Mechanically-Activated Synthesis and Mixed Conductivity of TbMO4−δ (M = Zr, Hf) Ceramics

Terbium hafnate and zirconate ceramics with submicron grain sizes were prepared via mechanically-activated synthesis. X-ray and electron diffraction and infrared (IR) absorption spectroscopy showed that TbZrO_4– has a disordered fluorite-type structure, while TbHfO_4– is partially ordered, containing pyrochlore microdomains. The oxygen ion transference numbers determined by the modified e.m.f. technique under oxygen/air gradient, vary in the range 0.08–0.26 at 873–1123 K, increasing with temperature. The activation energies for ionic and p-type electronic transport are 82–83 and 29–40 kJ/mol, respectively. The ionic conduction becomes dominant in reducing atmospheres, but tends to decrease at low p(O₂). Oxygen partial pressure dependencies of Seebeck coefficient can be described by a model common for oxide phases with mixed ionic and electron-hole conductivity. Due to partial cation ordering, terbium hafnate exhibits lower ionic and hole transport as compared to TbZrO_4–. The average thermal expansion coefficients of TbMO_4– (M = Zr, Hf) ceramics in air, calculated from dilatometric data, are (11.5–12.4) × 10^–6 K^–1 at 600–1200 K and (18.4–20.3) × 10^–6 K^–1 at 1200–1420 K.     

对苯基苯甲酸铕、铽配合物的合成、表征及荧光性能研究

分别合成了以对苯基苯甲酸为配体,铕、铽及掺杂铕、铽为中心的固态配合物。经元素分析、摩尔电导及差热-热重分析,推测其组成分别为:铕配合物:EuL3.3H2O、Eu0.5La0.5L3.3H2O、Eu0.5Y0.5L3.3H2O;铽配合物:TbL3.2H2O、Tb0.5La0.5L3.2H2O、Tb0.5Y0.5L3.3H2O(L=■-■-COO-。红外光谱、紫外光谱及核磁共振氢谱分析表明,对苯基苯甲酸的羧基氧原子与稀土离子配位。配合物的荧光光谱测定表明,铕系列和铽系列配合物都可发出其特征荧光,铕异核稀土配合物的荧光强度与相同配体的铕配合物相比,均有不同程度提高。     

Synthesis and Crystal Structure of A Bimetallic Terbium Complex Tb2 {μ-CH2 SiMe2 NC6 H3 ^iPr2 -2, 6}3 （THF）3

The reaction of 2, 6-^iPr2CbH3NHSiMe3 with Tb（CH2SiMe3）3（THF）2 in benzene at room temperature afforded a binuclear terbium complex Tb2 {μ-CH2 SiMe2 NC6 H3 ^iPr2 -2, 6}3（THF）3. X-ray diffraction revealed that Tb atoms were bridged by three methylene units. One Tb atom was six-coordinated by two nitrogen atoms, three methylene carbons, and one THF molecule, while the other Tb atom was six-coordinated by one nitrogen atom, three methylene carbons, and two THF molecules. Both Tb atoms adopted a distorted trigonal prism geometry.     

一种交联结构聚咪唑的制备及性能

本研究合成了1种多官能团的单体,即4-(3,5-双(3,4-二胺基)苯基)吡啶苯甲酸,并通过自聚合得到1种含有大量邻苯二胺端基的支化结构的聚咪唑(HPBI);HPBI与苯偶酰反应可以封锁未反应的端基,并且添加少量的聚醚苯偶酰(PEB)可得到交联结构的聚咪唑。利用FT-IR、UV-vis、DSC和TGA等测试手段对聚合物的结构与性能进行了表征和研究。该种交联结构的聚咪唑具有优良的热稳定性和物理机械性能。     

紫外长波草绿荧光功能材料的合成研究

以对甲苯磺酰氯(TSC)和邻氨基苯甲酸(ATRA)为原料,吡啶为溶剂,乙醇钠为催化剂,合成紫外长波草绿荧光功能材料.产品的性状为淡黄色粉末状晶体.通过原料物质的量配比、催化剂用量、反应温度、反应时间等四个方面的条件试验,找出了最佳工艺条件,收率大于20%.同时对该产品进行了初步的表征分析.     

The Method for Avoidance of Palladium/Carbon Catalyst Poisoning and Its Commercial Application

After utilizing an improved method for adding a non-precious promoter to the precious Pd/C catalyst during hydrogenation of benzoic acid, a new understanding concerning regeneration of deactivated Pd/C catalyst has been obtained, and an improved process has emerged. The improved process can avoid the conventional technical shortcomings related with hydrogenation of benzoic acid such as the quick decline of catalyst activity in a relatively short period of time and low palladium recovery from the spent catalyst. Furthermore, according to this process, cyclohexane carboxylic acid （CCA） can be produced Pavorably in a commercial scale at a high selectivity and product yield with a extended catalyst life.     

Syntheses, characteristics and fluorescence properties of complexes of terbium with benzoic acid and its derivatives

The binary complexes of terbium with benzoic acid and its derivatives (phthalic acid, iso-phthalic acid, oaminobenzoic acid, salicylic acid, sulfosalicylic acid) were synthesized and their compositions were identified by elemental analyses. UV, IR of the complexes were investigated. The UV spectra indicate that the complexes‘ ultraviolet absorption is mainly the ligands‘ absorption, but the location of peak drifts. The IR spectra show that the IR spectra of complexes are different from those of free ligands, and the band at 400 - 500 cm^-1 , due to the stretching vibration of Tb--O, is absent for free ligands. The fluorescence properties were investigated by using luminescence spectroscope, the results show that all the six complexes of terbium exhibit excellent luminescence, due to the transition from the lowest excited state ^5D4 to ^7F ground state manifold, the complexes of terbium with sulfosalicylic acid have the strongest fluorescence intensity, and is stronger than o-aminobenzoic acid-terbium, whose fluorescence intensity is regarded as the strongest one in the literature, and even stronger than some phosphor of terbium.     

利用熔融结晶法进行苯甲酸的提纯

对苯甲酸的熔融结晶提纯进行了实验研究,探究国内外现有的熔融结晶器与自发明的翅片结晶器和板式结晶器的分离效果。实验结果表明,翅片结晶器和板式结晶器优于传统管式结晶器。并得到翅片结晶器和板式结晶器最优实验条件,使得产品纯度达到99.99%。     

AlMCM-41介孔分子筛催化合成苯甲酸甲酯的研究

本文以介孔分子筛AlMCM-41为催化剂,采用碳酸二甲酯(DMC)作为酯化试剂与苯甲酸(BA)反应制备苯甲酸甲酯(BA)。反应结果表明,碳酸二甲酯是一种很好的酯化试剂,介孔分子筛AlMCM-41对此酯化反应是高效的催化剂。并且还发现苯甲酸的转化率和苯甲酸甲酯的选择性与催化剂上的Lewis酸位有很大联系。另外本文还讨论了此反应的机理。