用三组份同时分离法氨化萃取分离Gd—Tb—Dy

用普通分馏萃取工艺分离物质一次只能分离两个组份,若连续分离多种物质,则需很长工艺流程.文献[1]报导了用N_(26?)萃取分离La-Pr-Nd的三出口串级实验结果.本文报导用氨化HEH(EHP)同时萃取分离Gd-Tb-Dy的串级试验结果.     

表面电沉积Ni—La2O3复合镀层的Fe26Cr1Mo不锈钢的氧化行为研究

Ｆｅ２６Ｃｒ１Ｍｏ不锈钢在９００℃氧化时，生成的氧化层在冷却过程中大量剥落，经表面共电沉积ＮｉＬａ２Ｏ３复合镀层后，抗热循环能力明显提高。     

Drei Alkalimetall‐Erbium‐Thiophosphate: Von der Schichtstruktur bei KEr[P2S7] zur dreidimensionalen Vernetzung in NaEr[P2S6] und Cs3Er5[PS4]6

Three Alkali‐Metal Erbium Thiophosphates: From the Layered Structure of KEr[P₂S₇] to the Three‐Dimensional Cross‐Linkage in NaEr[P₂S₆] and Cs₃Er₅[PS₄]₆ The three alkali‐metal erbium thiophosphates NaEr[P₂S₆], KEr[P₂S₇], and Cs₃Er₅[PS₄] show a small selection of the broad variety of thiophosphate units: from ortho‐thiophosphate [PS₄]^3? and pyro‐thiophosphate [S₃P–S–PS₃]^4? with phosphorus in the oxidation state +V to the [S₃P–PS₃]^3? anion with a phosphorus‐phosphorus bond (d(P–P) = 221 pm) and tetravalent phosphorus. In spite of all differences, a whole string of structural communities can be shown, in particular for coordination and three‐dimensional linkage as well as for the phosphorus‐sulfur distances (d(P–S) = 200 – 213 pm). So all three compounds exhibit eightfold coordinated Er³⁺ cations and comparably high‐coordinated alkali‐metal cations (CN(Na⁺) = 8, CN(K⁺) = 9+1, and CN(Cs⁺) ≈ 10). NaEr[P₂S₆] crystallizes triclinically ( ; a = 685.72(5), b = 707.86(5), c = 910.98(7) pm, α = 87.423(4), β = 87.635(4), γ = 88.157(4)°; Z = 2) in the shape of rods, as well as monoclinic KEr[P₂S₇] (P2₁/c; a = 950.48(7), b = 1223.06(9), c = 894.21(6) pm, β = 90.132(4)°; Z = 4). The crystal structure of Cs₃Er₅[PS₄] can also be described monoclinically (C2/c; a = 1597.74(11), b = 1295.03(9), c = 2065.26(15) pm, β = 103.278(4)°; Z = 4), but it emerges as irregular bricks. All crystals show the common pale pink colour typical for transparent erbium(III) compounds.     

天冬酰胺Schiff碱稀土配合物的合成、表征与抗O-·2性能

合成了天冬酰胺－邻香草醛Schiff碱稀土配合物，用元素分析，摩尔电导率，磁化率测定，差热分析，红外与紫外光谱，1H NMR谱等手段对配合物进行了组成与结构表征，并采用EPR技术对化合物的抗超氧阴离子自由基性能进行了探讨。     

Energy-adjusted pseudopotentials for the rare earth elements

Nonrelativistic and quasirelativistic energy-adjusted pseudopotentials and optimized (7s6p5d)/[5s4p3d]-GTO valence basis sets for use in molecular calculations for fixed f-subconfigurations of the rare earth elements, La through Lu, have been generated. Atomic excitation and ionization energies from numerical HF, as well as SCF pseudopotential calculations using the derived basis sets, differ by less than 0.1 eV from numerical HF all-electron results. Corresponding values obtained from CI(SD), CEPA-1, as well as density functional calculations using the quasirelativistic pseudopotentials, are in reasonable agreement with experimental data.     

