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991.
Aurélie Pinto Rodrigues Patrícia Correia Oliveira Lúcia Guilhermino Laura Guimar?es 《Marine Biology》2012,159(9):2061-2074
This study investigated the effects of salinity on biomarkers of oxidative stress, energy metabolism, and neurotransmission of Carcinus maenas from an estuary low impacted by pollution and from an estuary under chemical stress in the NW Iberian Peninsula. Crabs were collected in the field and, following an acclimation period, they were exposed for 7 days to five salinity levels ranging from 4 to 45 psu. At the end of the exposure period, stress biomarkers were determined in samples of muscle and digestive gland. The biomarkers assessed in the muscle were the activities of the enzymes cholinesterases (ChE), of which acetylcholinesterase is involved in neurotransmission, and lactate dehydrogenase (LDH) and isocitrate dehydrogenase (IDH) that are involved in energy metabolism. The biomarkers assessed in the digestive gland were (1) the activities of the enzymes glutathione S-transferases (GST), glutathione reductase (GR), and glutathione peroxidase (GPx), involved in phase II biotransformation and the anti-oxidant defence system; (2) the levels of total glutathiones (TG), also belonging to the anti-oxidant system; and (3) the levels of lipid peroxidation as a measure of oxidative damage. The results showed a significant influence of salinity on neurotransmission, energy metabolism, anti-oxidant status, and oxidative damage of C. maenas. For some biomarkers, this influence was dependent on whether the crabs were collected at the low-polluted estuary or at the contaminated estuary. In particular, crabs collected at the low-polluted estuary showed altered neurotransmission and anti-oxidant defences (GR). Crabs collected at the impacted estuary showed alterations in neurotransmission, energy metabolism (IDH and LDH), biotransformation, and anti-oxidant defences (GST, GR, GPx, and TG), as well as in oxidative damage, indicating that salinity change superimposes higher stress on these organisms. For ChE, IDH, and TG, altered responses were induced by both hypo- and hypersalinity. 相似文献
992.
Simona?Kralj-Fi?erEmail author Jutta?M.?Schneider ?iva?Justinek Sabina?Kalin Matja??Gregori? Stano?Pekár Matja??Kuntner 《Behavioral ecology and sociobiology》2012,66(1):145-151
Sexual cannibalism particularly before mating is costly for the male victim but also for the female aggressor if she risks
remaining unmated. The aggressive spillover hypothesis explains the persistence of this behavior as a maladaptive side effect
of positive selection on aggressiveness in a foraging context. The hypothesis predicts that the occurrence of sexual cannibalism
is explained by female aggressiveness but is not related to male phenotype or behavioral type. An alternative hypothesis invokes
sexual selection and makes the opposite prediction namely that sexual cannibalism is an expression of female choice and should
hence mainly target males of low quality. We tested the above hypotheses on a sexually dimorphic nephilid spider Nephilengys livida, known for male monopolization of females via genital damage, female genital plugging, and mate guarding, by staging mating
trials during which we recorded mating behaviors and occurrences of pre- and postcopulatory cannibalism. We did not restrict
assessment of aggressiveness to the mating and foraging context but also included aggression against same sex conspecifics.
To assess female personalities, i.e., consistent individual differences in behavior including aggressiveness, we repeatedly
tested them for intra-sex aggression, voracity towards prey, locomotory activity, and boldness. Females exhibited consistent
differences in intra-sex aggressiveness, latency to attack prey, and boldness. Aggressive females had shorter latencies to
attack prey and were more active than non-aggressive ones. In contrast to the predictions of the aggressive spillover hypothesis,
females that were aggressive towards prey and towards other females were not more likely to attack a male than non-aggressive
females. In support of the mate choice hypothesis, less aggressive males were more likely attacked and cannibalized than more
aggressive ones. This hints at sexual selection for aggressiveness in males and raises the question of mechanisms that maintain
variation in male aggressiveness. 相似文献
993.
Dispersal attempts can be costly and may often end in failure. Individuals should therefore only disperse when the benefits
of dispersal outweigh the costs. While previous research has focussed on aspects of the individual that may affect dispersal
success, social factors may also influence dispersal outcomes. One way of achieving successful dispersal could be through
cooperative, or coalition dispersal. I investigated this possibility in the cooperatively breeding Arabian babbler Turdoides squamiceps. I found that coalition dispersal appears to be an effective strategy to ensure the success of dispersal attempts, with coalitions
more successful than lone individuals at taking over the breeding position in a new group. Lone dispersal was more costly
than coalition dispersal, with lone individuals suffering a greater loss of body mass during dispersal attempts. These results
suggest a substantial short-term benefit for this type of cooperative behaviour. There was no evidence for dispersal polymorphism
in the population, with no detectable phenotypic difference between dispersers and non-dispersers or those that dispersed
as part of a coalition compared with those that dispersed alone. 相似文献
994.
