全文获取类型
收费全文 | 405篇 |
免费 | 33篇 |
国内免费 | 97篇 |
专业分类
安全科学 | 40篇 |
废物处理 | 8篇 |
环保管理 | 58篇 |
综合类 | 169篇 |
基础理论 | 71篇 |
环境理论 | 6篇 |
污染及防治 | 77篇 |
评价与监测 | 12篇 |
社会与环境 | 71篇 |
灾害及防治 | 23篇 |
出版年
2023年 | 9篇 |
2022年 | 11篇 |
2021年 | 13篇 |
2020年 | 9篇 |
2019年 | 23篇 |
2018年 | 42篇 |
2017年 | 32篇 |
2016年 | 21篇 |
2015年 | 28篇 |
2014年 | 17篇 |
2013年 | 46篇 |
2012年 | 24篇 |
2011年 | 17篇 |
2010年 | 20篇 |
2009年 | 24篇 |
2008年 | 15篇 |
2007年 | 31篇 |
2006年 | 21篇 |
2005年 | 14篇 |
2004年 | 22篇 |
2003年 | 12篇 |
2002年 | 16篇 |
2001年 | 13篇 |
2000年 | 15篇 |
1999年 | 7篇 |
1998年 | 3篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 2篇 |
1990年 | 1篇 |
1987年 | 2篇 |
1984年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有535条查询结果,搜索用时 296 毫秒
471.
This article describes the development of a model to simulate the fate of iodinated X-ray contrast media (XRC) in the water cycle of the German capital, Berlin. It also handles data uncertainties concerning the different amounts and sources of input for XRC via source densities in single districts for the XRC usage by inhabitants, hospitals, and radiologists. As well, different degradation rates for the behavior of the adsorbable organic iodine (AOI) were investigated in single water compartments. The introduced model consists of mass balances and includes, in addition to naturally branched bodies of water, the water distribution network between waterways and wastewater treatment plants, which are coupled to natural surface waters at numerous points. Scenarios were calculated according to the data uncertainties that were statistically evaluated to identify the scenario with the highest agreement among the provided measurement data. The simulation of X-ray contrast media in the water cycle of Berlin showed that medical institutions have to be considered as point sources for congested urban areas due to their high levels of X-ray contrast media emission. The calculations identified hospitals, represented by their capacity (number of hospital beds), as the most relevant point sources, while the inhabitants served as important diffusive sources. Deployed for almost inert substances like contrast media, the model can be used for qualitative statements and, therefore, as a decision-support tool. 相似文献
472.
通过收集国内各地区水体、沉积物和土壤中抗生素的最新污染数据,试图从全国尺度范围进行分析,以反映我国环境中抗生素的污染状况,并利用风险商值(RQs)评估抗生素的生态风险.结果表明,我国各地水体、沉积物和土壤均受到不同程度的抗生素污染,南方地区水体污染较为严重,而西部地区则较轻.生态风险评价结果表明,我国水体中红霉素、罗红霉素、四环素、金霉素、磺胺甲唑和诺氟沙星是高风险污染物,占比为20.9%,主要分布在山东、湖北、浙江、四川、广东、海南、江苏和江西等地;江河沉积物中,诺氟沙星是高风险污染物,占比为11.1%,主要分布在黄河、海河、辽河和珠江等地;养殖场沉积物中,四环素、土霉素、金霉素和诺氟沙星是高风险污染物,占比高达72.5%;土壤中,四环素和金霉素是高风险污染物,占比为28.6%,主要分布在辽宁、四川、天津和山东等地,以上高风险区域应引起相关部门的重视.研究结果可为我国抗生素的污染防治提供科学依据和数据支撑. 相似文献
473.
Sabrina McCormick 《Disasters》2016,40(2):207-225
This paper focuses on the role of the formal response community's use of social media and crowdsourcing for emergency managers (EMs) in disaster planning, response and recovery in the United States. In‐depth qualitative interviews with EMs on the Eastern seaboard at the local, state and federal level demonstrate that emergency management tools are in a state of transition—from formal, internally regulated tools for crisis response to an incorporation of new social media and crowdsourcing tools. The first set of findings provides insight into why many EMs are not using social media, and describes their concerns that result in fear, uncertainty and doubt. Second, this research demonstrates how internal functioning and staffing issues within these agencies present challenges. This research seeks to examine the dynamics of this transition and offer lessons for how to improve its outcomes—critical to millions of people across the United States. 相似文献
474.
