleofthefluctuatingpressureisaunityi.e.,f=1,whichdoesnotsatisfythegravitysimilaritylaw.

简介：Travelingandstationaryinternalhydraulicjumpsindensitycurrentswithpositiveornegativeentrainmentcoefficientswereanalyzedbasedonsimpleassumptions.Anexpressionofinternalhydraulicjumpswithentrainmentcoefficientswasderived.Experimentaldata,publishedinliterature,ofstationaryinternalhydraulicjumpsinturbid,thermalandsalinedensitycurrentsincludingmeasuredvaluesofwaterentrainmentwereusedtocomparewiththeory.Comparisonwasalsomadeoftravelinginternalhydraulicjumpsbetweenmeasureddataandtheory.

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简介：TenhealthytreespecieswithregularmanagementwereselectedonthecampusofBeijingForestryUniversity,andtheybelongtotalltree,shrubandliana,respectively.Waterpotentialandhydraulicarchitectureparametersofone-year-oldtwigsweremeasuredinsunnydayinthelasttendaysofMarchtothemiddletendaysofMayin2002.Theresultsshowthatthedailychangeinwaterpotentialoftreespeciesexaminedappearsconvex,i.e.thewaterpotentialishigherinthemorningandevening,and...

简介：InthesouthernpartofChina,duetotherichrainfallsandfavourablytopographicallandscape,thereisabundanthydraulicenergyresourcescontainedinthecountlesssmallstreamsandriversinthemountainousandsemi-mountainousareas.Besidesthesmallhydropowergenerationwhichtransfersthepotentialenergytotheelectricalpower,thereisothertechnologyavailabletoutilisethepotentialenergydirectlyforthewaterliftingintheirrigationanddecentraliseddo-mesticwatersupplyinthevillagelevel.Thispaperintroducesthebasicprincipleofthehydraulicramop-erationanddescribestheapplicableopportunitiesforthehydraulicram.

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