盘锦地区电力负荷的季节性分析

本文从盘锦地区１９８７－１９９３年电力负荷的原始资料入手，运用移动平均并加以改良的方法，从具有季节性变化的电力负荷系列中，分离出季节性分量，提示了电力负荷发展变化的规律。文中分析了盘锦地区七年间电力负荷发展的自身特点，指出其循环变化的转折点，给出了未来近期负荷变化的趋势，为电力行业制定规划和组织生产提供了依据，对供电企业合理安排生产计划、适应市场经济带来启示。     

Pullout tests of epoxy-coated reinforcement in concrete

The bond strength and slip of epoxy-coated reinforcing bars in concrete have been evaluated by carrying out single pullout and double pullout tests. In extended single pullout tests, slip measurements were made while tensile force was applied to reinforcing bars embedded in concrete. In double pullout tests, 20 cycles of load were applied at levels of steel stress between zero and 0·5 times characteristic steel strength. Strains were measured by electrical resistance strain gauges glued inside the bars. Both epoxy-coated and uncoated bars were used in the investigation, to obtain comparative results. The strain gradient along the bar was found to be less for the coated reinforcement. In general, the epoxy coating was found to increase slip in bond and thereby reduce the bond performance of coated bars.     

上海市用电负荷管理系统主站异地冗灾备份方案研究

对上海市用电负荷管理系统主站灾备系统的建设进行可行性研究,根据系统现有结构,结合主流技术提出建议性的方案.重点对各种设备技术进行分析,包括涉及计算机、网络、软件等各方面的设备技术,提出建设原则及实施建议.     

垫层载荷试验应注意的几个问题

介绍了垫层上载荷试验的类型，通过工程实例对不同类型垫层上的载荷试验应注意的问题进行了分析和探讨，这对通过载荷试验确定双层地基承载力具有一定的实际意义，可供同类工程参考借鉴。     

Performance analysis of IEEE 802.11 ad hoc networks in the presence of exposed terminals

The paper evaluates the performance effects of exposed terminals in IEEE 802.11 ad hoc networks in finite load conditions. It derives analytical models for the estimation of channel utilization and media access delay for IEEE 802.11 ad hoc networks in finite load conditions with and without exposed terminals. The simulation results show that the analytical estimated channel utilization and media access delay metrics are fairly accurate.     

变压器有载合闸过程中故障分闸后铁心剩磁分析

通过有载合闸变压器模型,分析了变压器有载合闸过程中由于副边突然短路导致主保护动作时电流和磁通的暂态过程,并对变压器铁心内的剩磁作了定性的分析。     

蜗杆副的跑合工艺

叙述了蜗杆副跑合的目的、作用以及跑合过程的特点和跑合中应重视的几个问题。     

加固改造中的结构承重体系转换

从加固改造工程的实践出发 ,探讨了混合结构向框架结构体系转换的方法和构造措施 ,为实际工程提供了新的技术思路     

利用Excel表格进行供暖系统计算

利用Excel表格进行供暖工程设计计算，可以减少工作量，提高工作效率。介绍了房间热负荷和供暖管道水力计算方法。     

Bedload Transport in Alluvial Channels

Hydraulic, sediment, land-use, and rock-erosivity data of 22 alluvial streams were used to evaluate conditions of bedload transport and the performance of selected bedload-transport equations. Transport categories of transport-limited (TL), partially transport-limited (PTL), and supply-limited (SL) were identified by a semiquantitative approach that considers hydraulic constraints on sediment movement and the processes that control sediment availability at the basin scale. Equations by Parker et al. in 1982, Schoklitsch in 1962, and Meyer-Peter and Muller in 1948 adequately predicted sediment transport in channels with TL condition, whereas the equations of Bagnold in 1980, and Schoklitsch, in 1962, performed well for PTL and SL conditions. Overall, the equation of Schoklitsch predicted well the measured bedload data for eight of 22 streams, and the Bagnold equation predicted the measured data in seven streams.