油浸式电流互感器缺陷分析与状态诊断

分析了油浸式电流互感器的主要缺陷,指出该类设备适宜开展状态诊断,并提出了实施状态诊断的具体项目。     

引红济石调水工程地质特点及应对措施

陕西引红济石调水工程地质条件非常复杂,施工过程中多次出现断层破碎带塌方、突发性涌水、涌泥等地质难题。结合施工采用的方法、措施分析、研究地质特性和规律,总结施工过程中发生地质灾害的经验教训,认为可以通过加强施工过程控制来有效降低隧洞施工地质风险和灾害发生的可能,从而达到加快工程建设进度,节约工程投资的目的。     

EPON技术在智能变电站状态监测和视频监控系统中的应用

以太无源光网络（ethernet passive optical network,EPON）是一种新型的光纤接入网络技术,它具有低成本、高带宽、电磁干扰小、扩展性强、兼容性强等特点。在智能变电站中状态监测和视频监控系统数据量较大、实时性要求较低。采用EPON技术构建站内状态监测与视频监控系统,能够有效地解决出口带宽分配问题,且无需使用交换机,大大节省网络建设投资与全寿命周期维护成本,是智能变电站状态监测和视频监控系统有效的新型组网方案。分析了智能变电站状态监测和视频监控系统应用EPON技术的可行性,并提出220kV智能变电站EPON网络构建方案,为智能变电站状态监测和视频监控系统的数据传输提供了一种新型方案。     

用正交试验设计改善ITO＆CF基板的清洗效果

分析了ITO及CF玻璃基板表面污染的主要类型为有机物污渍和灰尘颗粒,污染主要来源于产品制作、包装、转运过程。利用正交试验设计法找出影响清洗效果的主要因素是清洗液浓度和超声清洗条件,并确定最优因素水平组合。优化后工艺条件应用于生产实践,测得接触角小于5°,灰尘粒子数平均少于6个;使线间隙≥8.0μm的CSTN-LCD产品生产良品率提高2.85%。     

Unified fixed‐point analysis of IEEE 802.11 WLAN under saturated and unsaturated conditions

Most of analysis so far for IEEE 802.11 wireless local area networks (WLANs) focuses on saturated condition. However, it is of practical value to take into account the unsaturation case. In this paper, we modified Bianchi's Markov back‐off model to make it applicable to unsaturated condition and the analytic results are provided by employing the renewal‐reward theorem. Under our proposed model, we study the fixed‐point solution of the system and provide a condition to guarantee both the uniqueness and balance of the fixed point. From the fixed point, we find that under unsaturated condition, network parameters should be adjusted according to the traffic load. Then, we study the system throughput. In the case where there are a large number of nodes, we provide closed‐form formulas for the collision probability, the aggregate attempt rate, and the throughput. We find that in such a scenario, the system yields similar performance as that under saturated situation. Moreover, we compare all the results with those under saturated condition and find the latter is a special case of our results. Hence, all of our analysis based on unsaturated condition well covers saturated condition. Our analytical results are validated through ns2 simulations. Copyright © 2010 John Wiley & Sons, Ltd.     

The Effects of Nonuniform Thermal Boundary Condition on Thermal Stress Calculation of Water-Cooled W/Cu Divertors

The thermal boundary condition has very important effects on the accuracy of thermal stress calculation of a water-cooled W/Cu divertor. In this paper, phase-change heat transfer was simulated based on the Euler homogeneous phase model, and local differences of liquid physical properties were considered under one-sided high heating conditions. The steady-state temperature field and thermal stress field under nonuniform thermal boundary conditions were obtained through numerical calculation. By comparison with the case of traditional uniform thermal boundary conditions, the results show that the distribution of thermal stress under nonuniform thermal boundary conditions exhibits tbe same trend as that under uniform thermal boundary conditions, but is larger in value. The maximum difference of maximum von Mises stress is up to 42% under the highest heating conditions. These results provide a valuable reference for the thermal stress caleulat.ion of water-cooled W/Cu divertors.     

槽车内介质的密闭装卸

通过规范改进槽车内介质的进出口,达到密闭装卸的目的。     

一类分式规划的对偶定理

本文在预不变凸性条件下,利用有效解概念,结出一类分式线性规划的一些对偶定理,这些定理为求解这类分式线性规划提供了简捷方法。     

澳大利亚变电站在线状态监视系统

电力市场的竞争促使电力公司降低电网检修成本，减少停电的次数，尤其是减少因设备缺陷而造成的被迫停电频率和停电时间。为实现这一目标，有效的状态监视将是一个强有力的工具。文中介绍澳大利亚TransGrid公司采用在线状态监测技术的设计理念、应用中的问题及解决措施，最后示出应用效果。