Thermochemistry of Ternary Complex Dy(Et_2dtc)_3(phen)

The ternary solid complex was synthesized with sodium diethyldithiocarbamate (NaEt2dtc), 1,10-phenanthroline (phen) and low hydrated dysprosium chloride in absolute ethanol by improved method of reference. The title complex was identified as the general formula of Dy(Et2dtc)3(phen) by chemical and elemental analyses. IR spectrum of the complex shows that the Dy3 coordinated with six sulfur atoms of three NaEt2dtc and two nitrogen atoms of phen. It is assumed that the coordination number of Dy3 is eight.The enthalpy change of liquid-phase reaction of formation, ΔrHθm(l), is determined as (-19.091±0.015) kJ·mol-1 at 298.15 K by a microcalorimeter, and the enthalpy change of the solid-phase reaction of formation, ΔrHθm(s), is calculated as (139.641±0.482) kJ·mol-1 on the basis of a thermochemical cycle. The thermodynamic of reaction of formation was studied by changing the temperature of liquid-phase reaction. The constant-volume combustion energy of the complex, ΔcU, is determined as (-16730.21±9.25) kJ·mol-1 by a precise rotating-bomb calorimeter at 298.15 K. Its standard enthalpies of combustion, ΔcHθm, and standard enthalpies of formation, ΔfHθm, are calculated as (-16749.42±9.25) kJ·mol-1 and (-2019.68±10.19) kJ·mol-1, respectively.     

一种新的稀土鞣剂—丙烯酸稀土络合物在皮革鞣制中的应用研究

现代的制革工业是从1858年德国化学家克哪卜发明铬鞣法开始的。铬鞣使皮革质量明显提高。我国从1898年开始,也由古老的硝皮走上了铬鞣的道路。因为铬鞣具有工艺技术成熟,产品理化性能稳定,操作简易等优点,所以一直被沿用着。但铬是国际公认的重要战略物资,铬鞣排出的废液中又严重污染环境,因此国内外都在积极研究部分或     

Thermochemistry on Coordination Behavior of Neodymium Chloride Hydrate with Diethylammonium Diethyldithiocarbamate

The complex of neodymium chloride lower hydrate with diethylammonium diethyldithiocarbamate (D-DDC) was synthesized conveniently in absolute alcohol and dry N2 atmosphere. The title complex was identified as Et2NH2 [ Nd(S2CNEt2)4] by chemical and elemental analyses and the bonding characteristics of which was characterized by IR. The enthalpies of solution of neodymium chloride hydrate and D-DDC in absolute alcohol at 298.15 K and the enthalpies change of liquid-phase reaction of formation for Et2NH2[ Nd (S2CNEt2)4] at different temperatures were determined by microealorimetry. On the basis of experimental and calculated results, three thermodynamic parameters (the activation enthalpy, the activation entropy and the activation free energy), the rate constant and three kinetic parameters (the apparent activation energy, the pre-exponential constant and the reaction order) of liquid-phase reaction of formation were obtained.The enthalpy change of the solid-phase title reaction at 298.15 K was calculated by a thermochemical cycle.     

2,4,6,8,10,12-六硝基-2,4,6,8,10,12-六氮杂三环[7·3·0·03.7]十二烷酮-5,11放热分解反应的动力学研究

用DSC研究了标题化合物在线性升温条件下的热行为和放热分解反应的动力学参数。结果表明:该反应的微分形式的经验动力学模式函数、表观活化能和指前因子分别为(1-α)-0.506,155.5kJ·mol-1和1013.5s-1,标题化合物的热爆炸临界温度为205.0℃。该反应的ΔS≠,ΔH≠和ΔG≠分别为6.0J·mol-1·K-1,146.5kJ·mol-1和143.7kJ·mol-1。     

