基于LonWorks现场总线的交通信号控制系统

利用LonWorks现场总线技术，设计开发了一种基于现场总线的交通信号控制系统，将信号控制器、LED信号灯、倒计时器及检测器等作为LON节点组成一个完整的网络系统，能够有效地完成灯色控制、LED灯故障检测、绿冲突检测、倒计时驱动及交通量检测等任务。现场应用结果表明：LonWorks现场总线技术的应用可大大提高交通信号控制系统的稳定性和可靠性。     

高校区域供热锅炉房节能改造

针对目前高校区域集中供热锅炉房实际运行中一个普遍存在的,即直接连接供暖系统,小温差状态运行,加大能源消耗问题。如何解决区域间相互设计温差的差异和矛盾。根据运行实践和计算结果,提出了用于区域供热的锅炉与用户在运行参数上相协调,并获得经济运行的设计方式。对已运行系统的改造或新建区域集中供热系统,具有施工简单、节省基建投资,同时具有运行耗电量小,运行费用小的优点。     

现场总线LonWorks与BACnet通讯网关的设计

本文主要介绍现场总线LonWorks与BACnet其通讯协议的特点，阐述现场总线LonWorks与BACnet通讯网关的设计的要点。     

Response of seasonal vegetation development to climatic variations in eastern central Asia

Meteorological records show that central Asia has experienced one of the strongest warming signals in the world over the last 30 years. The objective of this study was to examine the seasonal vegetation response to the recent climatic variation on the Mongolian steppes, the third largest grassland in the world. The onset date of green-up for central Asia was estimated using time-series analysis of advanced very high resolution radiometer (AVHRR) normalized difference vegetation index (NDVI) biweekly composite data collected between January 1982 and December 1991. Monthly precipitation and mean temperature data (1982-1990) were acquired from 19 meteorological stations throughout the grasslands of the eastern Mongolian steppes in China. Our results showed that while the taiga forest north of the Mongolian steppes (>50°N) experienced an earlier onset of green-up during the study period, a later onset was observed at the eastern and northern edges of the Gobi Desert (40°N-50°N). Responses of different vegetation types to climatic variability appeared to vary with vegetation characteristics and spring soil moisture availability of specific sites. Plant stress caused by drought was the most significant contributor to later vegetation green-up as observed from satellite imagery over the desert steppe. Areas with greater seasonal soil moisture greened up earlier in the growing season. Our results suggested that water budget limitations determine the pattern of vegetation responses to atmospheric warming.     

基于LonWorks技术的变电站监控系统

介绍了现场总线控制系统的特点,并基于LonWorks技术构成了一个变电站监控系统.给出了此监控系统的硬件和软件设计,采用893-LM系列智能监控模块做为现场智能节点,用国产组态软件组态王开发了监控软件.概述了OPC技术规范并通过893-LM OPC服务器实现了组态王与智能节点之间的通信.最后总结了基于LonWorks技术的变电站监控系统的优点.     

等圆心角法球面数控加工插补方法的研究

针对目前常用球面数控加工方法效率较低、加工精度不一的缺点，提出了一种改进方法即等角度分割插补法确定加工层切削深度。本文阐述了该方法的思路，详细推导了所需公式，经过仿真软件的验证，证明该方法具有较高的加工效率，且加工精度较高，能用于球面的数控粗、精加工，具有较好的实用价值。     

求激光漫反射中心新算法

分析激光在作为测量光源的特点，提出使用三角形法进行快速尺寸测量时求激光漫 反射中心的新算法。     

LonWorks技术在智能建筑系统集成中的应用

提出了当前我国智能建筑系统集成实施中存在的问题,介绍了LonWorks技术特点、控制网络结构及其在智能建筑中的应用优势,着重讨论了LonWorks技术在智能建筑系统集成中的应用,并给出了应用实例.最后分析了LonWorks技术在智能建筑中应用时应注意的问题.     

基于LonWorks总线的智能楼宇用电参数高精度采集节点设计

利用神经元芯片CY7C53120和单片机AT89S52设计了基于主机的智能楼宇用电参数采集Neuron节点,构成了LonWorks网络系统,采用AD637实现了电流与电压的真有效值高精度转换,给出了其硬件及软件模块。测试结果表明,系统实现了对楼宇中各用电参数的在线测量,误差控制在±1%以内。     

用分布式防火墙构建网络屏障

本文介绍了分布式防火墙的结构,工作原理和实现策略.分析了分布式防火墙对各类问题的解决机理.最后作者指出了分布式防火墙存在的一些问题.