CAN作为现场总线在车身控制系统中的应用

CAN总线也是现场总线的一种，它最初被应用于汽车的控制系统中。由于其卓越的性能，CAN总线的应用范围已不再局限于汽车工业，被广泛应用到自动控制、楼宇自动化、医学设备等各个领域。本文在分析了CAN总线的协议后，探讨了CAN总线控制系统的网络实现方案，并在此基础上研究了CAN总线节点的软、硬件的实现方法，并提出了CAN节点在实现过程中值得注意的地方。试验验证了其可行性。     

基于C8051F040的轿车车门CAN总线控制系统设计

车身线束应用总线控制是车身电子化控制的必然趋势,车门控制系统是车身控制系统的重要组成部分。设计了基于集成有CAN2.0B控制器的C8051F040单片机的车门CAN总线控制系统,并详细介绍了系统的硬件电路的工作原理和软件工作流程。     

现代CAD技术的发展

评述了当前CAD技术发展的动力，制造业环境的变化、企业结构重组以及现代化管理；分析了CAD技术发展的动向，即功能集成-信息／过程集成-异地协同设计-绿色设计；指出今后CAD技术应从CAD设计工具的完善、集成和CAD设计环境的完善方面进行工作。     

基于SOPC和量子框架的电控机械式变速器电控系统

针对传统嵌入式系统开发中软/硬件分离以及软件开放性不足等问题,提出利用软/硬件协同设计和量子框架的综合解决方案,形成了“五层/三总线/一框架”的软/硬件综合开发结构,并将其应用于AMT电控系统的设计中.实现了针对NiosⅡ软核的量子框架移植,并设计了AMT主活动对象的层次状态机.实现过程及试验结果表明,此种设计方案可提高系统开发的灵活性和软件的质量.     

拖拉机作业机组分布式控制系统结构模型

针对拖拉机作业机组自动驾驶控制要求,基于ISO 11783提出了一种分布式控制系统结构模型,其主总线完成整机通信和系统监控,子系统分总线完成部件控制.该模型属于多总线互连、分层管理的网络控制系统方式,具有数字化、模块化强的特点.运用TrueTime工具仿真该模型,各任务可调度.与单处理器集中控制方式不同,由于子系统采用了分总线,系统的控制性能由网络协议和控制算法综合决定.试验结果表明,系统的网络控制性能与仿真分析一致,可以有效地完成控制任务.     

汽车EPS/ABS集成控制硬件在环研究

针对汽车助力转向制动过程中的动力学耦合关系,通过建立汽车转向和制动系统模型,分别设计了单个ABS及EPS子系统控制器和集成控制器,对两系统进行了集成控制,并将控制器局域网络应用到两系统集成控制中,采用SAE J1939协议,设计了CAN总线通讯系统。最后基于LabView进行了软件仿真和硬件在环实车试验。结果表明：基于CAN通讯的集成系统工作稳定,抗干扰能力强,汽车在转向制动工况下综合性能得到改善。     

现场总线控制系统在泵站中的应用

为了研究现场总线控制系统在泵站中的应用，在简要介绍现场总线技术及现场总线控制系统结构和优点的基础上，着重分析了PROFIBUS现为总线，并据此阐述了现场总线技术在泵站中的应用及系统的通信实现。     

天水市城区供水现状及远程分布式

针对天水市城区供水现状，设计并实现了天水市城区远程分布式供水系统。该系统以流行的Profibus现场总线及无线数字通信技术为基础，采用先进的软件和硬件设计完成了水源地控制系统、水厂控制系统、供水调度系统及有线无线网络传输系统，实现了整体自动化。并采用先进的控制算法，变频器和软启动器相结合的硬件手段，较好地现实了节能、节水的目的。实际运行表明：该系统具有运行稳定、高效节能、自动化程度高、易于操作等优点.     

PDM与CAD信息集成技术的研究

随着PDM技术在国内应用范围的不断增加,PDM系统和CAD系统的信息集成越来越被各厂家所重视.在对二者信息集成的关键进行了详细研究的基础上,利用UG/OPEN API这个强有力的UG二次开发工具,实现了PDM系统与UG软件的产品信息的集成.     

设施园艺实用智能化温室的研究

探讨了适合于亚热带季风气候区设施园艺实用智能化温室的技术开发与集成.其内容包括:主体结构的优化方法,采用多态控制的混合通风系统与组合降温系统,基于现场总线技术-CAN总线的温室计算机分布式控制系统与管理软件,基于Web技术的栽培管理系统.系统的集成开发融合了温室实用智能化的特性,为设施园艺温室的技术发展提供了参考模式.     

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。