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   221篇
  免费   1篇
  国内免费   1篇
安全科学   3篇
废物处理   2篇
环保管理   20篇
综合类   82篇
基础理论   56篇
污染及防治   46篇
评价与监测   9篇
社会与环境   5篇
  2022年   2篇
  2020年   2篇
  2018年   5篇
  2017年   3篇
  2016年   3篇
  2015年   4篇
  2014年   5篇
  2013年   11篇
  2012年   16篇
  2011年   10篇
  2010年   7篇
  2009年   10篇
  2008年   8篇
  2007年   10篇
  2006年   10篇
  2005年   8篇
  2004年   8篇
  2003年   8篇
  2002年   10篇
  2001年   8篇
  2000年   3篇
  1999年   4篇
  1998年   4篇
  1995年   4篇
  1989年   2篇
  1986年   3篇
  1982年   2篇
  1978年   2篇
  1974年   2篇
  1970年   2篇
  1968年   1篇
  1967年   2篇
  1966年   4篇
  1965年   3篇
  1964年   1篇
  1963年   2篇
  1961年   1篇
  1958年   1篇
  1957年   1篇
  1956年   2篇
  1955年   2篇
  1954年   1篇
  1952年   2篇
  1951年   1篇
  1949年   2篇
  1938年   1篇
  1931年   1篇
  1924年   1篇
  1923年   1篇
  1922年   1篇
排序方式: 共有223条查询结果,搜索用时 29 毫秒
11.

Objective

Flood sediments were investigated due to the extreme flood situation around Dresden in August 2002

Method

The samples have been analyzed by screening inorganic and organic pollutants.

Results

It was observed that As, Pb, Cd, Zn, Cu, B and other heavy metals as well as DDT, PCB and Benzo [a] pyren were significantly enriched.

Conclusion

Depending on geogenic and anthropogenic impacts, the spatial distribution of these contaminants was different. Organic compounds were dislocated down stream from Czech Republic along the Elbe River. Because of the old ore mining, samples near the Mulde and Wei\eritz Rivers showed high metal pollution.

Perspective

More detailed and systematic investigations should be undertaken in the Elbe and Mulde river systems.  相似文献   
12.
The impact of intranest relatedness on nestmate recognition was tested in a population of polydomous and monodomous nests of the mound-building ant Formica pratensis. Nestmate recognition was evaluated by testing aggression levels between 37 pairs of nests (n=206 tests). Workers from donor colonies were placed on the mounds of recipient nests to score aggressive interactions among workers. A total of 555 workers from 27 nests were genotyped using four DNA microsatellites. The genetic and spatial distances of nests were positively correlated, indicating budding and/or fissioning as spread mechanisms. Monodomous and polydomous nests did not show different aggression levels. Aggression behavior between nests was positively correlated with both spatial distance and intranest relatedness of recipient colonies, but not with genetic distance or intranest relatedness of donor colonies. Multiple regression analysis revealed a stronger effect of spatial distance than of genetics on aggression behavior in this study, indicating that the relative importance of environment and genetics can be variable in F. pratensis. Nevertheless, the positive regression between intranest relatedness of recipient colonies and aggression in the multiple analysis supports earlier results that nestmate recognition is genetically influenced in F. pratensis and further indicates that foreign label rejection most likely explains our data.  相似文献   
13.
Systematic environmental screenings are still the exception in South-Eastern Europe. Especially, there is a decisive lack of information concerning the occurrence and behaviour of xenobiotic and toxic compounds like volatile-and non volatile halogenated organics, suppressed by the surrogate AOX, synthetic chelating agents, pesticides, like DDT as well as chlorate in the biosphere. The analysis of soils, waters and firns of a representative area in Bulgaria, the Pirin mountains, indicate a relatively low back ground pollution. The accumulation of the xenobiotics in this high mountain region is recognised to be low. Nevertheless, traces of pesticides and chelating agents like EDTA and NTA in ice (firns) and soils were found. The surrogate AOX should be a parameter, suitable for routine environmental screenings of such areas.  相似文献   
14.
15.
16.
17.
    
