简介：Consideringthatatpresenttheregularwavesincommonusehavetheprofilesymmetrizedtoaverticalaxis,whicharedifferentfromactualwind-drivenseawaves,andbasedonderivinglinearwave,solitarywave,fifthorderStokeswaveandstreamfunctionwavebyusingUnifiedVariationalPrincipleofWaterGravityWave(UVPWGW),thispaperderiveswind-drivenslantingprofilewavebyusingUVPWGW.Itsfeatureisthatundertheactionofwindpressure,thewaveprofileisnotsymmetrizedtoaverticalaxis,butthatitisintheforwardslantingform.

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简介：这篇论文建议分析和在失衡的网络电压下面的喂得二倍地的正式就职生成器(DFIG)调节的驾驶的一台风汽轮机的一个直接力量控制(DPC)图案。在积极、否定的同步参考依据描述的一个DFIG模型被介绍。活跃的定子产量和反应力量的变化充分面对否定顺序供应电压和转子流动被推出。一个提高的DPC计划被建议在网络unbalance期间消除定子有效功率摆动。建议控制计划移开积极、否定的顺序转子电流处理的转子电流管理者和分解。用PSCAD/EMTDC的模拟结果在一个2-MWDFIG风发电系统上被介绍在平衡并且失衡的网络条件下面验证建议控制计划的可行性。

简介：Thispaperproposesanadaptiverotorcurrentcontrollerfordoubly-fedinductiongenerator(DFIG),whichconsistsofaproportional(P)controllerandtwoharmonicresonant(R)controllersimplementedintherotorrotatingreferenceframe.Thetworesonantcontrollersaretunedatslipfrequenciesωslip+andωslip-,respectively.Asaresult,thepositive-andnegative-sequencecomponentsoftherotorcurrentarefullyregulatedbythePRcontrollerwithoutinvolvingthepositive-andnegative-sequencedecomposition,whichineffectimprovesthefaultride-through(FRT)capabilityoftheDFIG-basedwindpowergenerationsystemduringtheperiodoflargetransientgridvoltageunbalance.Correctnessofthetheoreticalanalysisandfeasibilityoftheproposedunbalancedcontrolschemearevalidatedbysimulationona1.5-MWDFIGwindpowergenerationsystem.

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简介：Thispaperpresentsreal-timemonitoringdataandanalysisresultsofthenon-stationaryvibrationsofanoperationalwindturbine.Theadvancedtime-frequencyspectrumanalysisrevealsvariednon-stationaryvibrationswithtimevaryingfrequencies,whicharecorrelatedwithcertainsystemnaturalmodescharacterizedbyfiniteelementanalysis.Undertheeffectsofstrongwindload,thewindturbinesystemexhibitscertainresonancesduetobladepassingexcitations.Thesystemalsoexhibitscertaininstabilitiesduetothecouplingofthetowerbendingmodesandbladeflapwisemodewithbladepassingexcitationsunderthevariationofwindspeed.Ananalyticalmodelisusedtoelaboratethenon-stationaryandinstabilityphenomenaobservedinexperimentalresults.ThepropertiesofthenonlinearinstabilitiesareevaluatedbyusingLyapunovexponentestimation.

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简介：请家长帮忙制作背景，使Alfi能在山上自由上下。1在鞋盒里画出高山的场景图。2用铅笔穿透盒子顶部，把线轴套在铅笔上。

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简介：Windshearreflectsthatthewindfieldisnotuniform,whichisoneoftheprimaryfactorswhichmaketheretrievalofthewindfielddifficult.Basedonvolumevelocityprocess(VVP)windfieldretrievaltechnique,theintensityofwindshearisidentifiedinthispaper.Afteranalyzingthetraditionaltechniquesthatrelyonthedifferenceofradialvelocitytoidentifywindshear,afixeddifferenceamongradialvelocitiesthatmaycausefalseidentificationinauniformwindfieldwasfound.Becauseofthenon-uniformityinwindshearareas,thedifferenceofretrievedresultsbetweensurroundinganalysisvolumescanbeusedasameasurementtoshowhowstrongthewindshearis.AccordingtotheanalysisofasevereconvectiveweatherprocessthatoccurredinGuangzhou,itcanbefoundthattheareasofwindshearappearedwiththestrengthsignificantlylargerthaninotherregionsandthemagnitudegenerallylargerthan4.5m/(s·km).Besides,bycomparingthevariationofwindshearstrengthduringtheconvection,itcanbefoundthatnewcellswillbemorelikelytogeneratewhenthestrengthisabove3.0m/(s·km).Therefore,theanalysisofstrongwindshear'smovementanddevelopmentishelpfultoforecastingsevereconvections.

