建筑沉降预测方法的研究

应用灰色系统理论预测高层建筑物的沉降,通过实测数据进行参数计算,然后对后续变形进行预测,其预测结果与实测结果完全吻合,较好地用于指导工程进度和安全评价。     

洞库掘进电动出碴运输系统的应用

<正>在长大洞库工程施工中,传统的作业方式是采用钻爆法掘进,内燃装载机将石碴铲装在工程自卸汽车上,由自卸汽车运至洞外处理。这种作业方式存在诸多问题,如装载机和自卸汽车在作业中排放的     

可变式钢模台车液压系统研制

根据新型可变式钢模台车变跨、变高等对液压系统要求,经方案设计、理论分析、液压元件选型、油路设计等,开发出了该台车的液压系统。该系统不仅满足台车的各项工作要求,而且与电气控制系统配合,解决了多油缸垂直升降和水平伸缩同步控制难题,实现了模板系统快速定位和精确校正,确保了洞库工程断面被复质量。     

离心式水泵吸不上水原因分析

简分析了离心式水泵吸不上水的原因。     

喷嘴结构对角接触球轴承油气润滑中气帘效应的影响

针对角接触球轴承油气润滑中的气帘效应问题,基于气液两相流理论,构建了轴承腔内油气两相流的数值分析模型,分析了轴承腔内气帘效应的形成机理及影响因素,对比分析了5种喷嘴结构对气帘效应的影响。结果表明：在高速工况下,内圈与滚动体接触区附近产生的气帘效应阻止润滑油到达润滑点;气帘效应随轴承转速的升高而加剧;使用D型喷嘴结构时,气帘效应的影响最小,滚动体接触区附近油相的体积分数最大,轴承润滑效果最佳。     

基于MD方法的HMX黏结剂优选研究

从优选高聚物黏结剂角度考虑,用分子动力学(MD)方法,对含少量液态黏结剂的奥克托今(HMX)炸药进行了MD模拟。选择端羟基聚丁二烯(HTPB)、聚叠氮缩水甘油醚(GAP)、硅橡胶和乙烯基酯(VE)4种黏结剂。通过计算HMX与黏结剂之间的结合能,选择结合能最大的一组的黏结剂作为最优黏结剂。结果表明,HTPB可作为最优黏结剂。     

表面织构对角接触球轴承润滑性能的影响

为研究油气润滑状态下表面织构对角接触球轴承润滑性能的影响,在角接触球轴承的内圈滚道上设计表面织构,基于气液两相流理论,采用多重参考坐标系(MRF)模型和流体体积(VOF)法,对高速角接触球轴承腔内润滑油流动特性进行数值分析,对比分析长沟槽、短沟槽、矩形、圆柱形4种表面织构对角接触球轴承润滑性能的影响,发现长沟槽形的表面织构对改善角接触球轴承的润滑性能效果最为显著,并进一步分析长沟槽形表面织构结构参数对轴承润滑性能的影响。结果表明：轴承腔内油相体积分数随着沟槽深度和面积率的增大先增大后减小,随着沟槽宽度的增加逐渐增大,存在最佳织构参数使得轴承腔内油相体积分数最大。因此,合理地设计织构参数能有效提高角接触球轴承润滑性能,该研究结果对角接触球轴承表面织构设计具有一定的参考价值。     

连杆凸轮减速器性能试验

介绍了研制的连杆凸轮减速器性能试验的方法和结果。对连杆凸轮减速器的承载能力、过载能力、效率、温升、噪声、动态性能、清洁度和工业运行等进行了试验。试验结果表明,该减速器具有承载能力大、传动效率高、运行可靠等优点。指出了试验过程中有待改进的方面。     

Capacitance-voltage characterization of fully silicided gated MOS capacitor

This paper investigates the capacitance-voltage （C-V） measurement on fully silicided （FUSI） gated metal-oxide-semiconductor （MOS） capacitors and the applicability of MOS capacitor models. When the oxide leakage current of an MOS capacitor is large, two-element parallel or series model cannot be used to obtain its real C-V characteristic. A three-element model simultaneously consisting of parallel conductance and series resistance or a four-element model with further consideration of a series inductance should be used. We employed the threeelement and the four-element models with the help of two-frequency technique to measure the Ni FUSI gated MOS capacitors. The results indicate that the capacitance of the MOS capacitors extracted by the three-element model still shows some frequency dispersion, while that extracted by the four-element model is close to the real capacitance, showing little frequency dispersion. The obtained capacitance can be used to calculate the dielectric thickness with quantum effect correction by NCSU C-V program. We also investigated the influence of MOS capacitor＇s area on the measurement accuracy. The results indicate that the decrease of capacitor area can reduce the dissipation factor and improve the measurement accuracy. As a result, the frequency dispersion of the measured capacitance is significantly reduced, and real C-V characteristic can be obtained directly by the series model. In addition, this paper investigates the quasi-static C-V measurement and the photonic high-frequency C-V measurement on Ni FUSI metal gated MOS capacitor with a thin leaky oxide. The results indicate that the large tunneling current through the gate oxide significantly perturbs the accurate measurement of the displacement current, which is essential for the quasi-static C-V measurement. On the other hand, the photonic high-frequency C-V measurement can bypass the leakage problem, and get reliable low-frequency C-V characteristic, which can be used to evaluate whether the full silicidation ha     

少齿数齿轮轴扭转变形及破坏分析

以顺、逆螺旋方向进行了少齿数齿轮轴的扭转试验,得到了顺逆向扭转变形和破坏的独特现象,探讨了扭转变形和破坏的原因.提出了少齿数齿轮设计时应考虑扭转失效破坏的因素.