A lower carbon footprint process for production of metals from their oxide sources

This paper will describe the solid oxide membrane (SOM) process as it applies to the energy-efficient and environmentally sound production of magnesium from magnesium oxide. Also, it will describe the challenges encountered while using this process for the production of transition metals like titanium from its higher oxides. Finally, a novel magnesiothermic SOM process will be proposed that can enable production of transition metals from its higher oxides.     

固体超强酸S_2O_8~(2-)/SnO_2-SiO_2催化合成环己酮1,2-丙二醇缩酮

采用沉淀-浸渍法制备了固体超强酸S2O28-/SnO2-SiO2,以它为催化剂催化环己酮和1,2-丙二醇合成了环己酮1,2-丙二醇缩酮;考察了带水剂种类及用量、酮醇摩尔比、催化剂用量、反应时间对产品收率的影响,并用正交实验对反应条件进行了优化。实验结果表明,适宜的反应条件为:n(环己酮)∶n(1,2-丙二醇)=1∶1.6、催化剂用量为反应物料总质量的2.0%、带水剂环己烷用量5.0mL、反应时间50min。在此条件下,环己酮1,2-丙二醇缩酮收率达到91.47%;催化剂的稳定性良好,在重复使用5次后环己酮1,2-丙二醇缩酮收率为82.20%,活性下降的主要原因为催化剂表面积碳和吸附了有机物;经傅里叶变换红外光谱和气相色谱质谱分析表明,产物为环己酮1,2-丙二醇缩酮,纯度为100%。     

Epitaxial growth of GaN on (0001) Al<Subscript>2</Subscript>O<Subscript>3</Subscript> via solution-cast seed layer formation process using Ga(mDTC)<Subscript>3</Subscript>

This paper reports an alternative method for the growth of GaN epitaxial layer on (0001) Al₂O₃ substrate by hot-wall vapor phase epitaxy technique. Tris (N,N-dimethyldithiocarbamato)-gallium (III), Ga(mDTC)₃ was introduced as a precursor material for the seed layer formation in the growth of GaN. Optimal growth conditions with seed layers formed by the Ga(mDTC)₃ concentration of 0.047 mol/L were identified: Growth temperature was found to be 850 °C, and optimal distance between the reactant outlet and substrate was determined to be 12.5 cm. Characterization results showed that this growth method produce high-crystallinity GaN epitaxial layers at a relatively lower growth temperature compared to the existing growth techniques and simplify the growth process.     

Porosity distribution in highly compressible cake: Experimental and theoretical verification of the dense skin

The rate of filtration and the water content of cake are influenced by the existence of a dense skin in a highly compressible cake. The phenomenon of the dense skin has been rarely studied, and its existence has not been verified experimentally. In this study, the porosity variation in a very compressible cake is measured by using a new experimental apparatus, and with this the existence of dense skin has been established experimentally. ‘Unified theory on solid-liquid separation’, a recently developed theory, is utilized for calculating the porosity variation in a very compressible cake.     

高精度智能转速测量模板的设计

介绍了一种利用高性能的16位单片机80C196KC进行转速实时高精度的测量方法，阐述了如何通过CAN总线实现与微机通讯；详细描述了硬件电路的设计，并给出了软件程序框图。     

初轧机主传动系统扭转自激振动的稳定性

用变量摄动法对初轧机主传动系统扭转自激振动的稳定性进行了初步研究，讨论了稳定性条件，为初轧机打滑状态的诊断、监测提供了参考依据。     

A novel in situ synthesis of dicalcium phosphate dehydrate nanocrystals in biodegradable polymer matrix

In the paper, we found a novel method to synthesize dicalcium phosphate dehydrate (DCPD) nanocrystals by in situ reaction in biodegradable PDLLA matrix. Calcium hydrid was selected as calcium source of DCPD, which is different from general methods. The method is not only simple and effective to synthesize Ca–P particles, but also can avoid the aggregation of inorganic nanoparticles in the course of their being dispersed into polymer matrix.     

超低渗广谱油层保护技术在板深51区块的应用

板深51区块存在压力敏感地层，在非目的层井段存在大段高渗低压砂岩，而目的层又属于高压低渗地层，属于难采油气田。室内进行的砂床滤失量、砂床封堵带承压能力、岩心封堵带的承压能力及油气层保护效果实验表明，在超低渗钻井液中增加固相含量，能够提高超低渗透膜结构强度，提高地层承压能力，降低砂床侵入深度，增强保护油气层效果，而且有选择性地增加有用固相效果更佳。基于这一理论，研究成功了超低渗广谱屏蔽暂堵油层保护技术，并在板深51区块长22—15井和长23—17K井进行了试验应用。该技术的关键是依据地层特性确定复配暂堵剂。长22-15井和长23-17K井射孔后未经过压裂、酸化、排液处理，获自喷高产，尤其是长22-15井形成自喷油流，创油田单井试采产量最高记录。应用结果表明，超低渗广谱保护油气层钻井液技术封堵隔层的承压能力强，很大程度地提高了漏失层的承压能力和破裂压力，较好地解决了含多套压力层系长裸眼段钻井过程中发生的漏失、井喷、卡钻、油气层保护等技术难题。