二道沟金矿床中的稀土元素地球化学特征

通过对未蚀变流纹岩，蚀变流纹岩和金矿石中稀土元素组成及分布模式的研究，表明岩浆热液与以大气降水为来源的地下水相混合后形成的成矿热液中稀土元素具有富集ＬＲＥ、稀土元素总量低以及Ｅｕ具有明显负异常的特征。     

高电导率的a—SiHY合金的低温电导特性

用射央求地在硅单晶衬底上沉积出电导率高达６０Ｓ／ｃｍ的ａ－ＳｉＨＹ合金薄膜。在２０－３００Ｋ，对于钇含量高的样品，其电导仍是热激活的。ｌｇσ与１／Ｔ的关系曲线能够被拟合成斜率不同的两条直线，直线的斜率和两直线间拐点所地 温度依赖于膜中钇的含量。但对钇含量低的薄膜，电导对温度的依赖关系度为σ∝ｅｘｐ（－１／Ｔ＾１／４）。结果表明，这些钇含量不同的样品在没的温度范围内具有不同的导电机制。     

Die Kristallstrukturen von KNdTe4, RbPrTe4 und RbNdTe4 — Untersuchungen zur thermischen Stabilität von KNdTe4 sowie Bemerkungen zu einigen anderen Vertretern der Zusammensetzung ALnTe4 (A = K,Rb, Cs und Ln = Seltenerd‐Metall)

Crystal Structures of KNdTe₄, RbPrTe₄, and RbNdTe₄ — Investigations concerning the Thermal Stability of KNdTe₄ as well as some Remarks concerning Additional Representatives of the Composition ALnTe₄ (A = K, Rb, Cs and Ln = Rare Earth Metal) Of the compounds ALnQ₄ (A = Na, K, Rb, Cs; Ln = Lanthanoid; Q = S, Se and Te) the crystal structures of the three new tellurides KNdTe₄, RbPrTe₄ and RbNdTe₄ were determined by X‐ray single‐crystal structure analysis and of the three additional new ones KCeTe₄, KPrTe₄ and CsNdTe₄ by X‐ray powder diffraction experiments. All six new compounds are isotypic with KCeSe₄. Characteristic for the crystal structure of the compounds mentioned above are layers built from (Q₂)^2— dumbbells in form of 4.3².4.3 nets with embedded cations A⁺ and Ln³⁺ between them, which are coordinated eightfold in form of square‐shaped antiprisms by Q ions. The distances Te‐Te within the dumbbells were found to be 277.8(2) pm for all investigated tellurides. By combination of X‐ray diffraction and DTA measurements it was shown that the compound KNdTe₄ is metastable at ambient temperature with a limited existence range between the temperatures 260 and 498 °C.     

CeAgAs2 — a New Derivative of the HfCuSi2 Type of Structure: Synthesis,Crystal Structure and Magnetic Properties

Single crystals of CeAgAs₂ have been obtained by chemical transport reactions starting from a pre‐reacted powder sample. The crystal structure was solved using X‐ray diffraction (space group Pmca, No. 57, a = 5.7586(4) Å, b = 5.7852(4) Å, c = 21.066(3) Å, Z = 8) and refined to a residual of R(F) = 0.029 for 46 refined parameters and 1020 reflections. The structure of CeAgAs₂ represents a new distorted and ordered variant of the HfCuSi₂ type. The characteristic feature of this structure are infinite cis‐trans chains of As atoms with As—As distances of 2.563(1) Å and 2.601(1) Å. CeAgAs₂ is paramagnetic (μ_eff = 2.37 μ_B, θ = —10.5(2) K), with antiferromagnetic ordering at 5.5(2) K and exhibits a metamagnetic transition starting at 4.6 kOe and T = 1.8 K.     

