液压泵站远程控制系统的PLC设计

本文对液压泵站远程控制系统采用PLC控制和上位机组态控制。系统PLC选取西门子S7—300系列,采用Win CC进行上位机软件设计。解决了传统液压站系统控制精度不高的问题,提高了系统工作的安全性和可靠性。     

闸门与水位自动监控系统的设计与

提出了闸门与水位自动监控系统的组网方案。设计了基于PLC技术的闸门控制和水位监视单元。利用PLC中CPU模块所内置的以太网卡和搭建的无线宽带通信系统实现了PLC和控制中心上位机的通信，并使用力控组态软件编制了上位机的控制界面，实现了以PLC、组态软件和无线宽带通信系统构成的监控系统对张掖市盈科灌区的党寨水管站与沿沟水管站的干渠与支渠的闸门与水位的自动监控。实践证明本系统达到了操作方便，性能稳定，自动化程度较高的控制效果。     

PL在水质在线监测系统取水配水

介绍了PLC在水质在线监测系统取水配水控制中的应用，包括取水配水系统构思，控制系统硬件设计方案以及软件设计。采用上位机结合PLC的方案，通过RS-232C相互传输数据，实现了对取水配水的自动控制，提高了取水配水系统的可靠性。     

基于VB平台下的PLC与PC集散系统通讯软件设计

介绍了以IBM-PC机为上位机和以西门子S7-200型PLC为下位机的水产集散控制系统，重点介绍没计相关软件，实现上位机与PLC的串行通讯。系统操作方便、性能价格比高，为建立我国水产养殖群基地、实现高效规模生产提供了技术措施。     

基于IFIX上位机电排站监控系统的设计与实现

针对目前我国电排站综合自动化与监控系统落后的现状,利用IFIX3．5上位机为平台,并结合西门子S7300PLC,构建电排站监控系统的监控结构。通过对监控系统上位机与下位机的通讯设计,并对PLC通讯组态参数及IFIX上位机通讯参数进行配置,采用MODBUS TCP通讯协议和基于客户端——服务器的数据交换。完成上位机数据库和组态监控画面的设计。为电排站的网络管理和信息集中提供了可行的方案,实现了对整个电排站的实时监控,保证了监控系统较高的可靠性与数据通信的实时性。     

基于FINS协议的计算机与PLC的通信

FINS协议用于OMRON的CompoBus/D、Controller Link、Ethernet等网络以及网络之间的通信。简要介绍了FINS协议,研究了基于FINS协议实现上位机和PLC串行通信的方法。PLC选用OMRON CP1H型机,上位机采用Visual C++6.0编程,调用FINS指令向PLC发送命令,与PLC进行信息交换。给出串口初始化、发送数据和接收数据等各部分程序代码。该方法为进一步开发基于FINS协议的PLC监控系统提供了有价值的参考。     

基于PLC的水泵测试控制系统设计

研究了以PLC为控制核心的水泵测试控制系统.采用VB.NET程序设计语言,在Windows操作系统环境下实现上位计算机与下位PLC的串行通信,以实现上位机对下位机的信号采集和实时监控.该系统能够实现对水泵测试过程的实时控制和安全保护.现场测试结果表明,该系统性能稳定,能满足测试要求.     

PLC在轧机冷却水系统的应用

文章介绍了轧机冷却水系统的工艺,描述其控制系统的组成及上位监控系统,给出了控制系统的主要连锁,最后指出采用PLC和上位监控的思路对于水系统的控制、集中操作及设备维护都是有益的。     

基于PLC的步进梁液压监控系统设计

传统的液压控制系统运行精度不高,基于PLC和组态控制的步进梁液压控制技术可以提高液压系统运行可靠性与安全性。本文通过PLC比例放大器、传感器、智能仪表等硬件连接及采用WinCC和PLC实现数据通讯与上位机画面设计,实现了对步进梁液压系统的工作状态进行监控,也可现场对运行参数进行设定和修改。     

西门子S7-200PLC在制糖业CASS工艺污水处理系统中的应用

介绍了西门子S7-200PLC在云南镇康县南华勐堆糖业有限公司污水处理自动控制系统中的应用。阐述了基于CASS工艺的污水自动控制系统,该控制系统由上位机、下位机以及现场仪表和执行部件组成,上位机采用组态王软件实现人机交互,下位机采用西门子S7-200系列的PLC实现数据采集及系统控制。实践证明,该系统运行可靠、稳定,能够满足工业生产的需求。     

Overland water and salt flows in a set of rice paddies

Cultivation of paddy rice in semiarid areas of the world faces problems related to water scarcity. This paper aims at characterizing water use in a set of paddies located in the central Ebro basin of Spain using experimentation and computer simulation. A commercial field with six interconnected paddies, with a total area of 5.31 ha, was instrumented to measure discharge and water quality at the inflow and at the runoff outlet. The soil was classified as a Typic Calcixerept, and was characterized by a mild salinity (2.5 dS m⁻¹) and an infiltration rate of 5.8 mm day⁻¹. The evolution of flow depth at all paddies was recorded. Data from the 2002 rice-growing season was elaborated using a mass balance approach to estimate the infiltration rate and the evolution of discharge between paddies. Seasonal crop evapotranspiration, estimated with the surface renewal method, was 731 mm (5.1 mm day⁻¹), very similar to that of other summer cereals grown in the area, like corn. The irrigation input was 1874 mm, deep percolation was 830 mm and surface runoff was 372 mm. Irrigation efficiency was estimated as 41%. The quality of surface runoff water was slightly degraded due to evapoconcentration and to the contact with the soil. During the period 2001–2003, the electrical conductivity of surface runoff water was 54% higher than that of irrigation water. However, the runoff water was suitable for irrigation. A mechanistic mass balance model of inter-paddy water flow permitted to conclude that improvements in irrigation efficiency cannot be easily obtained in the experimental conditions. Since deep percolation losses more than double surface runoff losses, a reduction in irrigation discharge would not have much room for efficiency improvement. Simulations also showed that rice irrigation performance was not negatively affected by the fluctuating inflow hydrograph. These hydrographs are typical of turnouts located at the tail end of tertiary irrigation ditches. In fact, these are the sites where rice has been historically cultivated in the study area, since local soils are often saline-sodic and can only grow paddy rice taking advantage of the low salinity of the irrigation water. The low infiltration rate characteristic of these saline-sodic soils (an experimental value of 3.2 mm day⁻¹ was obtained) combined with a reduced irrigation discharge resulted in a simulated irrigation efficiency of 60%. Paddy rice irrigation efficiency can attain reasonable values in the local saline-sodic soils, where the infiltration rate is clearly smaller than the average daily rice evapotranspiration.     

