简介:在电的运输性质上评估Ni替换的影响,p类型skutteruditesRyFe3NiSb12(R=Ba,Nd和Yb)系统地从2.5K被调查到800K。由小心地修改三fillers,Ba,Nd和Yb的充满的部分,搬运人集中精确被调整,它按比例改变到数统治的原子价计算的名字的价值。活动性和Seebeck系数的搬运人集中依赖表示在原子价乐队的二乐队贡献,和为热电的性能的优化搬运人集中在之间(5–9)×1020厘米−3。样品的热电导率用稀土元素的元素(Nd和Yb)填满的格子作为与相比显著地更低充满Ba,由于更低的反响的频率并且部分充满。与公司替换相比,Ni替换趋于关上乐队差距,它为RyFe3NiSb12。然而由于状态的密度的改进,当搬运人集中是类似的时,RyFe3NiSb12比RyFe2公司2在更低的温度范围的Sb12。0.73的ZT价值为Yb0.77Fe3在600K的NiSb12。
简介:One-dimensional(1D)nanomaterialsandnanostructureshavereceivedmuchattentionduetotheirpotentialinterestforunderstandingfundamentalphysicalconceptsandforapplicationsinconstructingnanoscaleelectricandoptoelectronicdevices.Zincsulfide(ZnS)isanimportantsemiconductorcompoundofII-VIgroup,andthesynthesisof1DZnSnanomaterialsandnanostructureshasbeenofgrowinginterestowingtotheirpromisingapplicationinnanoscaleoptoelectronicdevices.Thispaperreviewstherecentprogresson1DZnSnanomaterialsandnanostructures,includingnanowires,nanowirearrays,nanorods,nanobeltsornanoribbons,nanocables,andhierarchicalnanostructuresetc.Thisarticlebeginswithasurveyofvariousmethodsthathavebeendevelopedforgenerating1Dnanomaterialsandnanostructures,andthenmainlyfocusesonstructures,synthesis,characterization,formationmechanismsandopticalpropertytuning,andluminescencemechanismsof1DZnSnanomaterialsandnanostructures.Finally,thisreviewconcludeswithpersonalviewstowardsfutureresearchon1DZnSnanomaterialsandnanostructures.
简介:Thebovinehydroxyapatite(BHA)wasappliedtopreparebiologicaltissueengineeringscaffoldsbythemethodofextrusionfreeforming.Toachievethisgoal,BHAwereaddedtosodiumalginate(SA)solutiontoformaslurrysysteminappropriateproportion.Theresultingmixtureswerefabricatedtobeakindofcontrollableandporousscaffoldsfollowedwithcross-linkingin5%calciumchloride(CaCl2)solutionfor24h.Afterthat,thescaffoldsweresinteredinairat1000,1100,1200and1300℃for5h.Scanningelectronmicroscopy(SEM)andX-raydiffraction(XRD)studieswereperformedonthescaffoldstoanalyzeitsmicrostructureandconstituent.Toexploretheeffectofsinteringtemperatureonscaffolds,thecompressivestrength,volumeshrinkageandwaterabsorptivityofBHA-SAcompositescaffoldsaftersinteringwereinvestigated.TheresearchtestsindicatedthefeasibilityofapplyingBHApowderto3Dprinting.Besides,thescaffoldssinteredinarespectivelylowertemperaturepossessmuchmoreporesandperformedhigherwaterabsorptivity,whichmeansbettercellularaffinity.Andscaffoldssinteredbetween1100and1200℃presentshighercompressivestrength.
简介:Amathematicalmodelforthethree-dimensionalsimulationoffreedendriticgrowthandmicrostructureevolutionwasdevelopedbasedonthegrowthmechanismofcrystalgrainsandbasictransferequationssuchasheat,massandmomentumtransferequations.Manyfactorsincludingconstitutionalundercooling,curvatureundercoolingandanisotropy,whichhadvitalinfluencesonthemicrostructureevolution,wereconsideredinthemodel.SimulatedresultsshowedthatfinalmicrostructuralpatternsandfreedendriticgrowthcouldbepredictedreasonablyandcalculatedresultswerecoincidentwithexperimentalThesimulatedresultsoffreedendriticgrowthindicatedthatthestrengthofanisotropyhassignificanteffectsonfreedendriticgrowth,dendriteprofile,microsoluteandtemperaturedistribution.Thedendriticgrainprofileswithfully-grownparallelsecondaryarmtendtobeformedattheintensiveanisotropy,whilenearoctahedralgrainprofileswithsmallprotuberancesofsurfaceatlowstrengthofanisotropy.Thesimulatedresultsoffreedendriticgrowthalsoindicatedthattherearesmallmoltenpoolsleftininterdendriticareas.Thisishelpfultounderstandthefundamentaloftheformationofmicrostructurerelateddefectssuchasmicrosegregationandmicroporosity.
简介:三新奇Ba_5RNiNb_9O_(30)(R=La,Nd和Sm)陶艺在BaO-R_2O_3-NiO-Nb_2O_5系统被准备并且描绘。所有三混合物areparaelectjicphasesadopting。在房间温度的充满的四角形的钨铜(TB)结构。在1MHz,Ba_5RNiNb_9O_(30)陶艺有高电介质在范围193-245.3,在范围0.0059-0.0087的低绝缘的损失,和在范围的绝缘的常数(tau_e)的温度系数的常数-1140-1310X10~(-6)中心点degC。他们绝缘的常数的温度系数显著地Ba_5RNiNb_9O_(30)与那些相比被减少(R=La,Nd,Sm)陶艺。
简介:二维(2D)有multilayered质地的碳/碳(C/C)composites,特别与不同厚度高度粗糙(HT)pyrocarbon层,被等温的、等压的化学蒸汽渗入(CVI)准备技术。C/Ccomposites的机械性质上的矩阵微观结构的影响被极化的轻显微镜学调查,扫描电子显微镜学和三点的弯曲测试。结果证明有多层粗糙的pyrocarbon矩阵的样品与纯媒介粗糙的结构比那件拥有更高曲折的力量,它被归因于多重裂缝偏转并且在HT层以内的在不同粗糙的pyrocarbon层之间并且在亚层之间的界面的滑动。HTpyrocarbon层的厚度的增加改进样品的粘性并且在伪塑料行为显示破裂。