John?A.?VucetichEmail author Leah?M.?Vucetich Rolf?O.?Peterson 《Behavioral ecology and sociobiology》2012,66(2):295-303
For a wide range of taxa, partial prey consumption (PPC) is a frequent occurrence. PPC may arise from physiological constraints
to gut capacity or digestive rate. Alternatively, PPC may represent an optimal foraging strategy. Assessments that clearly
distinguish between these causes are rare and have been conducted only for invertebrate species that are ambush predators
with extra-intestinal digestion (e.g., wolf spiders). We present the first strong test for the cause of PPC in a cursorial
vertebrate predator with intestinal digestion: wolves (Canis lupus) feeding on moose (Alces alces). Previous theoretical assessments indicate that if PPC represents an optimal foraging strategy and is not caused by physiological
limitations, then mean carcass utilization is negatively correlated with mean kill rate and the utilization of individual
carcasses is uncorrelated with time between kills. Wolves exhibit exactly this pattern. We explore how the typical portrayal
of PPC by wolves has been not only misleading but also detrimental to conservation by promoting negative attitudes toward
wolves. 相似文献
995.
László?Zsolt?GaramszegiEmail author Anders?Pape?M?ller 《Behavioral ecology and sociobiology》2012,66(1):107-119
Hamilton and Zuk (Science 218:384–387, 1982) supported their influential hypothesis of parasite-mediated sexual selection based on a positive interspecific correlation
between the prevalence of blood parasites and the expression of male displays in birds. However, subsequent studies provided
mixed support for this relationship after considering several confounding factors. Here, we revisit this fundamental prediction
by refining the analyses through implementation of recent methodological advancements. First, we distinguish between prevalence
data obtained through microscopic and molecular tools, as PCR-based detection methods may be more sensitive for detecting
infection. Second, we use quantitative estimates of both acoustic and visual signals of males, in which color measurements
adopt the perspective of avian vision. Third, applying modern phylogenetic comparative approaches, we correct for phylogenetic
inertia as well as heterogeneity in sampling effort. Fourth, we distinguish between prevalence transition states, as we compare
species with and without evidence of infection and also monitor changes in parasite prevalence only in species in which blood
parasites are detected. We show that given the considerable variation among populations, the repeatability of prevalence at
the within-species level is modest. We failed to detect a strong interspecific relationship between the prevalence of blood
parasites and sexual traits. However, we found that an evolutionary increase from zero to non-zero prevalence is likely to
be accompanied by an increase in trait expression in males, but further increase from non-zero prevalence to a higher level
of infection tends to be associated with a reduced degree of trait elaboration. Our results provide some support to the Hamilton
and Zuk hypothesis, but the relationship between blood parasites and male displays varies among traits depending on degree
of infection. 相似文献
996.
Thomas?KlefothEmail author Christian?Skov Jens?Krause Robert?Arlinghaus 《Behavioral ecology and sociobiology》2012,66(4):547-559
To showcase the importance of genotype × environment interactions and the presence of predation risk in the experimental assessment
of boldness in fish, we investigated boldness in terms of feeding behavior and refuge use in two genetically different populations
of juvenile carp (Cyprinus carpio) in two replicated experimental conditions in ponds and laboratory tanks. The populations were expected to exhibit genetic
differences in boldness due to differential evolutionary adaptation to low-predation-risk pond aquaculture conditions. Boldness
was measured in variants of open-field trials with and without implementation of additional predation risk-stimuli by angling
on feeding spots. Without explicit implementation of risk, genotypes adapted to low-risk environments, i.e., domesticated
mirror carp behaved consistently bolder than their less domesticated scaled conspecifics in the pond environment, but not
in the laboratory environment. When we implemented artificial risk-stimuli by angling on previously safe feeding spots, boldness
differences among genotypes also emerged in the laboratory environment, indicating strong genotype × environment effects on
boldness behavior of carp. The expected genetic basis of boldness differences among genotypes was clearly supported in the
pond environment, while the laboratory study revealed these patterns only under inclusion of explicit risk-stimuli. Our study
thus underscores that boldness may involve both a basal component that is expressed independently of obvious predation risk
(e.g., in open fields) and a component revealed in relation to explicit predation risk, and both dimensions may respond differently
in behavioral tests. 相似文献
997.
Hydrochemical, multivariate statistical, and inverse geochemical modeling techniques were used to investigate the hydrochemical
evolution within the Ain Azel aquifer, Algeria. Cluster analysis based on major ion contents defined 3 main chemical water
types, reflecting different hydrochemical processes. The first group water, group 1, has low salinity (mean EC = 735 μS/cm).
