简介:AcalibratingdevicefortheRogowskicoilisdeveloped,whichcanbeusedtocal-ibratetheRogowskicoilhavingapartialresponsetimewithintensofnanoseconds.Itskeycomponentisastepcurrentgenerator,whichcangeneratetheoutputwitharisetimeoflessthan2nsandadurationoflargerthan300ns.Thestepcurrentgeneratoriscomposedbyapulseformingline(PFL)andapulsetransmissionline(PTL).ATEM(transverseelectromagneticmode)coaxialmeasurementunitisusedasPTL,andthecoiltobecalibratedandthereferencedstandardRogowskicoilcanbefixedintheunit.TheeffectofthedimensionsoftheTEMunitisdiscussedtheoreticallyaswellasexperimentally.
简介:Thechemicaloxygen–iodinelaser(COIL)istheshortest-wavelengthhigh-powerchemicallaserthathasbeendemonstrated.Thecharacteristics,suchasgoodatmosphericpropagation,shortwavelengthandexcellenttransmissionthroughopticalfibers,maketheCOILagoodcandidateforhigh-powerlaserapplication.TomodelthecompleteCOILlasinginteraction,athree-dimensionalformulationofthefluiddynamics,speciescontinuityandradiationtransportequationsisnecessary.Thecomputationalefforttocalculatetheflowfieldovertheentirenozzlebankwithagridfineenoughtoresolvetheinjectionholesissolargeastoprecludedoingthecalculation.Theapproachtomodelingchemicallasersthenhasbeentoreducethecomplexityofthemodeltocorrespondtotheavailablecomputationalcapability,addingdetailsascomputingpowerincreased.ThemodelingoflasingintheCOILmediumisproposed,whichiscouplingwiththeeffectsinducedbytransverseinjectionofsecondarygases,non-equilibriumchemicalreactions,nozzletailflowandboundarylayer.ThecoupledsteadysolutionsofthefluiddynamicsandopticsinaCOILcomplexthree-dimensionalcavityflowfieldareobtainedfollowingtheproposal.Themodelingresultsshowthattheseeffectshavesomeinfluenceonthelasingproperties.Afeasiblemethodologyandatheoreticaltoolareofferedtopredictthebeamqualityforlarge-scaleCOILdevices.
简介:Tosolvetheproblemabouttheinhomogeneousthermaleffectofpotheatedbycoilsalongthecircumference,anovelcoilwindingmethodisproposedandcomparedwiththegeneralwindingmethodinthepaper.First,basedontheBiot-SavartlawandAmpere’srule,themagneticinductiongeneratedbyastraightcurrentcarryingconductorandacurrentloopisdiscussed,respectively.Thenthenovelcoilwindingmethodisdevelopedbyadjustingthelocationofinhomogeneousjoints.Thejointsareperiodicallyscatteredalongthecircumferentialdirectionandsymmetricallydesignedaroundthecentralaxis.Numericalresultsshowthatthequitenon-uniformtemperatureinthebaseofpotatthecirculardirectioniseffectivelyimprovedbyusingtheproposedwindingmethod.Thepotentialdangerproducedbyhightemperatureatsomeregionofcoilsplateisminimized.Itisenergy-efficientandsafeforresidentialappliances.
简介:Asaresultsofmagnetoelasticinteraction,themechanicalbehaviorofcurrent-carryingcoilstructures,suchasdeformationandinstability,isakeyprobleminthedesignofstrongfieldmagnets.Inthispaper,anonlinearmathematicalmodelispresentedtodescribethedeformationandbucklingofD-typecurrent-carryingcoils,basedontheBiot-Savartlawandthebendingtheoryofcurvedbeams.Thebendingdeformation,thecriticalvalueofcurrentforthemagnetoelasticbucklingofthecurrent-carryingcoil,andtheeffectsofthetypeandnumberofsupportsatmiddlepartofthebendingcoilonthecriticalvaluearequantitativelyinvestigatedbyasemi-analyticalandsemi-numericalmethod.Thenumericalresultsareshowntobeingoodagreementwiththeexperimentaldata.
