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321.
系统概述了江苏省在农业生态环境建设方面所采取的完善肥药结构、多途径利用畜禽粪便及秸秆资源、优化种植业结构、环境综合治理、法制化等措施,同时探讨了严重影响农业环境污染防治效果的热点问题。 相似文献
322.
323.
Irina Herzon Johan Ekroos Jukka RintalaJuha Tiainen Tuomas SeimolaVille Vepsäläinen 《Agriculture, ecosystems & environment》2011,143(1):3-7
The set-aside obligation under the Common Agricultural Policy (CAP) brought widespread benefits for wild farmland species. Shortly after it was abolished in 2008, the national political process in Finland replaced it with a targeted agri-environment scheme for environmental fallow. Though potentially highly valuable, the value of the current scheme for securing biodiversity is yet to be confirmed. This study evaluates the importance of set-asides established under CAP to all birds of open farmland based on national monitoring data from 2001 to 2006. The set-aside fields supported 25-40% more species and held 60-105% more pairs of birds typical of open farmland in comparison with cereal fields within a similar landscape setting. The estimated effect of set-aside presence in farmland on the studied bird species is large enough to trigger considerable changes in bird populations on the national scale. The relevance of the results to the novel agri-environment scheme is discussed. 相似文献
324.
通过对"十一五"期间齐齐哈尔市辖区无公害农产品产地环境的监测、评价和分析,提出了齐齐哈尔市辖区公害农产品产地环境的对策。 相似文献
325.
David J.T. Douglas Juliet A. Vickery Tim G. Benton 《Agriculture, ecosystems & environment》2010,135(1-2):127-131
Managing arthropod populations on farmland for conservation purposes, such as food resources for declining farmland birds, requires information on the way distributions vary between crop types, for example under varying sowing regimes. In this study arthropods were sampled during one summer from fields of winter-sown and spring-sown barley. The relative timing of crop development had a strong influence on arthropod abundance between crop types, with winter barley supporting significantly higher abundance of total counts and many individual orders in early summer, but the reverse being the case in late summer. Fields of both crop types that received higher herbicide inputs showed reduced arthropod counts. 相似文献
326.
In many respects, the behavior of bumblebees is similar to that of the closely related honeybees, a long-standing model system
for learning and memory research. Living in smaller and less regulated colonies, bumblebees are physiologically more robust
and thus have advantages in particular for indoor experiments. Here, we report results on Pavlovian odor conditioning of bumblebees
using the proboscis extension reflex (PER) that has been successfully used in honeybee learning research. We examine the effect
of age, body size, and experience on learning and memory performance. We find that age does not affect learning and memory
ability, while body size positively correlates with memory performance. Foraging experience seems not to be necessary for
learning to occur, but it may contribute to learning performance as bumblebees with more foraging experience on average were
better learners. The PER represents a reliable tool for learning and memory research in bumblebees and allows examining interspecific
similarities and differences of honeybee and bumblebee behavior, which we discuss in the context of social organization. 相似文献
327.
Olivier Hatem Sander Kamel Frank Jacques-Eric Jacques Thomas Johanna Alkan Delphine Martin 《Environmental Science & Policy》2009,12(5):619-630
Scenario-based approaches in environmental and policy assessment studies are increasingly applied within integrated assessment and modelling frameworks. The SEAMLESS project develops such an integrated framework (SEAMLESS-IF) aiming to assess, ex-ante, impacts of alternative agro-environmental policies on the sustainability of agricultural systems. A particular challenge in this context is the consistent translation of a wide range of policy questions into scenarios that a modelling framework can assess. The present work defines a methodology for scenario-development in integrated policy assessment with specific emphasis on SEAMLESS-IF. After a general overview on scenario concepts for integrated policy assessment the adopted scenario concept and its development procedure is presented. They allow building integrated scenarios capturing the range of drivers of the assessed agricultural system in a consistent way across temporal and spatial scales. Then focus is on the particular procedures to translate the policy assessment questions into scenario parameters and to implement these parameters into SEAMLESS-IF. Two examples targeted at European and regional level combining integrated assessments of policy changes and technological innovations are considered to illustrate the SEAMLESS scenario concept. We conclude that the proposed methodology to translate policy assessment problems into scenarios effectively supports integrated assessment in SEAMLESS-IF or even in other modelling frameworks. 相似文献
328.
汽车门禁系统已成为汽车智能与安全领域的重要一部分.车主手持智能钥匙靠近汽车,通过车载基站与钥匙的双频通信,实现车门的开与关,还可实现发动机的一键启动.同时,对信号加密采用了改进的AES算法,加入了循环扩展密钥,加大了密码的破解难度.并对整个系统进行了建模仿真,分析了信号传输的误码率.图6,表1,参5. 相似文献
329.
土地整理立项决策评估的指标体系与方法探讨 总被引:5,自引:0,他引:5
土地整理立项决策评估是进行科学投资决策、正确选择整理项目的基础。根据我国土地整理产业发展现状,在深入分析与土地整理立项决策评估相关的社会、经济、技术、生态和组织管理等多种因子的基础上,初步构建了我国土地整理立项决策评估指标体系。运用可拓学中的物元理论和优度评价法,设立了土地整理立项决策评估的综合评判物元模型,给出了基于关联函数的可拓评估方法,并以国土资源部土地整理中心备选项目库的项目进行实例验证。模型输出的结果与项目评审专家组对各项目可行性的实际评估结论完全吻合。研究结果为土地整理立项决策提供了科学依据。 相似文献
330.