Weitere Oxochlorotitanate LnTiO3Cl der Seltenen Erden (LnSm?Lu) - Präparation,Kristallstruktur, elektronenmikroskopische Untersuchung

New Rare Earth Oxochlorotitanates LnTiO₃Cl (Ln?Sm? Lu) - Preparation, Structure and Electron Microscopic Investigations After the preparation of SmTiO₃Cl we made the attempt to prepare analogous compounds with the heavier rare earth elements. We present 2 methods to prepare powders of LnTiO₃Cl (Ln = Sm? Lu) together with a new method to prepare the rare earth oxychlorides LnOCl (Ln = Tm? Lu). There will be also presented 2 methods to get single crystals of these compounds via chemical vapour transport. The new rare earth oxochlorotitanates LnTiO₃Cl (Ln = Eu? Lu) are isotypic to SmTiO₃Cl. They crystallize in the monoclinic space group: C2/m (No. 12). The lattice parameters (Å) are between a = 9.716(3), b = 3.942(2), c = 10.100(4) (SmTiO₃Cl) and a = 9.748(1), b = 3.8454(5), c = 9.625(2) (LuTiO₃Cl), Z = 4. We observed a permanent decay of the cell volume with the decay of the radii of the cations. The structure of EuTiO₃Cl and DyTiO₃Cl was refined to R = 3.4% and R = 5.8% respectively. The crystal structure which has a certain similarity to brannerite can be described in a simplified way by saying that the rare earth and chlorine particles are located between walls of Ti? O-double-octahedra.     

纳米晶双相稀土永磁合金透射电镜薄膜样品的制备

探讨了纳米晶双相稀土永磁合金在ＰＴＦＥ夹具园片抛光法和在离子薄化技术中的电镜薄膜样品的制备,比较了利用离子薄化和电解双喷加离子薄化技术获得的纳米晶双相稀土永磁合金的透射电分析结果,优化了两种方法制备电镜薄膜样品的实验条件及参数范围。探索出较佳的有竽透电镜观察的纳米双相稀土永磁合金薄膜样品的制备方法。     

无机纳米稀土发光材料的制备方法*

无机纳米稀土发光材料作为一种重要的发光材料,由于具有独特的光、电和化学性质,使其在高性能磁体、发光器件、显示、生物标记、光学成像和光学治疗等方面得到了广泛的应用。稀土发光材料的这些性质与材料的尺寸和形状密切相关,近年来研究者已经利用多种合成方法制备了不同形状的纳米稀土发光材料,包括纳米线、纳米棒、纳米管、纳米纤维和纳米片等。本文综述了无机纳米稀土发光材料的几种常用的制备方法,包括水热/溶剂热法、有机/无机前驱体热分解法和超声辅助合成法等,评述了这些方法的优缺点,并结合课题组在无机纳米稀土发光材料制备方面的工作,对无机纳米稀土发光材料制备方法的发展进行了展望。     

Chemical composition of “AKD vapour” and its implication to AKD vapour sizing

Alkyl ketene dimer (AKD) sizing of paper involves the redistribution of the wax over the fibre surface upon heating. The two major mechanisms widely studied so far are the spreading of an autophobic precursor of molten AKD and AKD vapour transport and re-deposition on the fibre surface. All previous work assumed that the transport of AKD vapour could be expressed by the change of water contact angle with substrates that were exposed to the vapour. Information regarding the chemical composition of the vapour phase above the AKD wax has not been found in the literature. In this work, a simple method for analysing the chemical composition of the vapour is established. Our preliminary results indicated that the chemical composition of AKD vapour in the temperature range of 75–80 °C is dominantly fatty acids. This suggests that the sizing effect by actual AKD molecules via the vapour deposition mechanism is likely to be insignificant in this temperature range. This also implies that fatty acids play a positive role in AKD sizing. The chemical stability of AKD in this temperature range is also studied.     