简介:OwingtorecentprogressoflongYBCOcoatedconductors,coilswoundofYBCOconductorswillbedevelopedinnearfuture.ComparedwithcoilswoundofLTSconductom,coilswoundofHTSconductorsoperatedathighertemperaturearehardtobequenched.However,measuresforquenchprotectionarestillnecessary.EspeciallyYBCOcoatedconductorsthataremadebydepositionofthinYBCOfilmonNibasedalloysubstratessuchasHastelloytapesarehighlyresistivewhentheyarequenched,Therefore,
简介:AnovelpancakeRogowskicoilwithoutmagneticcoreisintroducedinthispaper.Owingtoitsspecialpancakewindingstructure,thecoilisoflowself-resistanceandhighself-inductance,andthushasexcellentlowfrequencycharacteristicintheself-integralmode.Moreover,becauseofitsuniqueinstallationmethod,thecoilhasaflexiblesensitivityandcanbeappliedundersituationswheretoroidalair-coreRogowskicoilsorprintedaircuitboard(PCB)coilsarenotavailable.TheparametersandperformanceofthepancakeRogowskicoilarepresented,andtheprincipleofshieldingisgiven.Measurementsofsteppulsecurrentandoscillatingpulsecurrentbythecoilarestudiedexperimentallytoillustrateitsgoodlinearity,reliableandflexiblesensitivityandexcellentfrequencycharacteristic,especiallyitsadvantageinlowfrequencycharacteristic.ThepancakeRogowskicoilcanbedesignedtoassumeround,squareorrectangleshape,andhasthusbroadprospectsinitsapplicationtothecurrentmeasurementinsuchareasasplasmaphysicsandpulsedpowertechnology.
简介:Thecentralpostisoneofthecriticalcomponentsforthelowaspectratiotokamak,whichenduresnotonlyatremendousohmicheatingbecauseitcarriesaratherhighcurrent,butalsoalargeneutronheatingandirradiationowingtotheplasmaoperation.TheDScopperalloyGlidcopAL-25[8]waschosenastheconductormaterialforitsadequatemechanicalpropertiesandphysicsproperties.Thecentralposthasacylindricalstructurewithlotsofcoolingchannels.Thelengthofthecentralpostforthenextgenerationofnuclearfusionsphericaltokamakswillbemorethan10mor20m.Thestructuralstabilityisverycrucial.Whentheappliedloadislargerthanthestructurecriticalbucklingload,thedevicewillloseitsstabilityandcollapse.Inordertocal'culatethecriticalbucklingload,a1/6-segmentfiniteelementmodelwasusedandtheforceactingonthecentralpostwassimulated.Theresultsshowedthattheverticalcompressivestressesmainlyaffectthestabilityofthecentralpost.Thelinearbucklinganalysisresultswithfiniteelementmethodbasedonsmalldeformationtheoryweregiveninthispaper.Therelationcurvesandfunctionsforbucklingfactor,dependingonthedifferentlengthsandtheradiusofthecentralpost,thediameterofcoolingchannelandthemaximumallowablecurrentdensity,werealsoshown.
简介:表明用层次潜伏的班(HLC)发现复杂、有趣的潜伏的结构的可能性的案例研究建模的在场的作者。类似的努力被张(2002)更早作的A,而是那研究与4或5个观察变量并且仅仅包含了仅仅小的应用程序2个潜伏的变量由于有效学习算法的缺乏。重要进步从那以后在算法的研究上被取得了,并且与几十个观察变量学习HLC模型现在是可能的。这允许我们比以前更信服地表明HLC模型的好处。作者成功地分析了2000数据用HLC模型设置了的卷挑战。获得的模型由22个潜伏的变量,和它的结构组成直觉地正在呼吁。它正在激动知道如此的大、有意义的潜伏的结构能自动地从数据被推断。
简介:InTokomak,thesupportoftheELMcoil,whichisclosetotheplasmaandsubjecttohighradiationlevel,hightemperatureandhighmagneticfield,isusedtotransportandbearthethermalloadduetothermalexpansionandthealternatingelectromagneticforcegeneratedbyhighmagneticfieldandACcurrentinthecoil.AccordingtothefeatureofITERELMcoil,themechanicalperformanceofrigidandflexiblesupportsunderdifferenthighnuclearheatlevelsisstudied.Resultsshowthatflexiblesupportshavemoreexcellentperformanceinhighnuclearheatconditionthanrigidsupports.Concerningthermalandelectromagnetic(EM)loads,optimizedresultsfurtherprovethatflexiblesupportshavebettermechanicalperformancethanrigidones.Throughthesestudies,reasonablesupportdesigncanbeprovidedfortheELMcoilsorsimilarcoilsinTokamakbasedonthenuclearheatlevel.
