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681.
Ebensperger LA Sobrero R Quirici V Castro RA Tolhuysen LO Vargas F Burger JR Quispe R Villavicencio CP Vásquez RA Hayes LD 《Behavioral ecology and sociobiology》2012,66(2):261-274
Intraspecific variation in sociality is thought to reflect a trade-off between current fitness benefits and costs that emerge from individuals' decision to join or leave groups. Since those benefits and costs may be influenced by ecological conditions, ecological variation remains a major, ultimate cause of intraspecific variation in sociality. Intraspecific comparisons of mammalian sociality across populations facing different environmental conditions have not provided a consistent relationship between ecological variation and group-living. Thus, we studied two populations of the communally rearing rodent Octodon degus to determine how co-variation between sociality and ecology supports alternative ecological causes of group living. In particular, we examined how variables linked to predation risk, thermal conditions, burrowing costs, and food availability predicted temporal and population variation in sociality. Our study revealed population and temporal variation in total group size and group composition that covaried with population and yearly differences in ecology. In particular, predation risk and burrowing costs are supported as drivers of this social variation in degus. Thermal differences, food quantity and quality were not significant predictors of social group size. In contrast to between populations, social variation within populations was largely uncoupled from ecological differences. 相似文献
682.
Meredith Root-Bernstein Nicolás Arévalo Rosas Layla P. Osman Richard J. Ladle 《Journal of Coastal Conservation》2012,16(4):585-596
Coastal areas can be a challenge for conservation due to multiple competing land uses including development, tourism, and extractive resource use. These multiple land uses often lead to human-wildlife conflicts. Here we propose that collaboration with industrial designers and architects has the potential to generate innovative and effective solutions to coastal human-wildlife conflicts. Many products for modifying animal behavior are already used by conservationists, such as barriers, corridors, and model predators. We propose that their effectiveness, quality, harmonization with local values, and integration with the designed human environment can be improved through collaboration with designers and architects. We illustrate this approach with a case study. We engaged in an industrial design- conservation collaboration focused on the design of multiple product proposals that would support a range of human-sea lion interactions in public parks and the fish market in Valdivia, Chile. The sea lions in Valdivia are a tourist attraction but also potentially dangerous. We produced images of seven proposed products of varying scales, facilitating a range of different sea lion- human interactions. Such collaborations can be useful for developing products that reduce human-wildlife conflicts and align conservation and management with local values. We urge researchers to publish conservation design proposals as well as tests of existing conservation products?? functionality, in order to improve conservation design practice around the world. 相似文献
683.
Portugal is strongly vulnerable to sea hazards due to intense vessel traffic and sea conditions. The southwest region off the Iberian Peninsula lies in the main route from the Mediterranean and Southern Hemisphere to the Northern Europe, causing a ship concentration in a narrow band off Cape S?o Vicente. Tankers represent a significant part of the vessel traffic and the occurrence of oil spills cannot be disregarded. Cape S?o Vicente region is part of a Natural Park with 110 Km of coastline, integrated in the European Natura 2000 network and its socio-economic context is closely related with sea resources exploitation, particularly fishing and tourism. Recognizing the importance of accurate information systems for the decision making process in an oil spill situation, this work presents the development of an integrated tool to support the process in the Algarve coast. The system relies in a regional operational mathematical model based on the MOHID modelling system. The system core is composed by three models (3D hydrodynamics, wave and Lagrangian transport) all linked in the same system and exchanging information in real time. Oil advection and weathering processes are coupled to the Lagragian transport model. The overall operational system includes external operational data products as inputs, to ensure a successful validation of the results. The system is linked to stakeholders and response authorities using a geographic referenced database based on Mapserver technology that will include relevant information for oil spill management. 相似文献
684.
M.?C.?KrautzEmail author L.?R.?Castro M.?González J.?C.?Vera H.?E.?González 《Marine Biology》2012,159(2):303-317
In this study, we determined variations in ascorbic acid (AA) concentrations in the gonads and liver, and of the innate immune
response (lysozyme activity and antiprotease) in the plasma of Engraulis ringens (anchoveta) and Strangomera bentincki (common sardine) during their reproductive seasons of 2007 and 2008 in the central area of the Humboldt Current. During the
main spawning season in 2007, colder environmental conditions, higher phytoplankton biomasses, low dinoflagellate abundance
and the dominance of large copepods in winter-early spring and of small copepods in late spring contributed to explain higher
AA concentrations in anchoveta tissues. During the warmer year of 2008, lower phytoplankton biomasses, a notable increase
of dinoflagellate abundance and the dominance of small-size copepods in winter and of larger copepods in spring occurred along
with a drastic drop in AA concentrations in anchoveta tissues. These results contrasted with those in common sardine, a species
in which AA did not vary as much as in anchoveta. An inverse trend between AA concentration in the liver and the gonadosomatic
index suggested the AA utilization during gonadic maturation. Innate immune parameters were determined for the first time
in small pelagic fish and constitute a new baseline data to evaluate their natural response to environmental changes. Changes
in the distribution and abundance of edible taxa containing AA and edible for fish along with variations in AA in fish tissues
during their reproductive season could become good indicators of the overall fish physiological condition resulting from variations
in the trophic web structure. 相似文献
685.
