简介:摘要导体屏蔽层和绝缘屏蔽层统称为半导电屏蔽层,分布在绝缘层内外两侧,能够缓和电缆内部的电场应力集中,均匀绝缘层表面电场应力分布,改善电缆内部电场的径向分布以提高电缆的电气强度,延长电缆的使用寿命。从改善电缆长期运行能力的电气性能及安全性能考虑,现代电缆结构和工艺中要求导体屏蔽层应是粘接型的,而绝缘屏蔽层则必须具备一定的可剥离性,并采用挤包工艺。
简介:Athree-dimensionalmodelofGaAs/A1GaAsquantumdoubleringsinthelateralstaticelectricfieldisinvestigatedtheoretically.Theeigenvalueproblemwiththeeffective-massapproximationissolvedbymeansofthefinite-elementmethod.Theenergylevelsandwavefunctionsofquantum-confinedelectronsandheavyholesareobtainedandshowanagreementwithourprevioustheoreticalandexperimentalstudies.ItisshownintheapproximationofneglectingtheCoulombattractionbetweentheelectronandheavyholethatarelativelylargeStarkshiftofexcitonemissionof4meVisattainablewithanappliedelectricfieldof0.7kV/cm.
简介:摘要:电力行业是我国社会体系重要组成部分,也是推动我国社会发展的主要原动力之一,很多电力生产设备及其应用都直接关系到我国电力生产及发展,所以各种电力仪器、设备及技术的应用一直备受人们重视及关注。压柜半绝缘电压互感器是近年来应用频率较高的一种电压互感仪器,具有很强的低压互感功能及控制工作,已经在各电力生产环节、电压管控环节得到了应用,并取得了良好的应用效果,减少了因为电压控制问题导致的各种电力生产事故发生率,提高了电力生产质量及效率,促进电力行业发展。所以深入研究中压柜半绝缘电压互感器试验是非常重要和必要的。
简介:ThereolutioncharacteristicofGaAs/GaAlAstrransmissionphotocathodeisanimportantparameterinthirdgenerationintensifiers.ThemodulationtransferfunctionofGaAs/GaAlAstransmissionphotocathodeisderivedfromasimpletwo-dimensionaldiffusionequation.Thetheoreticalresolutioncharacteristicofa2μmthickGaAs/GaAlAstransmissionphotocathodeiscalculated.TherelationshipbetweenresolutionandparametersinGaAs/GaAlAstransmissionphotocathodeisdiscussed.AconclusionisshownthatonecandesigntheGaAs/GaAlAstransmissionphotocathodeformaximumquantumefficiency,sincethesacrificeintheresolutiondoesn'tlimitsystemperformances.
简介:InGaAsP/GaAsSCHSQWlaershavebeenpreparedbyLPMOCVD.Thedependenceofthresholdcurrentdensityoncavitylengthwasexplained.Laserdiodesarecharacterizedbytheoutputpowerof1W20W,thresholdcurrentdensity(Jth)of330A/cm^2to450A/cm^2andexternaldifferentialquantumefficiency(ηd)of35%to75%,andthesecharacteristicsareingoodagreementwiththedesignedrequirement.
简介:WhenweuseMOCVDtechnique,anexcellentCdTeepi-layerwasgrownonGaAssubstratesandtheCdTe/GaAshybridsubstratessuitableforgrowingHg1-xCdxTe(CMT)wereobtained.ThexvalueinCMTisbetween0.2and0.8.TheelectricalpropertiesofCMTdependuponthethicknessofCdTeepi-layers.TheCdTe/GaAsinterfacewasexaminedbybothscanningelectronmicroscope(SEM)andelectronaugerspectra(EAS).TheinfluenceofdefectsobservedatinterfaceonelectricalandopticalpropertiesofCMTfihnswasdis-cussed.
简介:Weinvestigatethenonlinearresponseofterahertz(THz)metamaterialperfectabsorbersconsistingofelectricsplitringresonatorsonGaAsintegratedwithapolyimidespacerandgoldgroundplane.Theseperfectabsorbersonbulksemi-insulatingGaAsarecharacterizedusinghigh-fieldTHztime-domainspectroscopy.Theresonancefrequencyredshifts20GHzandtheabsorbanceisreducedby30%astheincidentpeakfieldisincreasedfrom30to300kV/cm.ThenonlinearresponsearisesfromTHzfielddriveninterbandtransitionsandintervalleyscatteringintheGaAs.ToeliminatetheFresnellossesfromtheGaAssubstrate,wedesignandfabricateaflexiblemetamaterialsaturableperfectabsorber.Theabilitytocreatenonlinearabsorbersenablesappealingapplicationssuchasopticallimitingandself-focusing.
简介:利用4.5MeV的氪离子(Kr^17+)辐照(100)晶向本征未掺杂和高掺锌(P型)、(100)和(110)混合晶向的高掺硅(N型)砷化镓(GaAs)半导体材料,辐照注量为1×10^12~3×10^14cm^-2,测试辐照后材料的拉曼光谱。随着辐照注量增大,材料的纵向光学(longitudinaloptical,LO)声子峰向低频方向移动,出现了明显的非对称展宽,并且N型样品辐照后,晶体结构损伤要大于P型与本征未掺杂样品。3种类型样品的LO峰频移随辐照损伤的变化趋势一致,研究表明,掺杂元素不影响材料本身的晶体结构,可能是因为混合晶向的生长方式导致辐照后N型GaAs结构稳定性变差。
简介:Zinchasbeendiffusedinton-typeInxGa1-xAs,InPandGaAsinclosedam-poules,andtheexperimentaldataforInxGa1-xAsrarelyreportedpreviouslyhavebeenob-tained,TheoreticallythelinearrelationsipbetweenlogarithmicdiffusioncoefficientlnDandthecompositionxhasbeendemonstrated,whichisingoodagreementwiththeexperimentalresults.ThecalculateddiffusionjunctiondepthforInGaAsbasedonthediffusionmodelinwhichD^∝c^2isassumedalsoagreeswellwiththatoftheexperment,Finallytheoveralldiffusiontimeinamultiayerheterostructurewasapproximatedast=(∑√-ti)^2.