简介:摘要:Ni 基催化剂是目前工业用碱水电解制氢的常规材料,但仍存在析氢本征活性低、产氢能耗高的问题。Ni与 d 区金属元素W进行合金化改性处理是提高 Ni 基催化剂本征活性的有效方法。本文通过一步电沉积法,在柠檬酸钠添加硼酸的电镀液体系中实现了低电流密度下 NiW 高催化活性镀层的制备,显著降低了电沉积能耗,有利于实现样品的大规模制备。研究了电沉积液中 NiW 比对沉积镀层催化活性的影响。溶液中少量 Ni 的存在即可有效促进 W 的还原。形成的 NiW(2:4)镀层展示出优异的协同效应,析氢催化活性显著提升,在100 mA cm-2 的电流密度下仅需施加203 mV的过电位,且在该电流密度下可稳定运行100 h,有望应用于工业化电解水制氢领域。
简介:摘要:Ni 基催化剂是目前工业用碱水电解制氢的常规材料,但仍存在析氢本征活性低、产氢能耗高的问题。Ni与 d 区金属元素W进行合金化改性处理是提高 Ni 基催化剂本征活性的有效方法。本文通过一步电沉积法,在柠檬酸钠添加硼酸的电镀液体系中实现了低电流密度下 NiW 高催化活性镀层的制备,显著降低了电沉积能耗,有利于实现样品的大规模制备。研究了电沉积液中 NiW 比对沉积镀层催化活性的影响。溶液中少量 Ni 的存在即可有效促进 W 的还原。形成的 NiW(2:4)镀层展示出优异的协同效应,析氢催化活性显著提升,在100 mA cm-2 的电流密度下仅需施加203 mV的过电位,且在该电流密度下可稳定运行100 h,有望应用于工业化电解水制氢领域。
简介:Fouriertransformedinfraredspectrometry(FTIR)and27AlMagicAnglespinning(MAS)nuclearmagneticresonancespectroscopywereemployedtocharacterizearsenateadsorptiononamorphousAlgelswithKegginstructureatpH=4–10.Thesestudieshaveproventhat:thesurfacecomplexspeciesofarsenateshowsignificantdifferencesunderacidicandalkalineconditions,whichwasdeducedbasedontheAs-Ostretchingvibrationbandslocatedrespectivelyat774and870cm-1;poorlycrystallineAl13(orAl)-arsenateprecipitationcouldbeeasilyformedunderacidmediumconditionandhighloadinglevel,whichwassupportedbycomparingtheAs-Ovibration(at≈732cm-1)ofprecipitationtoadsorbedAlgels;arsenate(AsO43-)adsorptionhasnoeffectontheKegginstructureofAlgelswithbasicity(R)=2.6and3.0,evenathighloadinglevel,asevidencedbythesignalat≈63×10-6ofmagicanglespinning(MAS)-27AlNMR.Theadsorptionenvelopewasdeterminedbyconventionalbatchexperiments.
简介:以便获得两高电镀物品迁居(他们)在高周波的表面的可靠性和罚款维的控制声学的波浪(锯)设备,4-layeredTi/Al-Mo/Ti/Al-Mo电极电影在128°Y-XLiNbO3上被调查由劈啪作响的底层免职。结果显示4-layered电影与常规Al-0.5wt.%Cu电影相比有改进他们可靠性。他们的一生比在5×的当前的密度测试的Al-0.5wt.%Cu电影的长约三倍107A/厘米2和200°C的温度。而且,4-layered电影容易在反应离子蚀刻被蚀刻,罚款维的控制为高周波的锯设备在模式复制期间被认识到。为4-layered电影,最佳瞬间数量和劈啪作响的参数为高他们可靠性是很重要的。
简介:在80%Al-20%CuO(质量分数)体系中,通过原位反应法制备Al2O3p-Al复合材料。采用不同方法研究CuO颗粒粒度对复合材料合成温度和显微组织的影响。结果表明,CuO颗粒粒度对Al-CuO体系的完全反应温度有显著影响:含有粒度小于6μmCuO颗粒样品的完全反应温度比含有粒度小于100μmCuO颗粒样品的完全反应温度低200°C。当反应温度低于某一临界值时,原位Al2O3颗粒和Al基体之间不能完全结合;当温度高于某一临界值时,原位Al2O3颗粒的形貌从棒状转变成近球形。这两个临界温度受CuO颗粒粒度的影响:含有粒度小于6μmCuO颗粒样品的临界温度比含有小于100μmCuO颗粒样品的临界温度低100℃。
简介:Thispaperpresentstheprincipleofphasemodulationoftheopticalwave,thatisusingadensefringefamilytomodulateanotherfringepattern,anditsapplicationinfringemultiplication.Itisofuniversalsignificanceinopticallyexperimentalmechanics.
