The effect of temperature on the dynamic characteristics of heat-resistant thermoplastic composites

Two thermoplastic and two thermosetting fibrereinforced plastic composites were subjected to dynamic tests over a wide range of temperature, covering both cryogenic and hot environments. The thermal behaviour of each composite, as indicated by its dynamic mechanical properties, was assessed individually, and was compared collectively with that of the other composites.     

底敞口充气浮箱研究和试验

提出底敞口充气浮箱的结构和概念。经模型模拟试验研究分析，经典浮力定律可用于这种浮箱的浮力计算；其动充气状况还具有一定的允许伤损面积。它的研究将为水陆两用车辆增大浮力，缩小外形，提高水上自下而上能力和潜驶潜伏提供具有诱惑力的工程应用前景。     

Performance of absorption refrigeration cycle at maximum cooling rate

The influence of irreversibility of finite-rate heat transfer on the performance of an absorption refrigerator is investigated using an endoreversible cycle model with continuous flow. The cooling rate is adopted as an objective function for refrigerator optimization. The maximum cooling rate and the corresponding coefficient of performance are derived. The optimal performance with respect to heat transfer areas of the refrigerator is analysed. In addition, certain significant conclusions are reached.     

三维定量储层地质模型与参数动态预测方法

提出了三维定量储层地质模型及其参数动态预测方法，用该方法可预测储层开采状态，水淹区及剩余油区分布和各剩余油区的可采储量，三维定量储层地质模型的预测图件可为合理开采提供依据。     

凝析气井井筒动态预测方法

利用垂直管流公式,结合流体相平衡热力学闪蒸计算,运用状态方程模拟,给出凝析气井井筒动态预测新方法.根据该方法.结合油藏数值模拟计算的结果,可准确地预测不同生产时期凝析气井的井筒动态.     

How to Control Robots Interacting with Dynamic Environment

The goal of this paper is to shed light on the control problem of constrained robot motion from the aspect of the dynamical nature of the environment with which the robot is in contact. Therefore, the criticism of traditional hybrid control which allows position/force feedback loops to split into independent control with respect to position and force, is not the main point we want to make. Reference to the papers written by the founders of hybrid control and their numerous followers served only to better understand the reason and motivation for suggesting a different approach to control of robots interacting with environment.The paper has a predominantly review character, based on recently published work. It also contains some new, unpublished results in the framework of the unified approach to the position/force control of robots, proposed by the present author and his co-workers. By pointing to the possibility of introducing an environment dynamics in the contact tasks of the machining type, the author emphasizes that the proposed dynamically interactive control can be applied to a completely different class of tasks, in which a contact is made between the system (constructions or structure) and very specific kinds of dynamic environments.     

Eight-year exploration of shrinkage in high-performance concrete

In this paper, an experimental and analytical exploration on the effect of water-binder ratio (w/b), silica fume and age on autogenous, carbonation, drying and total shrinkage of high-performance concrete (HPC) is outlined. Eight types of HPC were studied. Carbonation, internal relative humidity (RH) and strength were studied on specimens from the same batch of HPC that was used in the studies of shrinkage. The results indicate fairly good correlation between carbonation, shrinkage, w/b and RH. The type and amount of silica fume affected shrinkage.     

国外模拟IC的发展现状分析

本文主要根据电子整机的发展要求,从集成化、高性能和高可靠等三方面分析国外模似IC的发展,进而说明模拟IC总的发展趋势及其表现。最后指出,模拟IC正面临一个新的变革时期。     

�ݼ����߷����������Ϸ�

通过对J.J.Arps方程的推导,提出了油气藏产量递减曲线分析的最佳拟合法。用该法可直接求出递减指数N、初始递减率D1及油气递减前的稳定产量Qi,避免了使用试差法的大量运算过程,大大提高了油气藏工程中指标预测的精度。     

转子叶片在非均匀来流条件下的流体激振特性

该文通过研究得出非均匀来流对转子叶片流体激振的三个重要特征 :非均匀来流相对于转子叶片的非定常流中主频分量是产生叶片动应力的决定因素 ;非均匀来流的非均匀度 (相当于非定常流的波幅 )大小和叶片流体激振的动应力大小成正比 ;转子叶片流体的定常压力水平与叶片动应力的水平密切相关。图 4表 2