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961.
Stephen M. Mudge 《Chemistry and Ecology》1998,14(3):259-263
Vegetable oil spills are relatively uncommon compared to those of mineral oil in the marine environment. Evidence from the spillages that have occurred indicate that they can cause the death of animals in the vicinity through suffocation, inhibition of feeding and other non-specific toxic effects. Smothering of the intertidal area may lead to the development of anoxic conditions with associated changes in species diversity. Polymerisation appears to be a key process in determining the persistence of these oils in the intertidal region. Experiments have indicated that indigenous bacteria are capable of degrading the oil until it polymerises and work is being directed towards determining mechanisms to aid in the degradation process. in conclusion, vegetable oils are pollutants although the risk to the marine environment is small but that does not mean we should not be prepared for such events. 相似文献
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Nicola Weber Stuart Bearhop Sasha R. X. Dall Richard J. Delahay Robbie A. McDonald Stephen P. Carter 《Behavioral ecology and sociobiology》2013,67(3):471-479
Heterogeneities in behaviours of individuals may underpin important processes in evolutionary biology and ecology, including the spread of disease. Modelling approaches can sometimes fail to predict disease spread, which may partly be due to the number of unknown sources of variation in host behaviour. The European badger is a wildlife reservoir for bovine tuberculosis (bTB) in Britain and Ireland, and individual behaviour has been demonstrated to be an important factor in the spread of bTB among badgers and to cattle. Radio-telemetry devices were deployed on 40 badgers from eight groups to investigate patterns of den (sett) use in a high-density population, where each group had one or two main and three to eight outlier setts in their territory. Badgers were located at their setts for 28 days per season for 1 year to investigate how patterns differed between individuals. Denning behaviour may have a strong influence on contact patterns and the transmission of disease. We found significant heterogeneity, influenced by season, sex and age. Also, when controlling for these, bTB infection status interacting with season was highly correlated with sett use. Test-positive badgers spent more time away from their main sett than those that tested negative. We speculate that wider-ranging behaviour of test-positive animals may result in them contacting sources of infection more frequently and/or that their behaviour may be influenced by their disease status. Measures to control infectious diseases might be improved by targeting functional groups, specific areas or times of year that may contribute disproportionately to disease spread. 相似文献
966.
Scent-marking is a frequent behaviour of highly social ground squirrels and might play an important role in their social dynamics.
Female Columbian ground squirrels exhibit considerable scent-marking during the reproductive period. We examined how gestating
and lactating females responded to jugal gland scent-marks of same-sexed and opposite-sexed conspecifics with attention to
genetic relatedness and the geographical location of the territory of individuals. We tested the dear-enemy, threat-level
and kin-discrimination hypotheses to explain patterns of scent-marking. Females sniffed the scent of non-neighbouring males
significantly longer than other types of scent categories and tended to over mark the scent of females more than the scent
of males. Furthermore, females sniffed significantly longer at scents during gestation than during lactation. We concluded
that scent-marking mainly functioned in the defence of female territories and for protection of pups against infanticidal
females (threat-level hypothesis). Our results were also in accordance with the kin-discrimination hypothesis, because greater
attention was paid to the marks of non-kin females. Kin females might not pose an infanticidal threat, perhaps explaining
greater tolerance among related reproductive females. We concluded that scent-marking may be a relatively low-cost means of
territorial defence, as well as a means of communication of aspects of individual identity. 相似文献
967.
William A. Searcy Susan Peters Silke Kipper Stephen Nowicki 《Behavioral ecology and sociobiology》2010,64(8):1343-1349
One explanation for why female songbirds attend to male song is that the quality of a male's song is associated with the quality
of his developmental history. We tested this hypothesis by playing back to female swamp sparrows (Melospiza georgiana) songs recorded from males of either inferior or superior developmental histories, as assessed by their rates of mass gain
during the first 18 days post-hatching. Females showed significantly higher levels of courtship display in response to songs
of males with superior growth than to songs of males with inferior growth. Out of nine song traits measured, only song duration
correlated with variation in female response; duration was also the only trait that differed significantly in univariate comparisons
between the superior growth songs and the inferior growth songs. In a multivariate analysis, however, inferior growth songs
were best discriminated from superior growth songs by combining three song traits: trill rate, stereotypy, and the number
of notes per syllable. We suggest that early developmental stress degrades song in many small ways, and that it is the cumulative
effect of the resulting deficits that explains lower female response. 相似文献
968.
A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to alkaline copper quaternary (ACQ)-treated lumber used for decking and to determine how the impacts compare to the primary alternative product, wood plastic composite (WPC) decking. A model of ACQ-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inventory inputs, outputs, and impact indicators for ACQ-treated lumber were quantified using functional units of 1000 board feet and per representative deck (assumed to be 320 square feet (30 square meters) of surface decking material) per year of use. In a similar manner, an inventory model was developed for the manufacture, use, and disposal of the primary alternative product, WPC. Impact indicator values, including greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, smog forming potential, ecological toxicity, and eutrophication were quantified for each of the two decking products. National normalization was done to compare the significance of a representative deck surface per year of use to a family’s total annual impact footprint.If an average U.S. family adds or replaces a deck surfaced with ACQ-treated lumber, their impact “footprint” for GHG emissions, fossil fuel use, acidification, smog forming potential, ecological toxicity, and eutrophication releases each is less than one-tenth of a percent of the family’s annual impact. ACQ-treated lumber impacts were fourteen times less for fossil fuel use, almost three times less for GHG emissions, potential smog emissions, and water use, four times less for acidification, and almost half for ecological toxicity than those for WPC decking. Impacts were approximately equal for eutrophication. 相似文献
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Lynne Van Herwerden J. Howard Choat Stephen J. Newman Matthieu Leray Grethe Hillersøy 《Marine Biology》2009,156(8):1595-1607
Here the population genetic structure of an ecologically and economically important coral reef fish, the coral trout Plectropomus leopardus, is investigated in the context of contemporary and historical events. Coral trout were sampled from four regions (six locations)
and partial mtDNA D-loop sequences identified six populations (Fst = 0.89209, P < 0.0001): Scott Reef and the Abrolhos Islands in west Australia; the Great Barrier Reef (GBR), represented by northern and
southern GBR samples; New Caledonia and Taiwan, with Taiwan containing two genetic lineages. Furthermore, this study identified
source and sink populations within and among regions. Specifically, the northern population in west Australia (Scott Reef)
was identified, as the source for replenishment of the Abrolhos population, whilst New Caledonia was a source for recruitment
to the GBR. Based on these insights from a single mtDNA marker, this study will facilitate the development of rational management
plans for the conservation of P. leopardus populations and therefore mitigate the risk of population declines from anthropogenic influences. 相似文献