简介:ARogowskicoilisdevelopedtodetectthenanosecondpulsesignalsofthedischargecurrentwithawidebandwidthof800kHzto106MHzandhighsensitivityof2.22V/A.Perfor-mancetestsshowthattheRogowskicoilhasbothexcellentdynamicandstaticcharacteristics.CalibratingresultsandthecomparisonbetweenthestandardcurrentshuntandthedevelopedRo-gowskicoilforthemeasurementofnanoseconddischargepulsesdemonstratethatthedevelopedRogowskicoilcanreproducetheactualwaveformofthedischargecurrentaccurately.
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简介:DearEditor,Wearewritingthislettertoreportanunexpectedrarecaseofcentralretinalarteryocclusion(CRAO)happenedafterstent-assistedcoilingforinternalcarotidartery(ICA)aneurysminafemalepatient.CRAOisadevastatingocularemergencywithpoorvisualprognosisandnouniversalacceptedtreatmentatpresent.CRAOisusuallyassociatedwitharterialhypertension,diabetesmellitus,renaldisease.
简介:Objective:Toexplorethecausesoftheformationoftraumaticcarotid-cavernousfistulasandthetherapeuticeffectofdetachableballoonand/orcoilembolizationandthepreventionofitscomplications.Methods:FromOctober,1992toMarch,2002,17patientswithtraumaticcarotid-cavernousfistulasweretreatedwithdetachableballoonand/orcoilembolizationinourhospital.TheclinicaldataandimagingfeaturesofCT,MRandselectiveangiogramofthesepatientswereanalyzed.Results:Oneweekaftertreatmentwithembolization,theclinicalsymptomsofthe17patientswereremitted,andopticcacophony,nystagmus,exophthalmosanddropsyofconjunctivadisappeared.Twopatientsmanifestedsurgicalcomplications,onepatientdied.Sixteenpatientssurvived.Theywereallfollowedupformorethan2years,whichshowedonepatienthadhandicapinmovement,andinonepatientthesignsandsymptomsoftraumaticcarotid-cavernousfistulasreoccurred2monthsaftertreatment.Conclusions:Thedetachableballoonand/orcoilembolizationissafeandreliable.Itisagoodmethodtotreattraumaticcarotid-cavernousfistulas.
简介:生节是对在昆虫的细菌的挑战的占优势的细胞的防卫反应。在这研究,Chrysomyamegacephala的第三个中间形态幼虫与细菌被注射,Escherichia关口iK12(106CFU/mL,2μL),立即在eicosanoid生合成的禁止者的注射以前,它严厉地减少的生节反应。测试幼虫与2(dexamethasone),cyclo-oxygenase(消炎痛,布洛芬和piroxicam),双cyclo-oxygenase/lipoxygenase(phenidone)和lipoxygenase(esculetin)和这些减少了的phospholipase的特定的禁止者被对待除了esculetin的生节。细菌的影响在注射(5nodules/larva)的2h以内是明显的,并且在8h以后增加了到最大值(与15nodules/larva),然后显著地减少了超过24h(9nodules/larva)。dexamethasone的禁止的影响在注射(4对5nodules/larva)的2h以内是明显的,并且生节显著地与控制相比被减少,在24h(5对8nodules/larva)上。布洛芬,消炎痛,piroxicam和phenidone的增加的剂量导致了小瘤的减少的数字。小瘤继续在蛹的阶段期间存在。然而,dexamethasone的效果被与eicosanoid先锋多元不堡和对待注射细菌的昆虫颠倒丰满的酸,arachidonic酸。这些调查结果同意了我们eicosanoid能调停的看法响应在另一Dipteran昆虫C的细菌的感染的细胞的防卫机制。megacephala。