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   1483篇
  免费   47篇
  国内免费   23篇
安全科学   61篇
废物处理   65篇
环保管理   321篇
综合类   124篇
基础理论   473篇
环境理论   4篇
污染及防治   296篇
评价与监测   106篇
社会与环境   83篇
灾害及防治   20篇
  2023年   11篇
  2022年   25篇
  2021年   33篇
  2020年   26篇
  2019年   30篇
  2018年   38篇
  2017年   51篇
  2016年   54篇
  2015年   51篇
  2014年   53篇
  2013年   128篇
  2012年   71篇
  2011年   120篇
  2010年   71篇
  2009年   87篇
  2008年   103篇
  2007年   94篇
  2006年   77篇
  2005年   56篇
  2004年   55篇
  2003年   51篇
  2002年   33篇
  2001年   15篇
  2000年   14篇
  1999年   19篇
  1998年   15篇
  1997年   14篇
  1996年   18篇
  1995年   13篇
  1994年   18篇
  1993年   13篇
  1992年   15篇
  1991年   8篇
  1990年   5篇
  1989年   8篇
  1988年   6篇
  1987年   3篇
  1986年   5篇
  1985年   2篇
  1984年   3篇
  1983年   6篇
  1982年   6篇
  1981年   6篇
  1980年   7篇
  1978年   4篇
  1976年   2篇
  1975年   3篇
  1973年   2篇
  1959年   1篇
  1957年   1篇
排序方式: 共有1553条查询结果,搜索用时 265 毫秒
441.
Despite legislation and voluntary initiatives aimed at protecting the environment, previously undeveloped areas of Costa Rica are subject to new development opportunities. This growth has been largely unchecked, and has led to enormous amounts of foreign direct investment. This unchecked investment has led to destabilization of the natural environment, and, in the case of the Dominical?CUvita corridor on the Pacific Coast, has led to an observed increase in landsliding activity. Data collection for a landslide inventory of the study area was created via direct inspection and remote sensing techniques in December 2007 and November 2008. Evaluation of data was based on the slide location, surrounding land cover/land use, and evidence of reactivation. Data were subjected to a ??2 2 × 3 contingency table and the Freeman?CHalton extension of the Fisher exact probability test to gauge the level of impact from human-induced land-use change on the rate of landslide events. The results suggest more attention needed to monitor the impacts of human agency in the region lest landslide susceptibility become greater.  相似文献   
442.
Changes to larval fish assemblages may have far reaching ecological impacts. Correlations between habitat modification, contamination and marine larval fish communities have rarely been assessed in situ. We investigated links between the large-scale distribution of stressors and larval fish assemblages in estuarine environments. Larval fish communities were sampled using a benthic sled within the inner and outer zones of three heavily modified and three relatively unmodified estuaries. Larval abundances were significantly greater in modified estuaries, and there were trends towards greater diversity in these systems. Differences in larval community composition were strongly related to sediment metal levels and reduced seagrass cover. The differences observed were driven by two abundant species, Paedogobius kimurai and Ambassis jacksoniensis, which occurred in large numbers almost exclusively in highly contaminated and pristine locations respectively. These findings suggest that contamination and habitat alteration manifest in substantial differences in the composition of estuarine larval fish assemblages.  相似文献   
443.
A detailed study of the free and conjugated estrogen load discharged by the eight major sewage treatment plants into the Yodo River basin, Japan was carried out. Sampling campaigns were focused on the winter and autumn seasons from 2005 to 2008 and the free estrogens estrone(E1), 17β-estradiol(E2), estriol(E3), 17α-ethynylestradiol(EE2) as well as their conjugated (sulfate and glucuronide) forms. For both sewage effluent and river water E2 and E1 concentrations were greatest during the winter period (December-March). This coincides with the period of lowest rainfall and lowest temperatures in Japan. E1 was the dominant estrogenic component in effluent (means of 10-50 ng/L) followed by E2 (means of 0.5-3 ng/L). The estrogen sulfate conjugates were found intermittently in the 0.5-1.7 ng/L concentration range in the sewage effluents. The greatest estrogen exposure was found to be in the Katsura River tributary which exceeded 1 ng/L E2-equivalents during the winter period.  相似文献   
444.
We monitored curbside airborne particulate matter (PM) concentrations and its proinflammatory capacity during 3 weekends when vehicle traffic was excluded from Park. Ave., New York City. Fine PM concentration peaked in the morning regardless of traffic while ultrafine PM was 58% lower during mornings without traffic. Ultrafine PM concentration varied linearly with traffic flow, while fine PM spiked sharply in response to random traffic events that were weakly correlated with the traffic signal cycle. Ultrafine PM concentrations decayed exponentially with distance from a cross street with unrestricted traffic flow, reaching background levels within 100 m of the source. IL-6 induction was typically highest on Friday afternoons but showed no clear relationship to the presence of traffic. The coarse fraction (>2.5 μm) had the greatest intrinsic inflammatory capacity, suggesting that coarse PM still warrants attention even as the research focus is shifting to nano-particles.  相似文献   
445.