This paper presents a numerical simulation study that examines the CO2 injection‐induced salinity changes in groundwater formations. We use a simplified numerical model to simulate the migration of formation water caused by pressure build‐up during CO2 injection. A stacked reservoir consisting of a storage formation overlain by a geological seal and groundwater aquifer is modeled. We use a commercial reservoir simulator to run various realizations with different seal permeabilities, injection rates, lateral boundary conditions, and groundwater production rates. We then track salinity changes calculated by the simulations. We find that lateral boundary conditions and seal permeabilities are the most critical parameters that govern lateral and vertical displacement of formation water. If the seal permeability is high enough or the lateral boundary is closed, the vertical fluid displacement dominates the lateral displacement. Depending on seal thickness, injection rate and reservoir salinity, this has the potential to cause significant salinity change in the overlying groundwater aquifer. If the seal permeability is low or the lateral boundary is open, then the lateral displacement becomes dominant. If the storage formation extends to an up‐dip shallow groundwater formation, the higher the lateral fluid displacement the higher the increase in salinity of the groundwater. Moreover, salinity changes occur in the deeper part of the groundwater formation because displaced water is heavier than groundwater. This study shows that tracking salinity changes in numerical simulations may provide a quantitative measure of the change in groundwater quality. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd  相似文献   
18.
During the last 40 years, merchant ships have become safer and a number of new safety measures have been introduced. The purpose of the first part of this study was to investigate the trend of fatalities due to maritime disasters in the Danish merchant fleet over a 40-year period from 1970 to 2009, during which a total of 146 seafarers lost their lives. The relative risk of fatal accidents in the period 1990–2009 compared with the period 1970–1989 was 0.81 (CI: 0.58–1.14).The second part of the study focuses on seafarers who abandoned a merchant ship in the period from 1990 to 2009. The purpose was to investigate factors influencing survival. During the 20-year period 44 incidents were identified involving a total of 267 seafarers. Among these, 51 did not survive. The fatality risk for seafarers on small and large ships was 3.68 and 0.64 per 1000 years at risk, respectively. Among the 171 seafarers who were rescued dry, one was injured and did not survive (0.6%). Out of 64 seafarers ending up in the water, 18 (28%) did not survive. Among the remaining 32 seafarers, 23 were with great certainty inside the vessel when it sank and another nine may have remained inside the sinking vessel. None of these survived. Suboptimal organisation of the evacuation process was of importance in some cases. Survival suits and automatic emergency transmitters (EPIRB’s) have been shown to work in practice but their introduction has had limited influence on survival statistics.  相似文献   
19.
The concept of ecosystem services (ES) is being increasingly applied in environmental governance and science. To safeguard key ES in changing and complex social–ecological systems such as treeline areas, we need to (1) map key ES in different types of treeline landscapes, (2) identify the stakeholders benefiting from and threatening ES, and (3) examine how ES could be governed more sustainably. We explore these questions in European treeline areas by using quantitative and qualitative social science techniques to analyse responses from a survey of local scientific experts in 20 altitudinal and polar treeline areas in 15 European countries. In contrast to the prevalent consideration of treeline areas as a single type of a social–ecological system, we show that European treeline areas can be divided into two types that significantly differ in the delivery of ES. Our analyses allowed us to categorize stakeholders according to their benefits from and threats to ES; “Green key players” formed the most numerous group, while smaller number of stakeholder groups was categorized as “Harmless crowd”, “Occasional stressors”, and “Risky users”. However, behaviour of stakeholders is very much site-specific. Of 595 pairs of stakeholders analysed, we found <5 EU-wide “Allies” and “Opponents”. Recommendations for improved governance include adjusting governance instruments to specific problems in divergent treeline systems and creating participatory structures where stakeholders better interact with scientists and can genuinely influence management decisions.  相似文献   
20.
Sediment quality guidelines (SQGs) can be derived using different approaches and are commonly used in environmental management, reclamation, and risk assessment. The screening-level concentration (SLC) approach has been used in Ontario, Canada, to derive lowest effect levels (LELs) and severe effect levels for use as SQGs. This approach was adopted by the Canadian Nuclear Safety Commission (CNSC) to set guidelines for metals (As, Cr, Cu, Pb, Mo, Ni, Se, U, and V) and radionuclides (Ra-226, Pb-210, and Po-210) in sediment at northern Saskatchewan uranium mining and milling operations. The SLC approach is based on total metal and radionuclide concentrations in sediment, and corresponding benthic community composition data for a specific sampling site. In this study, sediment chemistry (total metals and radionuclides) and benthic community data from northern Saskatchewan uranium operations were compiled and examined. Results indicate that the CNSC-derived SQGs had limited relationships to observed effects, or lack thereof, on benthic invertebrate communities near uranium operations in Saskatchewan. The LELs were found to correctly align with effects at 95% of the sites that had effects, on a general basis, but on an element-specific basis many of the elements had concentrations at effect sites below their LELs. Furthermore, concentrations of the evaluated elements exceeded at least one LEL at 60% of the no-effect sites. The high number of exceedences of LELs at reference and no-effect sites (false-positives) calls to question the appropriateness of the CNSC-derived SQGs. It is suggested that alternatives to the SLC approach be explored.  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