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771.
Cattle treatment with antiparasitic drugs is associated with an important risk exposure for dung beetles. Previous studies demonstrated the impact of some avermectin and pyrethroid compounds on several species such as Onthophagus gazella and Neomyia cornicina. However, little information is available regarding the elimination of these compounds in faeces 8 days after a pour-on administration in dairy cows. The present study, utilising a dairy cow model with cypermethrin treatment, demonstrated that concentrations in dry faeces can reach levels of 5?mg?kg?1 between the first and fourth day after treatment and were present up to 3 months after a single dose of administration at a concentration around 10?µg?kg?1. Faecal samples were purified with three successive columns (silica gel, anion exchange phase, and basic alumina) and analysed by GC-MS. The limit of quantification of this method was 0.5?µg?kg?1. The high sensitivity of the method permitted one to see that the risk exposure of cypermethrin to dung beetles is longer than what was noted in the literature. According to other studies, repeated treatment with such agents may lead to the local extinction of dung beetles. Even if the impact of pyrethroid largely depends on the conditions of the ecosystem where the treated cattle are living, adverse effects of these agents may still occur. 相似文献
772.
The aim of this study is to determine the contents of aluminum, iron, manganese, nickel, copper, zinc, chromium, cadmium, lead, and mercury in sediments at 1–30?m depths of the Band?rma and Erdek Gulfs in the Southern Inner Shelf of the Marmara Sea. Sediment samples were collected from different depths (1?m, 5?m, 10?m, 20?m, 30?m) at each region in February 2008. Primary hydrographic conditions, such as temperature (6.6–14.5°C), salinity (22.6–26.875 psu), percentage of dissolved oxygen saturation (35–83 %), and pH (8.0–8.4) were recorded for each sampling point. Moreover the total organic carbon (0.5–2.9%) and the total calcium carbonate contents (0.8–60%) of sediment samples were determined. In surface sediments of both gulfs, Pb (21–62?mg?kg?1) and Cd (0.52–0.86?mg?kg?1) contents were determined to be higher than the shale average (Pb 20?mg?kg?1, Cd 0.2?mg?kg?1) while the other metal contents were measured to be lower in general. On the other hand, generally Hg (0.06–1.1?mg?kg?1) contents were higher than the shale average (0.3?mg?kg?1)at all of the examined stations in the Band?rma Gulf and lower than the shale average in the Erdek Gulf. 相似文献
773.
Bart De Smet Laurent Godet Jérôme Fournier Nicolas Desroy Mikaël Jaffré Magda Vincx Marijn Rabaut 《Marine Biology》2013,160(4):751-761
The tube-building polychaete Lanice conchilega can form dense populations, often called reefs, which promote benthic community change and constitute feeding grounds for secondary consumers. The aim of this study was to quantify the role of the L. conchilega reef of the Bay of the Mont Saint-Michel (BMSM) for feeding waders, by combining macrobenthos data, bird counts and bird diet information. Wader densities in the reef were on average 46.6 times higher than in non-reef areas. According to faecal analyses, waders in the reef mainly selected the accompanying fauna and especially crustaceans. The attractiveness of the reef to feeding birds may be largely explained by the high abundance, richness and biomass of macrobenthic species in the reef compared with the rest of the BMSM. 相似文献
774.
Ryota?L.?SakamotoEmail author Shin-Ichi?Morinaga Motomi?Ito Nobumitsu?Kawakubo 《Behavioral ecology and sociobiology》2012,66(5):669-674
Most estimations of the pollination efficiency of insects have been based on observation by the naked human eye. However,
insect behaviors are often too rapid to analyze sufficiently this way. Here we demonstrate the use of high-speed cameras to
analyze the fine-scale behaviors of Macroglossum pyrrhosticta, Xylocopa appendiculata, and Papilio dehaanii when visiting Clerodendrum trichotomum. The fine-scale nectar drinking time, number of contacts with anthers and/or stigmas, and frequencies of body part contact
with anthers and/or stigmas differed significantly among pollinator species. Pollination efficiency was not equal among pollinators.
In addition, M. pyrrhosticta made the least number of contacts with anthers and/or stigmas even though it showed the highest visitation frequency. These
results demonstrate that when examined from the viewpoint of rapid visitation behaviors, pollination dynamics differ among
pollinator species, and flower visits and pollination rates are not equal. 相似文献
775.
Hegyi Gergely Jenni-Eiermann Susanne Boross Nóra Garamszegi László Zsolt Laczi Miklós Kötél Dóra Krenhardt Katalin Jablonszky Mónika Markó Gábor Nagy Gergely Rosivall Balázs Szász Eszter Török János 《Behavioral ecology and sociobiology》2019,73(6):1-14
Behavioral Ecology and Sociobiology - Cooperation plays a crucial role in primate social life. However, the evolution of large-scale human cooperation from the cognitive fundamentals found in other... 相似文献
776.