Deficiencies with the current European reference method for the analysis using inductively couple plasma-mass spectrometry of metals in samples from stationary emissions sources are presented based on experimental data obtained from real samples. The effect of these deficiencies on the quality and accuracy of data is highlighted with biases of up to 40% being observed in real samples. Suggestions to improve the performance of the standard method are presented. In particular, the beneficial effect of using a drift correction procedure to account for the decrease in instrument sensitivity observed during an analytical measurement series is demonstrated. It is shown that this corrective procedure results in substantial improvements to the accuracy of data produced.  相似文献   
446.
Jessop A  Turner A 《Chemosphere》2011,83(11):1575-1580
We studied the leaching of copper and zinc from particles of discarded boat paint added to tap water (pH 7.3) and rain water (pH = 4.7), simulating conditions encountered during the hosing or runoff of antifouling waste. Leaching rates appeared to be diffusion-controlled and were greater in rain water than in tap water and were greater for Zn than for Cu. After a period of 120 h, between about 0.5% and 3% of total Cu and 5-30% of total Zn had been released to the aqueous phase. These observations suggest that Cu and Zn mobilised from fine antifouling particulates during washdown or rainfall events may be important contaminants of runoff and soils in the vicinity of boat repair facilities.  相似文献   
447.
Degaffe FS  Turner A 《Chemosphere》2011,85(5):738-743
Tire wear particles (TWP) abraded from end-of-life passenger car tires have been added at a concentration of 1 g L−1 to river water, sea water and mixtures thereof in order to examine the chemical controls on the leaching of Zn from the rubber matrix. Results of time-dependent experiments conducted over a period of 5 days were consistent with a diffusion controlled leaching mechanism with rate constants of about 0.04 mg L−1 h−1/2 in river water and between about 0.02 and 0.03 mg L−1 h−1/2 in sea water. Additional experiments revealed a reduction in Zn dissolution with both increasing salinity and pH and enhancement of leaching in the presence of fluorescent light compared with dark conditions. In corresponding experiments conducted in the presence of a fixed quantity (0.8 g L−1) of clean, fractionated estuarine sediment, aqueous Zn concentrations were reduced by at least an order of magnitude. Increasing the quantity of sediment resulted in a progressive reduction in Zn concentration until an apparent equilibrium was achieved, with partition coefficients defining the sediment-water distribution of Zn of about 550 mL g−1 and 270 mL g−1 in river water and sea water, respectively. Results are interpreted in terms of the dissolution of ZnO and other residual complexes from the matrix and the subsequent, rapid adsorption of Zn2+ ions to coexistent estuarine sediment. The findings of the study are discussed in terms of their implications for the transport, fate and effects of TWP Zn in aquatic environments that are likely to receive urban runoff.  相似文献   
448.
Extensive research has been conducted globally into conceptual frameworks for ecosystem services, the most notable being the Millennium Ecosystem Assessment (Millennium ecosystem assessment: ecosystems and human well-being; a framework for assessment. World Resources Institute, Washington, DC, pp 51, 53–55, 2005). The South East Queensland (SEQ) Ecosystem Services Framework (Australia) aims to provide the tools to enable government, industry, business, researchers, non-government organizations and land managers to apply the concept of ecosystem services in their planning and management practices. This article describes the Framework and the process that has produced matrices and maps that identify and illustrate the linkages between ecosystems, ecosystem functions, ecosystem services and the community’s well-being. The matrices and maps derived can identify areas in the region where the most ecosystem services are generated. This allows areas to be considered as valuable natural assets of the region, deserving appropriate protection measures or significant offsets if they are diminished or degraded in any way. Although the Framework requires further refinement and ongoing development, the process applied and the products produced has enabled decision makers to turn the concept of ecosystem services into practical application in SEQ.  相似文献   
449.
Natural resource professionals are increasingly faced with the challenges of cultivating community-based support for wetland ecosystem restoration. While extensive research efforts have been directed toward understanding the biophysical dimensions of wetland conservation, the literature provides less guidance on how to successfully integrate community stakeholders into restoration planning. Therefore, this study explores the social construction of wetlands locally, and community members’ perceptions of the wetland restoration project in the Cache River Watershed of southern Illinois, where public and private agencies have partnered together to implement a large-scale wetlands restoration project. Findings illustrate that the wetlands hold diverse and significant meanings to community members and that community members’ criteria for project success may vary from those identified by project managers. The case study provides managers with strategies for building community commitment such as engaging local citizens in project planning, minimizing local burdens, maximizing local benefits, and reducing uncertainty.  相似文献   
450.
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