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21.
Alkan Olsson J  Berg K 《Ambio》2005,34(7):507-512
The objective of this study was to increase the knowledge of local stakeholders' acceptance of model-generated data when used as a communication tool in water quality management. The R?nne? catchment in the southwest of Sweden was chosen as the study area. The results indicate the model-generated data served as a uniting factor. Simultaneously, the stakeholders were concerned with presented data, the main problems being sources of pollution, which were not accounted for, lack of trustworthiness when measuring pollution, and the uncertainty of the impact of natural variation and delayed effects. Four clusters of factors were identified as influencing stakeholders' acceptance of the model-generated data: confidence in its practical applications, confidence in the people involved in or providing material for the dialog (such as experts, decision-makers, and media), the social characteristics of the participants (such as age and profession), and the way of communicating the data (such as tone of communication, group composition, duration, and geographical scope of the dialog). The perception of the fairness of the practical application of given model-generated data was also an important factor for acceptance.  相似文献   
22.
The dynamic catchment model HBV-N has been further developed by adding routines for phosphorus transport and is now called the HBV-NP model. The model was shown to satisfactorily simulate nutrient dynamics in the R?nne? catchment (1,900 km2). Its sensitivity to input data was tested, and results demonstrated the increased sensitivity to the selection of input data on a subcatchment scale when compared with the catchment scale. Selection of soil and land use databases was found to be critical in some subcatchments but did not have a significant impact on a catchment scale. Although acceptable on a catchment scale, using templates and generalization, with regards to emissions from point sources and rural households, significantly decreased model performance in certain subcatchments when compared with using more detailed local information. A division into 64 subcatchments resulted in similar model performance at the catchment outlet when compared with a lumped approach. Adjusting the imported matrixes of the regional leaching of nitrogen, from agricultural land, against mean subcatchment water percolation did not have a significant impact on the model performance.  相似文献   
23.
In order to evaluate blood levels of some perfluorinated chemicals (PFCs) and compare them to current levels of classical persistent organic pollutants (POPs) whole blood samples from Sweden were analyzed with respect to 12 PFCs, 37 polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (DDE), hexachlorobenzene (HCB), six chlordanes and three polybrominated diphenyl ethers (PBDEs). The median concentration, on whole blood basis, of the sum of PFCs was 20-50 times higher compared to the sum of PCBs and p,p'-DDE, 300-450 times higher than HCB, sum of chlordanes and sum of PBDEs. Estimations of the total body amount of PFCs and lipophilic POPs point at similar body burdens. While levels of for example PCBs and PBDEs are normalized to the lipid content of blood, there is no such general procedure for PFCs in blood. The distributions of a number of perfluorinated compounds between whole blood and plasma were therefore studied. Plasma concentrations were higher than whole blood concentrations for four perfluoroalkylated acids with plasma/whole blood ratios between 1.1 and 1.4, whereas the ratio for perflurooctanesulfonamide (PFOSA) was considerably lower (0.2). This suggests that the comparison of levels of PFCs determined in plasma with levels determined in whole blood should be made with caution. We also conclude that Swedish residents are exposed to a large number of PFCs to the same extent as in USA, Japan, Colombia and the few other countries from which data is available today.  相似文献   
24.
在关于改善环境的科学与政策讨论中,最经常提到的话题之一就是如何使小型和中等规模的企业参与进来.  相似文献   
25.
Summary In a laboratory experiment it was shown that piscivorous predators reversed the outcome of competitive interactions between two fish prey species, juveniles of roach (Rutilus rutilus) and perch (Perca fluviatilis), by behaviorally affecting their use of two available habitats, an open water habitat and a structurally complex refuge. The shift in the competitive relationship was the result of predators forcing the juvenile fishes into a prey refuge with high structural complexity. While roach was competitively superior in the unstructured habitat, perch was superior in the structurally complex prey refuge. The reversal in competitive relationship was demonstrated both with respect to foraging rate and growth rate and resulted from the high structural complexity in the prey refuge interfering with the roach's swimming performance. Because survival and growth patterns through the juvenile stages have profound effects on the population/community dynamics of size-structured populations such as those of fish, behaviorally induced changes in competitive ability should have significant implications also at the population and community levels.  相似文献   
26.
Female choice on the basis of male traits has been described in an array of taxa but has rarely been demonstrated in reptiles. In the sand lizard (Lacerta agilis), and possibly in other non-territorial reptiles, a male's contribution to a female's fitness is restricted to his genes. In order to choose males of high genetic quality, females have to trade the fitness gain against the costs of active choice. In a Swedish population of sand lizards, long-lived males sired offspring with higher embryonic survival compared to offspring sired by short-lived males. In spite of this female sand lizards did not mate selectively with older and/or larger males. There appeared to be mo reliable cues to male longevity; age-specific male body size was highly variable. Furthermore, estimates of male nuptial coloration did not covary with ectoparasite load and, hence, females cannot use male coloration as a cue to heritable resistance to pathogenic parasite effects. When cues to male genetic quality are poor, or inaccurate, and males make no parental investment, we predict that female choice will be rare. Sand lizard females mating with many partners lay clutches with higher hatching success. Thus, females may obtain good genes for their young by multiple mating, thereby avoiding costs associated with mate choice.  相似文献   
27.
