压水堆控制棒导向筒结构改进对落棒的影响

为改善横向水力载荷对控制棒导向筒的作用，对靠近上腔室出口管嘴附近的控制棒导向筒（对称的４组：０２－２６，０３－２５，１１－２９，１２－２８）加设了保护套．在秦山核电站压水堆上腔室１４的可视化模拟体中，以水为介质进行了实验研究，把结果与未加设保护套的实验结果作了分析比较，得到了对靠近上腔室出口管嘴附近的控制棒导向筒加设保护套有助于改善流场对控制棒导向筒的水力载荷作用和确保控制棒能按指令在导向筒中自由升降和快速下插的结论．     

用微波实验测定光速

实验中，利用微波源发出各种频率的电磁波，在波导中借助测量线测定相应的电磁波的波长λg，计算光速c，验证麦克斯韦电磁场理论。     

Optimisation of the connection between TA-MS systems together with improved data interpretation for TA-MS applications

TA-MS provides chemical and thermal response information. In order for this information to be meaningful sampling must be performed with minimum dead volume and without cold spots. Dead volume leads to response lag and peak broadening. Cold spots result in sample condensation, leading to inaccurate data and potentially inlet blockage. This paper describes a hot zone inlet system and 'in-situ' probe both of which provide fast response, zero dead volume sampling directly to the MS. The paper also discusses data interpretation methodologies and introduces 'soft ionisation' as a means of providing simplified analysis of complex mixtures. This revised version was published online in July 2006 with corrections to the Cover Date.     

水力旋流分离器在油水分离领域的研究进展

水力旋流器利用密度差实现两相分离,具有结构简单、分离效率高等优点,因此在原油预脱水处理等油水分离领域得到广泛应用。 鉴于此,通过分析和收集水力旋流器相关文献,对油水分离领域水力旋流分离器的研究现状进行了阐述和总结,包括水力旋流分离器的发展历程、基本结构、内部流场和工作原理等相关方面;同时,对油水分离领域不同类型的水力旋流分离器进行了对比分析,发现在水力旋流器的结构参数优化以及内部液体流动规律等方面,单一结构的参数优化或单一、静态的系统分析不能系统全面地反映实际复杂工况。 因此,将计算机仿真模拟和相关先进检测技术相结合,用于旋流器的参数优化、内部液体流动规律分析以及构建预测模型等方面,对于旋流器的结构设计优化、分离效率提升等方面意义重大;另外,目前的研究多着重于旋流器的结构和流体特性等方面,对于旋流器内部的磨损、疲劳损伤等方面的研究较为缺乏;最后,对水力旋流分离器在油水分离方面研究的不足和发展方向进行了分析和展望。     

Shock waves and turbulence in a hypersonic inlet

A numerical investigation for an axisymmetric hypersonic turbulent inlet flow field of a perfect gas is presented for a three-shock configuration consisting of a biconic and a cowl. An upwind parabolized Navier-Stokes solver based on Roe's scheme is used to compute an oncoming flow Mach numberM =8, temperatureT =216 K, and pressureP =5.5293×10³ N/m². In order to assess the flow quantities, the interaction between shock and turbulence, and the inlet efficiency, three different flow calculations — laminar, turbulent with incompressible and compressible two-equationk- turbulence models — have been performed in this work.Computational results show that turbulence is markedly enhanced across an oblique shock with step-like increases in turbulence kinetic energy and dissipation rate. This enhancement is at the expense of the mean kinetic energy of the flow. Therefore, the velocity behind the shock is smaller in turbulent flow and hence the shock becomes stronger. The entropy increase through a shock is caused not only by the amplification of random molecular motion, but also by the enhancement of the chaotic turbulent flow motion. However, only the compressiblek- turbulence model can properly predict a decrease in turbulence length scale across a shock. Our numerical simulation reveals that the incompressiblek- turbulence model exaggerates the interaction between shock and turbulence with turbulence kinetic energy and dissipation rate remaining high and almost undissipated far beyond the shock region. It is shown that proper modeling of turbulence is essential for a realistic prediction of hypersonic inlet flowfield. The performed study shows that the viscous effect is not restricted in the boundary layer but extends into the main flow behind a shock wave. The loss of the available energy in the inlet performance therefore needs to be determined from the shock-turbulence interaction. The present study predicts that the inlet efficiency becomes relatively lower when turbulence is taken into account.     

Length of the flooded zone in the column inlet and evaluation of different retention gaps for capillary gas chromatography

In on-column or in splitless injection with recondensation of the solvent, the length of the flooded zone in the column inlet depends primarily on the wettability of the internal wall of the inlet. For columns with a coated inlet this explains why peak distortion due to band broadening in space by a certain sample volume is pronounced in one case and hardly observable in another. Glass or fused silica capillaries silylated with diphenyltetramethyldisilazane were found to give optimal retention gaps. They combine thorough and thermostable deactivation with good wettability and low retention power. On the other hand it is very easy to deactivate fused silica capillaries with Carbowax. The resulting retention gaps are suitable for a wide range of applications and are particularly attractive for the analysis of dirty samples which require frequent replacement of the inlet.     

Practical capillary gas chromatography—a systematic approach

Capillary gc is now rapidly expanding. Naturally, initiation is most often attempted on the basis of the experience acquired with packed columns. However, such an extrapolation is successful only if a number of essential peculiarities of capillary gc are considered. Based on practical examples this paper discusses six essential details: 1) design and maintenance of the gas flow paths, 2) the greatly increased importance of sampling technique, which should not be confined just to stream splitting, 3) the problems in quantitative analysis arising from small sample size, 4) specific sources of trouble related to small amounts of liquid phase, 5) specific arguments for the choice of the carrier gas, clearly pointing to hydrogen as the ideal carrier and, 6) the different way to approach column production. Figures for all selected examples are given.     

基于PLC的高炉鼓风机控制系统的设计与实现

简要阐述了用常规仪表控制高炉鼓风机存在的问题，并针对高炉风机的工艺着重介绍PLC控制系统的硬件配置及软件功能，该系统能够实现了高炉鼓风机的自动控制。     

“学校课程”的建构

澄清作为三级课程体制结构中的"学校课程"概念,分析"学校课程"的缘由和要义,参照泰勒提出的课程与指导原理,结合中国课程实际情况,初步梳理学校自主设计课程的思路、程序和相应的教师专业化、课程管理的要求。     

崖门口外围垦与潮汐水道稳定性分析及数值计算

提出了河口围垦工程二维流场计算与上游河网一维计算联网的整体数学模型，解决了二维计算中围垦工程对口门外界水流的反馈影响，结合崖门出海航道围垦工程方案的数值计算，将Ｐ－Ａ关系用于口外围垦与通航水道的稳定性分析中，对围垦工程可能对出海航道产生的作用和影响进行了具体的计算分析预测。