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对有线电视系统而言,雷电防护是一项很重要的工作,通过对雷电的种类及雷电入侵有线电视系统途径的分析,探讨了如何对系统中的接收天线、前端设备等环节进行雷电防护设计,对雷电防护中的接地技术也作了详细的介绍。 相似文献
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分析了雷电对信息系统造成危害原因及入侵渠道,并根据建筑物内信息系统所处区域的雷暴等级及雷电防护基本原则,提出了信息系统综合雷电防护技术措施. 相似文献
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自动站网络通信系统雷电防护包括广域网雷电防护、局域网雷电防护、光缆通信雷电防护等,这3种防护主要是防护雷电波入侵产生的感应雷以及由于自动站室内计算机局域网机房没有做好等电位连接造成的雷电损坏。1广域网雷电防护广域网的雷电防护主要是通信线、信号线不允许架空进入 相似文献
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对有线电视系统而言,雷电防护是一项很重要的工作,通过对雷电的种类及雷电入侵有线电视系统途径的分析,探讨了如何对系统中的接收天线、前端设备等环节进行雷电防护设计,对雷电防护中的接地技术也作了详细的介绍。 相似文献
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分析了雷电对信息系统造成危害原因及入侵渠道,并根据建筑物内信息系统所处区域的雷暴等级及雷电防护基本原则,提出了信息系统综合雷电防护技术措施。 相似文献
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在雷电防护的实践中,要求首先明确雷电防护的必要性,在防雷工程实施之前,对防护对象根据防护级别的划分来采用合适的防雷等级设计方案。需要确定雷电灾害风险的大小,并采取安全可靠、技术先进、经济合理的雷电防护方法。因此,在雷电防护管理工作中,雷电灾害风险评估体系建设具有深远意义,可为雷电灾害调查提供重要依据。 相似文献
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高层建筑雷电防护装置检测要点 总被引:2,自引:0,他引:2
随着城市环境条件的不断改善,高层建筑越来越多,而高层建筑遭受雷击的概率又远远高于低层建筑物。高层建筑内设备和线路密集,雷电对这些设备及线路的破坏威胁也大大增加。而如何做好高层建筑的雷电防护是摆在从事雷电防护工作人员面前的重要课题。其中,雷电防护工作有一个很重要的环节就是雷电防护装置的检测工作,检测数据的准确与否、检测工作质量的好坏直接影响着建筑物雷电防护措施的有效性。本文从采取雷电防护措施的几种方式着手,对新建高层建筑物雷电防护装置的检测要点做如下阐述。 相似文献
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Successful adaptation to environmental change and variability is closely connected with social groups’ ability to act collectively, but many social-ecological challenges exceed local adaptive capacity which necessitate assistance from governmental institutions. Few studies have investigated how local collective action can be used to enrol external support for adaptation. This paper reduces this research gap by analysing a locally driven adaptation process in response to coastal erosion in Monkey River Village, Belize. Drawing on literature on adaptation and political ecology, we examine the different strategies the local residents have used over time to influence government authorities to support them in curbing the coastal erosion. Our findings show that the local mobilisation generated government support for a temporary sea defence and that collective strategies emerge as a response to threats to a place specific way of life. Our case illustrates that it was essential that the villagers could ally with journalists, researchers and local NGOs to make their claims for protection heard by the government. The paper contributes to adaptation research by arguing that local collective action, seen as contestation over rights to protection from environmental change, can be a means for places and communities not prioritised by formal policies to enrol external support for adaptation. Our study supports and adds to the perspective that attention to formal arrangements such as adaptation policy alone has limited explanatory power to understand collective responses to change. 相似文献
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Michael Grubb 《Climate Policy》2013,13(1):1-2
Despite the increasing interest in climate change policy in the US, little systematic research has been conducted on the willingness of individuals to change their behaviour to mitigate the problem. Understanding behavioural change is critical if federal and local governments intend to implement programmes requiring actions to mitigate and adapt to climate change. This understudied aspect of climate change policy is addressed by quantitatively examining the degree to which residents living in the US are willing to alter their behaviour to mitigate climate change impacts, and by identifying the major factors contributing to this willingness. Based on a national survey, the reported willingness of individuals to alter behaviours is explained, using the components of risk, individual stress, capacity and ecological values. The findings indicate that specific personal traits and contextual characteristics trigger a significantly greater willingness to change longstanding behavioural patterns. These insights into the factors motivating behavioural change can provide guidance to decision makers at both federal and local levels on how best to implement climate change policies. 相似文献
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Multiple exposures and dynamic vulnerability: Evidence from the grape industry in the Okanagan Valley, Canada 总被引:7,自引:1,他引:7
