Cathode catalysis performance of SmBaCuMO5+δ (M=Fe,Co,Ni) in ammonia synthesis

The SmBaCuMO5+δ (M=Fe, Co, Ni) (SBCM) powders were synthesized by the citrate sol-gel method and the powders were sintered to ceramic pellets. The powders and sintered ceramic pellets were characterized with XRD, TEM and SEM measurements. The cathode catalytic performances of SBCM ceramic pellets for ammonia synthesis were studied from wet hydrogen and dry nitrogen at atmospheric pressure and low temperature, using SBCM ceramic pellets as cathode, Nafion proton exchange membrane as electrolyte, Ni-Ce0.8Sm0....     

Ni_(43)Mn_(46-x)T_xSn_(11)(T=Fe,Co,Ni)合金的马氏体相变和磁熵变

通过示差扫描量热仪和振动样品磁强计对Ni43Mn46-xTxSn11(T=Fe,Co,Ni)铁磁形状记忆合金的相变、磁性以及磁熵变进行了研究。结果表明,由于价电子浓度的增加,Fe,Co,Ni替代Mn使马氏体转变温度大幅提高。Fe,Ni掺杂对马氏体居里温度(TCM)影响不大,Co则使TCM略有下降;奥氏体居里温度(TCA)对成分比较敏感,Fe,Ni的加入均使TCA略有提高,而Co则会大大提高TCA。由于马氏体相变伴随着磁化强度的突变,Ni43Mn46-xTxSn11合金在马氏体相变附近具有较大的低场磁熵变,对于Ni43Mn41Co5Sn11在室温1T磁场下磁熵变达到了19J.kg-.1K-1。通过调节成分,磁熵变峰值温度可以在199和294K之间调节,同时保持了较大低场磁熵变。     

BiFe_(1-x)T_xO_3(T=Co和Ni)的晶体结构和磁性

比较了运用固相烧结法制备的BiFe1-xCoxO3和BiFe1-xNixO3的晶体结构、饱和磁化强度和矫顽力随掺杂量的依赖关系.结果发现,强磁性的立方结构是掺杂样品磁性的主要来源.Ni掺杂样品的居里温度比Co掺杂样品高,这是由于原子间距和离子种类的不同造成了磁性离子间超交换作用的强弱变化所致.Co离子具有较强的单离子各向异性和偏离立方结构的晶格畸变,造成了Ni掺杂样品的矫顽力比Co掺杂样品低.变温磁滞回线的结果表明,BiCoO3样品的磁晶各向异性随温度降低而增大.     

WC-8(Fe, Co, Ni)RE合金性能研究

用不同比例的Fe和Ni部分代替WC-8Co合金中的粘结剂Co，再添加微量的碳粉和稀土氧化物Y2O3制得WC-8(Fe，Co，Ni)RE硬质合金，测试了其物理机械性能，研究了粘结剂各种成分及烧结温度、烧结气氛对硬质合金性能的影响。在一定的烧结工艺下，以Fe和Ni部分代替Co所制得的WC-8(Fe，Co，Ni)RE硬质合金，其性能可以达到甚至超过YG8的标准，同时对影响WC-8(Fe，Co，Ni)RE硬质合金性能的一些因素进行了讨论。     

Study on preparation and gas sensing property of water-soluble polyaniline/SmBaCuMO_(5+δ)(M=Fe,Co, Ni) for NH_3

Water-soluble polyaniline(PANI), prepared by chemical-oxide and SmBaCuMO5+δ(M=Fe, Co, Ni)(SBCM) powders, prepared by sol-gel method were analyzed through Fourier transform infrared spectroscopy(FT-IR) spectra, X-ray diffraction(XRD), transmission electron microscopy(TEM) and energy dispersive spectroscopy(EDS) respectively, so as to investigate the gas sensitivities of PANI/SmBaCuFeO5+δ(SBCF) and its sensitivity to NH3 under room temperature. The results showed that all of SBCM powders were of double-perovskite structure and PANI was successfully obtained. Under the same condition, the gas sensor based on PANI/SmBaCuFeO5+δ(SBCF) material exhibited higher resistance sensitivity, better selectivity and shorter response-recovery time than others. The resistance sensitivities to NH3 increased with the increasing of atom radius of M in PANI/SBCM.     

