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   156篇
  免费   2篇
  国内免费   4篇
安全科学   3篇
废物处理   9篇
环保管理   54篇
综合类   20篇
基础理论   24篇
污染及防治   27篇
评价与监测   12篇
社会与环境   8篇
灾害及防治   5篇
  2023年   1篇
  2022年   2篇
  2021年   5篇
  2020年   2篇
  2019年   3篇
  2018年   2篇
  2017年   7篇
  2016年   4篇
  2015年   1篇
  2014年   4篇
  2013年   12篇
  2012年   10篇
  2011年   10篇
  2010年   8篇
  2009年   9篇
  2008年   9篇
  2007年   5篇
  2006年   11篇
  2005年   7篇
  2004年   6篇
  2003年   3篇
  2002年   4篇
  2001年   4篇
  2000年   3篇
  1999年   4篇
  1998年   5篇
  1997年   3篇
  1996年   1篇
  1995年   4篇
  1994年   2篇
  1993年   1篇
  1992年   1篇
  1984年   2篇
  1982年   1篇
  1981年   1篇
  1980年   3篇
  1979年   1篇
  1978年   1篇
排序方式: 共有162条查询结果,搜索用时 93 毫秒
61.
Compost application to turfgrass soils may increase dissolved organic C (DOC) levels which affects nutrient dynamics in soil. The objectives of this study were to investigate the influence of compost source and application rate on soil organic C (SOC), DOC, NO(3), and available P during 29 months after a one-time application to St. Augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze] turf. Compost sources had variable composition, yet resulted in few differences in SOC, DOC, and NO(3) after applied to soil. Available NO(3) rapidly decreased after compost application and was unaffected by compost source and application rate. Available P increased after compost application and exhibited cyclical seasonal patterns related to DOC. Compost application decreased soil pH relative to unamended soil, but pH increased during the course of the study due to irrigation with sodic water. Increasing the compost application rate increased SOC by 3 months, and levels remained fairly stable to 29 months. In contrast, DOC continued to increase from 3 to 29 months after application, suggesting that compost mineralization and growth of St. Augustinegrass contributed to seasonal dynamics. Dissolved organic C was 75%, 78%, and 101% greater 29 months after application of 0, 80, and 160 Mg compostha(-1), respectively, than before application. Impacts of composts on soil properties indicated that most significant effects occurred within a few months of application. Seasonal variability of SOC, DOC, and available P was likely related to St. Augustinegrass growth stages as well as precipitation, as declines occurred after precipitation events.  相似文献   
62.
The city of Missoula is located in a high mountain valley (elevation 3200 ft.) in western Montana and contains one of the largest populations in the entire Rocky Mountain Region completely enclosed by mountains. During the 2000/2001 Missoula Valley Sampling Program, ambient levels of 61 semivolatile organic compounds (SVOCs) and 54 volatile organic compounds (VOCs) were originally quantified before refining the analytical program to 28 of the most prominent SVOCs and VOCs found in the Missoula Valley airshed. These compounds were measured over 24-hr periods at two locations throughout an entire year. This study provides the first, comprehensive appraisal of the levels of SVOCs and VOCs measured simultaneously throughout all four seasons at two locations in the Missoula Valley, including those levels measured during the 2000 Montana wildfire season. Generally, SVOC levels were comparable between both sides of the Missoula Valley. However, there were nearly double the amount of VOCs measured at the more urban Boyd Park site compared with the rural Frenchtown sampling site, a result of the greater number of automobiles on the eastern side of the Valley. SVOCs and VOCs were measured at their highest levels of the sampling program during the winter. Forest fire smoke samples collected during the summer of 2000 showed significant increases in SVOC phenolic compounds, including phenol, 2-methylphenol, 4-methylphenol, and 2,4-dimethylphenol. Although there were modest increases in some of the other SVOCs and VOCs measured during the fire season, none of the increases were as dramatic as the phenolics.  相似文献   
63.
