扩展二次规划在电力系统无功优化中的应用

Based on the Simplex and Gradient method, a new algorithm (EBM) is presented for solving the quadratic programming with upper and lower bounds. Firstly the ideas of Beale''s method and extended LP are analysed, and then an extended Beale''s method (EBM) is     

Marine zoning revisited: How decades of zoning the Great Barrier Reef has evolved as an effective spatial planning approach for marine ecosystem‐based management

1. For more than 40 years, marine zoning has played a key role while evolving as part of the adaptive management of the Great Barrier Reef (GBR) Marine Park. The statutory zoning plan provides the primary integrating component that prohibits many threatening activities and manages the impacts of allowed human activities and competing uses by means of various zones, special management areas and other spatial management tools.
2. How zoning is applied, however, has changed considerably since the first zoning plan was finalized in 1981. Today, zoning is applied in combination with other layers of marine spatial planning; the effective combination of these management tools provides the integrated approach, considered one of the best for managing a large marine protected area.
3. The zoning plan provides the foundation for management of the GBR and is the fundamental component of the integrated marine spatial planning approach ensuring high levels of protection for significant areas of the GBR, while also allowing ecologically sustainable use.
4. The paper outlines the legal and managerial contexts of zoning, providing 38 lessons that may be useful for marine zoning and ecosystem‐based management elsewhere. It outlines aspects of zoning that have worked well in the GBR Marine Park and what has changed in the light of experience and changing contexts, and seeks to clarify various misconceptions about zoning and marine spatial planning.
5. The integrated management approach in the GBR utilizes a variety of spatial planning tools, which complement the underlying zoning; some of these comprise statutory management layers (e.g. designated shipping areas, special management areas, plans of management, fishery management arrangements, Traditional Owner agreements, defence training areas); other layers are non‐statutory (e.g. site plans).
6. This paper is written for planners, managers and decision‐makers considering the use of zoning to achieve effective marine conservation, protection and ecologically sustainable use.

     

基于EBM的水资源失衡风险导致的社会经济损失模型及应用

水资源系统与区域经济息息相关,利用经济数值反映水资源系统风险所致损失将更加直观。该文为了通过经济数值定量评价水资源失衡导致的风险,首先构建水资源失衡导致的经济损失风险模型,应用数据包络分析(epsilon-based measure,EBM)模型计算水资源利用效率,并结合黑龙江省水价及人均工资确定水资源失衡导致的经济损失值;然后,在EBM的基础上添加二阶段Tobit模型进一步分析水资源失衡风险经济损失原因。结果表明,2000—2020年黑龙江省由水资源投入不足导致的最小经济损失值为75.2亿元(2008年)、最大值为425.1亿元(2013年);水资源最小产出经济损失值为1 119亿元(2000年)、最大值为11 068亿元(2012年)。2000—2015年黑龙江省水资源风险经济损失逐年上升,水资源产出经济损失均占水资源风险经济损失的90%以上,预计2020年水资源风险经济损失为8 138.7亿元。在研究时段内黑龙江省水资源风险经济损失较高,水资源利用效率较低。黑龙江省水资源系统受到产业结构、经济发展水平和水利基础设施投资等驱动因素影响,需加大第二产业投入和水利基础建设投资,从而降低水资源风险经济损失,为后续水资源系统风险规避措施的制定提供支持。     

山东省农业机械化效率的时空分异特征

农业机械化水平不仅体现在农业机械装备的数量与主要农作物耕种收综合机械化率,更表现在农业机械的配置效率。为此,使用EBM超效率模型,测算了2011-2013年山东省17个地市农业机械化效率的变动状况。结果发现:山东省农业机械化综合技术效率总体上较低,且增长缓慢;山东省农业机械化综合技术效率呈现出"中间高、四周低"的空间格局,各地市农业机械化效率的空间差异明显,且未有收敛趋势;山东省农业机械化的纯技术效率总体上维持在较高的水平,且逐年上升,但纯技术效率空间差异大;山东省农业机械化的规模效率总体上不高,且增长幅度很小,有较大的上升空间。要想达到强有效前沿面,各地市需同比例缩减或单独缩减一定程度的拖拉机动力、拖拉机配套农具和联合收割机动力。     

我国农业用水效率的时空差异

使用EBM超效率模型,综合考虑投入变量的径向与非径向特征,并对有效单元的排序进行分析,测算了2011-2013年我国20个农业省份农业用水效率的变动状况,结果发现:我国农业用水效率总体上较低,且呈现下降趋势,农业水资源并未得到较好的利用。农业用水效率呈现出"西部高、东部低、中部居中"的空间格局。各省份农业用水效率的差异明显,并未呈现收敛的趋势。我国农业用水的纯技术效率总体上不高,且增长幅度很小,有较大的上升空间。我国农业用水的规模效率总体上较高,但是三年间却在持续下降,同时规模收益处于递增趋势的省份持续减少。要想达到强有效前沿面,分属3个等级的17个无效省份,需同比例缩减或单独缩减一定程度的农业用水量。     

循证医学实践——医学图书馆面临的机遇和挑战

对循证医学

的起源与发展、定义、核心思想，以及循证医学实践及其基本步骤、循证医学实践与文献检索的关系进行了综述。在此基础上，重

点阐述循证医学实践给医学图书馆带来的重大发展机遇和医学图书馆在循证医学环境下所面临的巨大挑战，并就如何抓住机遇、迎

接挑战提出了具体建议。

     