三氯化稀土催化下二乙氧基缩苯乙酮与乙酰氯的反 应: 合成1, 3, 5-三芳基苯 的新方法

报道催化量的三氯化钐存在下,乙酰氯与二乙氧基缩苯乙酮反应,高产率地得到1,3,5-三苯基苯。采用不同的溶剂及不同的稀土氯化物该反应均能顺利进行。此方法是一种合成1,3,5-三芳基苯类化合物的方便和有效的方法。文中对反应机理进行了讨论。     

酯交换反应合成酯基三氯化锡及其配合物

本文首次利用β-甲氧羰(或β-丁氧羰)乙基三氯化锡和醇的酯交换反应合成了一系列相应的β-烷基羰乙基三氯化锡, 并以此合成了它们与2, 2'-联吡啶、1, 10-菲罗啉、4, 7-二苯基-1, 10-菲罗啉的配合物。通过元素分析、摩尔电导、IR、UV、^1H NMR等对上述化合物进行了表征, 提出了β-烷氧羰乙基三氯化锡分子内Lewis酸催化的酯交换反应机理。     

Determination of rare earth elements in hot spring water and crater lake water samples by neutron activation analysis incorporating coprecipitation process using aluminium as a collector

Hot spring water and crater lake water samples were analyzed for their rare earth elements: (REE's) by neutron activation method, which, in the irradiation, sample preparation, incorporated a coprecipitation process in which aluminium was used as a collector. Ten REE's, La, Ce, Sm, Eu, Gd, Tb, Dy, Tm, Yb and Lu, were consequently detected and determined at the ppb level with satisfactory precision. It was shown that the aluminium coprecipitation is effective in enhancing concentrations of the REE's and reducing the amounts of interfering nuclides before neutron irradiation.     

从含氟硫酸稀土溶液中萃取铈过程产生第三相的原因

研究了二（2－乙基己基）磷酸（DEHPA）从含氟硫酸稀土溶液中萃取Ce4 过程中生成第三相的组成。运用X荧光光谱法和化学法测定了有机相中析出沉淀物的成分。并分析其原因,发现产生第三相主要是由于有机相对Ce^4 的还原作用造成的。研究了有机相的还原性,进而找出抑制其还原作用,避免第三相生成的方法。     

β-甲基-β-甲氧羰基乙基三氯化锡及其配合物的酯交换反应研究

报道了β-甲基-β-甲氧羰基乙基三氯化锡及其二苄基亚砜、六甲基磷酰胺配合物和醇的酯交换反应, 合成了一系列的β-甲基-β-甲氧羰基乙基三氯化锡及其配合物, 利用元素分析、IR、^1H NMR对其结构进行了表征, 并提出了分子内Lewis酸催化的酯交换反应机理。     

环烷酸类载体液膜体系对金属离子传输机理的研究

本文先在大块液膜体系中以环已烷甲酸为载体,通过正交设计,系统地研究了各种因素对希土离子输送作用的影响规律。比较了相同条件下RE~(3+)(希土)同Na~+,NH_4~+、Ca~(2+)和Fe~(3+)等离子的输送作用。发现在适当条件下,无皂化的羧酸载体对RE~(3+)离子具有良好的输送效果,同时证实,羧酸输送RE~(3+)离子是通过三个H~+离子与一个RE~(3+)离子的交换,而当载体皂化时,皂化的载体直接与接收相H~+离子发生交换,从而降低了羧酸对RE~(3+)离子的输送和分离效果。 在大块液膜研究的基础上,建立了一个以无皂化的环烷酸为载体的乳状液膜体系,从模拟离子矿的硫酸铵浸出液中萃取希土,通过正交试验确定了最优的液膜萃取条件,希土萃取率达96％以上,富集度30～40倍。     

Optimization of the electrothermal vaporization conditions for inductively coupled plasma excitation spectrometry: Selective volatilization versus covolatilization approaches

