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191.
Michael?D.?ArendtEmail author Albert?L.?Segars Julia?I.?Byrd Jessica?Boynton J.?David?Whitaker Lindsey?Parker David?W.?Owens Ga?lle?Blanvillain Joseph?M.?Quattro Mark?A.?Roberts 《Marine Biology》2012,159(1):127-139
Thirty-four juvenile loggerhead sea turtles captured by trawling from the Charleston, South Carolina (USA), shipping channel
(32°42′N; −79°47′W) between May 2004 and August 2007 were tagged with satellite transmitters to assess the extent to which
they remained near the capture location given their collection along a seasonal migratory corridor. Seventy-five percent of
juveniles were classified as seasonal residents. Migrants predominantly swam north in the spring and nomads wandered south
in the summer, but predictive indicators for non-resident status were not identified. All but one juvenile generally remained
south of 34°N, within 40 km of shore, and in waters <30 m deep throughout the year. Nine of 14 loggerhead sea turtles monitored
during the winter remained exclusively over the continental shelf, three briefly occurred in oceanic habitats, and two foraged
extensively in oceanic habitats. Residents distributed >15 km from shore between spring and autumn were three times as likely
to occur in oceanic habitats in winter. Modest seasonal movements contrasted with adults tagged at similar latitudes and with
juveniles tagged further north and suggest distinct foraging groups within a regional foraging ground. 相似文献
192.
This study examines the composition and activity of the planktonic community during the polar night in the high Arctic Kongsfjord, Svalbard. Our results are the first published evidence of bioluminescence among zooplankton during the Arctic polar night. The observations were collected by a bathyphotometer detecting bioluminescence, integrated into an autonomous underwater vehicle, to determine the concentration and intensity of bioluminescent flashes as a function of time of day and depth. To further understand community dynamics and composition, plankton nets were used to collect organisms passing through the bathyphotometer along with traditional vertical net tows. Additionally, using a moored bathyphotometer closed to the sampling site, the bioluminescence potential itself was shown not to have a diurnal or circadian rhythm. Rather, our results provide evidence for a diel vertical migration of bioluminescent zooplankton that does not correspond to any externally detectable changes in illumination. 相似文献
193.
Ivan Viegas Sónia Cotrim Marques Filipa Bessa Ana Lígia Primo Filipe Martinho Ulisses Miranda Azeiteiro Miguel ?ngelo Pardal 《Marine Biology》2012,159(1):33-43
This study provides a comprehensive examination of the life cycle dynamics of the brown shrimp (Crangon crangon L.) in the Mondego estuary, Portugal, a habitat located near the southern edge of the range of this species in European waters.
The phenology of all life stages was documented (from the occurrence of ovigerous females, developing embryos, planktonic
larvae and benthic post-larvae), and migration patterns of larvae into and out of the estuary were examined. Temperature-dependent
functions of egg and larval development were combined with data on field abundance to predict the timing and magnitude of
occurrence of larvae and recruits. Compared to brown shrimp at higher latitudes, southern conspecifics grow slower, mature
earlier and have smaller brood sizes, and larvae have a more protracted settlement period. The Mondego estuary, besides acting
as nursery area, is a dynamic platform for C. crangon to use in different stages, sizes and seasons. 相似文献
194.
Judith?MoralesEmail author Roxana?Torres Alberto?Velando 《Behavioral ecology and sociobiology》2012,66(1):135-143
In evolutionary biology, whether parents should enhance or reduce parental care according to mate ornamentation is a subject
of great debate. However, the evolution of female ornaments can shed light on this question. In theory, female ornamentation
should be traded off against fecundity and thus cannot be wholly informative to males without a direct indication of fecundity.
Hence, direct cues of offspring quality should affect the relationship between male investment and female ornamentation. Under
this hypothesis, we manipulated two direct cues of offspring quality (egg size and color) after first egg laying in the blue-footed
booby and registered male incubation patterns. In this species, foot color is a dynamic signal of current condition and in
females is traded off with egg size. We found that males spent more time incubating when paired with dull females but only
in nests with large eggs. Males also spent less time incubating small dull eggs. Results indicate that egg size, a direct
cue of reproductive value, affected the relationship between male effort and female ornamentation. Males may be willing to
help females that have invested in offspring at the expense of ornamentation, which suggests compensation when females are
in low condition. Another possibility is that males relax their effort when paired with highly ornamented and fecund females
because they have high parenting abilities. Our findings suggest that the information conveyed by female ornaments may depend
on direct cues of fecundity. Results also highlight that parental decisions are complex, modulated by a combination of information
sources. 相似文献
195.