添加稀土的WC-20(Fe/Co/Ni)硬质合金的研究

在铁镍部分代钴的基础上，实验添加不同量稀土，结果表明，加入适量稀土可使合金的抗弯强度的提高最大幅度达５．８％；硬度增加０．２～２．０ＨＲＡ。同时，对稀土强化铁镍代钴硬质合金的机理进行了初步探讨。     

添加稀土的WC-20(Fe/Co/Ni)硬质合金的研究

在铁镍部分代钴的基础上，采用常规硬质合金工艺，以不同的混合稀土添加量进行了实验。加入适量稀土可提高合金的抗弯强度，最大提高幅度为５８％，硬度也有一定的增加（０５～２ＨＲＡ）。同时，对稀土强化铁镍代钴硬质合金的机理进行了初步探讨。     

Mössbauer study of iron carbides: Cementite (Fe,M)3C (M = Cr,Mn) with various manganese and chromium contents

In many Mössbauer investigations on steel or iron based materials iron carbides play an important role. In Mössbauer phase analysis it is very helpful if the hyperfine parameters of different iron-carbides are known precisely. The results as revealed by investigation of pure cementite with various manganese and chronium contents are reported. The influence of chromium and manganese on the magnetic behaviour is presented. A preferred site occupation of chromium and manganese in the cementite was found.     

金属间化合物R_2Ni_(17-x)Alx(R=Gd，Tb)的磁特性

在铁磁和顺磁区研究了金属间化合物 R_2Ni_(17-x)Alx(R=Gd,Tb 和 0相似文献   

粉末冶金法制备La(Fe11.05Co0.85Si1.1)B0.25化合物的磁热效应

用非自耗电弧炉熔炼制备了La(Fe<,11.05>Co<,0.85>Si<,1.1>)B<,0.25>铸锭,并将该铸锭在氩气保护中球磨制粉,采用SPS(放电等离子烧结技术SparkPlasma Sintering)将该粉制成La(Fe<,11.05>Co<,0.85>Si<,1.1>)B<,0.25>合金,在高温(1070℃)下对其进行20 h热处理;空冷之后用XRD及SEM检测了铸锭热处理样品、SPS烧结样品及SPS热处理后样品的相及组织结构,利用VSM和磁热效应直接测量仪测量了这3种状态下合金的等温磁熵变和绝热温变.结果表明,铸锭合金的基相组织结构中晶粒大小规则较均匀,晶界清晰明显,在0～1.5 T的变化磁场下测得其等温磁熵变达到-5.22 J·(kg·K)<'-1>-,绝热温变也达到2.3 K,而采用SPS技术制得的样品的基相组织结构中没有明显晶界且夹杂较多,其等温磁熵变为-3.90 J·(kg·K)<'-1>,绝热温变为1.9 K(0～1.5 T);经过热处理的SPS样品基相组织结构中,有少量晶界形成,但晶粒大小不规则,测得其等温磁熵变为-3.72 J·(kg·K)<'-1>,绝热温变为1.5 K(0～1.5 T);与铸锭相比较,SPS技术制得的合金样品和经过高温热处理之后的SPS样品的绝热温变值和等温熵磁变值均降低,同比之下这两种样品较铸锭样品的居里点和半峰宽却发生了改变,均显著提高;可以看出采用SPS技术制备的室温磁制冷材料La(Fe<,11.05>Co<,0.85>Si<,1.1>)B<,0.25>能够在较宽的温度范围内制冷,但其磁热效应却相对降低.     

