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   1216篇
  免费   11篇
  国内免费   26篇
安全科学   50篇
废物处理   64篇
环保管理   137篇
综合类   207篇
基础理论   217篇
环境理论   1篇
污染及防治   433篇
评价与监测   77篇
社会与环境   52篇
灾害及防治   15篇
  2023年   18篇
  2022年   27篇
  2021年   36篇
  2020年   27篇
  2019年   27篇
  2018年   59篇
  2017年   53篇
  2016年   61篇
  2015年   49篇
  2014年   72篇
  2013年   93篇
  2012年   66篇
  2011年   98篇
  2010年   60篇
  2009年   55篇
  2008年   80篇
  2007年   71篇
  2006年   75篇
  2005年   49篇
  2004年   39篇
  2003年   19篇
  2002年   28篇
  2001年   14篇
  2000年   12篇
  1999年   4篇
  1998年   4篇
  1997年   7篇
  1996年   3篇
  1995年   5篇
  1994年   3篇
  1993年   5篇
  1991年   3篇
  1990年   3篇
  1989年   3篇
  1987年   2篇
  1986年   2篇
  1982年   1篇
  1976年   1篇
  1975年   1篇
  1973年   3篇
  1971年   1篇
  1966年   1篇
  1961年   1篇
  1960年   1篇
  1959年   1篇
  1958年   1篇
  1957年   1篇
  1954年   3篇
  1951年   1篇
  1936年   1篇
排序方式: 共有1253条查询结果,搜索用时 843 毫秒
891.
Total mercury content has been determined in fruiting bodies of European Blushers and topsoils collected from 11 sites across Poland in 2006-2008. Mercury analysis was carried out using a validated analytical method and cold-vapour atomic absorption (CV-AAS). The European Blusher effectively accumulated mercury in fruiting bodies. The mean values of total mercury in caps of European Blushers from background (uncontaminated) areas were from 0.22 to 1.0 (0.067-3.2) and in stipes from 0.16 to 0.65 (0.071-2.7) μg/g dry weight. In topsoil beneath to fruiting bodies, the median Hg concentration at 10 sites in Northern Poland varied between 0.030 and 0.072 (0.0096-0.19) μg/g dw, and in one site in Southern Poland was 0.20 (0.079-0.34) μg/g dw. Data on Hg in European Blushers from different countries were reviewed. The mean concentrations of total Hg in caps of European Blushers from two "pristine" sites in northern part of Poland were ~1.0 μg/g dw. A meal made with 300-500 g of fresh caps of European Blushers collected at such sites (assuming 90% water content in caps) can result in Hg intake of 0.0003-0.0005 mg Hg/kg bm (assuming a 60 kg bm), which is a dose equipotent to a new provisional tolerable weekly intake (PTWI) value set for inorganic Hg.  相似文献   
892.
This research characterizes associations between multiple pollutants in the near-road environment attributed to a roadway line source. It also examines the use of a tracer gas as a surrogate of mobile source pollutants. Air samples were collected in summa canisters along a 300 m transect normal to a highway in Raleigh, North Carolina for five sampling periods spanning four days. Samples were subsequently measured for volatile organic compounds (VOCs) using an electron capture gas chromatograph. Sulfur hexafluoride (SF6) was released from a finite line source adjacent to the roadway for two of the sampling periods, collected in the canisters and measured with the VOCs. Associations between each VOC, and between VOCs and the tracer, were quantified with Pearson correlation coefficients to assess the consistency of the multi-pollutant dispersion profiles, and assess the tracer as a potential surrogate for mobile source pollutants. As expected, benzene, toluene, ethylbenzene, and m,p- and o-xylenes (collectively, BTEX) show strong correlations between each other; further BTEX shows a strong correlation to SF6. Between 26 VOCs, correlation coefficients were greater than 0.8, and 14 VOCs had coefficients greater than 0.6 with the tracer gas. Even under non-downwind conditions, chemical concentrations had significant correlations with distance. Results indicate that certain VOCs are representative of a larger multi-pollutant mixture, and many VOCs are well-correlated with the tracer gas.  相似文献   
893.
De Marchi B  Scolobig A 《Disasters》2012,36(2):316-337
This paper reports on research work performed for Floodsite a European Community-funded project on the social aspects of vulnerability in the Adige/Sarca river basin of the Trentino-Alto Adige region, Italy. It identifies some limitations to the use of a fixed set of indicators, which fail to account for either local peculiarities or the intangible aspects that contribute to the shaping of social vulnerability. The authors employed a number of methods to investigate the opinions of professionals and residents on risk and safety, distinguishing between the individual and the institutional components of social vulnerability. Adopting a systemic perspective, they explored the interactions between these two elements, showing how they may give rise to unexpected phenomena. The 'safety paradox' and the 'efficiency paradox' are discussed, emerging when increased protection provided by structural devices and dedicated institutions translates into a lack of awareness and agency on the part of residents.  相似文献   
894.
The gas phase atmospheric degradation of diazinon has been investigated at the large outdoor European Photoreactor (EUPHORE) in Valencia, Spain. The rate constant for reaction of diazinon with OH radicals was measured using a conventional relative rate method with di-n-buthylether as reference compound being k = (3.5 ± 1.2) × 10−11 cm3 molecule−1 s−1 at 302 ± 10 K and atmospheric pressure. The available evidence indicates that tropospheric degradation of diazinon is mainly controlled by reaction with OH radicals, and that the tropospheric lifetime with respect to the OH reaction is estimated to be around 4 h whereas its lifetime with respect to the photolysis is higher than 1 d under our conditions. Significant aerosol formation was observed following the reaction of diazinon with OH radicals, and the main carbon-containing products detected in the particle phase were hydroxydiazinon, hydroxydiazoxon and 2-isopropyl-6-methyl-pyrimidinyl-4-ol.  相似文献   
895.