Time of departure and landing of nocturnal migrants are of great importance for understanding migratory strategy used by birds.
It allows us to estimate flying time and hence the distance that migrants cover during a single night. In this paper, I studied
the temporal schedule of nocturnal departures of European robins during spring migration. The study was done on the Courish
Spit on the Baltic Sea in 1998–2003 by retrapping 51 ringed birds in high mist nets during nocturnal migratory departure.
Take-offs of individual birds occurred between the first and tenth hour after sunset (median 176 min after sunset). Departure
time was not related to fuel stores at arrival and departure, stopover duration and progress of the season. The results suggest
that one reason for temporal variation in take-off time was differential response of European robins with high and low motivation
to depart to such triggers as air pressure and its trend. If these parameters reach a certain minimum threshold shortly before
sunset, robins with a high migratory motivation take off in the beginning of the night. When air pressure or its trend reaches
a maximum, it may trigger to take off later during the night birds with lower initial motivation for departure, including
those that have low refuelling efficiency. In regulation of timing of take-offs of robins, an important role is also played
by their individual endogenous circadian rhythm of activity which is related to the environment in a complex way. 相似文献
196.
Virginia?Gonzalez-JimenaEmail author Patrick?S.?Fitze 《Behavioral ecology and sociobiology》2012,66(2):305-315
Glucocorticoids affect physiology and behaviour, reproduction and potentially sexual selection as well. Short-term and moderate
glucocorticoid elevations are suggested to be adaptive, and prolonged and high elevations may be extremely harmful. This suggests
that optimal reproductive strategies, and thus sexual selection, may be dose dependent. Here, we investigate effects of moderate
and high elevations of blood corticosterone levels on intra- and intersexual behaviour and mating success of male common lizards
Lacerta vivipara. Females showed less interest and more aggressive behaviour towards high corticosterone males and blood corticosterone levels
affected male reproductive strategy. Males of moderate and high corticosterone elevations, compared with Control males, showed
increased interest (i.e., higher number of chases, tongue extrusions, and approaches) towards females and high corticosterone
males initiated more copulation attempts. However, neither increased male interest nor increased copulation attempts resulted
in more copulations. This provides evidence for a best-of-a-bad-job strategy, where males with higher corticosterone levels
compensated for reduced female interest and increased aggressive female behaviour directed towards them, by showing higher
interest and by conducting more copulation attempts. Blood corticosterone levels affected intrasexual selection as well since
moderate corticosterone levels positively affected male dominance, but dominance did not affect mating success. These findings
underline the importance of female mate choice and are in line with adaptive compensatory behaviours of males. They further
show that glucocorticoid effects on behaviour are dose dependent and that they have important implications for sexual selection
and social interactions, and might potentially affect Darwinian fitness. 相似文献
197.
Julie?A.?TeichroebEmail author Pascale?Sicotte 《Behavioral ecology and sociobiology》2012,66(3):453-466
Vigilance often decreases with increasing group size, due to lower predation risk or greater scramble competition for food.
A group size effect on vigilance is seldom seen in primates, perhaps because scanning and feeding often occur simultaneously
or because the distinction between routine and induced vigilance has not been investigated. We analyzed feeding and resting
observations separately while distinguishing between routine and induced scans in four groups of wild ursine colobus monkeys
(Colobus vellerosus) experiencing scramble competition for food and infanticide risk. We used linear mixed-effect models to test the effect of
group size, age–sex class, number of neighbors, number of adult male neighbors, and height in the canopy on scanning rates
(vigilance) with and without evident conspecific threat. Food type was also examined in the feeding models. Perceived predation
risk affected vigilance more than scramble competition for food and infanticide risk. Routine and induced vigilance were greatest
at lower canopy heights during feeding and resting and increased when individuals had fewer neighbors while resting. A group
size effect was found on induced vigilance while resting, but scanning increased with group size, which probably indicates
visual monitoring of conspecifics. Scanning rates decreased while feeding on foods that required extensive manipulation. This
supports the idea that vigilance is relatively cost free for upright feeders when eating food that requires little manipulation,
a common feature of folivore diets. In the presence of threatening conspecific males, close proximity to resident males decreased
individual vigilance, demonstrating the defensive role of these males in the group. 相似文献
198.