简介:四个参数,煤气的流动,旋转速度,精制时间,和炖的时间的效果,在7075的旋转impeller精炼上,艾尔被学习。C2精制的Cl6,精制的旋转impeller,并且7075艾尔合金的合成精制与对方相比。结果证明旋转impeller精炼的最大的影响参数是旋转速度,由煤气的流动,精制时间,和炖的时间列在后面。直角的分析获得的最佳纯化参数如下:400r/min,0.4mL/h的惰性的煤气的流动,15min的精制时间,和6min的炖的时间的转子速度。最好的排除效果能被C2Cl6和旋转impeller。C2Cl6,旋转impeller,并且合成精制分别地是34.5%,69.2%,和78%。旋转impeller精制的标本的机械性质比由C2精制的Cl6,但是比那些低由合成精制。
简介:TheweldabilityofSiCw/6061Alwasinvestigated.Fromtheresultsofexperiments,itisfoundthatthestrengthofjointismainlyinfluencedbyweldingtemperature,andhighstrengthofjointisobtainedunderweldingtemperaturebetweenliquidusandsolidusofmatrixalloy.DiffusionweldingofSiCw/6061.Alwassuccessfullyrealizedwithappropriateweldingparameters.
简介:Al-pillaredinterlayeredmontmorillonite(Al-PILM)waspreparedusingtheartificialNa-montmorillonitefromtheQingfengshanbentonitemineasastartingmaterialmixedwithAl-pillaringsolutions.ThemicrostructureofthematerialswasstndiedbyanX-raypowderdiffractometerandaFouriertransforminfrared(FTIR)spectrometer.Theresultsindicatedthatthebasalspacing[d(001)value]ofthematerialswasincreasedsignificantlyto1.9194nmrelativetoNa-montmorillonite(1.2182nm).Aftercalcinedfor2hat300℃,thebasalspacingwasstabilizedat1.8394nmandthelayeredstructureofthematerialswasnotdestroyed.Thermalanalysiswasconductedbyathermalgravimetryanddifferentialthermalanalysis(TG-DTA)instrument,itshowedthatAl-PILMlostphysicallyadsorbedwaterbelow230.6℃andwaterformedbydehydroxylationofthepillarsataround497.1℃,withapeakofthephasetransformationat903.0℃.
简介:AdditionofAl-5Ti-1Balloytomoltenaluminumalloyscanrefineα-Algrainseffectivelyandtherebyimprovetheirstrengthandtoughness.TiAl3andTiB2inAl-5Ti-1Balloyarethemainsecondary-phaseparticlesforrefinement,whiletheunderstandingontheeffectoftheirsizesonα-Algrainrefinementcontinuestobefragmented.Therefore,Al-5Ti-1Balloyswithvarioussizesandmorphologiesofthesecondary-phaseparticleswerepreparedbyequalchannelangularpressing(ECAP).Evolutionofthesecondary-phaseparticlesduringECAPprocessandtheirimpactonα-AlgrainrefinementwerestudiedbyX-raydiffractionandscanningelectronmicroscope(SEM).ResultsshowthatduringtheECAPprocess,micro-cracksfirstlyappearedinsideTiAl3particlesandthengraduallyexpanded,whichresultedincontinuousrefinementofTiAl3particles.Inaddition,micro-distributionuniformityofTiB2particleswasimprovedduetotheimpingementofTiAl3particlestoTiB2clustersduringdeformation.ExcessivelylargesizesofTiAl3particleswouldreducethenumberofeffectiveheterogeneousnucleusandthusresultedinpoorgrainrefinementeffectiveness.Moreover,excessivelysmallTiAl3particleswouldreduceinhibitoryfactorsforgraingrowthQandweakengrainrefinementeffectiveness.Therefore,anoptimalsizerangeof18-22μmforTiAl3particleswassuggested.
