Neodymium nitrilotris(methylenephosphonate)

Conditions for preparing neodymium nitrilotris(methylenephosphonate) and its pyrolysis were studied.     

Molecular Structure of Neodymium Diiodide

The molecular structure of neodymium diiodide was investigated in an electron diffraction study at T _exp = 795(10) K. The molecule has C_2v symmetry; the internuclear distance R_g(Nd–I) is 297.3(3) pm and _g = 132(3)°. The vibration frequencies were estimated from the experimental values of the root-mean-square vibration amplitudes.     

漆酚缩甲醛钕聚合物的特性与表征

由漆酚甲醛缩聚物(PUF)与三氯化钕制备漆酚缩甲醛钕聚合物(PUFN), 并采用元素分析、 IR、 DMTA和GPC对其进行表征. 结果表明, PUF与Nd3+发生配位反应, 其产物PUFN的弹性模量比PUF的大, 热稳定性提高, 并且具有优良的耐化学介质腐蚀性能, 对正丁醇和冰乙酸的酯化反应具有催化活性.     

Anhydrous Neodymium(III) Acetate

Anhydrous neodymium(III) acetate, Nd(OAc)₃ was obtained as light purple single crystals by direct oxidation of neodymium metal with malonic acid in a glass ampoule at 180 °C. It crystallizes with the monoclinic space group P2₁/a (no. 14) with a = 2201.7(2), b = 1850.0(1), c = 2419.0(3) pm, β = 96.127(8)°, V = 9796.8(1)·10⁶·pm³, Z = 40 [Nd(OAc)₃], R₁ = 0.0430 [I₀ > 2σ(I₀)]. Most of the Nd³⁺ cations are coordinated by nine (or eight) oxygen atoms of acetate ligands which bridge these polyhedra to slightly waved layers which are stacked in the [010] direction.     

Thermal Decomposition of Neodymium Amide Complexes

The decomposition of NdCl₃ L(L = N,N-dimethylformamide [DMF] or N,N-dimethyacetamide [DMA]) compounds has been investigated by thermogravimetric and differential thermal analysis (TGA and DTA) coupled with Fourier transform infrared (FTIR) spectroscopy. When heated in air, the NdCl₃L compounds decompose by a mechanism involving oxidation of the amide ligand to CO₂ and HCl. Some free armide is also released in the thermal decomposition in air. However, when heated under nitrogen, clean release of DMA or DMF is observed. In both cases, the amide is released two steps. From 30 to 40% of the amide is initially released with little or no associated enthalpy as measured by DTA. As the temperature is increased, the remaining 60 to 70% of the amide is released via an endothermic process. The enthalpy for this release is 53.1 - 3.8 kJ/mole for DMF and 40.9 - 1.1 kJ/mole for DMA, suggesting that DMF binds more strongly to Nd(III) than does DMA. Steric effects caused by the additional methyl group in DMA might be responsible for the weaker binding of this amide compared to DMF.     

Neodymium and samarium recovery by magnetic nano-hydroxyapatite

The removal and recovery of lanthanides has become important because of their wide applications in industry and also in environmental protection. The necessity for these elements requires the selective and effective separation technique. In this study, batch adsorption method as a green technology has been investigated for removal and recovery of Nd and Sm using magnetic nano-hydroxyapatite adsorbent (MNHA). According to results, the maximum adsorption capacities of Nd and Sm were calculated as 323 and 370 mg/g at optimum pH 5.5, respectively. Different types of adsorption isotherms and kinetic models were used to describe the Nd and Sm adsorption behavior, and the experimental results fitted Langmuir model and the pseudo-second-order kinetic models well. The adsorption of Nd and Sm was found as endothermic and spontaneous process with respect to obtained thermodynamic parameters. Recovery of adsorbed lanthanides and reusability of adsorbent was tested. Possible adsorption mechanisms were also discussed. The proposed adsorbent, MNHA has good adsorption ability and high sorption capacity for Nd and Sm with a chemisorption mechanism.     

钨酸钕单晶光谱及其上转移发光

采用提拉法生长出钨酸钕Nd2(WO4)3单晶,通过光谱测试研究了Nd^3 的能级结构,采用波长为808nm激光二极管作为激发光源,室温下观测到457和657nm两个波段的上转换荧光,分别相应于^2D5/2→^4I11/2和 ^2G7/2→^4I9/2跃迁,457和657nm处的上转移荧光强度与激发光功率分别成线性关系和平方关系。     

二烷基二硫代磷酸钕的摩擦磨损性能研究

用自制的二烷基二硫代磷酸和NdCl3为原料，通过交换反应制备了二异辛基二硫代磷酸钕和二异丙基二硫代磷酸钕，并鉴定了其结构，以四球实验比较了所合成的两种二烷基二硫代磷酸钕作为抗磨减摩剂的抗磨减摩性能，并与现在普遍使用的抗磨剂ZDDP进行了比较。以电子衍射X射线能谱（EDXA）分析了经四球机实验摩损10s后的蚀球表面元素组成，初步认证了稀土元素扩渗进入摩擦副表面是此类稀土配合物具有比ZDDP更好的抗磨减摩作用的原因之一。     

Phase Diagram of the Neodymium Chloride-Sodium Chloride System

Differential thermal analysis was used to study the phase diagram of NdCl3-NaCl system. The peritectic reaction was found to occur at 540±7°C. The peritectic compound was confirmed to be Na3Nd5Cl18 by means of X-ray diffraction analysis. The homogeneity range Na3Nd5Cl18 could not be defined accurately, but appeared to be between 59 and 70 mol% of NdCl3 at temperatures between 300 and 540°C. This revised version was published online in July 2006 with corrections to the Cover Date.     