Direct determination of rare earth impurities in high purity erbium oxide dissolved in nitric acid by inductively coupled plasma mass spectrometry

A novel method was developed for the direct determination of trace quantities of rare earth elements (REEs) in high purity erbium oxide dissolved in nitric acid by inductively coupled plasma mass spectrometry (ICP-MS) in this work. The mass spectra overlap interferences arose from Er matrix on the neighbouring and monoisotopic analytes of ¹⁶⁵Ho(100) and ¹⁶⁹Tm(100) were eliminated by adjusting instrumental peak resolution value from 0.7 to 0.3 amu. The matrix suppression effect of Er on the ion peak signals of REEs impurities was effectively compensated with spiking In as internal standard element. The limit of quantitation (LOQ) of REEs impurities was from 0.0090 to 0.025 μg g⁻¹, the recoveries of spiked sample for REEs were found to be in the range of 90.3-107% through using the proposed method and relative standard deviation (R.S.D.) varied between 2.5% and 6.7%. The novel methodology had been found to be suitable for the direct determination of trace REEs impurities in 99.999-99.9999% high purity Er₂O₃ and the results obtained from this method keep in good agreement with that acquired from high resolution ICP-MS.     

Determination of the apparent standard potential of the Dy/Dy(Ⅲ) system in the LiCl-KCl eutectic

The apparent standard potential of Dy/Dy(III) system in the LiCl-KCl eutectic has been determined by the logarithmic analysis of the semi-integrals of voltammograms, logarithmic analysis of chronopotentiograms and the open circuit potentiometry. The dysprosium equilibrium potentiab for various concentration of dysprosium chloride in the LiCl-KCl eutectic melt between 400-500℃ were first determined experimentally, and the apparent standard potential of this system and its temperature dependance have been calculated.     

Rare earth(III) perfluorooctanesulfonates catalyzed Friedel-Crafts alkylation in fluorous biphase system

The catalyst of rare earth(III) perfluorooctanesulfonates (RE(OSO₂C₈F₁₇)₃, RE = Sc, Y, La-Lu) were prepared from either rare earth chlorides(III) or oxides and perfluorooctanesulfonic acid. The perflates thus obtained act as novel catalysts for Friedel-Crafts alkylation in fluorous biphasic system. Perfluorohexane (C₆F₁₄), perfluoromethylcyclohexane (C₇F₁₄), perfluorotoluene (C₇F₈), perfluorooctane (C₈F₁₈), perfluorooctyl bromide (C₈F₁₇Br) and perfluorodecalin (C₁₀F₁₈, cis- and trans-mixture) can be used as fluorous solvents for this reaction. By simple separation of the fluorous phase containing only catalyst, alkylation can be repeated many times.     

纳米稀土-介质薄膜光电发射光谱和能带结构

用真空蒸发沉积的方法制备了纳米稀土(La、Nd、Sm)粒子 BaO介质薄膜.研究表明薄膜的光电发射光谱响应阈值受纳米稀土粒子形状和大小的影响,球形纳米稀土(Sm)粒子 BaO介质薄膜的光谱响应阈值波长为720 nm,条状纳米稀土(La和Nd)粒子 BaO介质薄膜阈值波长分别为650 nm和660 nm.研究得到纳米稀土粒子 介质薄膜等效界面位垒高度在1.7～2.0 eV之间.由于纳米稀土粒子与BaO介质各自逸出功不同,当构成薄膜后使得纳米粒子周围的空间电荷分布发生变化,纳米粒子周围的能带发生弯曲.     

Incorporation of rare-earth ions in Mg-Al layered double hydroxides: intercalation with an [Eu(EDTA)] chelate

Reaction of an aqueous slurry of an Mg₂Al-NO₃ layered double hydroxide with a four-fold excess of Na[Eu(EDTA)] gives a material which analyses for Mg_0.68Al_0.32(OH)₂[Eu(EDTA)]_0.10(CO₃)_0.11·0.66H₂O. The interlayer spacing of the material is 13.8 Å, corresponding to a gallery height of 9.0 Å, which accords with the maximal dimensions (9-10 Å) of the anion in metal-EDTA complex salts as determined by single crystal X-ray diffraction. Geometrical considerations show that the charge density on the layered double hydroxide layers is too high to be balanced by intercalation of [Eu(EDTA)]⁻ alone, necessitating the co-intercalation of carbonate ions which have a much higher charge density.