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   471篇
  免费   2篇
  国内免费   1篇
安全科学   45篇
废物处理   23篇
环保管理   8篇
综合类   32篇
基础理论   60篇
污染及防治   207篇
评价与监测   69篇
社会与环境   30篇
  2023年   7篇
  2022年   11篇
  2021年   17篇
  2020年   6篇
  2019年   25篇
  2018年   20篇
  2017年   31篇
  2016年   45篇
  2015年   9篇
  2014年   37篇
  2013年   94篇
  2012年   17篇
  2011年   28篇
  2010年   9篇
  2009年   10篇
  2008年   19篇
  2007年   17篇
  2006年   11篇
  2005年   12篇
  2004年   11篇
  2003年   14篇
  2002年   7篇
  2001年   1篇
  2000年   1篇
  1999年   2篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1993年   2篇
  1985年   1篇
  1982年   1篇
  1973年   1篇
  1963年   1篇
  1962年   1篇
  1961年   2篇
  1938年   1篇
排序方式: 共有474条查询结果,搜索用时 31 毫秒
241.
Excess fungicides can pose a serious threat to the soil environment. Fungicides can lower the microbiological and biochemical activity of soil and lead to yield declines. Soils contaminated with fungicides have to be remediated to maintain the optimal function of soil ecosystems. This study evaluates the effect of neutralizing substances on soil enzymatic activity and the yield of Triticum aestivum L. in soil contaminated with fungicides. Sandy loam (Eutric Cambisols) with pHKCl 7.0 was contaminated with an aqueous solution of Amistar 250 SC and Falcon 460 EC in the following doses: 0 (soil without fungicide – treated as a control), RD (dose recommended by the manufacturer) and 300?×?RD (dose 300-fold higher than the recommended dose). Soil was supplemented with bentonite and basalt meal at a dose of 10?g kg?1 DM of soil (dry mass of soil). The fungicide dose recommended by the manufacturer did not induce changes in soil enzymatic activity or the yield of T. aestivum L. Our findings indicate that the tested fungicides can be safely applied to protect crops against fungal pathogens. However, when applied at the dose of 300?×?RD, the tested fungicides strongly inhibited soil enzymatic activity and disrupted the growth and development of spring wheat. Soil supplementation with bentonite and basalt meal improved the yield of T. aestivum L., and bentonite was more effective in reducing fungicide stress. The analyzed substances were not highly effective in restoring biochemical homeostasis in soil.  相似文献   
242.
Environmental Science and Pollution Research - This article presents a bibliometric study of 200 European publications released between 2001 and 2016, about the contamination of mushrooms by...  相似文献   
243.
Introduction. With the current increases in occupational skin diseases, literature data attesting the decreasing efficiency of barrier creams with respect to the manufacturer’s declarations and legal regulations granting skin protection gels for employees, research is required to analyse and evaluate the recipes used for hydrophilic skin protection gels based on polyacrylates. Methods. This study investigated the rheological properties, pH and sensory perception of hydrophilic barrier gels based on polyacrylates. Results. The acrylic acid derivatives used were good thickeners, and helped to form transparent gels of adequate durability. They could be used to create hydrophilic films on the surface of the skin to protect it against hydrophobic substances. A correlation was shown between the results of the rheological properties and the barrier properties of the gels. This confirms the possibility of monitoring the quality of the gels at the stage of recipe development. Conclusions. Polyacrylates are viable for use in industry to produce hydrophilic barrier creams suitable for skin protection.  相似文献   
244.
The aim of study was to determine 9 organic acids in nine aboveground and seven wood-growing wild edible mushroom species originated from an area under the direct influence of a busy trunk road in Poland. The organic acids in the extracts of samples were identified by reversed-phase column liquid chromatography (RPLC). The presented results show that all the mushroom species were characterized by high variation in the profile and content of the analyzed acids. Each of mushroom species contained oxalic acid, the profiles of the other acids strictly depended on mushroom species. Among aboveground species, the highest total content of organic acids was found in Lepista gilva (267.5 ± 26.6 mg g?1 dry weight (DW)), while Laccaria amethystina was characterized by the lowest content (37.7 ± 6.5 mg g?1 DW). Within wood-growing species, the highest content of organic acids was determined in Flammulina velutipes (171.9 ± 26.7 mg g?1 DW), whereas the lowest content (34.2 ± 2.9 mg g?1 DW) of the studied acids was observed in Grifola frondosa.  相似文献   
245.
