AC800M系列控制器在水电站计算机监控系统中的应用

介绍了AC800M系列控制器的编程与调试环境、用于过程控制的对象连接与嵌入(OPC)技术、系统可靠性设计、系统通信网络等方面的特点。结合嘉陵江沙溪航电工程中水电站计算机监控系统的实施案例,主要阐述了AC800M系列控制器在国内水电站计算机监控系统中的具体应用。     

Supervised rank aggregation based on query similarity for document retrieval

This paper is concerned with supervised rank aggregation, which aims to improve the ranking performance by combining the outputs from multiple rankers. However, there are two main shortcomings in previous rank aggregation approaches. First, the learned weights for base rankers do not distinguish the differences among queries. This is suboptimal since queries vary significantly in terms of ranking. Besides, most current aggregation functions do not directly optimize the evaluation measures in ranking. In this paper, the differences among queries are taken into consideration, and a supervised rank aggregation function is proposed. This aggregation function is directly optimizing the evaluation measure NDCG, referred to as RankAgg.NDCG, We prove that RankAgg.NDCG can achieve better NDCG performance than the linear combination of the base rankers. Experimental results performed on benchmark datasets show our approach outperforms a number of baseline approaches.     

白云石烧结的试验研究

通过对不同产地高纯白云石的煅烧试验，揭示了白云石烧结的机理。由于白云石在煅烧过程中碳酸盐分解后形成多孔疏松结构，使其难以烧结致密。轻烧白云石经加水消化或机械粉碎和高压处理可破坏其团聚结构，促进烧结。添加少量Ｆｅ２Ｏ３或ＺｒＯ２等氧化物可降低白云石的烧结温度。     

团聚粉料的流动性和成型性能

以3种具有不同团聚特征的氧化铝粉料为对象,用粉料剪切仪测定了粉料的流动性。以单向加压成型测定了成型过程中压力与成型体密度变化。用压汞测孔仪及扫描电镜研究了团聚体的外形和气孔结构。通过以上各种观察,讨论了3种粉料的团聚体恃征及团聚特征对粉料流动性和成型性能的关系。     

基于公交网络的车载群智感知方法及其优化

公交车具有固定的行驶路线和发车周期、统一的车载设备标准、低隐私泄露风险等特性。根据公交车的特性,设计了一个基于公交网络的车载群智感知系统,系统中的数据中心通过公交网络中的公交车来采集城市数据,以满足数据用户的需求;随后研究系统中的任务分配问题和数据交易问题。基于贪婪算法设计优化任务分配策略以最小化系统的数据采集能耗成本,和根据博弈论设计最优数据交易策略以最大化系统的经济效益。最后通过仿真,验证了提出的策略的有效性和优越性。     

基于COM组件技术的企业进销存系统设计方法研究

随着企业竞争的日趋激烈,如何有效管理企业进销存链,提高企业竞争实力,成为大家关注的问题。该文以COM组件技术为背景,描述如何采用组件模型快速开发出灵活性高、易维护、安全性高、易扩展的企业进销存系统,并因而解决如何加速从软件设计到最终应用系统的问题。     

Numerical simulation of two-dimensional spouted bed with draft plates by discrete element method

A discrete element method (DEM)-computational fluid dynamics (CFD) two-way coupling method was employed to simulate the hydrodynamics in a two-dimensional spouted bed with draft plates. The motion of particles was modeled by the DEM and the gas flow was modeled by the Navier-Stokes equation. The interactions between gas and particles were considered using a two-way coupling method. The motion of particles in the spouted bed with complex geometry was solved by combining DEM and boundary element method (BEM). The minimal spouted velocity was obtained by the BEM-DEM-CFD simulation and the variation of the flow pattern in the bed with different superficial gas velocity was studied. The relationship between the pressure drop of the spouted bed and the superficial gas velocity was achieved from the simulations. The radial profile of the averaged vertical velocities of particles and the profile of the averaged void fraction in the spout and the annulus were statistically analyzed. The flow characteristics of the gas-solid system in the two-dimensional spouted bed were clearly described by the simulation results.     

分布式光伏发电站在特高压换流站的应用

在分析了国内外光伏发电发展形势的基础上,提出在特高压换流站建设分布式光伏发电站的思路,并给出具体的技术实现方案。对该技术方案进行了可行性和经济性分析,结果表明能提高特高压换流站的经济效益和站用电源的可靠性,适于与换流站同步建设。     

A Discussion on Stability of Mg-Al-spinel Crown of Glass Melters

In order to understand the failure mechanism of magnesia-alumina spinel crown of glass melters,a discussion on the stability of Mg-Al-spinel crown of glass melters was given in this paper.The discussion focused on the weight balance in the crown arch made of spinel or silica bricks,the creep of spinel crown bricks at high temperatures,the thermal stress distribution in crown bricks as well as at brick joints,and the displacement behavior of crown arch during heat-up of glass melter.It is believed that the tangential stress in spinel crown is much higher than that in silica crown due to the large differenee in their densities,and that the thermal stresses in the crown brick result in opening of a part of the brickto-brick joints at the cold side of the crown,and increase of the tangential stress needed for balancing the weight of the crown.Both defect migration in lattice or along grain boundary and viscous flow in glass phase at grain boundary contribute to the creep of crown bricks at high temperatures.The creep of the matrix of spinel brick is more significant than that of coarse grains because impurities,such as silica and calcia,are concentrated in it.For keeping the crown stable during heat-up period it is important to adjust properly the horizontal positions of each skew brick as temperature increasing based on correctly evaluating the thermal expansion according to the thermal expansion coefficient of the crown brick.     

第四十三讲：符合WIA—PA标准的工业无线芯片关键技术研究

WIA（WirelessNetworksforIndustrialAutomation）是具有自主知识产权的工业自动化无线网络,它具有高可靠性、实时性、安全性等特点。本文对符合WIA—PA标准的工业无线芯片的关键技术进行研究,关注WIA—PA工业无线芯片系统架构、通信基带电路、WIA—PA协议引擎优化、安全加密、低功耗设计等方面。旨在提供符合WIA—PA标准的工业无线芯片的设计参考,为降低系统开发难度、保护相关知识产权、提高技术性能奠定坚实的基础。