简介:Al-3B中间合金是亚共晶Al-Si合金的高效细化剂之一。实验研究了Al-3B中间合金中未溶AlB2颗粒对Al-7Si合金晶粒细化的影响。结果表明,AlB2颗粒的数目和沉降对晶粒细化效果都有重要影响。在实验结果和理论分析基础上,提出了Al-3B中间合金对亚共晶Al-Si合金晶粒细化的新机制,认为通过共晶反应形成的"Al-AlB2"包覆结构是导致晶粒细化的直接原因,未溶的AlB2颗粒是α(Al)相的间接行核基底。
简介:BasedontheMiedemamodelandExtendedMiedematheory,theformationenergiesofdifferentsolutecomponentsinEr-XbinarysystemandAl-Er-Xternarysystemswerecalculated.TheresultsshowthatthevariationoferbiumcontenthaslittleinfluenceonthechancerateoftheformationAl-ErcompoundintheAl-Mg-Mn-Zr-Ersystem.ThecalculatedformationenergiesintheEr-XbinarysystemandAl-Er-XternarysystemsindicatethatAl3Erphasecantakepriorityofdepositing,Al-Er-Zrternarycompoundsmayalsofoundwhichagreeswiththeexperimentalresultsinreferences.TheconsistencyofcalculationandexperimentprovesthattheintermetalliccompoundsintheAl-Mg-Mn-Zr-ErsystemcanbepredicteddirectlybycalculatingtheformationenergiesofthereactionsinEr-XbinarysystemandAl-Er-XternarysystemswiththeMiedemamodelandExtendedMiedematheory.
简介:这篇论文在Guiyang的地表的土壤描述象Cu和Zn那样的重金属污染物质的环境联盟者geochemical特征,GuizhouProvince的首都的城市。在土壤和geochemical标准的重金属的基线集中被建立了在环境上区分自然或人工的影响。用统计上分析方法,我们在Guiyang(18.8mg/kg)建立了Cu的基线,土壤(超过68.4mg/kg)可以承受Cu污染。Zn的数据是46。3mg/kg并且112。0mg/kg。Geoaccumulation指数分析显示有sufferednon污染到的地表的土壤为38%,38%,和22%的Cu帐户为中间污染中间污染,并且仅仅对严重污染中间污染的2%between。承受了Zn的非污染tomid污染的地表的土壤占41%,50%,和7%为中间污染,并且仅仅2%betweenmid污染到严重污染。Cu污染的最大的度在Guiyang的surficials油是5.09。没为53承受Cu污染报道的地表的土壤。2%。Cu的全部的污染度是稍微超过零。Guiyang的地表的土壤因此承受了slightCu污染。Zn污染度的最大的价值是2。85在地表的土壤ofGuiyang。77。8%地表的土壤还没承受了任何Zn污染。Zn的全部的污染度是不到零。在Guiyang的地表的土壤因此从Zn的污染是免费的。
简介:MagnesiumalloyEZ10(Mg-RE-Zn)wasdeformedintensionattemperaturesfrom20upto520°C.Arapiddecreaseoftheyieldandtensilestrengthwithtemperaturewasobservedattemperatureshigherthan300°C.Ontheotherhand,ductilityofsamplesrapidlyincreasedinthesametemperaturerange.Lightmicroscopyandscanningelectronmicroscopywasusedtorevealthereasonforthesebehaviours.Intermetallicparticlesingrainboundariesareresponsibleforexcellentmechanicalpropertiesatlowertemperatures.Diffusionalprocessesoccurringattemperatureshigherthan300°Csignificantlyinfluencedthedeformationmechanismaswellasthefracturecharacter.