简介:Permanentmagneticmaterialscapableofoperatingathightemperatureupto500°Chavewidepotentialapplicationsinfieldssuchasaeronautics,space,andelectroniccars.SmCoalloysarecandidatesforhightemperatureapplications,sincetheyhavelargemagnetocrystallineanisotropyfield(6–30T),highCurietemperature(720–920°C),andlargeenergyproduct([200kJám-3)atroomtemperature.However,thehighestservicetemperatureofcommercial2:17typeSmComagnetsisonly300°C,andmanyeffortshavebeendevotedtodevelopnovelhightemperaturepermanentmagnets.ThisreviewfocusesonthedevelopmentofthreekindsofSmCobasedmagnets:2:17typeSmComagnets,nanocrystallineSmComagnets,andnanocompositeSmComagnets.Theoxidationprotection,includingalloyingandsurfacemodification,ofhightemperaturepermanentmagnetsisdiscussedaswell.
简介:IntroductionIMI829titaniumaloyisakindofhightemperaturenearαaloy.Itsservicetemperatureisupto580℃.IthasbeenusedinRB211525E4en...
简介:因为它的吸引人的表演,超导的nanowire单身者光子察觉者(SNSPD)在极端紫、可见、在红外线附近的波长引起许多注意,并且它能在量信息技术是普遍的。然而,怎么增加罐头戏剧性地增加SNSPD的量效率的吸收仍然是一个顶研究问题。在这研究,洞综合的SNSPD的光吸收比上的事件媒介和洞材料的效果系统地用有限元素的方法被调查。模拟结果为光子表明那极化的平行到nanowire取向尽管nanowire的最大的吸收比对洞材料感觉迟钝,事件媒介的折射索引什么时候减少,确实增加。为垂直地极化的光子,事件媒介和洞材料起重要作用,并且吸收比曲线作为洞材料增加的折射索引接近平行案例。把结果基于这些,有能为平行、垂直的光子提高吸收比的前面照明结构的二洞综合的SNSPD被建议。最后,与高吸收比认识到极化无关的SNSPD的一个图案被介绍。
简介:Na离子电池由于他们的低费用和自然许多Na资源为大规模精力存储系统被认为一种有希望的选择到Li离子电池。大努力全球正在做为Na离子电池开发高效的电极材料,它为Na离子电池是批评的。这评论基于Na存储机制为Na离子电池提供阳极材料的全面概述:基于插入的材料,基于合金的材料,基于变换的材料和器官的composites。并且我们总结那些阳极材料的Na存储机制并且讨论他们的失败机制。而且,与那些阳极联系的问题和挑战被指出,并且可行策略为设计高效的阳极材料被建议。根据研究的当前的状态,尽管实质的进步被获得了,为为Na离子电池的合适的阳极材料的搜索仍然是挑战性的。不过,我们相信高效的Na离子电池在不久的将来将为在大规模精力存储系统的实际应用程序是有希望的。
简介:Theeffectofsolidificationrateonthemicrostructuredevelopmentofnickel-basedsuperalloyunderthetemperaturegradientof500K·cm-1wasstudied.Theresultsshowthat,withtheincreaseofdirectionalsolidificationratefrom50to800μm·s-1,boththeprimaryandthesecondarydendritearmspacingsofthealloydecreasegradually,andthedendritemorphologiestransformfromcoarsedendritetosuperfinedendrite.Thesizesofallprecipitatesinthesuperalloydecreasegradually.Themorphologyof...
简介:Thethermaldiffusioncoefficient,thermalconductivity,andthermalexpansioncoefficientofCuCralloypreparedbyinfiltrationweremeasuredbythermalconstanttesteranddilatometerbeforeandafterhighpressureheattreatment,atthesametime,theeffectofhighpressuretreatmentonthethermalphysicalpropertiesofCuCralloywasdiscussedbytheanalysisofitsmicrostructure.TheexperimentalresultsshowthathighpressureheattreatmentcanincreasethethermaldiffusioncoefficientandthermalconductivityofCuCralloy,butitchangesslightlyinthepressurerangeof1–6GPa.Asforthermalexpansioncoefficient,whenthetemperatureishigherthan130°C,itisobviouslyhigherthanthatofthealloywithouthighpressuretreatmentafter1GPapressuretreatment,andthehigherthetemperatureis,thelargertheirdifferencesare.
