EDELCA电力公司梯级调度自动发电控制系统

真正意义上的梯级调度自动发电控制（AGC）在国内尚属空白,委内瑞拉EDELCA电力公司的梯级联合调度已有30多年的经验,其AGC选择ACE（区域偏差控制）为控制方式,考虑各种复杂因素,控制功能针对不同的机组特性和运行情况有很大的灵活性。梯级调度AGC具有其自身的功能特点、目标函数、控制状态、参数及模式。     

多坐标系下目标跟踪的联合滤波

针对雷达目标观测和处理在不同的坐标系下完成，本文提出了联合滤波算法来跟踪机动目标。该算法以卡尔曼滤波器为基础，直角坐标系下和极坐标系下的算法相联合，不仅克服了两种坐标系下滤波算法的不足，而且对机动目标有很好的跟踪效果。仿真实验结果表明了该算法的有效性。     

Asymptotic efficiency properties of least squares in an ultrastructural model

This paper considers the estimation of both the intercept term and the slope parameter in a linear ultrastructural model using direct regression and reverse regression methods. Without assuming the errors to be normally distributed, asymptotic expressions for the bias and the variance of the estimators are derived and analyzed. The effect of departure of the errors from normality is also studied.     

浅谈监理工程师如何抓好施工阶段的投资控制

在多年工程实践的基础上研究、分析了施工阶段投资控制的方法问题。     

铜绿山矿新主井箕斗装、卸载装置改造

针对新主井箕斗装、卸载装置存在的问题,提出了改造方案,介绍 了装、卸载装置液压系统的设计、原理及使用效果。     

电子商务对企业集团营销手段的影响

介绍了电子商务，以及目前电子商务的发展趋势及对社会的影响，特别阐述了蓬勃发展的电子商务对企业集团的经营环境与手段的影响。     

SO_4~(2-)(S_2O_8~(2-))/Fe_2O_3-SiO_2固体超强酸对乙酸/丁醇酯化反应的催化性能研究

研究了SO2 -4/Fe2 O3 SiO2 固体超强酸对乙酸 /丁醇酯化反应的催化作用 ,得到合适的工艺条件 :复合氧化物中n(Fe)∶n(Si) =1∶2 ,浸渍的H2 SO4浓度 1mol/L ,5 5 0℃预焙烧活化 3h ,催化剂用量 0 .8g ,酯化反应时间 4h ,乙酸的转化率达 96 .3%。在此条件下制得S2 O2 -8/Fe2 O3 SiO2 固体超强酸催化剂 ,并考察了其催化活性 ,实验结果显示该固体超强酸具有更高的催化活性 ,乙酸转化率高达 98.6 %。     

乙烯装置制冷系统的用能分析

通过对制冷压缩机功耗的模拟和对实际运行数据的分析,比较了乙烯装置中的复迭多级制冷系统和混合冷剂制冷系统的用能状况,分析了混合冷剂制冷的优点和不足。采用AspenPlus10.2软件模拟的结果表明,采用混合冷剂制冷技术的丙烯-混合冷剂复迭制冷系统比传统的丙烯-乙烯复迭制冷系统节省功耗4.3GJ/h,制冷压缩机损系数则从47.6%减小到43.3%,而系统效率由25.0%提高到26.6%。虽混合冷剂在换热过程中出现的气液两相流,会在一定程度上抵消其在热力学效率上的优势,但混合制冷技术用于乙烯装置仍可降低能耗、提高热力学效率。     

声光技术在光纤系统中的应用

本文简要介绍了在光纤通信、光纤传感和光纤信号处理枝术等各种光纤系统中可能开发应用的固体声光技术和光纤声光技术。     

Steady laminar flow in a 90 degree planar branch

The flow characteristics of a Newtonian fluid in a two-dimensional, planar, right angled Tee branch are studied over a range of inlet Reynolds number of 10–800 by solving the Navier-Stokes equations using a finite element discretization. The effects of the branch length and the grid size on the interior flow field are examined to assess the accuracy of the solutions. In one case the computed velocity field is compared with the Laser Doppler anemometry measurements available in the literature and excellent agreement has been obtained. The computed velocity field is believed to be accurate within about 5%. Results are presented for two types of experimentally realizable boundary conditions—viz. equal exit pressure at the outlet of each branch and specified flow split between the branches. For the case of equal exit pressures the fractional flow in the main duct increases with increasing Reynolds number and the flow characteristics in the side branch become akin to that in a cavity. For the case of specified flow split, the number, size and strength of the recirculation zones increase as more fluid is forced to go into the side branch. The length of the side branch appears to have very little influence on the interior flow field, particularly at higher Reynolds number. This observation is rationalized as being due to the parabolized approximation becoming more valid at higher Reynolds numbers. The critical Reynolds number at which the first recirculation zone appears in the side branch increases with increasing fractional flow in the side branch and with decreasing side branch width.