Pore waters play an important role in phosphorus dynamics in aquatic ecosystems. Phosphorus concentrations in pore waters are much higher than above the bottom. This is confirmed by the results of this study concerning the hypereutrophic lake. Pore water was analyzed at 11 sampling stations in the upper layer of bottom sediments. This water was separated by centrifugation and phosphorus level was measured spectrophotometrically with ascorbic acid as a reducer. Total phosphorus concentration in pore waters ranged from 0.5 to 8.1 mgP l − 1 (mean 3.2 mgP l − 1). Mean phosphorus concentration in pore water samples of this lake was the highest in summer and the lowest in winter. High concentrations were observed in samples from the pelagial and low from the macrophyte zone.  相似文献   
246.
The paper presents the results of toxicity determinations carried out on sediment samples collected in the vicinity of the wreck of the German s/s Stuttgart (the southern part of the Gulf of Gdańsk, off the Polish coast) in relation to the determination of polycyclic aromatic hydrocarbons (PAHs). The toxicity of surface and core sediment samples was assessed using two biotest organisms-the bioluminescent bacteria Vibrio fischeri and the ostracod Heterocypris incongruens. PAH levels in these samples were determined by GC-MS. The surface sediments collected at W2 (ca. 34 m north of the shipwreck) and W4 (ca. 415 m north-east of the wreck) as well as the core sediments collected at WR3 (ca. 400 m north-east of the wreck) were the most heavily polluted with substances toxic to the biotest organisms. The chronic and acute toxicities in the case of most of the surface sediment samples studied are correlated. This may suggest that not only hydrophobic chemicals (like PAHs from fuel residues) but also more polar chemicals (resulting from the conversion of aromatic hydrocarbons) are responsible for the toxicity levels found. There is a clear dependence between the levels of chronic toxicity and PAH concentrations in the core sediment samples. In addition, a simultaneous decrease in the PAH content and chronic toxicity was noted in all the core sediment samples at depths below 80 cm.  相似文献   
247.
We studied the effect of storm water drained by the sewerage system and discharged into a river and a small reservoir, on the example of five catchments located within the boundaries of the city of Poznań (Poland). These catchments differed both in terms of their surface area and land use (single- and multi-family housing, industrial areas). The aim of the analyses was to explain to what extent pollutants found in storm water runoff from the studied catchments affected the quality of surface waters and whether it threatened the aquatic organisms. Only some of the 14 studied variables and 22 chemical elements were important for the water quality of the river, i.e., pH, TSS, rain intensity, temperature, conductivity, dissolved oxygen, organic matter content, Al, Cu, Pb, Zn, Fe, Cd, Ni, Se, and Tl. The most serious threat to biota in the receiver came from the copper contamination of storm water runoff. Of all samples below the sewerage outflow, 74 % exceeded the mean acute value for Daphnia species. Some of them exceeded safe concentrations for other aquatic organisms. Only the outlet from the industrial area with the highest impervious surface had a substantial influence on the water quality of the river. A reservoir situated in the river course had an important influence on the elimination of storm water pollution, despite the very short residence time of its water.  相似文献   
248.
Concentrations of toxic heavy metals (cadmium (Cd), lead (Pb)) and major nutritional and trace elements (Ca, Mg, P, Cu, Fe, Mn, Se, Zn) were analyzed in the milk of Simmental (n?=?20) and Holstein-Friesian (n?=?20) cows from an organic farm. Elements were determined using inductively coupled plasma emission atomic spectrometry. The conducted research showed that the milk of Simmental cows was characterized by the more advantageous mineral composition and lower concentration of noxious heavy metals compared to the milk of Holstein-Friesian cows. In the milk of Simmental cows, significantly lower concentrations of Pb and Cd (P?<?0.001) and Cu (P?<?0.05) and significantly higher concentrations of Fe and Mg (P?<?0.05) as well as nonsignificantly higher concentrations of Ca, Mn, and Se were found. In the milk of both breeds, very low Cu concentrations were recorded. The higher-than-recommended concentration of Pb in milk was also found. In the milk of both breeds, the significant positive correlations between concentrations of the following elements were observed: Pb–Cd, Pb–Se, Cd–Se, Cd–Mn, Zn–Cu, Zn–P, Ca–P, Ca–Mg, and Mg–P. The correlations between other elements within each of the analyzed breeds separately were also found.  相似文献   
249.
250.
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