This paper assesses the vulnerability of grape growers and winery operators in the Okanagan Valley, British Columbia to climate variability and change, in the context of other sources of risk. Through interviews and focus groups, producers identified the climatic and non-climatic risks relevant to them and the strategies employed to manage these risks. The results show that the presence of multiple exposures affects the way in which producers are vulnerable to climate change. Producers are vulnerable to conditions that not only affect crop yield, but also affect their ability to compete in or sell to the market. Their sensitivity to these conditions is influenced in part by institutional factors such as trade liberalization and a “markup-free delivery” policy. Producers’ ability to adapt or cope with these risks varies depending on such factors as the availability of resources and technology, and access to government programmes. Producers will likely face challenges associated with the supply of water for irrigation due to a combination of climatic changes and changing demographics in the Okanagan Valley, which in turn affect their ability to adapt to climatic conditions. Finally, adaptations made by producers can change the nature of the operation and its vulnerability, demonstrating the dynamic nature of vulnerability. 相似文献
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Sudden disruptions, or shocks, to food production can adversely impact access to and trade of food commodities. Seafood is the most traded food commodity and is globally important to human nutrition. The seafood production and trade system is exposed to a variety of disruptions including fishery collapses, natural disasters, oil spills, policy changes, and aquaculture disease outbreaks, aquafeed resource access and price spikes. The patterns and trends of these shocks to fisheries and aquaculture are poorly characterized and this limits the ability to generalize or predict responses to political, economic, and environmental changes. We applied a statistical shock detection approach to historic fisheries and aquaculture data to identify shocks over the period 1976–2011. A complementary case study approach was used to identify possible key social and political dynamics related to these shocks. The lack of a trend in the frequency or magnitude of the identified shocks and the range of identified causes suggest shocks are a common feature of these systems which occur due to a variety, and often multiple and simultaneous, causes. Shocks occurred most frequently in the Caribbean and Central America, the Middle East and North Africa, and South America, while the largest magnitude shocks occurred in Asia, Europe, and Africa. Shocks also occurred more frequently in aquaculture systems than in capture systems, particularly in recent years. In response to shocks, countries tend to increase imports and experience decreases in supply. The specific combination of changes in trade and supply are context specific, which is highlighted through four case studies. Historical examples of shocks considered in this study can inform policy for responding to shocks and identify potential risks and opportunities to build resilience in the global food system. 相似文献
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针对气候变暖采取稳健的适应措施已成为国际社会共识。该文综合了当前适应气候变化的国际谈判进展及已有的农业适应气候变化措施,指出适应资金严重不足,技术研发、应用与转让难以实施,以及适应气候变化行动实施能力的不足严重制约着适应气候变化行动的有效实施;关于农业适应气候变化的技术措施仍缺乏系统的理论研究与应用示范。在此基础上,提出了未来中国农业适应气候变化需要重点开展的研究任务,即农业气象灾变过程的新特点及其风险管理, 农业适应气候变化的大数据决策管理系统研发及适应气候变化的农业气候区划与减灾保产技术研究,以切实推进农业适应气候变化,为确保国家粮食安全与农业可持续发展提供支撑。 相似文献
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This article reviews Fuqing ZHANG’s contributions to mesoscale atmospheric science,from research to mentoring to academic service,over his 20-year career.His fundamental scientific contributions on predictability,data assimilation,and dynamics of high impact weather,especially gravity waves and tropical cyclones,are highlighted.His extremely generous efforts to efficiently transmit to the community new scientific knowledge and ideas through mentoring,interacting,workshop organizing,and reviewing are summarized.Special appreciation is given to his tremendous contributions to the development of mesoscale meteorology in China and the education of Chinese graduate students and young scientists. 相似文献
