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641.
Rochelle Constantine Debbie Steel Judy Allen Megan Anderson Olive Andrews C. Scott Baker Peta Beeman Daniel Burns Jean-Benoît Charrassin Simon Childerhouse Michael Double Paul Ensor Trish Franklin Wally Franklin Nick Gales Claire Garrigue Nadine Gibbs Peter Harrison Nan Hauser Amanda Hutsel Curt Jenner Micheline-Nicole Jenner Greg Kaufman Anne Macie David Mattila Carlos Olavarría Adrian Oosterman David Paton Michael Poole Jooke Robbins Natalie Schmitt Peter Stevick Alden Tagarino Kirsten Thompson Juney Ward 《Marine Biology》2014,161(5):1087-1093
Understanding the dynamics of population recovery is particularly complex when an organism has multiple, remote breeding and feeding grounds separated by one of the longest known migration routes. This study reports on the most comprehensive assessment of humpback whale (Megaptera novaeangliae) movements between remote Antarctic waters south of New Zealand and east Australia (EA), and the migratory corridors and breeding grounds of Australia and Oceania. A total of 112 individual whales were identified; 57 from microsatellites and 61 by fluke with 23 % (n = 26) matched to sites outside Antarctica. Despite large datasets from other southern regions being included in the comparison, the whales were predominantly linked to EA (n = 24). Only two matches to the Oceania catalogues directly north was surprising; therefore the primary feeding grounds of these endangered whales still remain unknown. The confirmation of the Balleny Islands as an important feeding ground for EA whales could provide an insight into reasons behind the rapid recovery of this population. Determining the feeding grounds of Oceania’s whales may explain whether prey energetics or migration length are limiting factors to their recovery and will allow an understanding of future ecosystem changes in these whales. 相似文献
642.
Large predatory fishes are disproportionately targeted by reef fisheries, but little is known about their trophic ecology, which inhibits understanding of community dynamics and the potential effects of climate change. In this study, stable isotope analyses were used to infer trophic ecology of a guild of large predatory fishes that are targeted by fisheries on the Great Barrier Reef, Australia. Each of four focal predators (Plectropomus leopardus, Plectropomus maculatus, Lethrinus miniatus and Lutjanus carponotatus) was found to have a distinct isotopic signature in terms of δ13C and δ15N. A two-source mixing model (benthic reef-based versus pelagic) indicated that P. leopardus and L. miniatus derive the majority (72 and 62 %, respectively) of their production from planktonic sources, while P. maculatus and L. carponotatus derive the majority (89 and 74 %, respectively) of their production from benthic reef-based sources. This indicates that planktonic production is important for sustaining key species in reef fisheries and highlights the need for a whole-ecosystem approach to fisheries management. Unexpectedly, there was little isotopic niche overlap between three of four focal predators, suggesting that inter-specific competition for prey may be low or absent. δ15Nitrogen indicated that the closely related P. leopardus and P. maculatus are apex predators (trophic level > 4), while δ13C indicated that each species has a different diet and degree of trophic specialisation. In view of these divergent trophic ecologies, each of the four focal predators (and the associated fisheries) are anticipated to be differentially affected by climate-induced disturbances. Thus, the results presented herein provide a useful starting point for precautionary management of exploited predator populations in a changing climate. 相似文献
643.
David D. Hope David B. Lank Ronald C. Ydenberg 《Behavioral ecology and sociobiology》2014,68(5):827-838
Ecological theory for long-distance avian migration considers time-, energy-, and mortality-minimizing tactics, but predictions about the latter have proven elusive. Migrants must make behavioral decisions that can favor either migratory speed or safety from predators, but often not both. We compare the behavior of adult and juvenile western sandpipers Calidris mauri during the course of their temporally segregated passages at a major stopover site. Here, the passage and winter arrival of an important predator, the peregrine falcon Falco peregrinus begins near the end of the adult sandpiper passage (July) and increases rapidly through the juvenile passage (August). The mortality-minimizing hypothesis predicts that as the falcon front is distant but approaching, sandpipers should initially increase the fuel-loading rate (lowered vigilance and predator apprehension) to increase migration speed and so maintain their head start. As the falcon front gains proximity to and passes over the stopover site, sandpipers should become increasingly cautious. Our measurements show that adults decreased vigilance during the period prior to falcon arrival, and had lower vigilance overall than juveniles. Juveniles were more apprehensive, flying further and longer in response to disturbance by a falcon silhouette. This trend was reversed in response to a human approach. Both groups were more vigilant and more apprehensive in a study year with earlier falcon arrival. These results suggest that late (juvenile) and early (adult) migrants minimize mortality on migration in different ways, adults by increased migratory speed at the expense of caution on stopover sites, and juveniles by increased caution at the expense of speed. 相似文献
644.
645.
