首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   154篇
  免费   12篇
  国内免费   6篇
安全科学   41篇
废物处理   4篇
环保管理   28篇
综合类   38篇
基础理论   20篇
污染及防治   8篇
评价与监测   6篇
社会与环境   12篇
灾害及防治   15篇
  2023年   1篇
  2022年   3篇
  2021年   6篇
  2020年   9篇
  2019年   6篇
  2018年   2篇
  2017年   5篇
  2016年   8篇
  2015年   11篇
  2014年   7篇
  2013年   9篇
  2012年   11篇
  2011年   4篇
  2010年   8篇
  2009年   3篇
  2008年   11篇
  2007年   11篇
  2006年   5篇
  2005年   4篇
  2004年   4篇
  2003年   4篇
  2002年   8篇
  2001年   4篇
  2000年   4篇
  1999年   1篇
  1998年   6篇
  1997年   5篇
  1996年   3篇
  1994年   1篇
  1993年   5篇
  1992年   1篇
  1991年   1篇
  1989年   1篇
排序方式: 共有172条查询结果,搜索用时 15 毫秒
101.
We present the results of a study using a document-based evaluation method to better understand how residents in vulnerable coastal areas respond to risk communications about sea-level rise (SLR) and to determine whether communications localized for specific populations improve reception. Similar to climate change communication, SLR risk communication presents challenges involving complex science, uncertainty, invisibility, and politicization. To be comprehensible and persuasive, risk messages must be appropriately framed and visually compelling and must take into account risk perceptions and diverse viewpoints. Our approach involves assessing people's encounters with actual risk messages to determine their reactions and responses. Participants in this study had difficulty understanding information and expressed attitudes including fear, fatalism, skepticism, and loss. SLR risks were also perceived as both temporally and spatially distant, creating a challenge for communicators trying to convey a sense of urgency. We conclude by considering the implications of audience-focused research for SLR risk communication.  相似文献   
102.
Interactive sea-level rise viewers (ISLRVs) are digital tools used to communicate about impacts of sea-level rise (SLR) and support decision-making. This study characterizes how ISLRVs communicate about SLR-related risks and provide decision-making support. It identifies key themes about fostering accurate mental models of SLR processes, informing about inundation likelihood, communicating about related social and ecological risks, and providing features users can apply to specific tasks. We present a framework for understanding this type of communication tool that designers can use to develop robust ISLRVs that can support audiences’ understanding and decision-making needs, and contribute to enhancement of coastal resiliency.  相似文献   
103.
间二异丙苯与空气发生一次氧化反应,是间二异丙苯氧化法制备间苯二酚的关键技术,采用DSC差式扫描量热仪和VSP2绝热量热仪等,研究间二异丙苯与空气反应生成一次氧化产物的热稳定性和绝热失控特性。结果显示:间二异丙苯与空气反应生成一次氧化产物的起始放热温度(T0)为129℃,绝热温升(ΔT ad)为222℃,最高失控压力(P max)为4.05 MPa,最大反应速率到达时间为24 h对应的温度(T D24)为49.6℃。在工业化实施时应优化工艺流程,在操作过程中严格控制反应温度,优化操作条件,以保证安全生产。  相似文献   
104.
在闽江河口鳝鱼滩潮汐沼泽湿地设置有植物与无植物2种中宇宙,每种中宇宙设置对照(CK)、CK-20cm、CK-40cm 3种高程处理,以此模拟研究淹水增强对有无植物2 种中宇宙的CO2和CH4排放通量的影响.结果表明,淹水增强未显著改变植物的总生物量和植物株高,但增加植物地下生物量,减少植物地上生物量.在有植物中宇宙中,土壤氧化还原电位(ORP)和溶解性有机碳(DOC)浓度随着淹水增强而增加.在无植物中宇宙中,DOC浓度也随着淹水增强而增加,但土壤ORP随淹水增强变化不显著.与CK相比,在CK-20cm和CK-40cm 2种高程处理中,有植物中宇宙中CO2排放通量分别增加43%和61%,而CH4排放通量则分别增加66%和84%.在无植物中宇宙中,CO2和CH4的排放通量随着淹水增强无显著变化.未来海平面上升50~100a内,有植被的潮汐沼泽湿地综合增温潜势会增加,土壤有机碳储量会显著下降;无植被的潮汐沼泽湿地综合增温潜势将下降,土壤有机碳储量不会显著改变.  相似文献   
105.
