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281.
为客观掌握油气管道生产运营岗位主要作业风险,实现油气长输管道企业作业风险管理,提出一种作业分级定量风险评价方法。首先,辨识油气管道系统主要危险作业类型和引起作业事故的危险有害因素;然后由作业分级法确定事故发生的可能性与严重性;最后建立基于作业分级的风险矩阵,得到各作业活动的风险级别。将该方法应用于某管道公司,以该公司生产区内部高处作业为例,对作业过程中的危险有害因素进行识别与评价,得出高处作业过程中各步骤的风险程度。结果表明该评价方法具有一定的可操作性,可反映各类危险作业过程中的风险程度,为后期有针对性的风险控制提供指导,有助于公司的风险管理。 相似文献
282.
为解决传统经验公式在预测气体泄爆中最大超压出现时的较大偏差或过于保守的问题,提出使用人工神经网络预测气体泄爆最大超压。基于124组实验数据,采用BP与RBF神经网络,通过优化算法计算与迭代循环对泄爆样本中的影响因素进行降维与选择,并确定2类神经网络本身在学习与计算气体泄爆样本时的相关参数。结果表明:PCA(主成分分析法)在当前样本条件下的降维效果较差,而通过迭代对比确认气体泄爆样本中的5类特征全部保留时神经网络的训练模拟效果最好;通过对124组实验数据进行随机挑选训练集与测试集的训练模拟结果发现,神经网络对气体泄爆中最大超压的预测效果较好;通过对比Molkov提出的和经Fakandu等改进的NFPA 68经验公式以及2类神经网络的预测结果表明,神经网络相比于传统气体泄爆经验公式具有明显优势。 相似文献
283.
JONATHAN M. JESCHKE SVEN BACHER TIM M. BLACKBURN JAIMIE T. A. DICK FRANZ ESSL THOMAS EVANS MIRIJAM GAERTNER PHILIP E. HULME INGOLF KÜHN AGATA MRUGAŁA JAN PERGL PETR PYŠEK WOLFGANG RABITSCH ANTHONY RICCIARDI DAVID M. RICHARDSON AGNIESZKA SENDEK MONTSERRAT VILÀ MARTEN WINTER SABRINA KUMSCHICK 《Conservation biology》2014,28(5):1188-1194
Non‐native species cause changes in the ecosystems to which they are introduced. These changes, or some of them, are usually termed impacts; they can be manifold and potentially damaging to ecosystems and biodiversity. However, the impacts of most non‐native species are poorly understood, and a synthesis of available information is being hindered because authors often do not clearly define impact. We argue that explicitly defining the impact of non‐native species will promote progress toward a better understanding of the implications of changes to biodiversity and ecosystems caused by non‐native species; help disentangle which aspects of scientific debates about non‐native species are due to disparate definitions and which represent true scientific discord; and improve communication between scientists from different research disciplines and between scientists, managers, and policy makers. For these reasons and based on examples from the literature, we devised seven key questions that fall into 4 categories: directionality, classification and measurement, ecological or socio‐economic changes, and scale. These questions should help in formulating clear and practical definitions of impact to suit specific scientific, stakeholder, or legislative contexts. Definiendo el Impacto de las Especies No‐Nativas 相似文献
284.
Jeremy R. Brammer Nicolas D. Brunet A. Cole Burton Alain Cuerrier Finn Danielsen Kanwaljeet Dewan Thora Martina Herrmann Micha V. Jackson Rod Kennett Guillaume Larocque Monica Mulrennan Arun Kumar Pratihast Marie Saint‐Arnaud Colin Scott Murray M. Humphries 《Conservation biology》2016,30(6):1277-1287
Many argue that monitoring conducted exclusively by scientists is insufficient to address ongoing environmental challenges. One solution entails the use of mobile digital devices in participatory monitoring (PM) programs. But how digital data entry affects programs with varying levels of stakeholder participation, from nonscientists collecting field data to nonscientists administering every step of a monitoring program, remains unclear. We reviewed the successes, in terms of management interventions and sustainability, of 107 monitoring programs described in the literature (hereafter programs) and compared these with case studies from our PM experiences in Australia, Canada, Ethiopia, Ghana, Greenland, and Vietnam (hereafter cases). Our literature review showed that participatory programs were less likely to use digital devices, and 2 of our 3 more participatory cases were also slow to adopt digital data entry. Programs that were participatory and used digital devices were more likely to report management actions, which was consistent with cases in Ethiopia, Greenland, and Australia. Programs engaging volunteers were more frequently reported as ongoing, but those involving digital data entry were less often sustained when data collectors were volunteers. For the Vietnamese and Canadian cases, sustainability was undermined by a mismatch in stakeholder objectives. In the Ghanaian case, complex field protocols diminished monitoring sustainability. Innovative technologies attract interest, but the foundation of effective participatory adaptive monitoring depends more on collaboratively defined questions, objectives, conceptual models, and monitoring approaches. When this foundation is built through effective partnerships, digital data entry can enable the collection of more data of higher quality. Without this foundation, or when implemented ineffectively or unnecessarily, digital data entry can be an additional expense that distracts from core monitoring objectives and undermines project sustainability. The appropriate role of digital data entry in PM likely depends more on the context in which it is used and less on the technology itself. 相似文献
285.
In Latin America and the Caribbean, river restoration projects are increasing, but many lack strategic planning and monitoring. We tested the applicability of a rapid visual social–ecological stream assessment method for restoration planning, complemented by a citizen survey on perceptions and uses of blue and green infrastructure. We applied the method at three urban streams in Jarabacoa (Dominican Republic) to identify and prioritize preferred areas for nature-based solutions. The method provides spatially explicit information for strategic river restoration planning, and its efficiency makes it suitable for use in data-poor contexts. It identifies well-preserved, moderately altered, and critically impaired areas regarding their hydromorphological and socio-cultural conditions, as well as demands on green and blue infrastructure. The transferability of the method can be improved by defining reference states for assessing the hydromorphology of tropical rivers, refining socio-cultural parameters to better address river services and widespread urban challenges, and balancing trade-offs between ecological and social restoration goals.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-021-01565-3. 相似文献
286.
概述了近年来沈阳市发展低碳经济工作的进展情况,介绍了沈阳市发展低碳经济具有的深厚基础以及政策、机制和体制机遇,并从建设大浑南低碳发展样板区、实施低碳交通体系建设工程、建设低碳电力供应工程、开展低碳社区建设工程等方面出发,提出了沈阳市实现低碳发展的战略构想。 相似文献
287.
康乐 《辽宁城乡环境科技》2013,(5):33-35
评述了近年来城市污水生物脱氮除磷理论和功能微生物的研究进展,重点介绍了生物处理的新方法:短程硝化反硝化处理法、厌氧氨氧化处理法、同步硝化反硝化处理法、同步反硝化除磷脱氮法,并总结了各处理工艺的应用状况。对生物脱氮除磷微生物学和新的理论技术发展趋势做出了展望。 相似文献
288.
289.
介绍了高中速过滤器的应用环境、工作原理和结构组成,并从结构组成及工艺环境和实际应用性价比方面,提出实际工作时选择高中速过滤器的注意事项。 相似文献
290.
介绍了刮油刮渣机的工作原理和基本结构组成及应用结构方式,并从工艺环境及应用选择的性价比方面,提出实际工作时选择刮油刮渣机的注意事项,达到设备的最大合理化应用。 相似文献