高层建筑供水方式及其耗能分析

文章探讨了高层建筑的供水方式及其耗能分析,详述了两种高层建筑的主要供水方式,并比较了它们在耗能方面上的优缺点.     

Wind energy resource assessment for five locations in Saudi Arabia

The analysis of recently collected wind data at five sites in Saudi Arabia namely, Dhulum, Arar, Yanbu, Gassim and Dhahran is presented. The five sites represent different geographically and climatologically conditions. The data collected over a period spanned between 1995 and 2002 with different collection periods for each site. Daily, monthly and frequency profiles of the wind speed at the sites showed that Dhulum and Arar sites have higher wind energy potential with annual wind speed average of 5.7 and 5.4 m/s and speeds higher than 5 m/s for 60 and 47% of the time, respectively. The two sites are candidates for remote area wind energy applications. The costal site's, i.e. Yanbu and Dhahran wind speed data indicated that the two sites have lower annual wind speed averages and wind blows at speed higher than 5 m/s during afternoon hours. That makes the two sites candidates for grid connected wind systems for electrical load peak shaving. The data of Gassim site showed that the site has the lowest wind energy potential compared to the others. The annual energy produced by a Nordex N43 wind machine is estimated to be 1080, 990, 730, 454 and 833 MWh for Dhulum, Arar, Yanbu, Gassim and Dhahran, respectively. The analysis showed that the estimated annual energy produced by the machine based on 10 min averaged data is 2.5% higher than the estimated energy based on 30 min averaged data.     

一种考虑不同期合闸的行波合闸保护新方法

当线路末端故障时，行波在线路末端的反射情况比较复杂，反向电流行波的极性有可能与正向电流行波的极性相反，而此时测距结果又与线路无故障时相同。因此，会造成行波测距式与行波极性比较式合闸保护的不正确动作。根据行波的折、反射理论，分析出当线路无故障时正向电流行波仅在线路末端发生反射，且电流行波的反射系数为-1，而当线路存在故障时，正向电流行波将在故障点发生反射，无论故障是否在线路末端，电流行波的反射系数都不会是-1。根据这一特征，提出了一种新的行波合闸保护方法。从原理上保证了在各种情况下保护都可以正确动作，大量的电磁暂态仿真结果也证明了这一点。     

钻井平台电站无功功率动态补偿技术的应用

论述了海洋钻井平台的功率因数及改善功率因数的重要意义和必要性，对实时无功功率动态补偿装置作了介绍，并对实施功率补偿后取得的效果和经济测算作了分析，提出了提高功率因数，进行功率补偿的推广应用建议。     

200 万t链箅机-回转窑球团生产线快速达产实践

介绍了邯钢200万t链箅机-回转窑酸性氧化球团生产线的工艺特点和主要设备,以及建成投产后试生产的有关情况。通过周密的部署和安排,该生产线实现了40天快速达产的目标。     

建筑节能发展缓慢的原因及其对策

我国实施建筑节能已近10年，但仍然只停留在试点、示范的层面上，尚未扩大到整体．分析了造成建筑节能发展缓慢的原因，并提出了推行和普及建筑节能的对策．     

Comments on “Is the cause of size effect on structural strength fractal or energetic-statistical?” by Ba?ant & Yavari [Engng Fract Mech 2005;72:1-31]

Aim of this letter to the Editor is at replying to the criticisms raised by Ba?ant and Yavari [Ba?ant ZP, Yavari A. Is the cause of size effect on structural strength fractal or energetic - statistical? Engng Fract Mech 2005;72:1-31] against the fractal approach to the size-scale effects on the mechanical properties of materials and the concept of the Multi-Fractal Scaling Law presented by Carpinteri [Carpinteri A. Scaling laws and renormalization groups for strength and toughness of disordered materials. Int J Solids Struct 1994;31:291-302]. These criticisms will be analysed thoroughly, showing how they also contain some mistakes and misunderstandings. The presented elucidations should redirect the discussion to a more correct scientific debate.     

原油集输太阳能加热节能技术的应用

在油田的采油、集输等过程中,传统技术使用燃烧煤、油、天然气和电加热方法来实现原油加热,造成大量的能源消耗和严重的环境污染。原油集输太阳能加热计算机控制节能系统,为油田的采油、集输开辟了节能新途径。该系统不仅具有自动化、智能化的特点,而且节能效果显著,实际节气率超过40%。文章介绍了该系统的结构、工作原理、功能特点以及应用效果。     

唐山建龙900mm冷轧机组的工艺与设备

较系统地介绍了我国第1条国产化的中宽带钢冷连轧生产线，即唐山建龙钢铁控股有限公司900mm冷连轧生产线的工艺流程、主要设备组成及技术特点。重点介绍了900mm 4机架六辊轧机的技术参数、性能特点及自动控制系统。该生产线投产以来，取得了较好效果。     

光声耦合与光子Cooper对

文中研究了光声耦合所导致的光子Cooper对的形成机制，计算了光子Cooper对的能隙（0.01eV）和尺度（10^-5m)以及内禀角动量（奇数），并简要讨论了几十开低温下介质中光的超流效应的可能性。由于在低温下， 光子Cooper对不容易受到热运动的激发，因此有可能存在光的超流现象。