SIMILARITY LAW OF FLUCTUATING PRESSURE WITHIN HYDRAULIC JUMP AREA

Through a series of model tests of five scales for 2-D free hydraulic jump, the da-ta of fluctuating pressure acting on the floor level within the hydraulic jump were obtained. Dur-ing the experiments, Froude number varied from 2.94 to 8.61, and Reynolds number rangedfrom 2×10~4 to 6×10~5. Experiment results indicate that the amplitude scale of fluctuating pres-sure is the length scale of model, i. e. P'=L, which agrees with gravity similarity law: Thefrequency scale of the fluctuating pressure is a unity i. e., f=1, which does not satisfy thegravity similarity law.     

面流消能近底紊动流速特性的研究(面流消能试验研究之一)

本文主要论述了面流消能五种典型流态近底紊动流速特性,总结出了近底时均流速和紊动强度沿程变化规律,提出了近底紊动流速可能出现的最大瞬时值及相应位置的计算公式。面流消能工程的下游防冲设计中考虑的主要水力参数之一是,消能段近底流速紊动可能出现的最大瞬时值及其相应的部位,但目前国内外研究成果较少。笔者通过水工模型试验重点研究了面流消能各典型流态近底流速及其紊动纵向分量沿程的变化规律,并提出了计算公式,为优化面流设计提供科学依据。     

液压胀形轧辊油槽深度的确定

对液压胀形轧辊（即国外的ＶＣ轧辊）辊套热装后的弹性变形进行了有限元分析，给出了确定油槽最小深度的计算公式。本文的有限元计算结果与实验结果吻合，某些结论可为液压胀形轧辊的结构设计提供理论依据。     

攀钢“501”滑动水口液压驱动系统的研制

介绍了为攀钢“５０１”滑动水口研制的专用液压驱动系统，对该系统的工作原理，性能特点，主要元件（设备）的选择原则等作了较为详细的说明介绍。     

深化内部改革 强化项目管理 走与国际接轨的道路

北京石化工程公司1994年完成设计投资额60亿元以上,取得了有史以来的最好成绩。其成绩的取得是和深化企业改革、健全矩阵式管理体制、狠抓项目管理、走与国际接轨的道路、加强精神文明建设等分不开的。     

DSP技术在液压混合动力汽车能源控制方面的应用

文章分析了液压混合动力汽车的发展趋势,简述数字信号处理器(DSP)作为控制器的优势和DSP作为控制器对并联式混合动力液压车的能源控制的工作原理,给出了能源控制系统DSP信号流程图和主程序流程图。测试结果表明,DSP能源控制系统能够比较精确的对液压混合动力车的能量消耗与分配进行控制,具有很好的应用前景。     

锰铁高炉的大修及改进

介绍了广西康密劳1^#锰铁高炉大修的方案选择和装备技术及今后技术进步方向。为我国其它锰铁高炉技术改造提供了一种参照方法。     

"The dismantling of our health system: Strategies for the survival of psychological practice": A reply to Cummings.

Comments on the original article, The dismantling of our health system: Strategies for the survival of psychological practice by Nicholas A. Cummings (see record 1986-22651-001). In response to this article, the current author says "no, no, no!" He believes that "survival with this degree of compromise amounts to doing anything for a buck." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamic analysis of the NPP pressure sensor system

The aim of the work was to develop on-line methods of control and diagnostics of pressure sensors at a NPP. The analysis was carried out along two lines:

1. i) The detection system including the sensor itself was modeled theoretically to obtain and study its transfer function, and to establish correspondence between the spectral characteristics of the pressure signal.

2. ii) The numerical processing of the signal using the AR technique to reconstruct the transfer function and evaluate the system's response, to a step impulse, as well as the spectral analysis. The hydraulic model presented indicate that the spectral lines observed at 10 Hz are due to longitu-dinal oscillations of water in the system branches, while the response time of the detection system is effectively the time of signal retardation in the porous ceramic diaphragms of the δ-cell of the sensor itself.