运载火箭发动机电磁阀绝缘电阻超差问题分析

在运载火箭发动机某次试车后的复测过程中,发现某电磁阀绝缘电阻下降,针对该情况,对电磁阀所用电磁铁进行了多余物、潮湿、接线片与壳体接触,以及线圈与壳体接触等四方面的分析和试验,结果表明,电磁阀绝缘下降是由多余物及潮湿两项因素共同导致,因此在后续的生产过程中,应严格控制接线板表面的质量,防止产生多余物。     

堡子矿强排水设备的选型计算

介绍了堡子矿地质概况,根据矿井突水量,计算确定强排水设备型号、排水管直径和壁厚,绘制了特性曲线,最后提出了预防水患的建议.     

考虑可制造性的拓扑优化结果的几何重构

拓扑优化结果是一个边界呈离散阶梯状的非参数化模型,这使得拓扑优化结果的制造变得困难,因此需要将拓扑优化结果参数化几何重构,获得光滑的边界以满足机械制造要求,并且尽量不影响拓扑优化结果的结构响应。针对该问题,首先对拓扑优化结果进行二值化处理和边界识别,然后利用链码对拓扑优化结果的离散边界点进行排序和分段,最后用B样条曲线分段描述拓扑优化结果的外边界与内边界完成参数化建模。通过算例验证了几何重构方法的可行性,算例表明在满足可制造性要求的前提下,重构模型的结构响应能够较好的与拓扑优化初始设计结果保持一致,结构响应误差可以控制在5%以内。     

Reverse water gas shift reaction over Co-precipitated Ni-CeO2 catalysts

The Ni-CeO2 catalysts with different Ni contents were prepared by a co-precipitation method and used for Reverse Water Gas Shift （RWGS） reaction. 2wt.%Ni-CeO2 showed excellent catalytic performance in terms of activity, selectivity, and stability for RWGS reaction. Characterizations of the catalyst samples were conducted by XRD and TPR. The results indicated that, in Ni-CeO2 catalysts, there were three kinds of nickel, nickel ions in ceria lattice, highly dispersed NiO and bulk NiO. Oxygen vacancies were formed in CeO2 lattice due to the incorporation of Ni^2＋ ions into ceria lattice. Oxygen vacancies formed in ceria lattice and highly dispersed Ni were key active components for RWGS, and bulk Ni was key active component for methanation of CO2.     

堡子矿主排水泵选型设计

井下排水系统是煤矿生产中主要系统之一,担负着井下积水排除的重要任务。山西阳泉煤业集团翼城堡子煤业有限公司正常及最大涌水量较大,排水系统复杂,主排水泵的运行状态和性能将会影响到排水系统整体作用的发挥。本文根据该矿实际涌水量,对主排水泵进行选型设计,根据水泵及管路系统的特性,对其特性曲线进行分析及校验计算,选出了合适的泵型,满足该矿实际需求。