A new version of the outlet port of a graphite furnace electrothermal vaporizer (upward streaming system) is described, in which the hot sample vapour is mixed with an auxiliary carrier argon stream of ambient temperature. The operation procedures using carrier volatilization of organic liquids as gas phase additives are also outlined. The selective volatilization and transport efficiency for As, Cd, Hg, Pb, Sb, Se and Zn could be increased by applying sodium thiosulfate as chemical modifier to solution samples with controlled nitric acid content. On the other hand, a near simultaneous vaporization of 16 elements using chlorination with CCl(4) vapour at 2100 degrees C could be performed for a multielement analysis. By wetting the auxiliary carrier argon stream, the linearity of the analytical curves was improved (except for chromium), when applying multielement standards. Linear analytical curves could also be obtained in the presence of alkali and alkaline earth metal matrices in multielement standards using halocarbon assisted electrothermal vaporization sample introduction.     

稀土萃取分离技术方法研究

稀土在工业诸多领域中发挥着关键作用,在增材制造材料和介电材料等高新技术领域均显示出可期的应用前景。稀土元素的分离是衔接稀土资源与高性能稀土功能材料的关键过程,所以高效提纯稀土元素变得尤为重要。本文梳理了化学沉淀法、离子交换与吸附法、萃取色层法、溶剂萃取法、液膜分离法这些经典方法和化学气相传输法、氧化还原法、萃取沉淀法、微生物法、非平衡溶剂萃取法这些新技术方法的优缺点和适用性,侧重分析了这些技术方法在节能减排方面的最新研究情况,并展望了稀土分离提纯领域的重点发展方向,以期为稀土资源的绿色高效开发利用提供依据和借鉴。     

Optimization of the electrothermal vaporization conditions for inductively coupled plasma excitation spectrometry: Selective volatilization versus covolatilization approaches

A new version of the outlet port of a graphite furnace electrothermal vaporizer (upward streaming system) is described, in which the hot sample vapour is mixed with an auxiliary carrier argon stream of ambient temperature. The operation procedures using carrier volatilization of organic liquids as gas phase additives are also outlined. The selective volatilization and transport efficiency for As, Cd, Hg, Pb, Sb, Se and Zn could be increased by applying sodium thiosulfate as chemical modifier to solution samples with controlled nitric acid content. On the other hand, a near simultaneous vaporization of 16 elements using chlorination with CCl₄ vapour at 2100° C could be performed for a multielement analysis. By wetting the auxiliary carrier argon stream, the linearity of the analytical curves was improved (except for chromium), when applying multielement standards. Linear analytical curves could also be obtained in the presence of alkali and alkaline earth metal matrices in multielement standards using halocarbon assisted electrothermal vaporization sample introduction.     

Evolution of surface characteristics of two industrial 7xxx aluminium alloys exposed to humidity at moderate temperature

This study analyses the evolution of surface characteristics of two industrial high-strength 7xxx aluminium alloys with a focus on alloy composition and environmental parameters. Based on storage and transport conditions of as-machined products, the effect of humidity—as liquid and vapour phase—on the natural oxide layer has been studied. The evolution of the natural oxide layer has been analysed by scanning electron microscopy and X-ray photoelectron spectroscopy. The growth behaviour of the surface layer is dominated by environmental conditions, while microgalvanic activity depends mainly on the alloys' chemical composition and differs significantly for tested alloys. Scanning transmission electron microscopy images demonstrated that the long-term exposure at moderate temperatures affects the microstructure near the surface, which differs for the analysed alloy compositions. An anomalous precipitation of zinc-rich particles at the surface and along the precipitate-free zone is observed for the alloy with higher Zn/Mg ratio and lower Cu content.     

