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简介：BaotouMotorWorksisastate-runmotorpro-ducerinChina.TheinventionofNd-Fe-Bperma-nentmagnethashelpedtheplantsuccessfullydevel-opZYNseriesdcmotorswhichpossesstheadvan-tagesofreducedvolume,lightweightandhigheffi-ciency.Since1991,thedcmotorhasbeenexten-sivelyappliedtometallurgicalmachinestotaketheplaceofthetraditionalZ3seriesmotors.

简介：Thispaperaimstodesignpunchingdieofthestatorandrotor.Byanalyzingandcomparing,wedeterminethebetterprocessingprogram.Notonlytoensuretheprecisionanddimensionalrequirements,butalsotoimproveefficiency.Throughdetailedanalysisoftheprocess,thispaperdeterminesthestructureoftwocompositemolds.Thedimensionsofitsconvexandconcavedieedgesizeandotherpartsarecalculatedandchecked.Finallythispapercompletesthedesignoftwomolds.

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简介：正弦电场驾驶的一个蛋白质马达系统被调查。Thesignal-to-noise比率(SNR)在断热的限制被导出。随机的回声的现象被作出对有利的裁决这个蛋白质马达系统。

简介：题目：一种多振子超声电机的设计目的：对超声电机而言，当多个压电振子并联时，由于以同一设计方案制作的电机振子往往具有不同的动态特性，因此会使得多振子电机的效率有所下降。即多振子电机工作的关键是如何使多个振子协同一致地驱动转子。为提高集成型多振子电机的效率和简化电机结构，提出一种构造贴片式多振子旋转超声电机的方法。创新点：1．提出圆周面内驱动的概念，发展已有的面内驱动概念（x-y面）；2．提出一种模态转换方法，通过多个振子弯曲振动的叠加形成设计电机的扭转振动；3．电机工作时，不仅各个振子处于共振状态，而且连接而成的定子同样处于共振状态，有利于提高电机的效率；4．验证多振子同步驱动的机理。方法：1．振子采用贴片式结构，由极化方向沿厚度方向的压电陶瓷和金属基体粘结而成；与使用兰杰文振子相比，使用贴片式振子易于简化电机的结构。2．各个振子首尾相连形成电机的定子，既可用于构造直线电机，又可转换成旋转电机。3．通过有限元方法对不同振子数构成的电机定子进行性能比较，并且分析设计电机的驱动机理；此外，通过仿真分析确定电机的最优尺寸。4．根据设计结果，加工原理样机，并且对加工的样机进行实验研究，探讨设计方法的可行性。结论：1．根据仿真分析结果，最终加工的电机定子包含5个振子。2．定子中各个振子的振动特性完全相同，振子同步工作。3．样机定子的内径为28mm，外径为35mm，高为30min；测得定子的纵振和扭转频率分别为44．42kHz和43．83kHz；当激励电压的频率为43．9kHz、峰值为100V时，电机的空载转速为45r／min，堵转力矩为0．3N·m，最大效率约为30％。4．本文所设计的电机，是一种多振子并行驱动的整体式电机，具有结构紧凑和多�

简介：Thisworkpresentsanumericalsimulationoftheflowfieldinaliquidpropellantrocketenginechamberandexitnozzleusingtechniquestoallowtheresultstobetakenasstartingpointsfordesigningthosepropulsivesystems.ThiswasdoneusingaFiniteVolumemethodsimulatingthedifferentflowregineswhichusuallytakeplaceinthosesystems.Astheflowfieldhasregionsrangingfromthelowsubsonictothesupersonicregimes,thenumericalcodeused,initiallydevelopedforcompressibleflowsonly,wasmodifiedtoworkproficientlyinthewholevelocityrange.ItiswellknownthatcodeshavebeendevelopedinCFD,foreithercompressibleofincompressibleflows,thejointtreatmentofbothtogetherbeingcomplexeventoday,giventhesmallnumberofreferencesavailableinthisarea.Hereanexistingcodeforcompressibleflowwasusedandprimitivevariables,thepressure,theCartesiancomponentsofthevelocityandthetemperatureinsteadoftheconservedvariableswereintroducedintheEulerandNavier-Stokesequations.ThiswasdonetopermitthetreatmentatanyMachnumber.Unstructuredmesheswithadaptiverefinementswereemployedhere.Theconvectivetermsweretreatedwithupwindfirstandsecondordermethods.ThenumericalstabilitywaskeptwithartificialdissipationandinthespatialcoverageoneusedafivestageRunge-KuttaschemefortheFluidMechanicsandtheVODE(ValueofOrdinaryDifferentialEquations)schemealongwiththeChemkinIIinthechemicalreactingsolution.Duringthedevelopmentofthiscodesimulatingtheflowinarocketengine,comparisontestsweremadewithseveraldifferenttypesofinternalandexternalflows,atdifferentvelocities,seekingtoestablishtheconfidencelevelofthetechniquesbeingused.ThesecomparisonsweredonewithexistingtheoreticalresultsandwithothercodesalreadyvalidatedandwellacceptedbytheCFDcommunity.