Mohamed Cissé Didier Montet Gérard Loiseau Marie-Noëlle Ducamp-Collin 《Journal of Polymers and the Environment》2012,20(3):830-837
The individual and interactive effects of glycerol and chitosan concentrations on edible film properties were investigated using response surface methodology. The results of ANOVA indicated that all the independent variables exhibited significant effect on the film properties. Chitosan concentration had a positive effect on CO2 permeability and negative effect on O2 while the glycerol concentration had a positive effect on permeability to both gases. Regarding water vapor permeability, the chitosan concentration had a negative effect, whereas the glycerol had no influence. Moreover, both chitosan and glycerol concentration influenced the elongation at break point (%A), and only glycerol concentration had a significant effect on tensile strength. Optimization by desirability approach was carried out on the independent variables to get the optimum levels within the experimental conditions. It was found that 1.5 % of chitosan and 25 % of glycerol (wt/wt of chitosan) retarded respiration and showed a strong permeability to water vapor. 相似文献
777.
Araceli Loredo-Treviño Gerardo Gutiérrez-Sánchez Raúl Rodríguez-Herrera Cristóbal N. Aguilar 《Journal of Polymers and the Environment》2012,20(1):258-265
Plastics are present in a lot of aspects of everyday life. They are very versatile and resistant to microbial attack. Polyurethanes
are used in several industries and are divided in polyester and polyether polyurethanes and there are different types among
them. Despite their microbial resistance, they are susceptible to the attack of fungi and bacteria but the mechanism to elucidate
its biodegradation are unknown. There are reports from bacteria and fungi that are capable of degrading polyurethane but the
studies about the enzymes that attack the plastic are focused on bacterial enzymes only. The enzymes reported are of type
esterase and protease mainly since these enzymes are very unspecific and can recognize some regions in the polyurethane molecule
and hydrolyze it. Fungal enzymes have been studied prior the 1990s decade but recently, some authors report the use of filamentous
fungi to degrade polyurethane and also report some characteristics of the enzymes involved in it. This review approaches polyurethane
biodegradation by focusing on the enzymes reported to date. 相似文献
778.
Joël Meunier Luma Delaplace Michel Chapuisat 《Behavioral ecology and sociobiology》2010,64(10):1655-1663
The ability to discriminate against competitors shapes cooperation and conflicts in all forms of social life. In insect societies,
workers may detect and destroy eggs laid by other workers or by foreign queens, which can contribute to regulate reproductive
conflicts among workers and queens. Variation in colony kin structure affects the magnitude of these conflicts and the diversity
of cues used for discrimination, but the impact of the number of queens per colony on the ability of workers to discriminate
between eggs of diverse origin has so far not been investigated. Here, we examined whether workers from the socially polymorphic
ant Formica selysi distinguished eggs laid by nestmate workers from eggs laid by nestmate queens, as well as eggs laid by foreign queens from
eggs laid by nestmate queens. Workers from single- and multiple-queen colonies discriminated worker-laid from queen-laid eggs,
and eliminated the former. This suggests that workers collectively police each other in order to limit the colony-level costs
of worker reproduction and not because of relatedness differences towards queens’ and workers’ sons. Workers from single-queen
colonies discriminated eggs laid by foreign queens of the same social structure from eggs laid by nestmate queens. In contrast,
workers from multiple-queen colonies did not make this distinction, possibly because cues on workers or eggs are more diverse.
Overall, these data indicate that the ability of F. selysi workers to discriminate eggs is sufficient to restrain worker reproduction but does not permit discrimination between matrilines
in multiple-queen colonies. 相似文献
779.
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
780.
Timothée Romuald Cook Frédéric Bailleul Amélie Lescroël Yann Tremblay Charles-André Bost 《Marine Biology》2008,154(2):383-391
Knowing the depth zone of neutral buoyancy of divers is important because buoyancy can determine how animals manage their
energy budget. In this study, we estimate the depth zone of neutral buoyancy of free-ranging cormorants for the first time,
using time-depth recorders. We discovered that vertical ascent rates of 12 Crozet and 15 Kerguelen diving blue-eyed shags
(respectively Phalacrocorax
melanogenis and P.
verrucosus) slowed down considerably at the 50–60 m depth zone. We suggest this was due to birds trying to reach the surface from that
point upwards using reduced locomotor activity because the force of buoyancy becomes greater than the force of gravity at
that depth. The results show a shift of this depth zone in relation to maximum targeted dive depth, suggesting cormorants
may control buoyancy through respiratory air volume adjustment. Interestingly, 60 m is close to the maximum depth zone reached
by these two species during dives lasting 4 min, their estimated behavioural aerobic dive limit. This suggests that the decision
to swim deeper has a direct consequence on the energy budget, with time spent recovering at the surface (time thus lost to
foraging) strongly increasing relative to the preceding time of submergence. Resources found in deeper waters must be of sufficient
quantity or quality to justify crossing the frontier of physical neutral buoyancy. 相似文献