基于精细积分法的干摩擦隔振系统稳定性的研究

本文利用摩擦隔振系统的计算模型，建立了系统的动力学方程，在此基础上，对干摩擦隔振系统的稳定性问题进行了分析，同时将精细积分法引入了求解过程，提高了计算的精度，并给出了相应的数值例题，本文的工作可为工程应用提供必要的计算依据。     

A COUPLING MODEL OF WATER FLOWS AND GAS FLOWS IN EXHAUSTED GAS BUBBLE ON MISSILE LAUNCHED UNDERWATER

The gas and water flows during an underwater missile launch are numerically studied. For the gas flow, the explicit difference scheme of Non-oscillation and Non-free-parameter Dissipation (NND) is utilized to solve the Euler equations for compressible fluids in the body-fitted coordinates. For the water flow, the Hess-Smith method is employed to solve the Laplace equation for the velocity potential of irrotational water flows based on the potential theory and the boundary element method. The hybrid Eulerian-Lagrangian formulation for the free boundary conditions is used to compute the changes of the free surface of the exhausted gas bubble in time stepping. On the free surface of the exhausted gas bubble, the matched conditions of both the normal velocities and pressures are satisfied. From the numerical simulation, it is found that the exhausted gas bubble grows more rapidly in the axial direction than in the radial direction and the bubble will shrink at its "neck" finally. Numerical results of the movement of the shock wave and the distribution of the Mach number and the gas pressure within the bubble were presented, which reveals that at some time, the gas flow in the Laval nozzle is subsonic and the gas pressure in the nozzle is very high. Influences of various initial missile velocities and chamber total pressures and water depths on both the time interval when the gas flow in the nozzle is subsonic and the peak of the gas pressure at the nozzle end were discussed. It was suggested that a reasonable adjustment of the chamber total pressure can improve the performance of the engine during the underwater launch of missiles.     

长螺旋水下灌注桩技术及其经济性探讨

阐述了长螺旋水下灌注桩的技术要点及技术参数控制标准,结合工程实例中桩基检测的结果,分析表明,采用长螺旋水下灌注桩技术施工便捷、噪声小、效率高、成本低,是一种经济、高效、环保的施工工艺.     

高层建筑外墙干挂花岗岩质量监控

结合安业大厦施工实例，介绍了高层建筑大面积干挂花岗岩的施工过程。为了确保工程一次成活达优，对实施工程质量进行全方位监控。首先确定质量监控的目的，明确专项管理组织及专项负责人，严格监理指令制度。同时针对监控的重点、难点和关键点，组织各方实现工程质量的监控。     

Influence of load and speed on wear characteristics of grey cast iron in dry sliding — selection for minimum wear

The wear of grey cast iron in dry sliding conditions has been studied with the aims of (1) finding the influence of working conditions on the wear rate, and (2) determining the region of speed and load where low wear is accomplished. Grey cast iron with flake and nodular graphite was submitted to investigation using a pin-on-disc machine. The results indicate that the flake graphite cast iron is more suitable for applications at speeds greater than 4 m s⁻¹ and lower loads, while nodular cast iron has greater wear resistance at lower speeds in the range of loads investigated - from 50 N cm⁻² to 200 N cm⁻²     

重油催化裂化干气氢提纯技术的开发

石家庄炼油厂和西南化工研究设计院合作开发的中国石化系统第一套利用变压吸附技术进行RFCC干气氢提纯工业试生产装置一年的平稳运行说明：提纯后产品氢纯度达99．9％，回收率大于85％；操作简便灵活；装置负荷弹性裕度大；经济效益显著。实践证明它是一项富有吸引力的新工艺，为重油催化裂化装置的挖潜增效展示了美好的前景。     

高炉煤气喷水降温控制方法

用ＫＭＭ调节器根据温控偏差和喷水量计算两个调节参数，对水量调节阀进行开度调节来控制最终喷水量，从而达到准确有效控制布袋除尘器入口煤气温度的目的。     

关于CEA混凝土膨胀剂的若干技术问题--与游宝坤同志讨论

作者阐述了CEA膨胀剂混凝土的膨胀量较大，干缩小，抗裂性能良好的特性，CEA与粉煤灰掺用提高强度，改善界面过渡层的性质，提高耐久性；CEA混凝土无Ca（OH）2溶出问题。文中列出GBJ119应用技术规范，说明CEA可用于防水工程。     

美国MK48系列鱼雷发展历程带给我们的启示

美国MK48系列鱼雷以其航程远、威力大而著称。经过40多年来的研制、改进和发展，目前已成为了世界上最杰出、最典型的大型鱼雷之一。该文仅根据其发展历程，从注重现役鱼雷的改造利用、抗干扰性能、浅水性能、良性竞争、新技术的开发以及标准化建设6个方面提出了带给我们的一些启示，供鱼雷研制和武器采购部门参考。     

水下封底混凝土与钢护筒粘结力试验

针对吊箱围堰施工中，混凝土与钢板间的粘结力无详实数据的现象，介绍了确定数据的实验模型、实验步骤，并分析了实验结果，以方便施工，指导施工。