城市燃气管网的完整性管理

不同地区城市燃气管道的建设和运营管理水平存在很大差距,在保障燃气管网安全运行方面存在诸多问题,亟需针对燃气输配管网开展完整性管理。简述了国内外燃气管道失效事故和主要诱因,梳理了相关标准和规范。提出了燃气管网完整性管理理念:综合考虑影响管网完整性的所有因素,采取一体化管理模式,达到经济合理地保证管网安全有效运行的目的。建立了燃气管网完整性管理体系框架,包括管理体系和技术体系两个层面,贯穿应用于组织完整性、数据完整性和管理过程完整性之中,并保持一定的灵活性。完整性管理技术是实施燃气管网完整性管理的核心,通过有机结合形成了6步循环管理流程,持续完善各种完整性管理技术,可以提升燃气管网的本质安全和运营效益。     

分布式大数据资产权益管理问题与对策

[目的/意义]数字技术成为数据生产要素充分开发利用的重要驱动力量,充分利用数据资源的底层伴生议题是产权管理。数据流转中存在所有权与使用权分离的问题,在合理合法、保障用户权益的基础上进行数据资源管理活动成为亟待解决的问题。[方法/过程]基于“实践基础-抽象化分析-一般的具体认识”总思路,本文首先识别出分布式大数据资产的实践情况,而后从技术资源规范、合理使用边界、权益复杂性和使用权解析这4方面抽象化分析其权益管理关键内容。[结果/结论]基于抽象化分析,从机构层面具体说明：1）数据政策的原理和条款,2）权益组合的场景与内容规划,3）数据资产的配置管理,和4）数据资产管理业务的建构标准、工作流程、涉及的协议与规定、评估措施,以期对图书馆等数据资源管理机构在分布式大数据环境下为用户开展数据资产权益管理提供启发。     

基于构件化生长模型的作物管理决策支持系统

运用系统分析原理和数学建模技术,通过分析不同作物生长模型的共性及特点,初步创建了基于通用算法框架的作物生长模型。并进一步结合气象生成模型、品种参数生成模型及策略分析评价模型,以C#为编程语言,应用面向对象的程序设计与软构件技术,建立了基于构件化生长模型的作物管理决策支持系统。系统实现了农作模拟预测、决策支持和人机交互技术的有机耦合,具有农作信息管理、动态模拟、方案评估、因苗预测、时空分析及系统维护等功能。系统的建立可为通用性、综合性数字化作物管理决策支持系统的构建奠定基础。     

种源“卡脖子”问题的识别、成因与破解路径研究——以农作物种业为例

我国是农业生产大国和用种大国,历届政府都非常重视种业发展,农业生产中应用的大多数品种是自主选育的。我国种业发展受益于国际合作,同时也因全球价值链地位和国际分工,在部分领域形成了进口依赖,不得不面对种源“卡脖子”问题。本文基于对农作物种业特殊属性的阐释,解读种源“卡脖子”问题的表现形式和内涵,建立种源“卡脖子”问题的识别筛选框架,分析种源“卡脖子”问题的成因,提出了种源“卡脖子”问题的破解路径。研究表明,农作物种业具有消费对象的特殊性、供求关系的差异性、生产与销售的季节性、自然风险与技术风险的叠加性等特殊属性。种源“卡脖子”问题的表现形式既包括种子、亲本等有形商品,也包括专利、基因等无形技术。种源“卡脖子”问题的内涵可以归结为种业国际合作的产物、种业垄断的极端形式,并有理性与非理性之分。通过要素密集度、技术预见度、技术垄断程度和全球竞争地位4个层次的识别筛选,我国种源“卡脖子”问题的成因在于种子贸易竞争力不足、自主创新能力较弱、知识产权保护及国际布局落后、商业化育种体系不健全和品种管理制度不合理。因此,破解种源“卡脖子”问题,需要从改革品种管理制度、改善种业发展环境和打造国际竞争联合体3...     

