全文获取类型
收费全文 | 857篇 |
免费 | 3篇 |
国内免费 | 3篇 |
专业分类
安全科学 | 16篇 |
废物处理 | 16篇 |
环保管理 | 134篇 |
综合类 | 269篇 |
基础理论 | 149篇 |
污染及防治 | 200篇 |
评价与监测 | 47篇 |
社会与环境 | 25篇 |
灾害及防治 | 7篇 |
出版年
2020年 | 7篇 |
2018年 | 16篇 |
2017年 | 10篇 |
2016年 | 16篇 |
2015年 | 13篇 |
2014年 | 20篇 |
2013年 | 68篇 |
2012年 | 23篇 |
2011年 | 32篇 |
2010年 | 23篇 |
2009年 | 22篇 |
2008年 | 33篇 |
2007年 | 35篇 |
2006年 | 19篇 |
2005年 | 21篇 |
2004年 | 35篇 |
2003年 | 20篇 |
2002年 | 24篇 |
2001年 | 12篇 |
2000年 | 13篇 |
1999年 | 18篇 |
1998年 | 8篇 |
1997年 | 12篇 |
1996年 | 17篇 |
1995年 | 12篇 |
1994年 | 25篇 |
1993年 | 7篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1988年 | 6篇 |
1983年 | 6篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 7篇 |
1978年 | 7篇 |
1977年 | 7篇 |
1968年 | 6篇 |
1965年 | 6篇 |
1964年 | 9篇 |
1963年 | 6篇 |
1962年 | 6篇 |
1961年 | 6篇 |
1960年 | 8篇 |
1959年 | 11篇 |
1957年 | 7篇 |
1956年 | 11篇 |
1954年 | 9篇 |
1939年 | 6篇 |
1924年 | 6篇 |
排序方式: 共有863条查询结果,搜索用时 15 毫秒
111.
112.
113.
Peter H. Roos Walter D. Weißenfels Manfred van Afferden Frank Pfeifer Walter G. Hanstein 《Environmental Sciences Europe》2000,12(1):13-19
The goal of the present work is to assess the adverse effects of soil bound polycyclic aromatic hydrocarbons (PAH) which remain in soils after biological remediation. We focus on risk assessment for mammalian species with respect to the oral uptake of contaminated soil particles and compare the results of a biomarker test with those of an ecotoxicological assay, the bioluminescence inhibition test withVibrio fischeri. As a biomarker effect in mammals, we determined the liver microsomal cytochrome P450 enzyme CYP1A1 which is induced by PAH in exposed rats. After biological soil treatment, different amounts of PAH remain in the soil depending on the soil properties and initial pollutant composition. Particularly, higher condensated PAH resists biological treatment due to its hydrophobicity. In addition, high amounts of organic carbon in the soils affect remediation efficiency. In the bioluminescence inhibition test, eluates of all biologically treated soils studied do not reveal any or only low inhibitory effects. In contrast, the oral uptake of biologically treated contaminated soils leads to induction levels for CYP1A1 similar to those in the untreated samples. A good correlation is obtained between CYP1A1 levels and the amount of 5 and 6-ring PAH in the soil samples. The main result is that the remediation efficiency determined by the luminescence test is not reflected by the biomarker test, a finding which indicates the high bioavailability of residual PAH in soils. Consequently, new criteria for human risk assessment can be delineated. 相似文献
114.
This laboratory study investigated the kinetics of leaf and DNA content decomposition in two varieties of tomato (Palmiro and Admiro) after incubation in soil for 35 days. Results revealed that the decrease of dry matter in leaves in both varieties did not follow a single exponential function and was better described by a double exponential model. Composite half-decrease times were 3.4 and 2.4 days for Palmiro and Admiro respectively. The same pattern was observed for DNA mass loss, although this was closer to a single exponential model with composite half-decrease times of 1.5 and 1.4 days. Genomic analysis showed that DNA in dried leaves at room temperature (not inoculated in the soil), remains intact or presents a weak degradation, and DNA extracted from leaves inoculated in non-sterile soil showed degradation after two days. These results indicate that before release an important quantity of DNA may be degraded inside plant tissues during decomposition in soil. 相似文献
115.