我国海岸带灾害的加剧发展及其防御方略   总被引:9,自引:0,他引:9  
中国大陆海岸带绵长1.8万公里,地跨12个省市,是我国人口密集、经济发展最快的地区。出现的严重灾害有台风、风暴潮、洪涝、地震海啸、海岸侵蚀、盐水入侵、海冰、地基下沉、污染、赤潮等十类,并互相叠加,形成年直接经济损失100亿元以上。全球海平面上升与人类活动加强,使海岸带灾害加剧发展,粗略估计到下世纪初中期,导致的损失可能达到1000亿元以上,是海岸带经济发展的重要制约因素。必须提高全民防灾意识,在调查研究基础上,拟订海岸带减灾规划;加强灾害的监测、预报和预警;加高加固防潮防洪大堤与护岸工程,疏浚内陆洼地和城市排洪河道,提高排水能力;保护地下水源,严格限制过量开采,以防止地面下沉和盐水入侵;合理开发海岸带资源,保护生态环境,严格限制超标排污;积极参加国际合作,逐步限制CO_2等温室气体的排放,和缓海平面上升趋势,争取大幅度减轻海岸带灾害。  相似文献   
106.
Recent studies have identified the need to adapt to climate change by allowing landforms and habitats to migrate landward, although implementation of actual adaptation responses is limited. Removing the barriers that shore protection structures create between coastal and upland habitats can reestablish exchanges of sediment and the ecological functions of the natural ecotone. The potential for removing these structures was evaluated in 12 national parks managed by the U.S. National Park Service. Criteria for removal included condition of structures, influence of natural processes, environmental benefits, public safety, and visitor access and use.We found that 145 structures out of a total of 407 could be removed or allowed to deteriorate. We highlight three adaptation projects that are currently being conducted, two of which involve removing structures. Reasons for not taking a more pro-active approach to removing protection structures include (1) conflicting policy directives; (2) presence of key access roads and critical archaeological and historic sites; (3) lack of data; (4) lack of funds and human resources; (5) reluctance to replace known problems with an unknown set of problems; (6) consideration of visitor desires; and (7) reluctance to allow erosion to occur. Demonstration projects are needed to provide information about adaptation strategies that promote enhancement of ecosystem functions. Projects to remove protection structures are likely to be viewed as successful only if results are specified as a positive product, and the distinction between the concept of loss (erosion of existing landforms and habitats) and the concept of gain (evolution of new landforms and habitats) is made clear.  相似文献   
107.
To examine whether U.S. public opinion may become as sharply polarized on adaptation responses as it has been on mitigation policies, we surveyed a sample of urban coastal residents in Maryland (n = 378). We then tested the impact of a community deliberative event (n = 40) with small-group sea level rise discussions as a depolarization strategy. Cultural worldviews which contribute to politically polarized beliefs about climate were predictive of perceptions of sea level rise risk. Living close to flooding hazards also significantly predicted respondents’ perceptions of household or neighborhood risks, but not of risks to the entire county. The event significantly increased topic knowledge among all participants and, among those with a worldview predisposing them to lower risk perceptions, significantly increased problem identification and concern about impacts. These results suggest small-group deliberation focused on local problem-solving may be an effective tool for reducing the polarizing effects of cultural worldviews on decision-making.  相似文献   
108.