A perfluorooctane sulfonic acid (PFOS) biomonitoring survey was conducted on great tit (Parus major) and blue tit (Parus caeruleus) nestlings from Blokkersdijk, a bird reserve in the proximity of a fluorochemical plant in Antwerp (Belgium) and Fort IV, a control area. PFOS, together with 11 organochlorine pesticides, 20 polychlorinated biphenyl congeners and 7 polybrominated diphenyl ethers were measured in liver tissue. The hepatic PFOS concentrations at Blokkersdijk (86–2788 and 317–3322 ng/g wet weight (ww) for great and blue tit, respectively) were among the highest ever measured and were significantly higher than at the control area (17–206 and 69–514 ng/g ww for great and blue tit, respectively). The hepatic PFOS concentration was species- and sex-independent and correlated significantly and positively with the serum alanine aminotransferase activity and negatively with the serum cholesterol and triglyceride levels in both species but did not correlate with condition or serum protein concentration. In the great tit, a significant positive correlation was observed between the liver PFOS concentration and the relative liver weight. In the blue tit, the hepatic PFOS concentration correlated positively and significantly with hematocrite values. None of the investigated organohalogen pollutants except for PFOS were suggested to be involved in the observed biological alterations.  相似文献   
64.
Tony WI 《Disasters》1980,4(1):52-52
  相似文献   
65.
Wang  Hui  Chen  Zijian  Walker  Tony R.  Wang  Yinggang  Luo  Qing  Wu  Hao  Wang  Xiaoxu 《Environmental geochemistry and health》2022,44(10):3639-3654
Environmental Geochemistry and Health - Characteristics, profile composition, ecological and human health risk of polycyclic aromatic hydrocarbons in surface dust collected from Shenyang city,...  相似文献   
66.
Tony Matthews 《Local Environment》2013,18(10):1089-1103
This paper characterises climate change as a “transformative stressor”. It argues that institutional change will become increasingly necessary as institutions seek to reorientate governance frameworks to better manage the transformative stresses created by climate change in urban environments. Urban and metropolitan planning regimes are identified as central institutions in addressing this challenge. The operationalisation of climate adaptation is identified as a central tenet of a comprehensive urban response to the transformative stresses that climate change is predicted to create. Operationalisation refers to climate adaptation becoming incorporated, codified and implemented as a central tenet of urban planning governance. This paper has three purposes. First, it examines conceptual perspectives on the role of transformative stressors in compelling institutional change. Second, it establishes a conceptual approach that characterises climate change as a transformative stressor requiring institutional change within planning frameworks. Third, it reports emergent results and analysis from an empirical inquiry which examines how the metro-regional planning regime of Southeast Queensland has responded to climate change as a transformative stressor via institutional change and the operationalisation of climate adaptation.  相似文献   
67.
68.
Claims of employment and productivity gains from environmental taxation are examined in the context of recent policy developments which have extended the traditional role of economic instruments in environmental regulation. Although the general existence of such spin-offs cannot be established, the debate has clarified guidelines for designing and implementing specific environmentally based taxes to help deliver sustainable development. Recent UK tax proposals have started to draw on the flexibility of fiscal instruments to tackle environmental problems. Innovations include earmarking taxes to fund allied spatial and sectoral programmes, recycling revenues to provide fiscally neutral improvements in tax efficiency and using taxation to help promote eco-efficiency.  相似文献   
69.
70.
Fetal sacrococcygeal teratoma can lead to a high output cardiac failure resulting in hydrops fetalis. One of the prenatal therapeutic options is to occlude the feeding vessels by radiofrequency ablation. We present a case of fetal sacrococcygeal teratoma diagnosed at 13 weeks of gestation. The tumour increased in size more than 100-fold over 5 weeks causing polyhydramnios and cardiac and placental enlargement. Thermocoagulation was performed at 18 weeks' gestation by passing an insulated electric wire through an 18-gauge needle placed close to the feeding vessels of the tumour at its neck. Blood supply to the tumour was successfully reduced. However, fetal death was diagnosed 2 days after the procedure. We speculate that it may be safer to limit the extent of coagulation in one attempt but to repeat the procedure at a later stage when necessary. Copyright © 2002 John Wiley & Sons, Ltd.  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