Preparation and properties of rare-earth containing oxide fluoride glasses

The preparation of the rare earth containing oxide fluoride glasses LnF₃ (Ln; Y through Lu)-BaF₂-AlF₃-GeO₂ in which the nominal content of LnF₃ reached 60 mol% in maximum and their basic properties such as density, refractive index and glass transition temperature were investigated and summarized in detail. Especially, in order to discuss the local structure around the rare earth ion in the glass, the Judd-Ofelt analysis (discussion with Ω parameters) of the HoF₃-BaF₂-AlF₃-GeO₂ glasses was carried out. The unique fluorescent behavior and the magnetic properties of LnF₃-BaF₂-AlF₃-GeO₂ glasses (Ln = Tb and/or Sm) were also studied.     

电感耦合等离子体发射光谱测定稀土铝合金中稀土和非稀土元素

本工作用 ICP-AES 法测定稀土-6063变形铝合金中 La、Ce、Pr、Nd、Sm、Gd、Fe、Mg、Ti、Zn,Cu 和 Mn,本方法不用化学分离,可一次同时测定这些元素,并做了 ICP光源参数、基体量变化、酸度(HCl)变化、稀土总量变化、共存元素 Fe 和 Mg 量的变化对被测元素的影响。本方法速度快、准确度高(除 Cu 稍差)。回收率91.0～110.0%,相对标准偏差±1.4～8.0%。     

~(13)C核磁共振研究稀土催化剂聚合双烯的机理

用~(13)C-NMR 方法测定了稀土顺丁二烯和聚异戊二烯链端结构及序列结构,从链端结构推测的聚合活性链端结构与前文是一致的。在聚异戊二烯中存在着“头-头”和“尾-尾”结构,这种结构引起活性链端甲基位置的改变,从而解释了稀土异戊二烯中3,4-链节的形成。测定了不同聚合温度对聚合物中顺、反结构含量的影响,可用活性链端的 anti-syn异构化加以解释。     

Thermal properties of rare earth dodecaborides

We have measured heat capacity and thermal expansion of rare earth dodecaborides REB₁₂ (RE=Y, Tb-Tm, Lu). YB₁₂ and LuB₁₂ are diamagnetics whereas the other dodecaborides are ordered antiferromagnetically. The amplitude of the heat capacity discontinuity at the Néel temperature and the shape of the heat capacity variation in the critical region for all these antiferromagnetics are characteristics for amplitude-modulated magnetic structures. In the ordered state TbB₁₂ reveals two first-order phase transitions, most likely due to magnetic structure changes. The heat capacity of ErB₁₂ just below the Néel point shows an anomaly of unclear origin. From the Schottky contribution to the heat capacity we have determined crystal field parameters. They are completely different than that is estimated from Point Charge Model.     

Y2O3:Eu纳米晶的硝基取代苯甲酸配合物固相热解制备和性能

以苯甲酸、邻硝基苯甲酸、间硝基苯甲酸、对硝基苯甲酸、3,5 二硝基苯甲酸等为配体制备了Y3+、Eu3+二元配合物,配合物中Y3+与Eu3+的摩尔比为9：1.利用这些配合物的爆炸式热分解特性通过固相热解反应制备了一系列Y2O3:Eu纳米晶.透射电镜观察,可以看出所得纳米晶呈球形,粒度介于40～60 nm,X射线衍射分析表明实验所得纳米晶属立方晶系,粒径与电镜观察所得结果基本一致；Eu3+的引入并不影响Y2O3的晶相组成；配体类型对纳米晶的结构没有显著影响,不过相对于硝基取代苯甲酸配合物,苯甲酸配合物热解所得Y2O3∶Eu纳米晶团聚严重；退火温度显著影响纳米晶粒度,退火温度高,纳米晶粒度大,反之亦然.荧光光谱测定表明所有Y2O3∶Eu纳米晶具有相似的发光行为,其中以苯甲酸配合物分解所得Y2O3:Eu纳米晶发光性能最为优越.     

稀土离子在多孔阳离子交换剂内的扩散动力学

研究了稀土离子在Amberlyst15、D001、XN1010多孔树脂内的自扩散。结果表明,扩散过程遵循二级分散扩散机制。用粒内扩散方程求算了有效粒内扩散系数e,将e分解为树脂孔道扩散系数p及树脂固相扩散系数s,p与该离子在外部溶液中的自扩散系数相近,而s接近于与实验用的多孔树脂交联度相同的凝胶树脂内的自扩散系数值。