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   374篇
  免费   8篇
  国内免费   2篇
安全科学   9篇
废物处理   33篇
环保管理   43篇
综合类   59篇
基础理论   65篇
污染及防治   122篇
评价与监测   34篇
社会与环境   18篇
灾害及防治   1篇
  2023年   5篇
  2022年   10篇
  2021年   11篇
  2020年   8篇
  2019年   8篇
  2018年   9篇
  2017年   15篇
  2016年   17篇
  2015年   15篇
  2014年   26篇
  2013年   25篇
  2012年   21篇
  2011年   36篇
  2010年   31篇
  2009年   14篇
  2008年   22篇
  2007年   22篇
  2006年   17篇
  2005年   13篇
  2004年   13篇
  2003年   7篇
  2002年   9篇
  2001年   5篇
  2000年   1篇
  1999年   4篇
  1998年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   2篇
  1993年   2篇
  1992年   1篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   1篇
  1983年   1篇
  1978年   1篇
  1975年   1篇
  1963年   1篇
  1955年   1篇
排序方式: 共有384条查询结果,搜索用时 15 毫秒
101.
Evaluation of the presence of drugs of abuse in tap waters   总被引:1,自引:0,他引:1  
A total of seventy samples of drinking water were tested for non-controlled and illicit drugs. Of these, 43 were from Spanish cities, 15 from seven other European countries, three from Japan and nine from seven different Latin American countries. The most frequently detected compounds were caffeine, nicotine, cotinine, cocaine and its metabolite benzoylecgonine, methadone and its metabolite EDDP. The mean concentrations of non-controlled drugs were: for caffeine 50 and 19 ng L−1, in Spanish and worldwide drinking water respectively and for nicotine 13 and 19 ng L−1. Illicit drugs were sparsely present and usually at ultratrace level (<1 ng L−1). For example, cocaine has mean values of 0.4 (Spain) and 0.3 ng L−1 (worldwide), whereas for benzoylecgonine, these mean values were 0.4 and 1.8 ng L−1, respectively. Higher concentrations of benzoylecgonine were found in Latin American samples (up to 15 ng L−1). No opiates were identified in any sample but the presence of methadone and EDDP was frequently detected. Total mean values for EDDP were 0.4 ng L−1 (Spain) and 0.3 ng L−1 (worldwide). Very few samples tested positive for amphetamines, in line with the reactivity of chlorine with these compounds. No cannabinoids, LSD, ketamine, fentanyl and PCP were detected.  相似文献   
102.
Characterization of bacterial communities at heavy-metal-contaminated sites   总被引:2,自引:0,他引:2  
The microbial community in soil samples from two long-term contaminated sites was characterized by using culture-dependent and culture-independent methods. The two sites investigated contained high amounts of heavy metals and were located in the upper Silesia Industrial Region in southern Poland. The evaluation of the aerobic soil microbial population clearly demonstrated the presence of considerable numbers of viable, culturable bacteria at both sites. A high fraction of the bacterial population was able to grow in the presence of high amounts of metals, i.e. up to 10 mM Zn2+, 3 mM Pb2+ or 1 mM Cu2+. Site 1 contained significantly (P < 0.05) lower bacterial numbers growing in the presence of 10 mM Zn2+ than site 2, while the opposite was observed for bacteria tolerating 1 mM Cu2+. This coincided with the contents of these two metals at the two sites. Ecophysiological (EP) indices for copiotrophs (r-strategists) and oligotrophs (K-strategists) pointed to high bacterial diversity at both sites. Fluorescence in situ hybridization (FISH) analysis indicated that Actinobacteria and Proteobacteria represent the physiologically active fraction of bacteria at the two sites. Shannon diversity (H′) indices for FISH-detected bacterial phylogenetic groups were not significantly different at the two sites.  相似文献   
103.
Carbon paste electrodes (CPEs) modified with a biosolid, two types of soils with different amounts of organic matter (OM), and two biocomposites (soils mixed with a biosolid) were used to assess and compare the Cu(II) ion retention properties of the organic matter contained in the samples. The accumulation of Cu(II) on the surface of the modified carbon paste electrodes (MCPEs) was performed under open-circuit conditions. When comparing the response of the MCPEs while assessing parameters such as pH, preconcentration time, and adsorption/desorption capacity, it was found that the reaction mechanism of the two soils is different between the soils and dissimilar from the biosolid; while the biocomposites show reaction mechanisms that are intermediate between those of the soils and the biosolid. This was proven with the use of infrared spectroscopy, since the FTIR spectra show similarities between the two soils and significant differences between the soils and the biosolid.  相似文献   
104.
