以太网远程供水测控终端系统的设计

介绍了一种新型铁路供水远程测控系统的设计方案，详细地说明了远程测控终端系统的硬件电路和软件设计。系统由监控中心和分布在供水现场的单片机系统组成。两者之间通过RS485／以太网转换模块经以太网进行通信。其实际应用结果表明：该系统可靠性高，运行稳定，有很强的推广价值。     

Irrigation scheduling performance by evapotranspiration-based controllers

Evapotranspiration-based irrigation controllers, also known as ET controllers, use ET information or estimation to schedule irrigation. Previous research has shown that ET controllers could reduce irrigation as much as 42% when compared to a time-based irrigation schedule. The objective of this study was to determine the capability of three brands of ET-based irrigation controllers to schedule irrigation compared to a theoretically derived soil water balance model based on the Irrigation Association Smart Water Application Technologies (SWAT) protocol to determine the effectiveness of irrigation scheduling. Five treatments were established, T1-T5, replicated four times for a total of twenty field plots in a completely randomized block design. The irrigation treatments were as follows: T1, Weathermatic SL1600 with SLW15 weather monitor; T2, Toro Intelli-sense; T3, ETwater Smart Controller 100; T4, a time-based treatment determined by local recommendations; and T5, a reduced time-based treatment 60% of T4. All treatments utilized rain sensors set at a 6 mm threshold. A daily soil water balance model was used to calculate the theoretical irrigation requirements for comparison with actual irrigation water applied. Calculated in 30-day running totals, irrigation adequacy and scheduling efficiency were used to quantify under- and over-irrigation, respectively. The study period, 25 May 2006 through 27 November 2007, was drier than the historical average with a total of 1326 mm of rainfall compared to 1979 mm for the same historical period. It was found that all treatments applied less irrigation than required for all seasons. Additionally, the ET controllers applied only half of the irrigation calculated for the theoretical requirement for each irrigation event, on average. Irrigation adequacy decreased when the ET controllers were allowed to irrigate any day of the week. All treatments had decreased scheduling efficiency averages in the rainy season with the largest decrease of 29 percentile points with a timer and rain sensor (T4) and an average decrease of 20 percentile points for the ET controllers, indicating that site specific rainfall has a significant effect on scheduling efficiency results. Rainfall did not drastically impact the average irrigation adequacy results. For this study, there were two controller program settings that impacted the results. The first setting was the crop coefficients where specific values were chosen for the location of the study when calculating the theoretical requirement whereas the controllers used default values. The second setting was the soil type that defines the soil water holding capacity of the soil. The ET controllers were able to regularly adjust to real-time weather, unlike the conventional irrigation timers. However, the incorporation of site specific rainfall measurements is extremely important to their success at managing landscape water needs and at a minimum a rain sensor should be used.     

基于Wi—Fi的自动灌溉控制器设计与实现

针对传统的灌溉控制器布线多、施工难,且采用RS485与计算机通信时距离受限等问题,设计和实现了一个基于wi—Fi的自动灌溉控制器,能在远程计算机上以Web网页的方式实时控制灌溉、显示监测信息。该控制器可同时测量8路模拟量、3路数字量,并可以控制7路交流电磁阀。该灌溉控制器具有友好的监测操作界面,并且实现了广泛的信息共享。因此,在农业领域具有广阔的应用前景。     

基于LonWorks开放控制网络的设计

介绍了LonWorks开放式控制网络、开放控制网络的设计原理和在智能化建筑中LonWorks控制网络与计算机信息通讯网络的TCP／IP链接，并提出了有关正确设计LonWorks网络的原则和方法，以及如何有效利用该技术来建立开放控制网络。     

安全协议中的潜在攻击

阐述了网络安全协议中一些常见的攻击方式,并论述了这些攻击产生的原因和避免此类攻击的方法.     

计算机数据通信规约测试及故障分析系统

为确保电网调度自动化系统(EMS／DMS)远动信息准确可靠，本文结合电网调度自动化系统生产运行维护中的实际应用情况，叙述了利用实时数据通信规约测试及故障分析系统准确诊断并快速处理解决远动信息的故障与异常问题及生产应用等进行了阐述。     

船舶修造企业油漆堆放车间易燃易爆控制报警系统的研发

为解决沿海修造船厂的油漆堆放车间,在夏季高温下容易引起有毒与易燃气体的挥发泄漏而引起着火和工作人员中毒的威胁,设计了一种基于现场数据采集模块与PC设备以及移动无线设备的监控报警设备。介绍基于RS485总线MODBUS-RTU协议的数据采集单元的设计方法,单片机采集温度与有毒气体的实现方法,以及基于移动设备终端安卓系统下的应用软件的实现方法。     

Linux下基于SSL和netfilter安全系统的设计

本文简要介绍了应用层级的安全协议SSL和Linux中netfilter框架结构及其过滤数据包的机制.最后通过SSL和netfilter相互结合,提出了一种对计算机网络系统本身及其传输的信息都具有安全防护的设计.     

小麦基因组SRAP扩增体系的初步研究

对影响SRAP扩增结果的各种因素包括DNA、引物、dNTPMixture、TaqDNA聚合酶的浓度及变性、复性、延伸的时间及温度进行了摸索。获得了能够稳定扩增小麦基因组的体系:20μL体系中DNA25ng,dNTP188mmol/L,TaqDNA聚合酶0 75U,引物25ng。扩增程序为:94℃1min,37℃1min,72℃10sec,5个循环;94℃1min,50℃1min,72℃10sec,35个循环;72℃1min。     

农村综合信息服务平台云存储技术研究与应用

云存储技术通过集群应用、虚拟化、分布式文件系统等将网络中大量不同类型的存储设备集合起来协同工作,以此缓解老式数据中心的存储压力。目前许多涉农信息平台的文件管理与共享浪费了极大的空间,越来越多涉农企业的发展需要一个基于云存储技术的农村综合信息服务平台。以云存储为设计基础,一方面通过研究重复数据删除技术,提出了一种在客户端利用Hash的MD5算法进行文件级别的重复数据删除操作后再将数据存入云服务器中的方法,以此为涉农信息平台提供企业内部统一的文件共享;另一方面利用实时性更强,占用网络带宽更少,以及通信效率更高的Web通信协议,完整地采用基于HTML5 Web Socket协议的Web通信来实现涉农企业间的网络商务洽谈。