Effects of metal contamination on soil biota activity were investigated at 43 sites in 5 different habitats (defined by substratum and vegetation type) in a post-mining area. Sites were characterised in terms of soil pH and texture, nutrient status, total and exchangeable metal concentrations, as well as plant species richness and cover, abundances of enchytraeids, nematodes and tardigrades, and microbial respiration and biomass. The concentrations of total trace metals were highest in soils developed on mining waste (metal-rich dolomite), but these habitats were more attractive than sandy sites for plants and soil biota because of their higher content of organic matter, clay and nutrients. Soil mesofauna and microbes were strongly dependent on natural habitat properties. Pollution (exchangeable Zn and Cd) negatively affected only enchytraeid density; due to a positive relationship between enchytraeids and microbes it indirectly reduced microbial activity.  相似文献   
896.
This study was conducted to evaluate the effect of commercially available engineered iron oxide nanoparticles coated with a surfactant (ENPFe-surf) on effluent water quality from a lab-scale sequencing batch reactor as a model secondary biological wastewater treatment. Results showed that ∼8.7% of ENPFe-surf applied were present in the effluent stream. The stable presence of ENPFe-surf was confirmed by analyzing the mean particle diameter and iron concentration in the effluent. Consequently, aqueous ENPFe-surf deteriorated the effluent water quality at a statistically significant level (p < 0.05) with respect to soluble chemical oxygen demand, turbidity, and apparent color. This implied that ENPFe-surf would be introduced into environmental receptors through the treated effluent and could potentially impact them.  相似文献   
897.
This paper provides data on baseline concentrations, interrelationships and bioconcentration potential of 12 metallic elements by King Bolete collected from 11 spatially distant sites across Poland. There are significant differences in concentrations of metals (Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr, Zn) and their bioconcentration potential in King Bolete Boletus edulis at 11 spatially distant sites surveyed across Poland. These have resulted from significant geographical differences in trace metal concentrations in a layer (0-10 cm) of organic and mineral soil underneath to fruiting bodies and possible local bioavailabilities of macro- (Ca, K, Mg, Na) and trace metals (Al, Ba, Cd, Cu, Fe, Mn, Sr, Zn) to King Bolete. The use of highly appreciated wild-grown edible King Bolete mushroom has established a baseline measure of regional minerals status, heavy metals pollution and assessment of intake rates for wild mushroom dish fanciers against which future changes can be compared. Data on Cd, Cu and Zn from this study and from literature search can be useful to set the maximum limit of these metals in King Bolete collected from uncontaminated (background) areas. In this report also reviewed are data on Al, Ba, Ca, Cd, Cu, Fe, K, Mg, Mn, Na, Sr and Zn accumulation in King Bolete.  相似文献   
898.
可见光活性纳米TiO2光催化涂料的抗菌性能研究   总被引:1,自引:0,他引:1  
基于过渡金属离子掺杂技术,制备了在室内光辐照条件下具有良好光催化抗菌性能的可见光响应型铁掺杂TiO2光催化涂料。研究结果表明,在可见光活性光催化涂料中添加1%的纳米TiO2时,抗菌效果最好,光照24 h后对大肠杆菌、白色念珠球菌、黑曲霉的杀菌率分别达到99.9%、97.2%、82%。采用致孔剂聚乙二醇6 000对光催化剂改性后,能加快该涂料的抗菌性能,光照6 h后杀菌率就能达到99.9%。表明该涂料在室内可见光照射下具有较好的广谱抗菌效果,能抑制和杀灭多种微生物。  相似文献   
899.
Sim WJ  Lee JW  Lee ES  Shin SK  Hwang SR  Oh JE 《Chemosphere》2011,82(2):179-186
Twenty-four pharmaceuticals were measured in wastewater from 12 municipal wastewater treatment plants (M-WWTPs), four livestock WWTPs (L-WWTPs), four hospital WWTPs (H-WWTPs) and four pharmaceutical manufacture WWTPs (P-WWTPs). The total concentration of pharmaceuticals in the influent samples was highest in the L-WWTPs followed by the P-WWTPs, H-WWTPs and M-WWTPs. The effluents had different patterns of pharmaceuticals than their corresponding influents because of the different fate of each compound in the WWTPs. Non-steroidal anti-inflammatory drugs (NSAIDs) were the most dominant in the influents from the M-WWTPs and P-WWTPs, while antibiotics were dominantly detected in the L-WWTP. In the H-WWTP influents, NSAIDs, caffeine and carbamazepine were dominant. In the P-WWTPs, the distribution of pharmaceuticals in the effluents varied with sampling sites and periods. The M-WWTP influents had the highest daily loads, while the effluents showed somewhat similar levels in all source types.  相似文献   
900.
The aim was to determine half-life of six most abundant PCB congeners in the body of early adolescents. In 304 environmentally exposed children, PCB serum concentration was determined at the age of 8 and 12 years. Half-life was determined for each child assuming exponential decrease or for the whole cohort using multiple regression. Results obtained by both approaches were in agreement. PCB reuptakes corrupting half-life estimates for each child and each congener were evaluated. If one of the serum PCB concentration values fell below the level of detection (LOD) the pair was excluded and if PCB half-life value exceeded the arbitrary value of 30 years. The following median half-lives in years 4.46, 10.59, 9.7, 4.7, 9.1 and 9.8 were obtained for PCB congeners 118, 138+163, 153, 156+171, 170 and 180, respectively. The elimination half-life values were not systematically related to PCB serum concentration at any examination age. Between half-life values, percentage of children with significant reuptakes and PCB congener abundance in serum were found significant associations.  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