Road-killed mammals, birds, and reptiles were collected weekly from highways in southern Brazil in 2002 and 2005. The objective was to assess variation in estimates of road-kill impacts on species richness produced by different sampling efforts, and to provide information to aid in the experimental design of future sampling. Richness observed in weekly samples was compared with sampling for different periods. In each period, the list of road-killed species was evaluated based on estimates the community structure derived from weekly samplings, and by the presence of the ten species most subject to road mortality, and also of threatened species. Weekly samples were sufficient only for reptiles and mammals, considered separately. Richness estimated from the biweekly samples was equal to that found in the weekly samples, and gave satisfactory results for sampling the most abundant and threatened species. The ten most affected species showed constant road-mortality rates, independent of sampling interval, and also maintained their dominance structure. Birds required greater sampling effort. When the composition of road-killed species varies seasonally, it is necessary to take biweekly samples for a minimum of one year. Weekly or more-frequent sampling for periods longer than two years is necessary to provide a reliable estimate of total species richness.  相似文献   
105.
Surface films on impervious surfaces mediate the fate of organic contaminants in urban areas. Using sheltered 3-mm diameter glass beads as a surrogate impervious urban surface, studies in downtown Toronto showed that surface films developed at a consistent rate of 1.6–2.6 nm day−1. Linear film growth was observed up to and including the last day of three studies of 89-, 273-, and 84-day duration. Total PCB content (sum of 15 PCB congeners) also increased linearly, at a similar rate as the surface film. A complementary study using unsheltered beads showed that up to 80% of film mass and PCB content were removed by film wash-off during rain events. The film growth rate on beads exposed at a rural site, 200 km northeast of Toronto, was 12–20 times lower with PCB burdens that were 7–22 times lower compared to Toronto. Based on these findings, it is estimated that approximately 56–226 g of PCBs are captured by a 70 nm thick film covering just the horizontal surface area of Toronto. This is a substantial quantity of PCB that is available for rapid surface–air exchange and wash-off.  相似文献   
106.
This article examines the advantages of the use of biomarkers as environmental indicators by applying it to Paraiba do Sul watershed, one of the most important Brazilian water bodies, which is in a critical environmental situation. We use a multibiomarker approach in fish as an integrated strategy to assess the impact of pollution. It comprehends a general biomarker of fish health, the condition factor (CF), and specific biomarkers of contaminant exposure such as metallothionein (MT), acetylcholinesterase (AChE) activity and biliary polycyclic aromatic hydrocarbons (PAH) metabolites. Our results revealed different effects in the fish from diverse locations with varying degrees of pollution. Furthermore, fish located just upstream of the water-treatment plant of the metropolitan area of Rio de Janeiro has shown to be affected by metals. This study indicates the usefulness of integrating a set of biomarkers to define the effects of anthropogenic inputs in aquatic bodies under complex polluted situations.  相似文献   
107.
108.
109.
110.
Environmental indicators can be used as a first stage in progress towards comprehensive environmental impact measures [J. Environ. Manage 65/3 (2002) 285]. In this article, we develop a 'pollutant interaction matrix method' that allows calculation of a global environmental protection index (Ep) in order to verify the eco-compatibility of an industrial activity. Two methods are proposed for the Ep index evaluation (which represents the numerical measure of the environmental sustainability): the Direct Method (Epd) and the Weighted Method (Epw). Both methods need to define, in the whole industrial process, homogeneous sectors (defined as construction sites where activities of the same type are carried out). Furthermore, for each activity a set of parameters (t, duration of pollution effect, P, quantity of pollutant produced,G, hazard of the pollutant) are required to evaluate the relative pollution index Y. All indices calculations were carried out using a set of matrices. The correct use of Ep evaluation provides an improvement in the total environmental performance of companies because it points out possible critical operations in each homogeneous sector which require solutions. The methodology is applied to evaluate the environmental pollution risk of a company that produces polymer materials and to improve their environmental performance. The results obtained show that the whole productive process has a low environmental impact factor. Nevertheless the applied methodology puts in evidence some processes that generate local pollution in specific areas of the factory and which could be dangerous for the workers' health.  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