简介：摘要： Motor-Cad是十分强大的电机设计分析工具。本论文基于Motor-Cad设计了某功率型号的外转子直驱式轮毂电机并对其性能进行了研究，电机采用永磁同步电动机，相对于传统的车用驱动电机，这种电机具有高效、高功率密度、结构简单紧凑等一系列优点，特别适合作为车用电机使用，对其性能的研究也表明，设计的电机能够完全满足电动车使用要求。

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简介：由生命周期评价(LCA)的申请方法论，这份报纸估计生产的环境影响和在中国在电的车辆使用的拖拉马达的处理。结果证明拖拉马达生产和处理的全部的精力使用，标准排出物和温室气体(GHG)排出物是大约2,899，MJ，4.5，kg并且259.5，kg每分别地交通。在调整排出物之中，SOx排放由全部的质量评价第一，由公司，PM10，没有x，PM2.5，和不稳定的有机化合物(VOC)列在后面。为大多数精力消费和排出物的马达材料生产阶段报道，由集会阶段和end-of-life处理列在后面舞台。在这研究，环境表演分析为材料生产阶段被扩大到在第二等的材料和主要材料的使用之间的比较。用100%，第二等的材料与百分之百主要的材料的使用相比在GHG排出物在精力消费，在调整排出物的49.8%减小，和49.3%减小导致52.9%减小，这被发现。

简介：Physicalactivity(PA)isaneffectivemeansofcurbingtheprevalenceofchildobesity,andfundamentalskillsarehypothesizedtobeanimportantfactorthatdeterminesphysicallyactiveorinactivebehaviorinchildren.Researchevidencesuggeststhatadolescentsandyoungadultswithproficientmotorskillsinsport-relatedactivitiesaremorelikelytohaveaphysicallyactivelifestyle.1Becausephysically

简介：Thisstudypresentedanoff-lineidentificationmethodofinductionmotor(IM)parameters.Beforestartup,theinverterdriveperformedautomaticallyamodifiedDCtest,alocked-rotortest,ano-loadtestandastep-voltagetesttoidentifyalltheparametersofaninductionmotor.Nomanualoperationandspeedsignalswererequiredintheprocess.Inordertoobtaineffectivemessagesandimprovetheaccuracyofidentification,thediscretefastFouriertransform(DFFT)andtheleast-squareswereusedtoprocessthesignalsofcurrentsandvoltages.Aphase-voltagemeasuringmethodformotorswasalsoproposed,whichmeasureddirectlytheactualconductingtimeofthreeupperswitchesintheinverterwithoutneedforadead-timecompensator.Thevalidity,reliabilityandaccuracyofthepresentedmethodshavebeenverifiedbytheexperimentsonaVSI-fedIMdrivesystem.

简介：Theeffectsofexerciseondecision-makingperformancehavebeenstudiedusingawidevarietyofcognitivetasksandexerciseinterventions.Althoughthecurrentliteraturesupportsabeneficialinfluenceofacuteexerciseoncognitiveperformance,themechanismsunderlyingthisphenomenonhavenotyetbeenelucidated.Wereviewstudiesthatusedsingle-pulsetranscranialmagneticstimulation(TMS)toprobetheexcitabilityofmotorstructuresduringwhole-bodyexerciseandpresentaframeworktoaccountforthefacilitatingeffectsofacuteexerciseonmotorprocesses.Recentresultssuggestthat,evenintheabsenceoffatigue,theincreaseincorticospinalexcitabilityclassicallyreportedduringsubmaximalandexhaustingexercisesmaybeaccompaniedbyareductioninintracorticalinhibition.Weproposethatreducedintracorticalinhibitionelicitsanadaptivecentralmechanismthatcounteractstheprogressivereductioninmuscleresponsivenesscausedbyperipheralfatigue.Suchareductionwouldrenderthemotorcortexmoresensitivetoupstreaminfluences,thuscausingincreasedcorticospinalexcitability.Furthermore,reductionofintracorticalinhibitionmayaccountforthemoreefficientdescendingdriveandfortheimprovementofreactiontimeperformanceduringexercise.Theadaptivemodulationinintracorticalinhibitioncouldbeimplementedthroughageneralincreaseinreticularactivationthatwouldfurtheraccountforenhancedsensorysensitivity.

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简介：Asaresultofthenonlineareffect,acousticstreaminghasbeenwidelyusedforincreasingthetransportcoefficientordrivingarotor,forexample,inresonantcavitiesandnon-contactultrasonicmotors.IthasbeendemonstratedbyexperimentsthatatemperaturegradienttransversetothewavepropagatingdirectioncansignificantlyincreasethevelocityofthestreamingBowsinresonantcavities.Tocheckwhetherthetransversetemperaturegradientcanalsoincreasetheworkingvelocityofacousticstreaming-drivenmotors,weinvestigatethisissuebynumericallysolvingthehydrodynamicequations.Itisfoundthatthevelocityoftherotoronlyweaklydependsonthetransversetemperaturegradient,e.g.,evenwithatemperaturedifferenceof40℃betweentherotorandthestator,thevelocityincreasesonly~8.8%.

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简介：Thispaperdealswithon-linestateandparameterestimationofareasonablylargeclassofnonlinearcontinuous-timesystemsusingastep-by-stepslidingmodeobserverapproach.Themethodproposedcanalsobeusedforadaptationtoparametersthatvarywithtime.Theotherinterestingfeatureofthemethodisthatitiseasilyimplementableinreal-time.Theefficiencyofthistechniqueisdemonstratedviatheon-lineestimationoftheelectricalparametersandrotorfluxofaninductionmotor.Thisapplicationisbasedonthestandardmodeloftheinductionmotorexpressedinrotorcoordinateswiththestatorcurrentandvoltageaswellastherotorspeedassumedtobemeasurable.Real-timeimplementationresultsarethenreportedandtheabilityofthealgorithmtorapidlyestimatethemotorparametersisdemonstrated.Theseresultsshowtherobustnessofthisapproachwithrespecttomeasurementnoise,discretizationeffects,parameteruncertaintiesandmodelinginaccuracies.Comparisonsbetweentheresultsobtainedandthoseoftheclassicalrecursiveleastsquarealgorithmarealsopresented.Thereal-timeimplementationresultsshowthattheproposedalgorithmgivesbetterperformancethantherecursiveleastsquaremethodintermsoftheconvergencerateandtherobustnesswithrespecttomeasurementnoise.