熔融碳酸盐燃料电池(MCFC)用γ-LiAlO_2粉末的制备

本文简介了熔融碳酸盐燃料电池(MCFC)及其优点;叙述了合成LiAlO_2的方法,用Al_2O_3(a,γ)成功地制得了稳定的适合于MCFC用的γ-LiAlO_2,在MCFC工作温度(923K)下,β-LiAlO_2是不稳定的;973-1073K时,β-LiAlO_2向γ-LiAlO_2转变速度明显增大;a-LiAlO_2要在1073K以上转变为γ-LiAlO_2.     

基于因素分析的复合神经网络及其在软测量中的应用

针对工业生产中,众多因素对生产影响程度不同的特点,提出了一种基于因素分析的复合神经网络(FA-MNN)模型.介绍了FA-MNN模型的结构,改进了神经网络的学习算法,并将其应用于氧化铝高压溶 出过程中苛性比值及溶出率的软测量,利用现场实际运行数据进行仿真,结果表明FA-MNN模型能有效实现苛性比值及溶出率的在线检测.     

Single step synthesis of GdAlO3 powder

A novel method for preparation of nano-crystalline gadolinium aluminate (GdAlO₃) powder, based on combustion synthesis, is reported. It was observed that aluminium nitrate and gadolinium nitrate exhibit different combustion characteristics with respect to urea, glycine and β-alanine. While urea was proven to be a suitable fuel for direct formation of crystalline α-Al₂O₃ from its nitrate, glycine and β-alanine are suitable fuels for gadolinium nitrate for preparation of its oxide after combustion reaction. Based on the observed chemical characteristics of gadolinium and aluminium nitrates with respect to above mentioned fuels for the combustion reaction, the fuel mixture composition could be predicted that could lead to phase pure perovskite GdAlO₃ directly after the combustion reaction without any subsequent calcination step. The use of single fuel, on the other hand, leads to formation of amorphous precursor powders that call for subsequent calcination for the formation of crystalline GdAlO₃. The powders produced directly after combustion reactions using fuel mixtures were found to be highly sinterable. The sintering of the powders at 1550 °C for 4 h resulted in GdAlO₃ with sintered density of more than 95%. T.D.     

铝酸钠溶液中晶体附聚机理研究

本文研究了铝酸钠溶液中晶体的附聚机理。认为晶体的附聚过程为：晶体中粒度相对最小且粒度相近的粒子发生附聚，形成略大些颗粒，略大一些颗粒且粒度相近的粒子又发生附聚，这样依次实现的过程，直到溶液过饱和度不能满足对应粒级粒度粒子发生附聚的要求为止。     

Microstructural evolution and relevant mechanical properties of Al-rich transparent magnesium aluminate ceramics

A novel phenomenon is found that the grain growth of aluminum-rich magnesium aluminate is suppressed to 5 μm, despite of high-temperature hot-isostatic-press at 1750 °C. For the transparent MgO-nAl₂O₃ (n = 1.2, 1.5, 2.0), the transmittance and strength tended to be enhanced with increasing Al₂O₃ content, having the highest values 80 % at 550 nm and 214.3 MPa for n = 2.0. This is due to the different microstructural evolution depending on the composition. When the excessive Al₂O₃ was small, the inhomogeneous microstructure with bimodal grain size and lots of rod-shaped particles were observed. However, as the Al₂O₃ amount increased, the microstructure became homogeneous with reducing the grain size and the rod-shaped particles. The microstructural and compositional analysis revealed that the rod-shaped particle were generated due to the trace potassium impurity as well as the different cationic diffusion rate, and the suppression of grain growth was induced by the severe Al segregation at the grain-boundaries.     

硼酸加入量对γ-LiAlO2：Eu^3＋红色荧光粉发光性能的影响

利用溶胶–凝胶法合成γ-LiAlO2：Eu^3＋荧光粉,用X射线衍射、扫描电子显微镜和荧光光谱仪研究了助熔剂H3BO3对γ-LiAlO2：Eu^3＋红色荧光粉物相结构、发光性能、形貌的影响。结果表明：合成的样品仍为四方晶系结构;其发光强度随H3BO3加入量的增加先增强,后减弱,当加入H3BO3量为0.8%（摩尔分数）时...     

纤维素―铝酸锶复合膜的制备及表征

将微晶纤维素溶解于氯化1-正丁基-3-甲基咪唑([Bmim]Cl)离子液体中,加入铝酸锶荧光粉,然后流延成膜,制备得到了纤维素―铝酸锶复合膜。利用红外光谱、X射线衍射、热重分析、扫描电镜和荧光发射光谱对复合膜进行了表征。结果表明,铝酸锶荧光粉在纤维素膜中分布均匀,铝酸锶荧光粉和纤维素之间存在着一定的相互作用,纤维素对荧光粉体发光影响较小。     

酸溶二步法制备聚合氯化铝的试验研究

以铝矾土和铝酸钙粉为原料,在实验室采用酸溶二步法制备液体聚合氯化铝产品（PAC）,通过实验考查制备工艺的主要影响因素,找到最佳生产条件：100～110 mL浓度为20%盐酸中,投加氧化铝含量51.22%的铝酸钙粉12 g和氧化铝含量26.50%的铝钒土15 g;最佳温度范围为100～110℃;最佳反应时间在7 h左右。在此工艺参数控制条件下,制备出液体聚合氯化铝产品的盐基度为83%,氧化铝含量为13.4%,符合GB 15892—2009《生活饮用水用聚氯化铝》的指标。     

Conversion of calcium aluminate cement hydrates at 60°C with and without water

There have been different hypotheses about the transformation mechanisms of calcium aluminate cement hydrates and this work aims to clarify the long‐running debate about the conversion approaches. In this work, CAH₁₀ and C₂AH₈ were produced from the pastes of calcium aluminate cement (CAC) cured for 24 hours at 10 and 20°C separately. And the cured pastes were continually cured at 60°C for 3 days with water and without water, respectively. The hydration of the pastes was halted by freeze‐drying, and the phases and microstructure of hydrates were investigated by XRD and SEM, respectively. The results indicate that CAH₁₀ and C₂AH₈ converted into C₃AH₆ and AH₃ in water presence at 60°C, but did not transform into C₃AH₆ and AH₃ without water. It is confirmed that the conversion of CAH₁₀ and C₂AH₈ to C₃AH₆ and AH₃ happens through preceding solution of CAH₁₀ and C₂AH₈ and subsequent precipitation of C₃AH₆ and AH₃.     

The effect of synthesis conditions on the physicochemical properties of magnesium aluminate materials

Magnesium aluminate-based materials were prepared by applying different methods: (i) mechanochemical milling of the initial mixture of magnesium and aluminium nitrate powders (in appropriate stoichiometric amounts) followed by heat treatment at temperatures of 650 °C and 850 °C and (ii) melting of the mixture of nitrate precursors at 240 °C followed by thermal treatment at 650 °C, 750 °C and 850 °C. The effect of synthesis method on the structure and morphology of the obtained solids was studied by using various techniques such as: nitrogen adsorption-desorption isotherms, powder XRD, IR spectroscopy and SEM. It was shown that the mechanochemical milling performed before calcination procedure leads to obtaining of nanocrystalline magnesium aluminate spinel phase at lower temperature of 650 °C in comparison with the method using thermal treatment only (at 750 °C). The obtained nanomaterials exhibit mesoporous structure.