用于直流传动控制系统的串行通讯

介绍了用Visual Basic提供的串行通讯控件，通过编程实现了PC机与应用单片机触发电路的直流传动系统的通信。     

Exploring regional irrigation water demand using typologies of farms and production units: An example from Tunisia

Most methods used to predict irrigation water consumption at a regional scale are based on biophysical models and cropping patterns. Their aim is to provide accurate estimations of “water demand” that are useful for water resource management. However, in the case of free access to the water resource, for example pumping from a water table, it is only possible to prevent overexploitation by “managing” the demand for water, which thus needs to focus on farmers’ choices and behavior. In this paper, we propose a framework to represent agricultural activities using typologies of farms and production units aggregated at a regional scale. The framework can be used to estimate consumption of irrigation water and of other inputs, as well as the production of outputs. The framework can also be used to evaluate the effects of technical, economic or institutional changes on farm income, and to predict the consequences of changes for farmers’ choices at regional scale. We used this method in Central Tunisia to estimate irrigation water demand in 1999. We then simulated the changes that would occur if drip irrigation were adopted. The results of the simulation showed some savings in water and in labor, and, with fertigation, an increase in yields. Using drip irrigation would consequently enable farmers to extend the area of drip-irrigated land. We then simulated the widespread adoption of drip irrigation and the resulting extension of irrigated areas: the results showed no savings in water at the regional scale. These hypotheses were confirmed in 2005 using new typologies to estimate the new demand for irrigation water. We also simulated the effects of economic changes on farm incomes. A major increase in the cost of water affected a minority of farms, which consumed only 17% of total irrigation water, whereas a slight decrease in watermelon and melon prices affected a majority of farms, which consumed 78% of total irrigation water. Water demand management tools therefore need to focus on the effects of technical, economic, or institutional changes and on farmers’ choices.     

注塑模多型腔流道优化设计

在注塑成型过程中,浇注系统尤其是多型腔浇注系统的设计合理与否对产品质量和效益都有决定性影响。为此,不袭用传统的浇注系统设计方法,在前人研究的基础上导出了新的流道系统优化设计模型,并在MODEFLOW软件模拟中得到验证。     

论天气系统下云的观测

在地面气象观测工作中,云的观测是一项最基本的观测要素,它既是现在天气的重要判定依据,也是未来天气预测的重要指标,所以做好云的观测是观测工作的重中之重.地面气象观测中只有把云和与它相对应的天气系统联系起来,借助天气形势的分析判断,把地面气象观测和天气系统的分析判断有机结合起来,用天气学的原理和方法来指导我们的地面气象观测.     

信息管理与信息系统本科专业培养方向刍议

本文在分析信息管理与信息系统专业内涵的基础上,指出了传统情报学的不足并调查了部分高校开办此专业情况,对我校信息管理与信息系统专业的课程设置、本科培养方向进行探讨,并提出了本校本专业课程改革的建议。     

海南省高校图书馆服务体系现状调查与发展对策

通过对海南省8所高校图书馆的主要服务项目及基本状况进行调查,提出了持续改进服务水准所面-]名的问题,阐明了高校图书馆今后应着眼于更深层次的服务资源配置、平台搭建、绩效评估等问题,以提升高校图书馆的整体服务效益.     

我国取消农业税制的效应分析

本文从税种设立法律依据、税收的经济效应和社会效应入手，注重税收与所有制、税收与管理、税收与现代社会和市场经济建立的关系研究，对我国农业税制改革进行了评价。既充分肯定了取消农业税制的重大意义。也对可能带来的负面作用进行了分析，并提出了消除负面作用的措施。     

电子阅览室"一卡通"管理系统的组建实践

电子阅览室“一卡通”管理系统是图书馆自动化的新领域，也是解决图书馆电子阅览室管理的一种有效手段。本文从该系统的组成、结构、功能等方面入手，阐述该系统的组建实践；并针对试运行阶段出现的问题。提出了一些解决方案。     

红壤丘陵山区人为活动对植被恢复影响研究

利用在湘南丘陵山区的2个长期定位试验,研究该地区自然植被恢复的情况。结果表明：频繁刈割不仅使植物的生物量逐年下降,植物种类减少,特别是抑制木本植物的生长。对该地区植被自然恢复过程中的白茅草问题进行的针对性研究证明,施肥可使白茅草过度繁殖而死亡。频繁刈割地力不断耗竭,白茅草生物量锐减,特别是在施氮肥的条件下生长最差。