The second group waters are classified as Cl–HCO3-alkaline earth type. The third group is made up of water samples, the cation composition of which is dominated by Ca and
Mg with anion composition varying from dominantly Cl to dominantly HCO3 plus SO4. The varifactors obtained from R-mode FA indicate that the parameters responsible for groundwater quality variations are
mainly related to the presence and dissolution of some carbonate, silicate, and evaporite minerals in the aquifer. Inverse
geochemical modeling along groundwater flow paths indicates the dominant processes are the consumption of CO2, the dissolution of dolomite, gypsum, and halite, along with the precipitation of calcite, Ca-montmorillonite, illite, kaolinite,
and quartz. 相似文献
998.
Patinha C Reis AP Dias C Cachada A Adão R Martins H Ferreira da Silva E Sousa AJ 《Environmental geochemistry and health》2012,34(2):213-227
Previous environmental biomonitoring studies indicated higher environmental lead (Pb) pollution levels at the districts of
Aveiro and Leiria (Portugal). In evaluating the risk for human health, which is associated with contaminated soils after oral
uptake, total soil concentrations have generally been held against criteria established from toxicological studies based upon
the assumption that the uptake of the contaminant is similar in the toxicological studies and from the soils assessed. This
assumption is not always valid, as most toxicological studies are carried out with soluble forms of the contaminants, whereas
many soil contaminants are or become embedded in the soil matrix and thus exhibit limited availability. This study intends
to estimate the soluble fraction of Pb in the soils from central Portugal, and to assess the bioaccessibility of Pb and, hence,
infer exposure and risk for human health. Yet, as the physical–chemical properties of the soil exert some control over the
solubility of Pb in the surface environment, the relation between such soil properties and the estimated soluble and/or bioaccessible
fractions of Pb is also investigated. Other objective, with a more practical nature, was to give some contribution to find
a suitable in vitro mimetic of the gastrointestinal tract environment. The results indicate relatively low total metal concentrations
in the soils, even if differences between regions were observed. The Aveiro district has the higher total Pb concentration
and the metal is in more soluble forms, that is, geoavailable. Soils with higher concentrations of soluble Pb show higher
estimates of bioaccessible Pb. Soil pH seems to influence human bioaccessibility of Pb. 相似文献
999.
John?M.?Townsend-MehlerEmail author Fred?C.?Dyer 《Behavioral ecology and sociobiology》2012,66(2):275-286
While there has been considerable research on the behavioral processes that underlie animals’ ability respond to shifting
rewards, it remains unclear how animals coordinate multiple processes over time. To investigate this, we compared the behavior
of honeybees (Apis mellifera) and bumblebees (Bombus impatiens), in an open-ended search task. Bees were given brief access to a high-quality food source, which then became non-rewarding.
Then, over an extended period, we examined (1) bees’ tendency to persist at the depleted site, (2) their tendency to return
to a different low-quality food source where they had been foraging previously, (3) their tendency to return to the hive,
and (4) how previous reward history influenced their tendency to shift among these options. Compared to bumblebees, honeybees
were much slower to abandon the depleted site and were much more likely to make trips to the hive while bumblebees were much
more likely to return to the familiar low-quality site. These observed species differences are interpreted in terms of evolved
individual and social differences between these species. We show evidence of well-studied behavioral processes such as extinction,
negative contrast effects, and reliance on a social group, and provide, for the first time, a picture of how these processes
interact with one another as part of a common sequential decision-making process. 相似文献
1000.
Matteo?Pizzolon Lisa?Locatello Robert?R.?Warner Nicole?Chimento Livio?Finos Maria?B.?RasottoEmail author 《Behavioral ecology and sociobiology》2012,66(3):497-504
Recent theoretical models predict that the relative allocation to advertisement and parental care depends on whether paternal
care is necessary for offspring survival: In species with exclusive male care, male investment in attraction is expected to
reliably indicate paternal care effort and male phenotypic quality. Previous research, yielding contrasting results, has considered
how one trait involved in mate attraction interacts with parental care or a specific aspect of male quality. In the blenny
Salaria pavo, we perform a comprehensive analysis of the interplay between overall male attractiveness and male quality, the latter in
terms of fertility, condition, and parental care. In this fish, males are larger than females, exhibit two sexually dimorphic
traits (head crest and anal glands), and solely care for eggs. We generated a male attractiveness index through principal
component analyses of morphological traits and quantified parental effort as the total time spent in egg care. In addition,
we analyzed the relationships between specific components of attractiveness and male qualities. In agreement with theory predictions,
we found that male overall attractiveness is a reliable indicator of fertility, in terms of sperm number, but is unrelated
to body condition and parental care effort, with males able to perform high levels of care regardless of their level of advertisement.
However, the relative expression of head crest area appears positively related to sperm number but is traded-off with parental
care effort. These findings underline the need, in addressing real patterns, to consider interactions between multiple aspects
of male display and quality. 相似文献