农产品加工中的营养学思考与营养食品生产

中国农产品生产及其加工曾经经历过注重产品数量扩增、技术设备改进和卫生安全的发展阶段,目前正处在挑战和发展机遇并存的转折时期.中国农产品生产及其加工业应把握时机,应用营养科学为指导,科学地制定"十一五"期间的发展战略,丰富和发展营养食品产业,促进农产品生产和加工全面满足人民营养健康需要和市场需求,这将是开拓发展领域,实现产品升级换代,提升竞争能力和增值潜力,主动迎接国际挑战的战略举措,也是实践"以人为本"的科学发展观的具体体现.     

计算机视觉描述缺素番茄叶片颜色变化的研究

利用计算机视觉系统代替人眼对番茄缺素进行自动识别的方法，通过对缺素番茄叶片彩色图像的分析研究，利用图像处理技术中的颜色分析方法，分析缺N和正常叶片的特征量随着缺素时间的变化规律．提出用G体均值、H色调均值来定量描述缺N叶片随时间的变化。结果表明：利用计算机视觉能定量描述缺N叶片颜色随缺素时间的变化。     

Irrigation and food security in the 21st century

Global food projections indicate that food prices in the next threedecades will likely be stable or decline, but progress inreducing malnutrition in developing countries will be slow. Smallshortfalls in crop productivity growth would lead to rising foodprices and worsening malnutrition. Increased food production fromirrigation is essential, and will require expansion of irrigatedarea and water supplies, and improved efficiency of use of existingwater supplies. Neither of these growth factors will prove easy, andboth will require complex institutional and policy reforms. Failureto meet food production needs through efficient expansion andintensification of irrigated agriculture would increase pressure onland resources and hasten the process of environmental degradation.Irrigation and water development strategies have been hampered bya lack of understanding of the links between water scarcity, foodproduction, food security, and environmental sustainability.Research to improve this understanding would have high payoffs.     

论计算机网络安全的形式及基本防范措施

本文探讨了计算机网络安全的形式和如何防范的基本措施.     

农民工社会保障相对独立性初探

以农民工社会保障体系与城镇、农村社会保障体系的关系为研究视角,提出了在现阶段农民工社会保障应相对独立于城镇社会保障体系和农村社会保障体系,这是农民工职业、身份、风险的变化的要求,是农民工社会保障不宜纳入城镇社会保障体系的现实选择。在此基础上,本文还提出建立相对独立的农民工社会保障体系的基本框架:即以工伤保险为先,医疗保险、失业保险、养老保险、最低保障为主,内容逐步扩充。     

A tool for community-based assessment of the implications of development on water security in hillside watersheds

Development and population growth in Latin American countries with steep slope farming are likely to further increase pressures on water and land resources. A methodology was developed for assessing water availability and use under different development pathways at a watershed scale to determine whether water security is a potential problem, and if so, under what conditions it is likely to occur. This methodology makes use of a GIS-based spatial water budget model for simulating stream water availability, water use and stream flow control on a daily basis at a watershed scale. Here, we analysed water availability under three plausible development scenarios for the 3246 ha Cabuyal River watershed in southwest Colombia in the year 2025: Corporate Farming (CF), Ecological Watershed (EW), and Business as Usual (BU). Simulated average river flows at the watershed outlet were, respectively, 874, 796 and 925 l s⁻¹ for the CF, EW and BU scenarios. The contribution of base flow to river flow (base flow index) was on average, 80.8, 85.6 and 77.9%, respectively, for the three scenarios. The watershed had the potential to meet the anticipated increase in water use under each explorative scenario. However, dams were necessary to store irrigation water in the CF scenario, otherwise over 60% of the available water would have been used during the dry season. Such a high figure raises concerns about effects on aquatic and riparian ecology, concentrations of potential contaminants, water reserves for especially low rainfall years, and the watershed resilience to meet temporarily higher water needs during the day. Analyses indicated that current water-use conflicts in the watershed can be resolved if irrigation water supply is separated from drinking water supply. This study helped reduce some of the complexity associated with the interdependencies between land and water resources, the impact of using them, and spatial linkages within the watershed. Results of this study can be used for teaching local stakeholders about basic landscape responses and helping multi-institutional alliances to become proactive and to guide development to the benefit of local communities.     

计算机网络安全分析及对策

随着计算机技术网络的快速发展,网络安全成为人们研究的焦点。本文分析了网络攻击的主要方式和网络安全的关键,举例让我们对病毒的攻击有深入了解,再采用相应的技术防范。     

草地贪夜蛾蛹寄生蜂——霍氏啮小蜂生物学特性

草地贪夜蛾是2019年初入侵我国的重要农业害虫,国外对草地贪夜蛾的生物防治技术研究较深入,报道较多的是寄生性天敌,霍氏啮小蜂是其重要的蛹期寄生性天敌.为探明不同糖源和不同温度条件下霍氏啮小蜂对草地贪夜蛾的生防潜力,本研究比较了不同糖源和不同温度对霍氏啮小蜂发育的影响.结果表明,蜂蜜、蔗糖、葡萄糖均能显著延长霍氏啮小蜂雌...     

县域农业可持续发展的生态安全评价——以吉林省通榆县为例

以吉林省通榆县为例,构建了县域农业可持续发展的生态安全评价指标体系,采用均方差法确定了评价指标的权重,对研究区1985、1990、1995、1998、2001、2004年6个时段的农业生态安全进行了评价.从评价结果可以看出,近20年,通榆县农业生态安全呈现下降态势,安全等级处于Ⅲ～Ⅴ级,安全状态从敏感态下降到风险态.1998年是研究区农业生态安全变化的转折点,从1998年起,农业生态安全有所回升.在分析变化原因的基础上,提出农业可持续发展的生态安全建设对策.     

河北太行山区土地资源生态安全研究

本文在PSR模型的基础上,从土地自然资源现状、土地社会经济环境压力、人文响应三方面出发,选取与山区土地资源密切相关的27项因素构建指标体系,对河北太行山区土地资源生态安全进行评价。采用ArcView、ArcGis软件对河北太行山遥感图像进行处理,获取土地方面数据并结合其他统计数据,运用相关数学方法,计算研究区1987、2000年各县综合生态安全值,对生态安全状况进行安全度分区分析,研究认为,该区域土地资源生态安全状况处于较差状态,且局部有恶化趋势,进而剖析其主要制约因素,提出相应改善安全状况的建议。