Responding to global change represents an unprecedented challenge for society. Decision makers tend to address this challenge by framing adaptation as a decision problem, whereby the responses to impacts of change are addressed within existing decision processes centred on defining the decision problem and selecting options. However, this ‘decision-making perspective’ is constrained by societal values and principles, regulations and norms and the state of knowledge. It is therefore unsuitable for addressing complex, contested, cross-scale problems. In this paper we argue that simply broadening the decision-making perspective to account for institutions and values is not enough. We contend the decision-making perspective needs to be connected with a broader ‘decision-context perspective’ that focuses on how the societal system of decision processes affects the manner in which a particular problem is addressed. We describe the decision context as an interconnected system of values, rules and knowledge (vrk). The interaction of systems of vrk both creates and limits the set of practical, permissible decisions; the types of values, rules and knowledge that influence the decision and the capacity for change and transformation in the decision context. We developed a framework to analyse the interactions between values, rules and knowledge and their influence on decision making and decision contexts of adaptation initiatives, and applied it retrospectively to three projects on adaptation to sea-level rise. Our analysis revealed: (1) specific examples of how interactions between vrk systems constrained existing framings of decision making and the development of options for coastal adaptation; (2) limitations in the adaptive management strategies that underpinned the projects and (3) how the linked systems of vrk can allow adaptation practitioners to structure adaptation as a process of co-evolutionary change that enables a broader set of social issues and change processes to be considered. Adaptation projects that focus on the decision context represent a pragmatic alternative to existing decision-focused adaptation. By using the vrk model to diagnose constraints in decision processes, we show how the reframing of adaptation initiatives can reveal new approaches to developing adaptation responses to complex global change problems.  相似文献   
109.
The impending form and extent of climate change and its direct impacts present disproportionate challenges for the most socially and economically disadvantaged groups within populations. Evaluating the vulnerability of disadvantaged groups in the context of climate change has presented tremendous theoretical, methodological and policy challenges especially where vulnerability assessment research is focused at the local community level. This study addresses the challenges by developing an interdisciplinary methodology, based on expert knowledge, and uses the state of South Australia as a case study. It focuses on key indicators that measure the exposure of local communities to climate change and socio-economic vulnerabilities of local populations. A main contribution in this study is the novel incorporation of physical, environmental and socio-demographic data sets and extensive use of spatial modelling and estimation methods to spatially define climate change and social vulnerability “hot spots”. This paper assesses vulnerability under moderate and high Intergovernmental Panel on Climate Change CO2 emission scenarios in order to generate an assessment model to be used before planning is done. The result is the creation of a practical tool through which decision-makers can better understand how the complexity of one's local spatial context influences the unique exposure, which different vulnerable communities have, to the impacts of climate change. This paper presents a useful tool that can be used in the initial assessment phase by planners and policy-makers to better assist those who are limited in their ability to adapt to climate change.  相似文献   
110.
In the work presented in this paper, the explosion and flammability behavior of combustible dust mixtures was studied. Lycopodium, Nicotinic acid and Ascorbic acid were used as sample dusts.In the case of mixtures of two dusts, the minimum explosive concentration is reproduced well by a Le Chatelier's rule-like formula, whereas the minimum ignition energy is a linear combination of the ignition energies of the pure dusts.An unexpected behavior has been found in relation to the explosion behavior and the reactivity. When mixing Lycopodium and Nicotinic acid or Ascorbic acid, the rate of pressure rise of the mixture is much higher than the rate of pressure rise obtained by linearly averaging the values of the pure dusts (according to their weight proportions), thus suggesting that strong synergistic effects arise; but it is comparable to that of the most reactive dust in the mixture.The observed behavior seems to be linked to the presence of minerals in the Lycopodium particles which catalyze oxidation reactions of Nicotinic acid and Ascorbic acid, as suggested by TG analysis.In the case of mixtures of three dusts, a similar behavior is observed when the concentration of Lycopodium is twice that of the other two dusts.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号