475.
把信息化技术用于油气田安全领域,用采集的现场数据评估安全生产环境,实现油气田安全信息化是近年来的新课题。为了有效地监测和预防油三高气田(高含硫、高产量、高压力)井喷事故造成的灾害,讨论了基于网络架构的重大事故现场监测数据采集管理系统软件的研究与设计,包括气象数据,传感器数据,监测设备GPS数据与视频信息的实时采集、处理、分析与显示,并且分段说明了该系统各部分的设计和实现的重点.该系统具有友好的人机界面,并且引入了流媒体技术、无线传感器技术等多种先进技术,能够最大程度地得到全面的表征油气田安全的数据与信息;该系统已经在研究实例龙岗油气田的实验中证明了具有安全生产方面的现实意义。 相似文献
476.
Ashutosh Mittal Tarun Kataria Gautam K. Das 《International Journal of Green Energy》2013,10(4):347-368
Evaporative cooling of water in a small porous clay vessel was studied under controlled humidity conditions. In steady-state experiments performed at an ambient temperature of 23 °C, the cooling effect increased from 4.7 to 8.3 °C as the ambient relative humidity decreased from 60 to 15%. External heat and mass transfer coefficients, estimated from the steady-state measurements, were used in mathematical models to predict the experimentally observed transient temperature variation of the water under ramp changes of the ambient relative humidity. With a prototypical cool chamber containing water tested in Kolkata, India under an ambient temperature of 34.5–35 °C, the cooling effect reached a maximum of 7 °C between 3 and 3:30 PM and then declined to 4.5 °C around 6 PM. 相似文献
477.
Witold Gądor Elżbieta Jankowska 《International journal of occupational safety and ergonomics》2013,19(3):361-379
AbstractThis paper presents the results and conclusions from experimental investigations concerning filtration properties of nonwovens. The needled nonwovens were made from polyester fibres (PTE) with average fibre diameter 12 µm and polypropylene fibres (PP) with average fibre diameter 32 μm. Nonwovens were produced out of each of those fibres or out of a mixture of polyester and polypropylene fibres. This paper also presents investigations of nonwoven fabric made of polypropylene fibres (PP) with average fibre diameter 2.6 μm, which was formed according to melt-blown technology. Oil mist, as challenge aerosol, was used to evaluate the performance of filter media at various aerosol velocities. The average oil mist test aerosol particle diameter was 0.3 μm. Filter penetration was measured at oil mist concentration 0.24 g/m3. 相似文献
478.
《Environmental Communication: A Journal of Nature and Culture》2013,7(4):468-488
Climate change and imagined futures are intricately linked, discussed by policy-makers and reported in the media. In this article we focus on the construction of future expectations in the press coverage of the 1992 and 2012 United Nations conferences in Rio de Janeiro in British and Dutch national newspapers. We use a novel combination of methods, semantic co-word networks and metaphor analysis, to study imagined futures. Our findings show that between 1992 and 2012 there was an overall shift from future-oriented hope to past-oriented disappointment regarding implementing international agreements on climate change policy, but with subtle and interesting differences between the UK and The Netherlands. Certain national differences seem to be stable over time and are indicative of rather dissimilar policy cultures in two nations which are geographically quite close. 相似文献
479.
《Environmental Communication: A Journal of Nature and Culture》2013,7(1):92-109
Current research suggests that the media play an important part in informing and engaging citizens in environmental issues. Building on these findings, this study adopts a political socialization approach to citizens' involvement in everyday-life pro-environmental behavior. Multivariate analysis of recent survey data from Swedish adolescents (N = 1148) demonstrates direct as well as indirect relationships between frequency of news media use, talk about environmental issues with parents and peers, and extent of pro-environmental behavior. The findings are consistent with the notion that news media use promotes behavior by raising awareness of environmental issues. The results are also discussed in terms of a citizen-communication framework according to which interpersonal communication translates environmental information gleaned from news sources to adolescents' everyday-life reality, thereby motivating pro-environmental behavior. Future directions for examining causal mechanisms in more detail are discussed. 相似文献
480.
王爱冬 《中国环境管理干部学院学报》2002,12(1):48-52
本文从社会转型期容易产生腐败问题为切入点,分析了加强和改进政治权力制约的必要性,并根据我国的实际情况,提出了为治理和减少腐败而加强和改进对政治权力制约的对策和办法。 相似文献