用于高频谐振器的PbTiO_3基压电陶瓷

传统的PZT压电陶瓷的相对介电常数较大,一般为1 000以上,用于高频谐振器不易与线路匹配;而PbTiO3基压电陶瓷的相对介电常数较小,一般仅为200左右,对于10 MHz以上频率的谐振器,用PbTiO3基压电陶瓷作为压电振子是最佳的选择。本文主要研究用于高频谐振器的MnO2和Nd2O3改性PbTiO3基压电陶瓷的性质。PbTiO3基压电陶瓷的性质的改善是与此种陶瓷的制备工艺,显微结构和电导机制紧密相关的。     

A direct numerical simulation of transition phenomena in a mixed convection channel flow

This study intends to provide an increased understanding of the laminar-turbulent transition phenomena for the buoyancy-assisted heated vertical channel flow during the early transient stage. The spectral method with weak formulation is applied in the direct numerical simulation. Initial disturbances consist of the finite-amplitude two-dimensional TS wave and a pair of three-dimensional oblique waves for the K-type disturbances. The results from the harmonic energy competitions of different wave modes show that for the buoyancy-assisted heated flow, the (k_x=1, k_z=1) or (1,1) and (1,0) modes would gain energy immediately and start to rise at almost the same rate. This phenomenon is different from that of the buoyancy-opposed flow, where the (1,1) mode decays slowly in the beginning until other modes gain enough energy and then it begins to grow quickly and overtakes the (1,0) mode after a short time period. These different transition patterns match with the experimental results that the flow transition is supercritical and subcritical for the buoyancy-assisted and -opposed flows, respectively. Buoyancy-assisted heated flow transition follows the general trend of an isothermal flow in the beginning, but the thermal-buoyant force is crucial in accelerating the instability and also causing notable differences during the subsequent transition process. All of the results for the vortex structures development, kinetic energy budget of the disturbances, flow visualization by tagged fluid particles, and the local temperature fluctuations are consistent in pointing to a clear pattern for the buoyancy-assisted heated flow transition.     

40kg试验焦炉的研制

文章介绍了40kg试验焦炉，分析和比较了试验焦炉与生产焦炉的差异，指出它们之间的模拟条件是炭化室宽度、煤料堆密度、炼焦速度和单向传热。     

6m焦炉移动设备故障分析及处理

对6m焦炉移动设备运行特点及损坏原因进行了分析，并对6m焦炉移动设备PLC系统，液压系统的故障及其处理方法进行了探讨。     

横管初冷器液体喷洒系统的改进

介绍了横管初冷器液体喷洒系统存在的问题，改进方法及效果。     

低密度MTC固井液在低渗透气井的试验研究

针对陕甘宁盆地低渗透气田天然气井地层漏失等问题，通过室内试验，设计了密度为１．４１～１．６０ｇ／ｃｍ３的二级固井高炉矿渣——ＭＴＣ水泥浆和ＡＰＩＧ级水泥——ＭＴＣ水泥浆。目的提高固井质量、降低固井成本。结果通过对高炉矿渣的水化机理和两种ＭＴＣ水泥浆对比分析，认为高炉矿渣——ＭＴＣ转化法较ＡＰＩＧ级水泥——ＭＴＣ转化法，具有外加剂用量少、抗压强度高、体系简单、固井成本低等特点。结论两种低密度ＭＴＣ水泥浆配方设计合理，性能优良，能满足现场施工的要求。     

大型焦炉计算机优化控制系统

本文介绍一个大型焦炉计算机优化控制系统，它不仅实现了燃烧系统的ＤＤＣ控制，而且完成了结焦终点的在线预报和以焦炉能耗最小为目标的优化控制。     

焦炉装煤烟尘治理的烟气量计算

通过对焦炉装煤烟尘治理的烟气量计算和研究,提出不同治理系统的烟气量计算方法及应采取的措施。     

水对植物纤维水泥复合板生产的影响

研究了水对植物纤维水泥复合板性能的影响。选择合适的水分可以提高板材静弯曲强度,减小板材变形。     

气体悬浮焙烧炉内衬烘炉曲线的确定

根据所使用的低水泥浇注料的性能，对中铝山西分公司检修厂4号焙烧炉制定了合理的烘烤曲线，提高了耐火内衬的质量，延长了内衬的使用寿命。