La0.7Sr0.3Mn1-xRxO3(R=Co,Ni)的共沉淀法合成及磁性研究

用液相共沉淀法合成了La0.7Sr0.3Mn1-xRxO3(R=Co,Ni)样品.利用XRD对样品结构进行表征,结果表明,由于Co2 半径与Mn3 离子半径不匹配,当Co2 含量x>0.07时,样品La0.7Sr0.3Mn1-xRxO3的结构由正交晶系向单斜晶系转变,而Ni2 离子半径与Mn3 离子半径相近,Ni的掺杂并没有改变系列样品La0.7Sr0.3Mn1-xRxO3的晶体结构.通过振动样品磁强计测试样品的磁性,结果表明,La0.7Sr0.3Mn1-xRxO3(R=Co,Ni)系列样品的比饱和磁化强度随掺杂浓度的增加而减少,这是由于Co2 和Ni2 取代Mn3 后,引起B位离子的电场差的减少.样品的稳定性降低,而使得比饱和磁化强度降低.     

Study of Reactivity of Oxygen Species on SmMO_3(M=Mn,Fe)by TDS and TPRS

With O_2 and CO as the molecular probes,the reactivity of oxygen species of perovskite-likeoxides SmMnO_3 and SmFeO_3 was studied by thermodesorption spectroscopy(TDS)and temperature-programmed reaction spectroscopy(TPRS)in an ultrahigh vacuum system.The results of the experimentimplied that the oxidation of CO on SmMO_3 may follow Langmuir-Hinshelwood mechanism.     

利用粉末掺和技术生产(Nd,Mm)2(Fe,Co,Ni)14B型烧结磁体

概述了利用粉末掺和技术制得（Nd，Mm）2（Fe，Co，Ni）14B型各项异性磁体的基本情况及该材料的主要性能。     

Centrifugal Metallothermic SHS of Cast Co–Cr–Fe–Ni–Mn–(Х) Alloys

Russian Journal of Non-Ferrous Metals - A relatively new approach to obtaining metal materials containing several principal elements in equiatomic concentrations which look promising for replacing...     

M-Cu(M:Fe,Co)合金亚稳液相分离时液相间的界面能

基于Becker界面能模型,由合金相图和液态合金的过剩热力学数据,计算了M-Cu (M:Fe,Co)包晶合金亚稳液相分离时液相间的界面能.     

Effect of the F–D Exchange Interaction on the Properties of Thin-Film Mdm Structures (M—Fe,Co, Ni; D—Tb2O3)

Powder Metallurgy and Metal Ceramics - The effect of f–d interaction on the current–voltage characteristics of metal–dielectric–metal (MDM) structures consisting of...     

Nd2Fe14B/Fe3B基纳米复合粘结磁体的磁特性

通过实验研究了Nd2Fe14B／Fe3B双相纳米复合磁粉分别与几种不同性能的磁粉复合成粘结磁体后磁性能的变化。通过对复合磁体的理论分析得知，由Nd2Fe14B／Fe3B与RE2Fe14B或铁氧体磁粉复合成的粘结磁体中，成分间并未发生化学反应。以Nd2Fe14B／Fe3B铁氧体复合粘结磁体为例，根据理论分析推出的剩磁Br-成分含量关系曲线与实际曲线吻合得很好，表明剩磁与成分含量间存在着近似的线性关系，从而可通过数学手段建立磁性能参数与成分含量的函数关系式，用于简化混粉工艺。另外，添加铁氧体可对该复合磁体较差的热稳定性起到补偿作用，并减少了磁不可逆损失。     

LaNi_5、LaNi_4M(M=Mn、Fe、Co、Cu)贮氢金属间化合物在合成氨反应中催化性能研究

本文讨论了LaNi_5、LaNi_4M(M=Mn、Fe、Co、Cu)贮氢金属间化合物在合成氨反应中的催化活性,文中详细地研究了LaNi_4Mn在合成氨反应中的反应速率与温度、压力、空速的关系。实验结果表明LaNi_4M在氨合成反应中生成了LaN和Ni_4M。