Vicki?L.?StokesEmail author Peter?B.?Banks Roger?P.?Pech 《Behavioral ecology and sociobiology》2012,66(2):329-338
Residency status of individuals in populations may be an important determinant of the outcomes of interspecific competition
between native and introduced species. We examined direct behavioral interactions between two similarly sized rodents, the
alien Rattus rattus and native Rattus fuscipes when they were respective residents and intruders in a small enclosure. Resident individuals were dominant in their behaviors
toward intruders irrespective of the species that was resident. In contrast, interactive behaviors between conspecifics were
often neutral or amicable, supporting suggestions that R. rattus and R. fuscipes are social animals. We then tested whether rodent species use heterospecific odors to avoid aggressive competitive interactions
and partition space in the field. Neither R. fuscipes nor R. rattus responded to traps scented with the odors of male or female heterospecifics. If R. fuscipes does not recognize the odor of introduced R. rattus, then odors will not be cues to the presence or territorial space of competing heterospecifics. Rather, findings from both
enclosure and field trials suggest that direct aggressive interactions between individual R. rattus and R. fuscipes probably facilitate segregation of space between these two species in wild populations, where resident animals may typically
be the winners and exclude heterospecific intruders. These findings have implications for the invasion success of introduced
rodents such as R. rattus into intact forests, where native populations may have competitive advantage because of their residency status. 相似文献
199.
Maren?HuckEmail author Eduardo?Fernandez-Duque 《Behavioral ecology and sociobiology》2012,66(3):505-517
According to the Evolutionary Theory of the Family, the replacement of one pair-member by an intruder may have profound consequences
for the existing offspring. Step-parents are expected to provide less care towards unrelated immatures than to genetic offspring,
unless caring also serves as a mating strategy. Furthermore, because an intruder will be a potential mate for opposite-sexed
offspring, relationships between offspring and same-sex parents are predicted to deteriorate. To test these predictions, we
studied an Azara’s owl monkey (Aotus azarai) population in Argentina exhibiting serial monogamy and bi-parental care. Since 1997, we have collected demographic data
from ca. 25 groups and inter-individual distance data from ca. 150 marked individuals. First, we compared survival and dispersal
age of immatures in groups with and without replacements to investigate whether parental care serves as a mating strategy.
Second, we compared sex-specific age at dispersal for groups with replacement of opposite-sex parents, same-sex parents, or
in stable groups in order to test whether relationships between offspring and same-sex parents deteriorated after the replacement
of the other parent. Survival and dispersal ages were not negatively associated with replacements, suggesting that male care
might serve, at least partly, as a mating strategy. The time lag between a replacement and the subsequent dispersal of female
offspring was greater if the intruder was a male, while the offspring and same-sex parents were less often nearest neighbors
after replacements than before. Our results suggest that family disruption through the replacement of a parent is not associated
with decreased offspring survival or early dispersion of juveniles, but deteriorates parent–offspring relationships. 相似文献
200.
Gábor?HerczegEmail author László?Zsolt?Garamszegi 《Behavioral ecology and sociobiology》2012,66(1):161-169
The study of correlations between different behaviours in a population—referred to as behavioural syndromes—has begun to flourish
during recent years. However, the evolutionary mechanisms that cause behavioural traits to vary non-independently from each
other are still poorly understood. Here, we bring behavioural syndromes into a new perspective, in which the phenomenon is
regarded at the individual level and on a continuous scale instead of as a population-level presence/absence trait. As the
correlation between behaviours is never perfect (i.e. r < 1), individuals are likely to vary in how consistently they behave. Therefore, we can predict that if behavioural syndromes
at the population level are results of natural selection, the consistency in a suite of behaviours—and not the behavioural
configuration per se—should be heritable and involve fitness advantages at the individual level. We define a variable that
describes the individual deviation from the hypothetical perfect correlation predicted by the syndrome. The use of such a
variable depicting the consistency of behaviours of individuals allows us to make solid evolutionary inferences about correlated
behaviours from patterns of individual instead of population variation. We suggest that, by adopting the concept of syndrome deviation, understanding the evolution of behavioural syndromes and, in particular, testing competing evolutionary hypotheses about
the origin of behavioural syndromes becomes possible in a more rigorous manner than before. 相似文献