Walter Klingmüller 《Die Naturwissenschaften》1979,66(4):182-189
Genetic engineering has ushered in a new era in biology. Although many problems are still to be solved, there are examples that point to a possible later application for the benefit of mankind: Bacteria can be manipulated to degrade crude-oil spillages, to produce human insulin and to bind nitrogen from the air. If all the bacteria that are indigenous to agricultural soils could be made to bind nitrogen, an increase in soil fertility might well result. 相似文献
116.
Rodrigo Navia Georg Hafner Georg Raber Karl E Lorber Elke Sch?ffmann Walter Vortisch 《Waste management & research》2005,23(3):249-259
The main physicochemical characteristics of the volcanic soil of Southern Chile, with allophane as the main pedogenic mineral phase were analysed and compared with common zeolites (clinoptilolite) of the European market. The ultimate goal of this study was to test volcanic soil for the use as mineral landfill liner. The main results indicated that the clay and silt fractions together of the volcanic soil were between 38 and 54%. The buffering capacity of the volcanic soil was higher compared with the studied zeolites, whereas the cationic exchange capacity of the volcanic soil (between 5.2 and 6.5 cmol + kg(-1)) is of the same order of magnitude of the studied zeolites (between 9.7 and 11.4 cmol + kg(-1)). Moreover, the anionic exchange capacity of the volcanic soil was higher compared to the zeolites analysed. The hydraulic conductivity of the volcanic soil, measured in the laboratory at maximum proctor density, ranges between 5.16 x 10(-9) and 6.48 x 10(-9) m s(-1), a range that is comparable to the value of 4.51 x 10(-9) m s(-1) of the studied zeolite. The Proctor densities of the volcanic soil are in a lower range (between 1.11 and 1.15 g ml(-1)) compared with zeolites (between 1.19 and 1.34 g ml(-1)). The volcanic soil physicochemical characteristics are comparable to all the requirements established in the Austrian landfill directive (DVO, 2000). Therefore, the use as mineral landfill basal sealing of the analysed volcanic soil appears reasonable, having a pollutant adsorption capacity comparable to zeolites. It is of special interest for Southern Chile, because there are no alternative mineral raw materials for basal liners of landfills. 相似文献
117.
Walter M. Farina 《Behavioral ecology and sociobiology》1996,38(1):59-64
Dancing and trophallactic behaviour of forager honey bees, Apis mellifera ligustica >Spinola, that returned from an automatic feeder with a regulated flow rate of 50% weight-to-weight sucrose solution (range:
0.76–7.65 μl/min) were studied in an observation hive. Behavioural parameters of dancing, such as probability, duration and
dance tempo, increased with the nectar flow rate, though with very different response curves among bees. For trophallaxis
(i.e. mouth-to-mouth exchange of food), the frequency of giving-contacts and the transfer rate of the nectar increased with
the nectar flow rate. After unloading, foragers often approached other nest mates and begged for food before returning to
the food source. This behaviour was less frequent at higher nectar flow rates. These results show that the profitability of
a food source in terms of nectar flow rate had a quantitative representation in the hive through quantitative changes in trophallactic
and dancing behaviour. The role of trophallaxis as a communication channel during recruitment is discussed.
Received: 14 January 1995/Accepted after revision: 14 August 1995 相似文献
118.
119.
Richard H. McCuen Walter J. Rawls Bob L. Whaley 《Journal of the American Water Resources Association》1979,15(4):935-947
ABSTRACT: While the correlation coefficient and standard error of estimate are frequently used when comparing models of seasonal water yield, the following criteria may be more important in selecting one model from among several alternatives: rationality of the regression coefficients, the distribution of the residual errors, and the correctness of indicators of the relative importance of the predictor variables. These criteria were used to compare seasonal water yield models that were calibrated using multiple regression, stepwise regression, principal components regression, polynomial regression using a principal components rotation, and constrained pattern search. Hydrologic data from the Upper Sevier River basin in southern Utah were used to illustrate the comparative analysis process. The prediction equations used the April-July streamflow volume as the criterion variable. 相似文献
120.