瓦房店市水果生产标准化发展研究

瓦房店市是我国重要的水果生产基地,在国内水果生产领域占有重要地位。随着水果市场化的不断深入,如何满足和适应国内外市场需求成为瓦房店市水果生产的关键问题。从瓦房店市水果生产实际出发,阐述了实施水果生产标准化的必要性,提出了发展水果生产标准化的具体措施。     

金谷子耐旱TG118引种试种及推广应用

对引进的谷子新品种金谷子耐旱TG118进行品种比较试验和多点试种。结果表明：该品种抗旱、耐瘠、适应性强,稳产、高产、抗病抗风抗倒伏强,品质优良,粮草兼用,种植简单,省工易管;一般产量在6000kg/hm2以上,比当地主栽品种增产20%以上。最高产量达9450kg/hm2,适于在辽西北地区推广应用。     

对《种子法》存在问题的探讨

《种子法》是我国种植业第一部法律。自实施以来,为依法加强种子管理提供了有力的法律支撑,促进我国种子产业发生翻天覆地的变化。但随着依法管理工作的深入和种子产业的快速发展,《种子法》及配套规章的一些问题逐步显现出来。对《种子法》及配套规章存在的问题进行深入分析,对需要进一步补充的章节以及需要调整的内容进行深入探讨,以求更加完善和明确。     

Review of the Egyptian experience in implementing land drainage projects

About 30 years have passed since the Government of Egypt embarked on implementing a series of large scale drainage projects. At present, about 3.8 million acres have been provided with drainage systems on the basis of systematic pre-drainage investigations and designs. The target is to provide drains in approximately 6.4 million acres in the Nile Valley and Delta.The implementation of the subsurface drainage system is carried out by the public sector and private contractors under direct supervision of governmental regional departments. The implementation process depends on many factors related to the drainage material, machinery, manpower, site requirements, farmers and organizations involved. Problems and constraints are sometimes challenging, however, the annual rate of implementation has gradually increased to 170,000 acre/year.This paper discusses the different aspects involved in the implementation process of drainage systems. The development in materials, machinery and construction technologies will be reviewed. Institutional and management factors are going to be also considered.     

和谐社会理论建设的几点哲学思考

在新世纪,面对机遇和挑战,党的十六大把“社会更加和谐”作为全面建设更高水平的小康社会的一个重要目标。中国人素有社会和谐的理想;西方人自古也向往社会和谐;借鉴东西方两种和谐社会思想的经验、教训,构建社会主义和谐社会理论。     

A European irrigation map for spatially distributed agricultural modelling

We present a pan-European irrigation map based on regional European statistics, a European land use map and a global irrigation map. The map provides spatial information on the distribution of irrigated areas per crop type which allows determining irrigated areas at the level of spatial modelling units. The map is a requirement for a European scale assessment of the impacts of irrigated agriculture on water resources based on spatially distributed modelling of crop growth and water balance. The irrigation map was compiled in a two step procedure. First, irrigated areas were distributed to potentially irrigated crops at a regional level (European statistical regions NUTS3), combining Farm Structure Survey (FSS) data on irrigated area, crop-specific irrigated area for crops whenever available, and total crop area. Second, crop-specific irrigated area was distributed within each statistical region based on the crop distribution given in our land use map. A global map of irrigated areas with a 5′ resolution was used to further constrain the distribution within each NUTS3 based on the density of irrigated areas. The constrained distribution of irrigated areas as taken from statistics to a high resolution dataset enables us to estimate irrigated areas for various spatial entities, including administrative, natural and artificial units, providing a reasonable input scenario for large-scale distributed modelling applications. The dataset bridges a gap between global datasets and detailed regional data on the distribution of irrigated areas and provides information for various assessments and modelling applications.     

粉质仪和拉伸仪在面粉生产中的应用

在介绍粉质仪和拉伸仪结构和原理的基础上,探讨了粉质曲线中吸水率、形成时间、稳定时间、弱化度和评价值等指标与面粉品质的关系,以及如何根据拉伸曲线中面团最大拉伸阻力、延伸度和拉伸曲线面积等指标来评价面团品质,并结合生产实际,概述了粉质仪和拉伸仪在面粉生产中的作用。     

农村信息化服务的现状及建设措施

分析当前我国农村信息化服务的现状,提出加强农村信息化服务的新举措。     

车辆ABS控制算法的研究及探讨

对现代汽车的ABS控制算法作了一些简单的介绍,同时指出了它们的一些缺陷,相应地提出了几种对ABS的其它控制方法并加以探讨,其中着重论述了ABS门限值控制算法中参考车速的确定方法和基于附着系数的控制算法。