含能材料放热分解反应体系热爆炸的临界温升速率估算式

从反应进度和反应体系能量变化的关系、热分解过渡到热爆炸的充分必要条件和非等温反应的动力学方程，导出了绝热、近似绝热、一级自催化和表观经验级数自催化分解反应体系热爆炸的临界温升速率(dT/dt)rb估算式。提出了估算(dT/dt)Tb值的相应方法。     

Phase Chemistry of the Complexes of RE Amino Acids

Forty-three phase diagrams of ternary system concerning rare earth salts, a-amino acids and water,which were constructed by phase equilibrium methods, were expounded. The influences of the factors such as cations, anions, the structure of amino acids, temperature on the phase diagrams were discussed. Under the guidance of phase equilibrium results, over 150 new solid complexes were prepared. IR, reflecting, UV, FS, and Raman spectra for these complexes were investigated and the regularity of ““tripartite effect“, “tetrad effect“,“Nephelanxeric effect“, “Oddo-Harkins“ was observed. Thermal decomposition processes of the complexes were confirmed. Based on the comparison with the known crystal structures of rare earth-amino acid-complexes, an estimarion method for predicting the crystal structure data of series complexes was founded. The constant volume combustion energies of the complexes were determined by RBC-1 type rotating bomb calorimeter. The standard enthalpies of combustion and standard enthalpies of formation were calculated for these complexes.     

Enthalpies of Solution of Complexes of Rare Earth Nitrate with L-α-Histidine in Water

The enthalpies of solution in water of complexes of RE(NO3)3(RE = La - Nd, Sm- Lu, Y) with L-α-Histidine (His) were measured at 298.15 K. The standard enthalpies of formation of RE(His)^3 (aq) were calculated. The “tetrad effect” regularity was observed from the curve, which is the enthalpies of solution plotted against the atomic numbers of the elements in lanthanide series.     

溶胶-自蔓延燃烧法制备纳米材料的研究进展 推荐 下载阅读CAJ格式全文 下载阅读PDF格式全文

溶胶-自蔓延法具有溶胶-凝胶法和自蔓延法制备纳米材料的操作简单易行、无需煅烧、所得产物粒径小、分布比较均匀等优点.以硝酸盐-柠檬酸体系为例,综述了溶胶-自蔓延燃烧法的产生和发展,以及在制备一些简单纳米氧化物、以及燃料电池材料、铁氧体材料、超导粉体材料、介电陶瓷粉体材料和热敏陶瓷材料等几个方面的实际应用.最后展望了这一领域的应用和发展前景.     

半化学法制备0.80Pb(Mg1/3Nb2/3)O3-0.20PbTiO3 陶瓷的研究

研究了制备纯钙钛矿相0．80Pb(Mg1／3Nb2／3)O3-0．20PbTiO3(缩写为PMNT)陶瓷的半化学法新工艺．详细讨论了除Nb2O5外，其它反应物以其非氧化物形态分别代替PbO、MgO和TiO2，以及PbTiO3或同成分的0．80PMN-0．20PT等钙钛矿相子晶对PMNT预烧粉体中钙钛矿相含量的影响；探讨了烧结温度对半化学法制备的PMNT陶瓷介电性能的影响，并对PMNT陶瓷的相组成、显微组织及介电性能进行了表征和测定．结果表明：提高镁组分的反应活性对提高预烧粉体中钙钛矿相含量的效果较好，同时以钛酸四丁酯取代TiO2的效果最好；半化学法工艺简单，能在850。C／2h预烧条件下制得几乎纯钙钛矿相的PMNT粉体，经过较低的烧结温度(950℃／2h)可制得致密的、介电性能优异的PMNT陶瓷．     

油酸在纳米材料合成中的研究与应用

油酸作为溶剂或表面活性剂在制备单分散纳米晶材料方面有着重要的作用,通过其合成的纳米材料已日益成为研究和应用的热点.本文综述一些重要单分散纳米晶金属材料和氧化物材料的制备方法、合成原理及其应用,着重介绍了油酸在制备单分散纳米晶材料方面的作用机制.最后展望了单分散纳米晶材料的未来.