Yonggang?Nie Ronald?R.?Swaisgood Zejun?Zhang Xiaobin?Liu Fuwen?WeiEmail author 《Behavioral ecology and sociobiology》2012,66(5):721-730
The giant panda (Ailuropoda melanoleuca) is notoriously difficult to study in the wild, but its interesting reproductive ecology makes the effort worthwhile. Perhaps
more than most species, the panda is energy-limited, which alters the cost/benefit analysis of its reproductive ecology. Using
global positioning system/very high frequency radiocollars to locate mating aggregations, we used behavioral observations
and fecal testosterone assays to gain insight into male panda reproductive effort and strategies, and test theories relating
to reproductive competition. Male pandas initially competed fiercely for access to females that were about to be fertile,
but once male competitive status was determined, aggression rates declined. Contact aggression was only observed during the
first 2 days of mating aggregations; thereafter, it was replaced with noncontact aggression and avoidance. Agonistic interactions
were highly asymmetrical, with contest losers (subordinates) showing less aggression and more avoidance than contest winners
(dominants), both before and after contest outcome was established. The competitively superior male displayed mate-guarding
tactics and secured all observed copulations. Contrary to theoretical predictions, testosterone levels did not predict aggression
levels or contest winners and also were not affected by winning or losing a contest. Body size appeared to be the primary
determinant of contest outcome. We discuss our findings in light of theoretical predictions, such as those arising from the
“challenge hypothesis,” in the context of the giant panda’s foraging and nutritional ecology. 相似文献
646.
Thomas Breuer Andrew M. Robbins Claudia Olejniczak Richard J. Parnell Emma J. Stokes Martha M. Robbins 《Behavioral ecology and sociobiology》2010,64(4):515-528
Variance in male reproductive success is expected to be high in sexually dimorphic mammals, even when it is modulated by the
costs and benefits of group living. Here, we investigate the variance in reproductive success of male western gorillas (Gorilla gorilla), a highly dimorphic primate with long-term male–female associations, using 12.5 years of data collected at Mbeli Bai in
northern Congo. Access to mates and offspring survival were both major sources of variance in male reproductive success. Males
with larger harems had lower offspring mortality with no apparent reduction in female fertility or observed tenure length,
so the size of harems did not seem to be limited by female feeding competition or by the risk of takeovers and infanticide
by outsider males. The lower mortality in larger harems may reflect improved vigilance against predators, and females may
cluster around males that enhance offspring survival. Thus, this study illustrates how a detailed analysis of the components
of male reproductive success can shed light on the interrelated social and ecological aspects that affect it. 相似文献
647.
Simulation of information propagation in real-life primate networks: longevity, fecundity, fidelity 总被引:1,自引:1,他引:0
In many vertebrate species, we find temporally stable traditions of socially learned behaviors. The social structure of animal
populations is highly diverse and it has been proposed that differences in the social organization influence the patterns
of information propagation. Here, we provide results of a simulation study of information propagation on real-life social
networks of 70 primate groups comprising 30 different species. We found that models that include the social structure of a
group differ significantly from those that assume random associations of individuals. Information spreads slower in the structured
groups than in the well-mixed groups. While we found only a minor effect on the path lengths of the transmission chains, robustness
against information extinction was strongly influenced by the group structure. Interestingly, robustness against information
loss was not correlated with propagation speed but could be predicted reasonably well by relative strength assortativity—a
structural network metric. In those groups where highly pro-social individuals preferentially interact with other pro-social
individuals, information was more likely to be lost. Our results show that incorporating group structure in any social propagation
model significantly alters predictions for spreading patterns, speed, and robustness of information. 相似文献
648.
Characterizing the Florida Keys National Marine Sanctuary (FKNMS), USA, has gained much attention over the past several decades
because of apparent changes in the benthic community structure over space and time representative of patterns occurring in
the Caribbean region. We used a 5-year dataset (1996–2000) of macroalgal and sponge cover and water quality measurements as
predictor variables of hard coral community structure in the FKNMS. The 16 water quality variables were summarized into 4
groups by principal component analysis (PCA). Hierarchical agglomerative cluster analysis of the mean and standard deviation
(SD) of the principal component scores of water quality variables separated the reef sites into two main groups (and five
sub-groups), referred to as reefs of similar influence (RSI). The main groups corresponded with their geographical locations
within the Florida Keys: the reefs in the Upper and Middle Keys being homogeneous and collectively, having lower water quality
scores relative to reefs in the Lower Keys. Canonical correspondence analysis (CCA) between hard coral cover and key predictor
variables (i.e., water quality, macroalgal cover and sponge cover) also separated the reefs in the Lower Keys from reefs in
the Upper–Middle Keys, consistent with results of the cluster analysis, which categorized reefs based on RSI. These results
suggest that the prevailing gradient of predictor variables may have influenced the structuring of coral reef communities
at a spatial scale larger than the individual reef. Furthermore, it is conceivable that these predictor variables exerted
influence for a long time rather than being a recent event. Results also revealed a pattern showing reduction in hard coral
cover and species richness, and subsequent proliferation of macroalgae and sponges during the study period. Our analyses of
the Florida Keys present a pattern that is consistent with the characteristics of a reef that has undergone a “phase-shift,”
a phenomenon that is widely reported in the Caribbean region. 相似文献
649.
650.