Preparation of Compound Ultrafine CeO2 by Wet-Solid-Phase Mechanochemical Modification

To satisfy practical requirements from industrial applications, an alternate route for synthesis compound ultrafine CeO2 powders by wet-solid-phase mechanochemical modification using industrial grade hydrated cerium carbonate as raw material was proposed.The effect of modifier reaction percentage, reaction time, calcining temperature and modifier amount on particle size, density, suspensibility, and hardness of compound CeO2 powder was investigated.The phase evolutions of preparation process were characterized by XRD.SEM micrograph of the final product shows that compound CeO2 powders obtained are well-dispersed, spherically-shaped, uniformly-sized and submicron-sized particles.The method is readily available in raw material, low in cost, simple in process, and has great potential for industrialization.The compound CeO2 powders of different physical properties can be synthesized by controlling the above-mentioned influence factors in preparation process.     

粒径均匀的氧化铟粉末的研制

以金属铟，硫酸，氨水为原料，通过工艺条件的选择，制备出过滤性良好的氢氧化铟沉淀物。该沉淀物经过干燥，煅烧不需将氧化物粉碎就可以得到粉末状氧化铟。最佳工艺条件为：反应液中铟离子初始浓度调节在70g/L以下，碱添加量为铟含量的3－4倍；沉淀反应温度控制在90℃以上。     

前驱体热解法制备Al2O3的物相转变及其合成

本文着重考查了Al2O3的前驱体一碳酸铝铵沉淀的形成过程及煅烧过程物相变化，发现可通过调节反应条件和加入合适的表面活性剂，来控制碳酸铝铵晶核的形成及晶体的生长速度，有效地阻止了Al2O3的团聚，并在温度1150摄氏度下制备出分散的Al2O3，其平均粒径为－2um，比表面为－3m^2/g。     

基于时间序列的养护站选址的CFLP优化算法

通过对传统的CFLP选址模型进行分析与改进,建立了基于时间序列的养护站选址的CFLP优化算法,并将该算法应用于典型的高速公路养护站的选址,结果表明,该算法是合理的,对于高速公路养护站的选址具有重要的参考价值.     

Evaluating the fractionation of ion-adsorption rare earths for in-situ leaching and metallogenic mechanism

The fractionation of ion adsorption rare earths (IAREs) along the depth in a shaft of a deposit at Dajishan, Jiangxi, China was comparatively evaluated using the partition values (PVs) and relative fractionation values (RFVs) of the leached rare earths (REs). It is found that both PVs and RFVs can objectively reflect the migration and fractionation of REs, but RE content and abrasion pH could not. However, the RFVs can provide more information to quantitatively evaluating the migration and fractionation characteristics of REs along the selected direction and region than PVs could, which is of significance for designing the optimal procedures of in-situ leaching based on the determined flow direction of injecting solution. It is demonstrated that the migration of Ce, Pr, and Nd along the depth direction is inert, and that of REs post Sm and Y is active. Meanwhile, the migration of La shows region characteristics which is active in the upper and inert in lower region. More interesting, the dependence of RFVs on atomic number of REs displays a tetrad group variation trend. However, the fractionation of REs among clay minerals with different particle sizes is not evident, especially for the clay in the bottom region. These results indicate that the migration and fractionation of REs not only are dominated by the adsorption of their hydrated ions, but also rely on their hydrolysis tendency, which provide information for understanding the metallogenic mechanism of IAREs.     

冲击地压、岩爆、矿震的关系及其数值模拟研究

全面论述了冲击地压、岩爆与矿震现象，对其进行了具体定义，指出三者之间的关系。采用数值计算手段对冲击地压与岩爆现象进行对比分析，指出它们的异同。在此基础上，建议对“冲击地压一、“岩爆”和“矿震”这3个术语区别使用。     

Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

Y2O3isoftenusedinthemanufactureofphos phorsandceramics[1～3].However,itisalsousedas selectivecatalysts[1,4,5],suchasforthedehydrationof2alkanols,thedimerizationofmethane,1butene isomerization,hydrogenationof1,3butadieneandac etonealdoladdition,andsupport[6,7]formetalsthat catalyzetheformationofmethanolfromCO2andH2.It iswidelyacceptedthatthecatalysispropertiesofox idesdependstronglyontheirphysicalcharacteristics,especiallyontheirspecificsurfaceareaandporous structure.Agreatdealofattentionhasb…     

稀土氧化物对高氯酸铵热分解的作用及机制

采用草酸沉淀法、碳酸氢铵沉淀法和乙二醇溶胶凝胶法制备了多种稀土氧化物,用差热分析技术比较了不同稀土氧化物对高氯酸铵热分解的催化作用。结果表明：所有稀土氧化物均能使高氯酸铵的第一放热峰滞后,而第二放热分解峰提前;随着稀土添加量的增加,两分解峰逐渐靠近,最终合并为一个分解放热峰,分解热也大大提高。不同稀土氧化物种类对高氯酸铵热分解的催化作用有一定的差异,轻稀土镨和钕的氧化物使分解峰表现为前弱后强的两个相连的峰,中稀土钐和钆的氧化物表现为单一的强峰,而重稀土铒和镱的氧化物表现为前强后弱的两个分立的放热峰。对于同一种稀土氧化物,制备方法的不同对催化高氯酸铵的热分解也有差异,这与产物的比表面积有关,随着产物比表面积的增加,催化效果越明显。用能带理论解释了氧化稀土对AP热分解过程的影响,把氧化稀土作为半导体来考虑,正是由于它们储存和释放电子的功能性质导致了AP第一分解峰的滞后和第二分解峰的提前。     

增塑体系对氢化丁腈橡胶性能的影响

研究增塑剂种类及用量对氢化丁腈橡胶（HNBR）性能的影响。结果表明：采用增塑剂TP-95的HNBR胶料的t₁₀和t₉₀较短，相应硫化胶具有较好的耐低温性能；采用增塑剂DOS的HNBR硫化胶具有较大的硬度和拉伸强度以及良好的耐油性能；随着增塑剂用量的增大，HNBR胶料的门尼粘度明显下降，硫化剂的耐低温性能改善；当采用20份增塑剂DOS时，HNBR硫化胶具有较好的物理性能和耐油性能，同时具有不错的耐低温性能。     

有机酸类缓冲介质对稀土－偶氮肿Ⅲ显色性能的影响

比较研究了甲酸、乙酸和一氯醋酸三种有机酸溶液对稀土－偶氮Ⅲ显色性能的影响，结果表明：在用偶氮Ⅲ显色测定稀土时，选择甲酸溶液作缓冲介质最好。