含钕稀土有机高分子的研究进展

稀土高分子是一类具有许多优异性质和很高应用价值的功能材料 ,其开发和应用前景十分迷人。文章对含钕的稀土有机高分子近几十年来的研究发展情况作了综述     

联苯甲酰双缩氨基脲硝酸钕水合物晶体结构的测定

联苯甲酰双缩氨基脲硝酸钕水合物分子式为[Nd（C16H16N6O2）（NO3）3（H2O）]·H2O，Mr＝690．2，正交晶系，空间群为Fdd2，晶胞参数，利用2312个可观测衍射进行结构修正，最后R＝0.048。晶体中含有2个水分子，其中1个参加配位。3个硝酸根呈双齿配应；有机配体中有2个N原子和两个O原子参与配位，Nd的总配位数为11。     

Neodymium sorption by clay minerals and zeoliferous rocks

The sorption of neodymium from its aqueous solutions (concentration range approx. 10–450 mg l^–1) by montmorillonite, kaolinite and a clinoptilolite-containing rock has been investigated, using¹⁴⁷Nd as radioactive tracer and -ray spectrometry. The neodymium uptake by montmorillonite was found to be much higher than of the other two materials in the whole investigated concentration range. However, in the case of montmorillonite and zeoliferous rock, the uptake ability is lower than that allowed by the measured CEC values and can be described by Langmuir-type equations. In the case of kaolinite, the observed higher than CEC-allowed uptake values could be attributed to sorption by mechanisms other than ion-exchange. The corresponding data obey a Freundlich-type sorption equation. Among the three geological materials investigated, montmorillonite exhibits the highest perspectives of application for the treatment and disposal of neodymium and trivalent actinides in nuclear industry.     

8-羟基喹啉萃取Pr3+，Nd3+的机理探讨

研究了8-羟基喹啉(HQ)从盐酸介质中萃取Pr 3 ,Nd 3 的行为. 通过对Pr 3 ,Nd 3 萃取平衡常数的测定结果发现,8-羟基喹啉对Pr 3 ,Nd 3 的萃取反应具有相近的平衡常数. Kex(Pr 3 )=10 -11.83,Kex(Nd 3 )=10 -11.70. 从稀释剂的种类,水相酸度,萃取剂浓度,Ac -浓度4个方面探讨了8-羟基喹啉萃取Pr 3 ,Nd 3 的机理. 结果显示,Ac -在溶液中分别与Pr 3 ,Nd 3 络合,并以Pr(Ac -) 2 ,Nd(Ac -) 2 的形式参与萃取反应;不同稀释剂随着介电常数的增大,萃取率逐渐变小,萃取率的顺序为:庚烷＞环己胺＞四氯化碳＞二甲苯＞甲苯＞氯仿＞二氯甲烷. 探讨了8-羟基喹啉萃取Pr 3 ,Nd 3 的机理.     

漆酚缩甲醛钕聚合物催化合成环己酮乙二醇缩酮

以环己酮和乙二醇为原料,漆酚缩甲醛钕聚合物为催化剂合成了环己酮乙二醇缩酮。实验结果表明：在环己酮100mmol,n(环己酮)：n(乙二醇)=1：1,漆酚缩甲醛钕聚合物3．0g,环己烷7．5mL,回流反应1．0h,目标化合物的收率达74％。     

纳米氧化钕的制备及其催化性能的研究

Nanometer-sized neodymium oxide has been synthesized by humid solid state reaction at room temperature， and characterized by scanning electron microscope， laser light scattering and X-ray diffraction. The effects of nanometer -sized neodymium oxide on catalyzing thermal decomposition reaction of hexogen (cyclotrimethylenetriamine， RDX) and absorbent powder (nitrocellulose absorbed nitroglycerin， NC/NG) have been investigated by DSC method. The mechanism of these catalytic reactions has also been proposed. The experimental results show that nanometer-sized neodymium oxide can catalyze the decomposition reaction of RDX and NC/NG effectively. The experimental results further suggest that nanometer-sized neodymium oxide is a potentially useful combustion catalyst of nitroamine propellant.     

二甲基甲酰胺中四种钕盐的电导

通过电导测量研究了四种钕盐：Nd(CF3SO3)3、Nd(ClO4)3、Nd(NO3)3和NdCl3在极性非质子溶剂DMF中的电导性质.利用线性拟合方法求得在25 ℃下Nd(CF3SO3)3和Nd(ClO4)3的极限摩尔电导率分别为278.8和 280.7 S•cm2•mol－1.用间接方法求得Nd(NO3)3 与NdCl3 的极限摩尔电导率分别为297.2和287.3 S•cm2 •mol－1.在25～65 ℃温度范围内，Nd(CF3SO3)3和Nd(ClO4)3的电导率随温度呈线性变化. Nd(NO3)3和NdCl3的电导行为表现出明显的离子缔合.     

聚合负载三氯化钕配合物的合成及其催化活性——含硫醇和亚砜基团的配合物

合成了含—CH     

Analytical Electron Microscopy of a Magnesium Alloy Containing Neodymium

 Microstructure and phase composition studies of QE-22 magnesium based alloy with 2–3% Ag, 1.8–2.5% Nd and min. 0.4% Zr, before and after full heat treatment have been carried out using various electron microscopy techniques like EDX mapping, line scans and TEM with SAED. An extrapolation technique enabled to eliminate the influence of Mg-matrix on the quantitative analysis results and allowed to estimate the composition of the second phase which was mostly (Mg, Ag)₁₂Nd type in the as cast alloy and (Mg, Ag)₁₂Nd and Mg₁₂Nd₂Ag equilibrium precipitates after the precipitation process.