我国食用葵生产率增长的源泉分析——基于主产省区定点监测样本数据

提升食用葵的生产率是推动其产业可持续发展与保障我国油料作物安全的有效路径。基于国家特色油料产业技术体系的农户调查数据，运用较前沿的GML和EBM模型，分析了我国食用葵全要素生产率变化的整体情况及其在不同产区和生产者上的差异表现，探讨了其中的驱动因素。结果表明，食用葵的生产率整体上正表现出明显的增长趋势，技术效率改进是其中的最主要动力，进一步减少技术效率损失的重点在于改进劳动与物质生产资料的投入规模。在地域上，黑龙江、宁夏、河北和吉林4地是推动食用葵生产率快速增长的最主要产区，而陕西食用葵的生产率正面临着下降的压力。各主要产区稳定增长并提升增速的关键在于，立足当地的自然资源禀赋实现种植面积的改进。在主体上，中青年生产者是推动生产率增长的中坚力量，实现其技术效率与生产率进一步提升的关键是劳动投入的改进，而推动老年生产者生产率增长的重点在于物质生产资料投入上的节本增效。对此，应当进一步加强先进生产技术的研发与应用，优化食用葵生产的空间布局，在积极培育新型经营主体的同时，用活土地托管等生产社会化服务。     

Key principles of ecosystem‐based management: the fishermen's perspective

Despite the growing popularity of ecosystem‐based management (EBM) in national legislation and in research and institutional literature, there is often an implementation gap ‘on the ground’, impeding widespread adoption in fisheries. This gap reflects in part the differing understandings of EBM held by fishermen and by management institutions. To explore and seek to close this gap, the underlying principles of EBM considered priorities by fishermen were systematically compared with the priorities identified in the published literature. The fishermen's priorities were determined by asking Atlantic Canadian fishermen to identify the EBM principles they consider most important. Four priority principles were identified: Sustainability, Stakeholder Involvement, Develop Long‐Term Objectives and Use of All Forms of Knowledge. The latter two were not frequently noted as priorities in the literature, while some literature priorities were less commonly chosen by fishermen, indicating a significant difference in perspectives on EBM. The rationale for fishermen's choice of priorities was explored by analysing the fishery management issues they raised – many directly connected to the above four priorities. In addition, another principle, Commit to Principles of Equity, often arose as an implicit priority among fishermen. We suggest that success in implementation of EBM may depend on reconciling differing priorities among its underlying principles, and combining knowledge and expertise from fishermen with research and institutional sources. The comparative methodology used here, which could be replicated elsewhere, should lead to better recognition of local challenges in EBM implementation and encourage support for EBM, to further its contribution to sustainable fisheries.     

Evaluating impacts of fishing on benthic habitats: A risk assessment framework applied to Australian fisheries

Ecosystem-based management (EBM), in the context of fishing, considers impacts on all parts of an exploited marine ecosystem. Understanding the impacts of fishing on habitats is a necessary part of adopting EBM, but multi-scale data that describe the types and distributions of habitats, and the interactions of fishing with them, are typically limited or entirely lacking. An approach developed to address habitat impacts, and applied to all offshore bottom contact fisheries in Australian waters, forms part of a hierarchical risk assessment framework - the Ecological Risk Assessment for the Effects of Fishing (ERAEF). Its progressively quantitative hierarchical approach enables higher-risk interactions to be identified and prioritised in the early and intermediate assessment stages by screening out lower-risk interactions. The approach makes the best use of all available data, but it can also be inferential where data are lacking. At the intermediate level of the ERAEF, a semi-quantitative approach uses a general conceptual model of how fishing impacts on ecological systems, with a focus at the level of regional sub-fisheries defined by fishing method (gear type). A set of quantifiable attributes for habitats are used to describe the ‘susceptibility’ of each habitat to damage that may be caused by specific fishing gears; resilience is generalised as a habitat's inherent ‘productivity’ (ability to recover from damage). In the ERAEF, photographic imagery was used effectively to provide a standardised method to classify habitats, to visualise the attributes assessed, and to communicate with stakeholders. The application of the ERAEF to habitats is illustrated using results from a multi-sector fishery off southern Australia that has five primary sub-fisheries: two bottom trawl (‘otter trawler’ or ‘dragger’), bottom set auto-longline, bottom set gill net, and Danish seine. In the case of the otter trawl sub-fishery, a set of 158 habitat types was considered, of which 46, mostly on the outer continental shelf and slope, were identified as potentially higher risk and deserving management attention. Strengths of the ERAEF approach for benthic habitats include methodological flexibility and wide applicability, and in being interactive and inclusive - bringing stakeholders, scientists and managers together to ‘put habitat on the radar’ and to develop management solutions. Limitations include difficulties in construction and validation of scored attributes and scale dependence. In the context of ecological risk management, this method offers a way to assess risks to marine habitats in a rigorous, transparent, and repeatable manner.     

医学图书馆如何在循证医学实践中深化信息服务和用户教育

简述了循证医学的定义和核心思想，对医学图书馆在循证医学实践中的作用进行了分析，探讨了医学图书馆深化在循证医学实践中信息服务和用户教育等问题。