触摸屏和PLC在粮食烘干机中的组合应用

触摸屏和PLC的结合应用已成为现代控制领域的主流,通过触摸屏实现对现场工作的控制和监控。本文介绍了以PLC和触摸屏相结合在粮食烘干机中的组合控制系统,实现了对变频器和现场工作单位的控制,并在触摸屏上显示所采集的信息,系统性能稳定,工作可靠,易于扩展,达到了设计的要求。     

基于MODBUS总线通讯的土槽台车电气控制系统设计

针对土槽台车原继电器控制系统和电磁离合器调速存在的问题,采用PLC、变频器和触摸屏技术进行了系统的升级改造,主要包括电气控制系统的硬件设计,PLC与变频器基于MODBUS总线通讯的实现和人机界面的设计等.三菱FX系列小型PLC通过MODBUS总线可以控制ABB大功率变频器ACS800的启停、给定参考速度,并可以实时读取变频器的主要运行参数.     

计算机监控系统现场总线选择与应用研究

根据东深供水改造工程计算机监控系统的要求，分析不同现场总线的特点，科学合理地选择和应用现场总线，并将应用情况加以总结，为现场总线在水利水电工程的应用提供参考和借鉴。     

物联网环境下基于触摸屏的微小型农业机械MPS研究

触摸屏是应用于工业现场的一种监控设备,在工业控制中的应用越来越广泛.本文首先提出与构建了MPS物联网架构.其次分析了模块化生产加工系统MPS流程,通过EV5000组态软件实现触摸屏组态,完成对MPS系统现场单元的动态过程监控.     

现场总线在变电站监测监控中的应用

介绍了现场总线系统的结构特点和技术性能,基本现场总线的变电站监测监控系统的设计与实现方法,最后还介绍了基于现场总线的民站监测监控系统的优点和应用前景。     

郓城电网自动化系统中的总线技术

该文阐明了基于各种总线控制系统的技术特点,结合采用各种总线技术的产品在郓城电网系统中应用的历程和现状,特别是现场总线技术在郓城电网系统中的应用情况。     

提高变电站自动化CAN总线通讯性能

CAN总线作为一种有效支持分布式控制或实时控制的串行通信网络,目前已在工业自动化、建筑物环境控制、医疗设备等领域得到了较广泛的推广和应用。该文在叙述了CAN总线通讯一些特点的基础上,结合变电站自动化系统中现场总线的实际运用情况,着重对现场安装、调试工程中,CAN总线通讯质量的优化方案进行探讨和研究。     

基于CC-Link总线的三菱PLC实训设备控制方案的设计

文章对三菱PLC实训设备进行升级改造,将传统的单站控制改造为以CC-Link总线控制模式,以三菱Q00U系列PLC为主站,FX3U系列PLC为从站,同时设计人机界面HMI(触摸屏)与主站相连,通过CC-Link通讯对伺服传动系统与步进电机等执行元件进行控制。     

现场总线技术概述

本文介绍了几种常用的现场总线,并对其特点、性能和应用范围做了概述,最后介绍了现场总线和工业以太网的结合,及现场总线的控制网络结构与发展趋势。     

基于SMP的总线式软运动控制引擎设计

提出了基于SMP实时架构的EtherMAC实时以太网主站的设计方法,开发了一种运行于内核空间的运动控制引擎,并给出了一种通过在共享内存建立内存堆栈方式的跨平台编程接口设计方法。通过设计总线抽象层将总线控制资源抽象,降低了运动控制引擎与总线之间耦合性,增强了总线系统或从站设备的可替换性。原型机进行功能验证表明,该引擎实现了较好的易用性和可移植性,并间接增强了EtherMAC的实时性能。     

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.     

车用发动机润滑油失效规律与更换周期研究

研究在正常使用条件下１０Ｗ／３０－ＱＣ级润滑油用于某型车用发动机时所表现的失效规律,确认期服从两参数Ｗｅｉｂｕｌｌ分布,并给出分布的尺度参数η和形状参数ｍ之最佳线性无偏估计（ＢＬＵＥ）同时,还为定量分析,计算车用发动机润滑油的使用可靠性和合理确定其更换周期提供了一套可供借鉴的方法,并给出了具体的计算实例。     

农村剩余劳动力就业问题的探讨

论述了我国农村剩余劳动力就业的意义,并针对我国农村剩余劳动力的现状,提出多渠道促进农村剩余劳动力就业的途径和办法。     

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。     

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。     

乡（镇）农业技术推广体系存在的问题及对策

乡（镇）农技推广体系是农业发展的关键。介绍朝阳市农业技术推广体系的现状,针对目前体制及运行机制、服务手段等方面存在的问题,提出适合朝阳市乡（镇）农技推广体系改革与发展的对策,以期对全省农技推广体系改革和发展起到一些借鉴作用。     

草莓的采收与贮藏

草莓果味酸甜爽口,营养价值高,为人们所喜爱的应市鲜果之一。由于草莓易受损伤和微生物侵染,因此其采收、贮藏过程极为重要。介绍草莓采收过程中的注意事项以及11种贮藏保鲜技术的实施步骤和操作方法,推介9种加工方式,为草莓产业化提供技术支持。     

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。     

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.