Magnetocaloric effect and magnetic properties of La_（0.9）Ce_（0.1）（Fe_（0.99）Mn_（0.01））_（11.6）Si_（1.4）H_（1.6） compound

Magnetocaloric effect and magnetic properties of La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4 and its hydride La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4H1.6 were investigated. The Curie temperature of La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4 was increased by hydrogen absorption. XRD patterns showed that the structure of La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4H1.6 remained NaZn13-type. The Curie temperature (TC) of the sample was increased from 174 K to 331 K. The homogeneity of the hydrogen absorption for La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4H1.6 was proven very well by the random measurement of DSC. The magnetic entropy △SM of La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4H1.6 had peak at 326 K. The peak value of-△SM-was 12.3 and 7.8 J/(kg.K) under magnetic field change of 0-2 T and 0-1 T,respectively,which was comparable with Gd5Si2Ge2. The negative slope and inflection point of the Arrott curve indicated that the first-order magnetic transition of La0.9Ce0.1(Fe0.99Mn0.01)11.6Si1.4 was reserved after hydrogen absorption.     

Sintering of Ce（0.8）Sm（0.2）O（1.9）

Ce0.8Sm0.2O1.9（SDC）powder was prepared with an oxalate coprecipitation route.SDC solid solutions were sintered at various temperatures ranging from 1100~1450 ℃,and characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,density measurements,and electrical conductivity measurements.The optimized processing parameters for densification were to uniaxially press the sample at 200~400 MPa and sinter it at 1350~1400 ℃ for 4 h.The density of the sintered pellets was 〉90% of the theoretical density;their soakage was 〈0.5%;and the average grain size was 1~2 μm.The conductivities of the typical sintered specimen were 0.0133 and 0.0211 S·cm-1 at 550 and 600 ℃,respectively;Its activation energy for ionic conductivity was 0.62 eV.The dense SDC bulk material could be used as the electrolyte layer of low temperature solid oxide fuel cells.     

A study on hydrogen storage and electrochemical properties of La_（0.55）Pr_（0.05）Nd_（0.15）Mg_（0.25）Ni_（3.5） （Co_（0.5）Al_（0.5））_x （x=0.0, 0.1, 0.3, 0.5） alloys

The La0.55Pr0.05Nd0.15Mg0.25Ni3.5(Co0.5Al0.5)x(x=0.0, 0.1, 0.3, 0.5) alloys were prepared by magnetic levitation melting under an Ar atmosphere, and the effects of Co and Al on the hydrogen storage and electrochemical properties were systematically investigated by pressure composition isotherms, cyclic voltammetry, Tafel polarization and electrochemical impedance spectroscopy testing. The results showed that the alloy phases were mainly consisted of (La,Pr)(Ni,Co)5, LaMg2Ni9, (La,Nd)2Ni7 and LaNi3 phases, and the cell volumes of (La,Pr)(Ni,Co)5, LaMg2Ni9, (La,Nd)2Ni7 and LaNi3 phases expanded with Co and Al element added. The hydrogen storage capacity initially increased from 1.36 (x=0) to 1.47 wt.% (x=0.3) and then decreased to 1.22 wt.% (x=0.5). The discharge capacity retention and cycle stability of the alloy electrodes were improved with the increase of Co and Al contents. The La0.55Pr0.05Nd0.15Mg0.25Ni3.5(Co0.5Al0.5)0.3 alloy electrode possessed better electrochemical kinetic characteristic.     

HPBI对镧（Ⅲ）,铈（Ⅲ）,铕（Ⅲ）,钍（Ⅳ）,铀（Ⅵ）的溶剂萃取行为

本工作研究了HPBI~a(以氯仿为稀释剂)对La(Ⅲ)、Ce(Ⅲ)、Eu(Ⅲ)、Th(Ⅳ)、U(Ⅵ)的萃取行为。探讨了萃取机理和几种萃取类型。计算了每种体系的萃取常数。该体系已用于从U(Ⅵ)中分离Th(Ⅳ)及从La(Ⅲ)、Ce(Ⅲ)、Eu(Ⅲ)中分离Th(Ⅳ)。比较了HPBI、HPMBP~b、HTTA的萃取常数,结果表明HPBI萃取上述几种金属要优于HPMBP和HTTA     

Structure and high-temperature electrochemical properties of La_（0.60）Nd_（0.15）Mg_（0.25）Ni_（3.3）Si_（0.10） hydrogen storage alloys

The structure and high-temperature electrochemical properties of the as-cast and annealed (940 °C, 8 h) La0.60Nd0.15Mg0.25Ni3.3Si0.10 hydrogen storage alloys were investigated. The X-ray diffraction revealed that the multiphase structure of the as-cast alloy with LaNi5 phase as the main phase was converted into a double-phase structure with La2Ni7 phase as the main phase after annealing. The surface morphology studied by scanning electronic microscope (SEM) showed that the annealed alloy had a much higher anti-corrosion ability than the as-cast alloy. Both alloys presented excellent activation characteristics at all test temperatures. The maximum discharge capacity of the as-cast alloy decreased when the test temperature increased, while the temperature almost had no effect on the annealed alloy. As the test temperature increased, the cyclic stability and charge retention of both alloys decreased, and these properties were improved significantly by annealing.     