The trophic ecology of Octopus vulgaris paralarvae collected in 2008 off the Ría de Vigo, NW Spain (42° 12.80′ N–9° 00.00′ W), was approached by both morphological
and molecular methods. External digestion of prey and posterior suction of the liquefied contents by wild O. vulgaris paralarvae made the morphological identification of gut contents impossible. Thus, a PCR-based method using group-specific
primers was selected to identify prey consumed by O. vulgaris paralarvae in the pelagic realm. The mitochondrial ribosomal 16S gene region was chosen for designing group-specific primers,
which targeted a broad range of crustaceans and fishes but avoided the amplification of predator DNA. These primers successfully
amplified DNA of prey by using a semi-nested PCR-based approach and posterior cloning. Homology search and phylogenetic analysis
were then conducted with the 20 different operational taxonomic units obtained to identify the putative organisms ingested.
The phylogenetic analysis clustered ingested prey into 12 families of crustaceans (11 belonging to the order Decapoda and
1 to the order Euphausiacea) and two families of fishes (Gobiidae and Carangidae). According to the Czekanowski’s Index (CI),
the trophic niche breadth of O. vulgaris paralarvae is low (CI = 0.13), which means that these paralarvae are specialist predators at least during the first weeks
of their life cycle. It is the first time that natural prey has been identified in O. vulgaris paralarvae collected from the wild, and such knowledge may be critical to increasing the survival of O. vulgaris hatchlings in captivity, a goal that has been actively pursued since the 1960s by aquaculture researchers. 相似文献
686.
Kátya?G.?AbrantesEmail author Jayson?M.?Semmens Jeremy?M.?Lyle Peter?D.?Nichols 《Marine Biology》2012,159(1):57-64
Stable isotope analysis is increasingly used in ecological studies. Because lipid content influences δ13C, lipids should be removed from lipid-rich samples before δ13C analysis. To account for differences in δ13C arising from differences in lipid content, relationships between lipid content, C:N ratio and Δδ13C with lipid removal can be used to normalise lipid content to uniform levels. We investigate these relationships for salmonid
muscle and evaluate the suitability of previously published normalisation equations for these fish. Salmonids with a wide
range of condition (muscle lipid content = 3–35% of dry weight) were considered. There were no consistent relationships between
lipid content or C:N ratio and Δδ15N. There were linear relationships between C:N ratio and lipid content (L = −16.53 + 6.27 × C:N); C:N ratio and Δδ13C (Δδ13C = −1.87 + 0.65 × C:N); and lipid content and Δδ13C (Δδ13C = 0.01 + 0.10 × L), which should be used on salmonid stable isotope studies. 相似文献
687.
Crop pest and disease incidences at plot scale vary as a result of landscape effects. Two main effects can be distinguished. First, landscape context provides habitats of variable quality for pests, pathogens, and beneficial and vector organisms. Second, the movements of these organisms are dependent on the connectivity status of the landscape. Most of the studies focus on indirect effects of landscape context on pest abundance through their predators and parasitoids, and only a few on direct effects on pests and pathogens. Here we studied three coffee pests and pathogens, with limited or no pressure from host-specific natural enemies, and with widely varying life histories, to test their relationships with landscape context: a fungus, Hemileia vastatrix, causal agent of coffee leaf rust; an insect, the coffee berry borer, Hypothenemus hampei (Coleoptera: Curculionidae); and root-knot nematodes, Meloidogyne spp. Their incidence was assessed in 29 coffee plots from Turrialba, Costa Rica. In addition, we characterized the landscape context around these coffee plots in 12 nested circular sectors ranging from 50 to 1500 m in radius. We then performed correlation analysis between proportions of different land uses at different scales and coffee pest and disease incidences. We obtained significant positive correlations, peaking at the 150 m radius, between coffee berry borer abundance and proportion of coffee in the landscape. We also found significant positive correlations between coffee leaf rust incidence and proportion of pasture, peaking at the 200 m radius. Even after accounting for plot level predictors of coffee leaf rust and coffee berry borer through covariance analysis, the significance of landscape structure was maintained. We hypothesized that connected coffee plots favored coffee berry borer movements and improved its survival. We also hypothesized that wind turbulence, produced by low-wind-resistance land uses such as pasture, favored removal of coffee leaf rust spore clusters from host surfaces, resulting in increased epidemics. In contrast, root-knot nematode population density was not correlated to landscape context, possibly because nematodes are almost immobile in the soil. We propose fragmenting coffee plots with forest corridors to control coffee berry borer movements between coffee plots without favoring coffee leaf rust dispersal. 相似文献
688.