基于开源J2EE框架的高校实验教学管理系统研究

依据高等院校实验教学管理的应用需求,在分析开源框架体系结构的基础上,通过整合Struts、Spring和Hibernate,利用分层解耦、框架管理层次的思想构建了一个基于开源J2EE的应用架构,并据此架构开发了高校实验教学管理系统。系统可靠性高,安全性好,可扩展性和可维护性强,能有效提高高校实验教学管理和服务效率。     

Simulation of corn yields in the Upper Great Lakes Region of the US using a modeling framework

We examined the utility of a site-based simulation model for corn (MAIZE) applied to the Upper Great Lakes Region (UGLR) of the United States for 1992–1996. To evaluate model outputs, we used a modeling applications system integrative framework (MASIF) to simulate corn yields in the UGLR. We divided the region into two ecological zones (upper UGLR-1 and lower UGLR-2) and compared MAIZE and USDA National Agriculture Statistics Service (NASS) yield estimates in each zone. There was greater agreement between MAIZE and NASS yields at lower yield values. As NASS yields increased, MAIZE yields also increased, but to a greater extent than did NASS yields. We conducted a mean spatial analysis of maize yield from 1992 to 1996. We also conducted a spatial analysis of 1994, 1995 and 1996. There are both spatial and temporal differences when yields are mapped.     

供应链管理绩效评价的一种有效评价方法

简要阐述了供应链绩效评价的必要性,构建供应链企业内部、外部及整体绩效评价的框架模型,最后运用模糊综合评价方法从定量的角度对企业绩效评价方法进行研究,并给出评价过程。     

WTO农业补贴规则演变对中国的启示

无论是《GATT1947》,还是《农业协定》或《农业框架协定》,都未禁止农业补贴政策,而是采取了逐步强化限制的措施。这使各成员国意识到,大幅度削减对生产和贸易带来扭曲作用的农业补贴措施趋势是不可逆转的。展望未来,中国要进一步改革调整农业补贴政策,完善农业补贴法律体系,适应农业补贴规则导向。     

安徽省智慧农业发展战略与发展机制研究

安徽省智慧农业的发展处于初级阶段,目前主要还是示范应用。通过文献分析法与实地调查法,发现安徽省智慧农业发展中存在规划协调不完备、技术不成熟、成本制约发展、专业技术人才数量较少等问题。为了加快安徽省智慧农业的发展步伐,可选择政府与市场双轮驱动的战略框架。一方面,政府推动智慧农业发展。另一方面,市场拉动智慧农业发展。还应构建安徽省智慧农业发展的政、产、研协同系统,着力培育安徽省智慧农业发展机制,可从规划协调机制、技术体系推进机制、政策扶持机制和人才培养机制四个方面合力推进。     

An integrated watershed modelling framework to explore the covariation between sediment connectivity and soil erosion

Quantitative identification of the covariation between sediment connectivity and soil erosion can contribute to provide the key information for watershed sediment management. However, this covariation and its spatiotemporal response mechanisms are still unclear, especially whether this covariation can be used as a basis for identifying critical source areas of sediment in large-scale ecological restored watersheds. In this study, an integrated methodology framework by the revised universal soil loss equation (RUSLE), index of connectivity (IC) and sediment delivery ratio (SDR) was proposed to visually assess the spatiotemporal characteristics of erosion and sediment yield processes in the Yanhe Watershed with large-scale ecological restoration from 1985 to 2020 and to identify the covariation between sediment connectivity and erosion in subbasins. The soil erosion estimated by RUSLE has decreased by over 80% since 1985 owing to increased vegetation cover and the effective implementation of soil conservation measures, but the upper reaches still have high erosion intensity due to differences in specific controlling factors such as topographic conditions and land cover, requiring focused soil conservation practice. The IC results showed that as the vegetation restoration and soil conservation measures in the Yanhe Watershed varied from year to year, their spatial and temporal patterns had a strong influence on the distribution of sediment connectivity, and some local areas in the middle reaches showed local minima of IC in 1995, 1998 and 2010 mainly due to the implementation of long-term ecological restoration project. The developed IC-Erosion maps indicated that areas with high connectivity but low erosion accounted for over 60% of the total watershed area from 1985 to 1999, demonstrating a reverse correlation between sediment connectivity and erosion. Meanwhile, over 40% of the erosion occurred in a few areas (approximately 20%) with high connectivity and high erosion from 2000 to 2004, which can be characterized as the critical areas of erosion. The methods and results of this study provide ideas for separately defining both erosion and connectivity and quantifying bi-variable erosion–connectivity classification, which can be easily viewed on a scatterplot.