简介:PhasesandmicrostructuresofthreehighZncontainingAl–Zn–Mg–Cualloyswereinvestigatedbymeansofthermodynamiccalculationmethod,opticamicroscopy(OM),scanningelectronmicroscopy(SEM)energydispersivespectroscopy(EDS),X-raydiffraction(XRD),anddifferentialscanningcalorimetry(DSC)analysis.TheresultsindicatethatsimilardendriticnetworkmorphologiesarefoundinthesethreeAl–Zn–Mg–Cualloys.Theas-cast7056aluminumalloyconsistsofaluminumsolidsolution,coarseAl/Mg(Cu,Zn,Al)2eutecticphases,andfineintermetalliccompoundsg(MgZn2).Bothofas-cast7095and7136aluminumalloysinvolvea(Al)eutecticAl/Mg(Cu,Zn,Al)2,intermetallicg(MgZn2),andh(Al2Cu).Duringhomogenizationat450°C,fineg(MgZn2)candissolveintomatrixabsolutely.Afterhomogenizationat450°Cfor24h,Mg(Cu,Zn,Al)2phasein7136alloytransformsintoS(Al2CuMg)whilenochangeisfoundin7056and7095alloys.ThethermodynamiccalculationcanbeusedtopredictthephasesinhighZncontainingAl–Zn–Mg–Cualloys.
简介:各向异性的MnBi/NdFeB(0wt%的MnBi内容,20?wt%,40?wt%,60?wt%,80?wt%,并且100?wt%)混合结合的磁铁被用MnBi粉末和再结合(HDDR)NdFeB粉末塑造压缩准备。在房间温度的磁性的大小证明与MnBi内容增加,MnBi/NdFeB混血儿的磁性结合了磁铁都逐渐地减少,当混合磁铁的密度几乎线性地改善时。在293-398的一个温度范围?K,混合磁铁的coercivity温度系数从0.59逐渐地改善?%比较。建模和频率与二低角落频率认为压力消除阀门是一个秒顺序系统是合理的试验性的结果表演。PID控制,死了的乐队赔偿控制和鷸?鷸??
简介:AnimprovedmethodhasbeendevelopedforenrichinganddeterminingtraceIn,Pt,Sn,Co,Hg,Pb,Ni,Bi,Pd,CuandAginhigh-puritygallium.SamplewastreatedbyPDM(partialdissolutionofmatrix)withHCl(11mol/L)-HNO3(0.5mol/L)toasmallresidueofwhichGawasthenremovedbyextractionwith1mlisopropylether.TheconcentratedimpuritiesweredeterminedbyAESprocedure.Therecoveriesfortheele-mentsattherangeof0.02~0.2μgare95~103%;therelativestandarddeviationsfordeterminedimpuritiesoverarangeofn.10-7~n·10-8%are4.3~12%;thedetectionlimitofmostelementscanreachn·10-7~n·10-8%levelwiththeexceptionofHgandPt.Thismethodhasbeensuccessfullyusedtoanalyzemanysam-plessentbyfactoriesandinstitutes.
简介:TiO2/Au/TiO2多层的薄电影用dc(直接水流)在房间温度在聚合物底层被扔磁控管劈啪作响方法。由改变每层的厚度,TiO2/Au/TiO2多层的电影的光、电的性质能被定制适合不同应用。厚度和Au层的光性质和Au绝缘的接口的质量为Au绝缘的多层的薄电影的电、光的表演是批评的。在8nm的厚度,Au层形成有最低抵抗力和它的连续结构一定为高发射度薄。多层的栈能被优化有6的一个表电阻?在在在波长的680nm的超过80%的发射度的/sq.。当时,山峰发射度向长波长区域变二TiO2的厚度(上面、更低)层增加。当二部TiO2电影的电影厚度是45nm时,高发射度价值为全部可见轻波长区域被获得。
简介:Soil,cropandresidents'hairoverXiaoqinlinggoldminingregion,China,whichwasselectedasacasestudy,weresampledandanalyzedforHg,Cd,Pb,Cu,Cr,AsandZnconcentrations.Theconcentrationsofheavymetalsinsoilorcropandhairsampleswereusedtoassesstheirpotentialecologicalrisks,ortofindtheresponsestothesemetalsasevidencestoprovethepotentialriskwascomingdowntoobservedharm,respectively.Theresultsshowedthat,thesemetalsinsoilwererankedbyseverityofecologicalriskasHg>Cd>Pb>Cu>Cr>As>Zn,basedontheirsingle-elementindexes.Intheviewofthepotentialecologicalriskindexes,ofallsoilsamples,abouthalfhadsignificantlyhighorhighpotentialecologicalrisk,whichcoveredmorethan74%ofthestudiedregion.Mostoftheriskswere97.41%fromHg,PbandCd,especially,84.37%fromHg.Boththesingle-elementandpotentialecologicalriskindexesindicatedthat,theecologicalriskgradeshadaspecialspatialcharacteristic,andincreasedfromnorthwesttosoutheastgenerally.Thiswasagreedwiththespatialdistributionofthestrengthingoldminingactivitiesoverthestudiedregion.TheconcentrationsofHgandPbwerehigherthantheirrelativebackgroundsinthecorps,andwereeven9.48and25.09timeshigherthantheirrelativebackgroundsinresidents'hair,respectively.Alltheseshowedthattheheavymetalsinthesoilhadahighpotentialecologicalrisk,especially,hadbeenaffectingthesecrops'growingandyield,andeventheresidents'healththroughfoodstrains.Obviously,thesemetals'potentialecologicalharmhadbeencomingdowntoobservedharmtotheecology.