无水稀土氯化物的新制备方法: 从稀土氧化物出发制备无水稀土氯化物

本文报道从稀土金属氧化出发, 在THF中与TMSCl/CH3OH反应, 制备无水稀土氯化物LnCl3.nTHF的方法。此法具有产物纯度高, 产率好, 制备条件温和, 操作方便等优点, 因而具有一定的实用性。     

还原-硅化法制备稀土硅化物（NdSi2，YSi2）纳米晶及其性能(英)

本文采用无水的氯化钕和氯化钇及硅粉作为起始原料，在高压釜中在650 ℃的温度条件下，通过还原-硅化途径成功地合成了硅化钕（NdSi₂）和硅化钇（YSi₂）。X射线衍射结果显示他们分别是四方相的二硅化钕和六方相的二硅化钇结构。透射电镜照片表明他们的平均粒径分别是40 nm和60 nm。样品的光致发光结果说明他们在波长分别为441 nm和366 nm处能发光。热重曲线显示他们在流动空气的介质中在550 ℃以下具有很好的抗氧化性。     

甲苯磺丁脲稀土络合物的制备及其性质研究

本文报导了15种甲苯磺丁脲稀土络合物的制备方法。用元素分析确定了它们的组成,测定了它们的物理化学性质,对它们的红外光谱、紫外光谱、核磁共振谱、X-射线粉末图进行了研究,并讨论了它们的热稳定性。     

A method to investigate the interaction of rare earth elements in aqueous solution with metal oxides

A method is described which can be used to investigate the interaction of dissolved metals with particulate material. Low level concentrations (10^–9M) of rare earth radiotracers were used to investigate their sorption onto synthetic mineral oxide surfaces. The preparation of rare earth radiotracers by neutron activation is discussed in detail. A kinetic approach was employed to investigate the interaction of dissolved metals and suspended mineral oxides. Amorphous iron oxyhyroxide, a phase commonly found in nature, was used in sorption experiments carried out in seawater at pH 7.8 and 2°C. Results of this study indicate a high affinity of the rare earth elements (REE) for the iron oxide surface (evidenced by fast uptake and high partition coefficients) and reveal a fraction between light and heavy REE.     

Concerning the 1,5-stereocontrol in tin(iv) chloride promoted reactions of 4- and 5-alkoxyalk-2-enylstannanes: trapping intermediate allyltin trichlorides using phenyllithium

Transmetallation of the 5-benzyloxy-4-methylpent-2-en-1-yl(tributyl)- and -(triphenyl)stannanes 1 and 8 using tin(iv) chloride generates an allyltin trichloride that reacts with aldehydes to give (Z)-1,5-anti-6-benzyloxy-5-methylhex-3-en-1-ols 2. The allyltin trichloride believed to be the key intermediate in these reactions has been trapped by phenyllithium to give anti-5-benzyloxy-4-methylpent-1-en-3-yl(triphenyl)stannane 9. Transmetallation of this anti-5-benzyloxy-4-methylpent-1-en-3-yl(triphenyl)stannane 9 generated an allyltin trichloride that reacted with aldehydes to give the (Z)-1,5-syn-6-benzyloxy-5-methylhex-3-en-1-ols 23 and was trapped by phenyllithium to give syn-5-benzyloxy-4-methylpent-1-en-3-yl(triphenyl)stannane 24. Similar stereoselectivity was observed for tin(iv) chloride promoted reactions of this syn-5-benzyloxy-4-methylpent-1-en-3-yl(triphenyl)stannane 24 with aldehydes and with phenyllithium. The allyltin trichlorides generated by transmetallation of 4-hydroxy- and 4-benzyloxy-pent-2-enyl(triphenyl)stannanes 34 and 35 were similarly trapped by phenyllithium to give 4-hydroxy- and 4-benzyloxy-pent-1-en-3-ylstannanes 36 and 37 whose configurations were established by correlation with known compounds. This work confirmed the configurations of the intermediate allyltin trichlorides involved in tin(iv) chloride promoted reactions of 4- and 5-alkoxypent-2-enylstannanes with aldehydes and showed that the high levels of remote stereocontrol were due mainly to kinetically controlled transmetallation. A fuller mechanistic scheme is proposed for the reactions in the 5-benzyloxy-4-methylpent-2-enylstannane series together with relevant (119)Sn NMR data.