Stable icosahedral phase in Mg_（44）Zn_（44）Gd_（12） alloy

The microstructure of the as-cast Mg 44 Zn 44 Gd 12 alloy was investigated by using X-ray diffraction(XRD),differentical scanning(DSC),scanning electron microscopy(SEM) and a detailed transmission electron microscope.The XRD,DSC and SEM results indicated that the as-cast Mg 44 Zn 44 Gd 12 alloy were mainly composed of three types of phases:the primary solidification phase,the dendritic phase and the eutectic phase.The primary solidification phase had an icosahedral structure.The dendritic phase was the W-phase,and eutectic structure phase was the Mg 7 Zn 3 phase.Microstructures of icosahedral phase(I-phase),W-phase and Mg 7 Zn 3 phase in Mg 44 Zn 44 Gd 12 alloy were investigated.The results indicated that the I-phase in Mg 44 Zn 44 Gd 12 alloy was a face-centered icosahedral quasicrystal with stoichiometric composition of Mg 42 Zn 50 Gd 8 which had an excellent thermal stability up to 420 °C.The solid solution of the Gd gradually decreased during solidification,which played an important role in activating the formation of Mg 7 Zn 3 phase and W-phase from icosahedral phases.     

P_（507）（煤油）／（Sm－Eu－Gd）Cl_3（EuCl_2）－HCl体

本文在选定的工艺条件下，在振动筛板柱中研究了Ｐ（５０７）（煤油）／（Ｓｍ－Ｅｕ－Ｇｄ）Ｃｌ３（ＥｕＣｌ２）－ＨＣｌ体系的两相流动特性和传质特性。结果表明，该体系在振动柱中有良好的流动特性。在流比２．５～４．０，振幅＝１０ｍｍ，频率＝３００～３５０ｍｉｎ（－１）条件下，两相总液泛通量达２２０Ｌ／ｄｍ２·ｈ，存留分数一般为１２～１５％。用分段近似计算法，估算了柱子的传质效率。对于较难萃取的组分Ｓｍ，平均传质单元高度为０．５２ｍ，平均理论级当量高度为１．８２ｍ。     

LaCo_（13）基及R_2（Fe_（1－x）Co_x）_（17－y）Al_y化

ＬａＣｏ_（１３）基及Ｒ_２（Ｆｅ_（１－ｘ）Ｃｏ_ｘ）_（１７－ｙ）Ａｌ_ｙ化合物的结构及磁性ＴｈｅＳｔｒｕｃｔｕｒｅａｎｄＭａｇｎｅｔｉｃＰｒｏｐｅｒｔｉｅｓｏｆＬａＣｏ_（１３）－ＢａｓｅｄＳｙｓｔｅｍｓａｎｄＲ_２（Ｆｅ_（１－ｘ）Ｃｏ_ｘ）_（１７－...     

Synthesis and Crystal Structure of N-phenylthiocyano-phenylthioformamide-bis （ η5-methylcyclopentadienyl） （tetrahydrofuran） Samarium （Ⅲ）

The insertion reaction of phenyl isothiocyanate into the Ln-S bond was studied. Phenyl isothiocyanate reacted with [(CH3C5H4)2Sm(SPh)(THF)]2 to give the title complex, (CH3C5H4)2Sm[SC(SPh) NPh](THF),in good yield, which was characterized by elemental analyses, IR, ^1H NMR and X-ray structural determination. The crystal structure analysis of complex shows that samarium atom is coordinated by two CH3C5H4 groups, one O atom of THF, and N and S atoms from the SC(SPh)NPh ligand to form a distorted trigonal-bipyramidal geometry.     

硒（Se）锗（Ge）光度分析近况

综合评述了近年来（１９８２－１９９２）国内外有关硒、锗的光度分析方法，探讨了多种显色剂与Ｓｅ、Ｇｅ显色体系的光度性质、特点及应用，其中重点阐述了相关的显色体系。     

微波法制备（Ce,Tb）MgAl_（11）O_（19）绿色荧光粉

采用微波法制备（Ce,Tb）MgAl11O19绿色荧光粉,对制备的样品进行了正交结果分析,确定了微波辐射法合成该体系的最佳工艺条件,即保温时间90 min、煅烧温度1 450℃、升温速率15℃/min。采用分光光度计、粒度分析仪、X射线衍射仪对最佳工艺条件下制备的样品进行了表征,样品的最大发射光谱峰位于545 nm、相对亮度为102.2%、色坐标为x=0.323 4;y=0.597 4、粉体中心粒径D50=6.59μm、粒度分布大小均匀。