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随着对气候变化研究的不断深入,气候变化脆弱性问题也得到了更多的关注。相对于水资源、森林等其他自然生态系统,农业受气候变化的影响最大,科学地评价其对气候变化的脆弱性,对于制定合理有效的适应对策具有重要意义。从气候变化脆弱性与农业对气候变化脆弱性的定义、研究内容和评价方法等角度综述了研究进展,在此基础上分析了目前该领域存在的问题,包括情景应用、方法和不确定性等方面,并展望了未来脆弱性评价的发展方向。 相似文献
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气候变化影响与适应问题的谈判进展 总被引:2,自引:0,他引:2
从《气候变化框架公约》(以下简称《公约》)第一次缔约方会议到目前为止,几乎历次会议都涉及气候变化影响与适应的谈判内容,但谈判进展甚微。通过综述《公约》谈判进程中与适应气候变化有关的主要决定,分析了适应气候变化影响与适应问题谈判的制约因素,最后提出了我国在气候变化影响与适应问题谈判中应持的立场。 相似文献
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Nicholas P. Webb Christopher J. Stokes Nadine A. Marshall 《Global Environmental Change》2013,23(5):1164-1177
This paper demonstrates how biophysical and socio-economic assessments of adaptation options can be integrated to test the effectiveness of options and anticipate social risks and potential barriers to adoption. We present the approach by combining a model analysis with a multiple-criteria evaluation of 12 adaptation options by graziers from the Australian rangelands. Our results show that strategies to manage stocking rates and pasture spelling are likely to be effective in improving climate resilience in the rangelands and are easy-to-implement, short-term solutions. Improving land condition is found to have the greatest potential long-term benefits, but was not considered by the graziers to be feasible or effective due to perceived difficulties of implementation. Areas of concordance identified in the assessments may be used to engage with stakeholders and build a foundation for incorporating climate change considerations into management and policy. The approach also highlights discordant views within the assessments that may result from differing management objectives, adaptive capacity and climate-risk perception. These factors are potential impediments to adaptation. The integrated assessment approach enables adaptation strategies and policy recommendations to be developed that have greater relevance to individual stakeholders, and supports capacity building to facilitate the most effective adaptation actions. 相似文献
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The focus of this study is on how changes in formal and informal institutions have differential impacts across populations in terms of vulnerability of livelihoods to drought, and the unequal processes that shape adaptation to new conditions. Drought vulnerability occurs as a result of exposure and sensitivity to interrelated economic, social, political, and ecological dynamics. There is a need for approaches that can evaluate how the ability to reduce these exposures and sensitivities becomes socially stratified. Building on our understanding of institutional and biophysical constraints in one pastoralist group ranch, we use an approach that draws on quantitative and qualitative data to combine analyses of entitlements, access, and adaptive capacity. We asked how, in a context of changing herding institutions, the ability to adapt to drought and other stressors, is differentiated among actors. We found that herders with higher livestock wealth are more likely to have entitlement sets that include factors that enable access to secure cattle grazing on private wildlife conservation lands, and access to more distant areas with herds of sheep and cattle – two key means of reducing exposure to drought vulnerability, leading to greater coping ability during drought. Those with lower livestock wealth rely disproportionately on illicit, precarious access to external grazing resources. Higher livestock wealth families experienced disproportionately lower sensitivity to drought with smaller losses of cattle, and likely have decreased sensitivity to drought-related market fluctuations, while others are primarily reliant on small stock and/or precarious access pathways. However, rather than naturalize this differential ability as merely increased adaptive capacity for some that are better able to adapt to novel, local conditions, we argue this instead reflects the unequal footing that households find themselves on, in a shifting institutional landscape of structural and relational access constraints and reconfigurations of reciprocity, that are intertwined with interventions by state and non-state actors. 相似文献