Soil C and N changes with afforestation of grasslands across gradients of precipitation and plantation age 总被引:3,自引:0,他引:3
Afforestation, the conversion of unforested lands to forests, is a tool for sequestering anthropogenic carbon dioxide into plant biomass. However, in addition to altering biomass, afforestation can have substantial effects on soil organic carbon (SOC) pools, some of which have much longer turnover times than plant biomass. An increasing body of evidence suggests that the effect of afforestation on SOC may depend on mean annual precipitation (MAP). The goal of this study was to test how labile and bulk pools of SOC and total soil nitrogen (TN) change with afforestation across a rainfall gradient of 600-1500 mm in the Rio de la Plata grasslands of Argentina and Uruguay. The sites were all former grasslands planted with Eucalyptus spp. Overall, we found that afforestation increased (up to 1012 kg C x ha(-1) x yr(-1)) or decreased (as much as 1294 kg C x ha(-1) x yr(-1)) SOC pools in this region and that these changes were significantly related to MAP. Drier sites gained, and wetter sites lost, SOC and TN (r2 = 0.59, P = 0.003; and r2 = 0.57, P = 0.004, respectively). Labile C and N in microbial biomass and extractable soil pools followed similar patterns to bulk SOC and TN. Interestingly, drier sites gained more SOC and TN as plantations aged, while losses reversed as plantations aged in wet sites, suggesting that plantation age in addition to precipitation is a critical driver of changes in soil organic matter with afforestation. This new evidence implies that longer intervals between harvests for plantations could improve SOC storage, ameliorating the negative trends found in humid sites. Our results suggest that the value of afforestation as a carbon sequestration tool should be considered in the context of precipitation and age of the forest stand. 相似文献
689.
Human health impacts of exposure to metals through extreme consumption of fish from the Colombian Caribbean Sea 总被引:1,自引:0,他引:1
Fabio Fuentes-Gandara José Pinedo-Hernández José Marrugo-Negrete Sergi Díez 《Environmental geochemistry and health》2018,40(1):229-242
The health risks of metal exposure due to the high consumption of fish were assessed for a riverine population living on the Caribbean coast of Colombia. The concentrations of metals (Cd, Cr, Cu, Hg, Ni, Pb and Zn) in the edible tissues of fish were determined and used for risk assessment. The daily fish consumption of residents (n = 95) was as high as 283, 366 and 469 g/day in children (CH), women of childbearing age (WCHA) and the remaining population groups (RP), respectively. The estimation of the potential risk (HQ) indicated that there was no health risk from most of the metals, because they did not exceed their related reference doses, with values of HQ < 1. Although the concentrations of Pb and Hg were not particularly high in fish (<0.2 µg/g), their possible health effects for vulnerable groups are of great concern due to the extremely high fish intake. The Pb intake for all groups was higher than the lower confidence limit of the benchmark dose for nephrotoxicity and neurodevelopmental effects in children. The weekly intake of methylmercury was also elevated, with values approximately 3, 2 and 1.5 times the provisional tolerable weekly intake for CH, WCHA and RP, respectively. Moreover, higher Hg levels were found in top predators, whereas maximum levels for other metals were found in bottom-feeding fish. This study highlights that an accurate data of daily intake, a continuous monitoring of metals in fish and their related fish consumption advisories to protect subsistence fishing communities are recommended in a local and worldwide context. 相似文献
690.
Pablo Souza-Alonso Luís González Antonio López-Nogueira Carlos Cavaleiro Nuria Pedrol 《Chemistry and Ecology》2018,34(2):126-145
Acacia longifolia, a highly invasive species that invades coastal ecosystems in Mediterranean areas, produces significant impacts at different scales. Abundant foliage and thick canopies create a dense atmosphere that led us to hypothesise that the release of volatile organic compounds (VOCs) could play a role in the reduction of biodiversity observed in invaded areas. Therefore, we suggested that VOCs emitted by A. longifolia could exert inhibitory effects on physiological and biochemical parameters of native species. Using glass chamber bioassays, we evaluated the effect of aerial contact between VOCs from different plant parts of A. longifolia material and some native species. Volatile chemical composition was further analysed using GC-MS. Our results indicated that VOCs produced a notably reduction of seed germination. Furthermore, volatiles from leaves and flowers significantly decreased root length, shoot length and biomass for all species. Proline and malondialdehyde content did not significantly increase after contact with VOCs. Finally, chemical profile of VOCs from flowers, leaves and litter was significantly different, both qualitatively and quantitatively. As far as we know, our results constitute the first evidence of phytotoxicity induced by VOCs from A. longifolia, suggesting that flowers and leaves could influence its surrounding environment through VOCs release. 相似文献