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简介：Theauthorshadinventedtheuniquewindpowerunitcomposedofthelarge-sizedfrontwindrotor,thesmall-sizedrearwindrotorandthepeculiargeneratorwiththeinnerandtheouterrotationalarmatureswithouttheconventionalstator.Thisunitiscalled'IntelligentWindPowerUnit'bytheauthors.Thefrontandtherearwindrotorsdrivetheinnerandtheouterarmatures,respectively,whiletherotationaltorqueiscounter-balancedbetweenbotharmatures/windrotors.Thispaperdiscussesexperimentallytheacousticnoisefromthefrontandtherearwindrotors.Theacousticnoise,inthecounter-rotatingoperation,isinducedmainlyfromtheflowinteractionbetweenbothrotors,andhasthedominantpowerspectrumdensityatthefrequencyofthebladepassinginteraction.Thenoiseiscausedmainlyfromtheturbulentfluctuationduetotheflowseparationontheblade,whentherearwindrotorstopsorrotatesinthesamedirectionasthefrontwindrotor.

简介：Thegeophysicalmodelfunction(GMF)describestherelationshipbetweenabackscatteringandaseasurfacewind,andenablesawindvectorretrievalfrombackscatteringmeasurements.ItisclearthattheGMFplaysanimportantroleinanoceanwindvectorretrieval.TheperformanceoftheexistingKu-bandmodelfunctionQSCAT-1isconsideredtobeeffectiveatlowandmoderatewindspeedranges.However,intheconditionsofhigherwindspeeds,theexistingalgorithmsdivergealarmingly.owingtothelackofinsitudatarequiredfordevelopingtheGMFforthehighwindconditions,theQSCAT-1appearstooverestimatethes0,whichresultsinunderestimatingthewindspeeds.Severalmatch-upQuikSCATandspecialsensormicrowave/imager(SSM/I)windspeedmeasurementsofthetyphoonsoccurringinthewestPacificOceanareanalyzed.TheresultsshowthattheSSM/Iwindexhibitsbetteragreementwiththe'besttrack'analysiswindspeedthantheQuikSCATwindretrievedusingQSCAT-1.Onthebasisofthisevaluation,acorrectionoftheQSCAT-1modelfunctionforwindspeedabove16m/sisproposed,whichusesthecollocatedSSM/IandQuikSCATmeasurementsasatrainingset,andaneuralnetworkapproachasamultiplenonlinearregressiontechnologytechnology.InordertovalidatetherevisedGMFforhighwinds,themodifiedGMFwasappliedtotheQuikSCATobservationsofHurricaneIOKE.ThewindestimatedbytheQuikSCATforTyphoonIOKEin2006wasimprovedwiththemaximumwindspeedreaching55m/s.AnerroranalysiswasperformedusingthewindfieldsfromtheHollandmodelasthesurfacetruth.TheresultsshowanimprovedagreementwiththeHollandmodelwindwhencomparedwiththewindestimatedusingtheQSCAT-1.However,largebiasstillexisted,indicatingthattheeffectsofrainmustbeconsideredforfurtherimprovement.

简介：ThisstudyinvestigatedtheflowcharacteristicsalteredbyJangBogoAntarcticResearchStationusingcomputationalfluiddynamics(CFD)modeling.ThetopographyandbuildingsaroundJangBogoStationwereconstructedwithcomputeraided-designdataintheCFDmodeldomain.Wesimulated16caseswithdifferentinflowdirections,andcomparedtheflowcharacteristicswithandwithoutJangBogoStationforeachinflowdirection.Thewinddatarecordedbythesite’sautomaticweatherstation(AWS)wereusedforcomparison.WindroseanalysisshowedthatthewindspeedanddirectionaftertheconstructionofJangBogoStationwerequitedifferentfromthosebeforeconstruction.Wealsoinvestigatedhowvirtualwindfenceswouldmodifytheflowpatterns,changingthedistanceofthefencefromthestationaswellastheporosityofthefence.Forwesterlyinflows,whentheAWSwasdownwindofJangBogoStation,thedecreaseinwindspeedwasmaximized(-81%forwest-northwesterly).ThewindspeedreductionwasalsogreaterasthedistanceofthefencewasclosertoJangBogoStation.Withthesamedistance,thefencewithmediumporosity(25%–33%)maximizedthewindspeedreduction.Theseresultssuggestthatthelocationandmaterialofthewindfenceshouldbeselectedcarefully,orAWSdatashouldbeinterpretedcautiously,forparticularprevailingwinddirections.

简介：改进IC的收益的一个新格子更少路由器被介绍。产量的改进被减少电路失败是可能的发生的临界区完成。更少的区域路由器从一个新奇成本函数有益于在路由过程期间计算临界区的这个格子，和启发式的联盟者在导致临界区是可能的更少的芯片区域上放模式。路由器也考虑另外的目的，例如路由布通率和网长度。获得更多的灵活性和更高的布通率利用格子更少路由。当超过99%维持路由布通率时，试验性的结果证明临界区被21%有效地平均减少。电子增补材料这篇文章(doi:10.1007/s11390-007-9092-9)的联机版本包含增补材料，它对授权用户可得到。

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