简介:Rotation in Reaction 19F+51VRotationinReaction19F+51V¥WangQi;LuJun;XuHushan;LiSonglin;ZhuYongtaiandZhangYuhuIndLssi...
简介:Theeffectofbismuth(Bi)forbothVO2+/VO2+andV3+/V2+redoxcouplesinvanadiumflowbatteries(VFBs)hasbeeninvestigatedbydirectlyintroducingBionthesurfaceofcarbonfelt(CF).TheresultsshowthatBihasnocatalyticeffectforVO2+/VO2+redoxcouple.Duringthefirstchargeprocess,BiisoxidizedtoBi3+(neverreturnbacktoBimetalinthesubsequentcycles)duetothelowstandardredoxpotentialof0.308V(vs.SHE)forBi3+/BiredoxcouplecomparedwithVO2+/VO2+redoxcoupleandBi3+exhibitno(orneglectable)electro-catalyticactivity.Additionally,therelationshipbetweenBiloadingandelectrochemicalactivityforV3+/V2+redoxcouplewasstudiedindetail.2wt%Bi-modifiedcarbonfelt(2%-BiCF)exhibitsthehighestelectrochemicalactivity.Usingitasnegativeelectrode,ahighenergyefficiency(EE)of79.0%canbeachievedatahighcurrentdensityof160mA/cm2,whichis5.5%higherthanthepristineone.Moreover,theelectrolyteutilizationratioisalsoincreasedbymorethan30%.Eventhecelloperatedat140mA/cm2forover300cycles,theEEcanreach80.9%withoutobviousfluctuationandattenuation,suggestingexcellentcatalyticactivityandelectrochemicalstabilityinVFBs.
简介:Vanadiumalloys(V-Cr-Tiseries)areimportantcandidatematerialsforblanketcomponentsoffusionreactorsduetotheirlowactivationandhighstrengthatelevatedtemperatures.Low-temperatureirradiationembrittlementdeterminestheoperationtemperaturelimitofVanadiumalloysfortheapplicationtostructuralmaterialsoffusionreactorsirradiationresponseofvanadiumalloysneedstobeclarifiedfortheirapplication.Inthepresentstudy,specimensoftwoalloys(V-4Cr-4TiandV-5Cr-5Ti)wereirradiatedwithenergeticHeionsandheavyionstounderstandhardeningofthealloysduetoheliumaccumulationandcascadedamageproduction.
简介:Accordingtothewell-establishedlight-to-electricityconversiontheory,resonantexcitedcarriersinthequantumdotswillrelaxtothegroundstatesandcannotescapefromthequantumdotstoformphotocurrent,whichhavebeenobservedinquantumdotswithoutap–njunctionatanexternalbias.Here,weexperimentallyobservedmorethan88%oftheresonantlyexcitedphotocarriersescapingfromInAsquantumdotsembeddedinashort-circuitedp–njunctiontoformphotocurrent.Thephenomenoncannotbeexplainedbythermionicemission,tunnelingprocess,andintermediate-bandtheories.Anewmechanismissuggestedthatthephotocarriersescapedirectlyfromthequantumdotstoformphotocurrentratherthanrelaxtothegroundstateofquantumdotsinducedbyap–njunction.Thefindingisimportantforunderstandingthelow-dimensionalsemiconductorphysicsandapplicationsinsolarcellsandphotodiodedetectors.
简介:为了深入研究可行的中高轨成像技术,本文从探测能力角度(用最低发射激光功率表示)深入分析和比较3种主动干涉合成孔径成像技术——傅立叶望远镜(又称为相干场成像或条纹场扫描成像)、成像相关术(又称为强度相关成像)和剪切光束成像。本文利用光电倍增管的信噪比模型和激光作用距离方程,较为细致地分析每种技术在满足单次信噪比(SNR=5)条件下的极限探测能力。通过仿真分析得出:傅立叶望远镜、成像相关术和剪切光束成像所需的最低单光束单脉冲能量分别为11.4J、0.73MJ和3.1MJ。最终得出傅立叶望远镜是上述3种主动成像技术中在目前技术水平下最适合中高轨目标(约36000km)高分辨成像的可用技术的结论。