This study presents the concentrations of about 50 metals and ions in 33 different brands of bottled waters on the Swedish market. Ten of the brands showed calcium (Ca) concentrations ≤10 mg L−1 and magnesium (Mg) levels <3 mg L−1, implying very soft waters. Three of these waters had in addition low concentrations of sodium (Na; <7 mg L−1), potassium (K; <3 mg L−1) and bicarbonate (HCO3 ≤31 mg L−1). These brands were collected from barren districts. Nine of the brands were collected from limestone regions. They showed increased Ca-levels exceeding 50 mg L−1 with a maximum of 289 mg L−1. Corresponding Mg-levels were also raised in two brands exceeding 90 mg L−1. Two soft and carbonated waters were supplemented with Na2CO3 and NaCl, resulting in high concentrations of Na (644 and 648 mg L−1) and chloride (Cl; 204 and 219 mg L−1). Such waters may make a substantial contribution to the daily intake of NaCl in high water consumers. The storage of carbonated drinking water in aluminum (Al) cans increased the Al-concentration to about 70 μg L−1. Conclusion As there was a large variation in the material as regards concentrations of macro-elements such as Ca, Mg, Na, K and Cl. Supplementation with salts, e.g., Na2CO3, K2 CO3 and NaCl, can lead to increased concentrations of Na, K and Cl, as well as decreased ratios of Ca/Na and larger ratios of Na/K. Water with high concentrations of e.g., Ca and Mg, may make a substantial contribution to the daily intake of these elements in high water consumers. Al cans are less suited for storage of carbonated waters, as the lowered pH-values may dissolve Al. The levels of potentially toxic metals in the studied brands were generally low.  相似文献   
28.
Environmental conditions, primary production, and zooplankton populations were studied from May, 1969 to November, 1970 at one station in Kungsbacka Fjord, Sweden. The fjord, with an arca of 53 km2, is a moderately polluted estuary, with a small tidal range. Data for primary production and environmental parameters were correlated using Spearman's rank correlation coefficient. The annual rate of primary production in 1970 was about 100 gC·m-2. Carbon fixation was about 80 g·m-2 in May–November in1969 and 1970. The average monthly rate was highest in June, 1970, with 25 gC·m-2; about 15 gC·m-2 was recorded in August–October of both years. Carbon fixation by the phytoplankton was estimated to be about 2,800 tons in the whole fjord in 1970. The average fresh-water inflow to the fjord, amounting to about 13 m3·sec-1, added about 380 tons of organic carbon, 45 tons of nitrogen, and 4.5 tons of phosphorus per month. Primary production displayed strong correlation with temperature at different depths (P<0.05 to 0.001), indicating the sediments to be the most important nutrient source. A total of 19 holoplanktonic zooplankton species was identified, copepods being the dominant group. The highest zooplankton biomass, 800 to 900 mg·m-3, was recorded in June of both years. The production of copepods in May–October was about 1 gC·m-2 in both years. The total secondary production of the zooplankton was calculated as only 1.8 gC·m-2 in 1970.  相似文献   
29.
The maintenance of biodiversity by securing representative and well-connected habitat networks in managed landscapes requires a wise combination of protection, management, and restoration of habitats at several scales. We suggest that the integration of natural and social sciences in the form of "Two-dimensional gap analysis" is an efficient tool for the implementation of biodiversity policies. The tool links biologically relevant "horizontal" ecological issues with "vertical" issues related to institutions and other societal issues. Using forest biodiversity as an example, we illustrate how one can combine ecological and institutional aspects of biodiversity conservation, thus facilitating environmentally sustainable regional development. In particular, we use regional gap analysis for identification of focal forest types, habitat modelling for ascertaining the functional connectivity of "green infrastructures", as tools for the horizontal gap analysis. For the vertical dimension we suggest how the social sciences can be used for assessing the success in the implementation of biodiversity policies in real landscapes by identifying institutional obstacles while implementing policies. We argue that this interdisciplinary approach could be applied in a whole range of other environments including other terrestrial biota and aquatic ecosystems where functional habitat connectivity, nonlinear response to habitat loss and a multitude of economic and social interests co-occur in the same landscape.  相似文献   
30.
Disappearance rate constants are reported for the reductive transformation of 17 halogenated aliphatic hydrocarbons in anaerobic sediment-water samples. Statistical experimental design in combination with multivariate chemical characterization of their chemical properties was used to select the compounds. Degradation followed pseudo first-order kinetics through at least two half-lives for 15 of the 17 compounds. Of all the compounds investigated, 1,2,3-trichloropropane and dichloromethane were unique in that they were dehalogenated according to zero-order kinetics. Reductive dehalogenation was the sole transformation reaction taking place.  相似文献   
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