简介:Theeffectsofisothermalholdingprocessonthemicrostructureevolutionofsemi-solid7075strengthaluminumalloyproducedbytherecrystallisationandpartialremelting(RAP)processwereinvestigated.Tensilemechanicalpropertiesofas-receivedandthixoformedalloysatroomtemperaturewereexamined.Theresultsshowthatthemicrostructureofas-receivedalloyexhibitsremarkableorientationalongthedeformationdirection.Withtheincreaseofisothermalholdingtime,thesolidparticlegrainsizecontinuouslyincreasesandthedegreeofspheroidizationalsoimproves.Coalescencemechanismisdominantwhenreheatedat595°CandOstwaldripeningmechanismisdominantwhenreheatedat615°Cinthesemi-solidstate.Alowercoarseningrateisobservedfor615°C(coarseningrateK=391μm3s-1)comparedwiththecoarseningratefor595°C(coarseningrateK=501μm3s-1).TheRAP7075aluminumalloycanbesuccessfullythixoformedandthefillingofcomponentsisgoodafterthixoforming.Thethixoformedcomponentsexhibitfavoritemechanicalproperties.
简介:IsothermalcompressionofaTi-5.6Al-4.8Sn-2.0ZralloywasconductedonaThermecmaster-Zsimulatoratthedeformationtemperaturesrangingfrom960to1060°C,thestrainratesrangingfrom0.001to10.0s-1,andthemaximumheightreductionof70.0%.Inthetwo-phaseregionoftheTi-5.6Al-4.8Sn-2.0Zralloy,thevolumefractionofαphasedecreaseswithanincreaseindeformationtemperature,butthegrainsizehasaslightvariationwithdeformationtemperature.ThestrainrateaffectsbothmorphologiesandgrainsizeoftheαphaseintheisothermalcompressionoftheTi-5.6Al-4.8Sn-2.0Zralloy.Theoptimalheightreductionalsocontributestothesmallandwell-distributedαphaseintheisothermalcompressionofTi-5.6Al-4.8Sn-2.0Zralloy.
简介:Anisotropicpowderwaspreparedwithprecursor(NdDy)-(FeCoNbCu)-Bsinteredmagnetsbyhydrogendecrepitation,desorption,andsubsequentannealingtreatment.Thehydrogendesorptionwasperformedinmagneticfieldsof0,1,3,and5T.Theorientationoftetragonalphasegrainsofthepowderwasevaluatedfromthehysteresisloopsmeasuredbyextractionmagnetometer.Residualhydrogencontentofthepowderwasevaluatedbythermal-magneticanalysis.ThepowderwithHcj,Br,and(BH)maxof1138kA·m-1,1.029T,and172.5kJ·m-3,respectively,wasachievedundertheconditionofthemagneticfieldof3T.Magneticpropertiesofthepowder,especially,theremanenceofthepowder,areenhanceduponmagneticfields,whichisduetobetterorientationofpowderparticlesandlessresidualhydrogeninthepowderresultedfromthemagneticfieldduringthehydrogendesorptionprocess.
简介:Usingorganicaquaregia,arecentlydiscoveredpowerfulorganicleachingagent,aneffectiveprocessofrecoveringPtdirectlyfromPt-Aubimetallicnanoparticleswasdemonstrated.ThepuritiesofthePtrecoveredfromamixtureofAuandPtnanoparticlesandfromPt-Aucore-shellnanoparticlecatalystareashighas(99.49±0.22)%,and(95.02±0.08)%,respectively.Thenovelrecoveryprocesspromisesapplicationsincatalysisindustry.