简介:Na0.5CoO2的费密表面拓扑学用混合密度被学习功能的理论。我们首先学习一个单身者(CoO2)(0.5-)有从0%~20%变化的非局部的Hartree-Fock交换的百分比的层模型。结果看那混合非局部的Hartree-Fock交换是否仅仅在1%和5%之间,费密表面拓扑学类似于试验性的。与在混合密度的3%HF交换功能就在Na-0.5CoO2系统的效果ofNa离子而言,我们结束费密表面被切开加倍洞,小差距在在Brillouin地区和费密表面之间的交叉附近开。我们两个都,非局部的Hartree-Fock的数量在功能的混合密度交换的结果表演然后一离子在费密表面拓扑学上有许多影响。
简介:CuO-CoO-MnO/SiO2nanocompositeaerogels被经由大音阶的第五音胶化过程和乙醇supercritical弄干技术作为先锋把tetraethylorthosilicate(TEOS)用作Cu,公司和Mn醋酸盐的Si来源,和水的答案准备。gelatination机制被原子磁性的回声(NMR)和X光检查光电子光谱学(XPS)调查。CuO-CoO-MnO/SiO2nanocompositeaerogels的微观结构和作文被扫描电子显微镜学(FE-SEM)的地排放描绘,传播电子显微镜学(TEM),电子散光谱学(版本)和XPS。特定的表面区域,毛孔尺寸和nanocompositeaerogels的毛孔尺寸分发被Brunauer-Emmett-Teller(赌注)方法决定。产品被煤气的层析(GC)分析。结果证明CuO-CoO-MnO/SiO2nanocompositeaerogels是多孔的,与10150nm,216nm的毛孔尺寸分布,7.68nm的一种平均毛孔尺寸,和664.4695.8m2/g的一个特定的表面区域的粒子尺寸分布。在nanocompositeaerogels的转变金属的臼齿的部分是0.71%-13.77%。这种结构是有利的不仅增加装载催化剂,而且作为cocatalysts充分利用转变金属氧化物的效果;CuO-CoO-MnO/SiO2nanocompositeaerogels能在diphenyl碳酸盐的更安全、环境友好的合成和催化作用的另外的地被用作一个新奇催化剂搬运人。
简介:Inthisstudy,nanocrystallineCo–Ni–MgferritepowderswithcompositionCo0.5Ni0.5-xMgxFe2O4aresuccessfullysynthesizedbytheco-precipitationmethod.Asystematicinvestigationonthestructural,morphologicalandmagneticpropertiesofun-dopedandMg-dopedCo–Niferritenanoparticlesiscarriedout.Thepreparedsamplesarecharacterizedusingx-raydiffraction(XRD)analysis,Fouriertransforminfraredspectroscopy(FTIR),fieldemissionscanningelectronmicroscopy(FESEM),andvibratingsamplemagnetometry(VSM).TheXRDanalysesofthesynthesizedsamplesconfirmtheformationofsingle-phasecubicspinelstructureswithcrystallitesizesinarangeof32nmto36nm.ThelatticeconstantincreaseswithincreasingMgcontent.FESEMimagesshowthatthesynthesizedsamplesarehomogeneouswithauniformlydistributedgrain.TheresultsofIRspectroscopyanalysisindicatetheformationoffunctionalgroupsofspinelferriteintheco-precipitationprocess.ByincreasingMg2+substitution,roomtemperaturemagneticmeasurementshowsthatmaximummagnetizationandcoercivityincreasefrom57.35emu/gto61.49emu/gand603.26Oeto684.11Oe(1Oe=79.5775A·m-1),respectively.ThehighervaluesofmagnetizationMsandMrsuggestthattheoptimumcompositionisCo0.5Ni0.4Mg0.1Fe2O4thatcanbeappliedtohigh-densityrecordingmediaandmicrowavedevices.
简介:ThepermeabilityandstabilityofSm_(0.7)Sr_(0.3)CoO_(3-δ)(SSCO)regardingthespecialrequirementsforcarboncaptureandstorage(CCS)applicationwereinvestigated.PureCO_wasusedasthesweepgasat900°C,leadingtothattheoxygenpermeationfluxdecreasesbyabout34%.SeveralcyclesofchangingthesweepgasbetweenheliumandCO_2indicatethegoodreversibilityofthisdegradation.BothcarbonateformationandadsorptionofCO_2onthemembranesurfaceareresponsibleforthedegradationofthemembraneperformance.ThebetterCO_2resistanceresultsfromthesubstitutionofSmforSrduetothehigheracidityofSm_2O_3(1.278)thanthatofSrO(0.978)andadiscontinuouslayerofcarbonate.