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421.
Joana F. M. F. Cardoso Johannes IJ. Witte Henk W. van der Veer 《Marine Biology》2007,152(6):1271-1282
In estuarine areas, bivalve species can be found in a variety of environments, where they experience large differences in
environmental conditions. In the present paper, the importance of different habitats (intertidal, subtidal and adjacent coastal
waters) for the persistence of the population was evaluated for the bivalve Macoma balthica (L.) in the western Dutch Wadden Sea estuary. Intra-specific variation in growth and reproductive output were followed during
the year and related to local abiotic conditions. Significant differences in growth and reproductive investment were found
between locations. Young individuals were mostly found in the intertidal area, where growth in terms of somatic mass was good.
These areas were not favourable for adult individuals, since growth in shell length was low and many individuals did not reproduce.
In the subtidal, where the highest densities were found, somatic and gonadal mass indices were low. Coastal areas had the
lowest densities and showed high growth in terms of shell length and body mass. The habitat with the highest reproductive
effort per individual was not the most important habitat in terms of reproductive output due to differences in density and
in size of the habitat type. For M. balthica, the subtidal habitat contributed the most to the reproductive output of the western Dutch Wadden Sea population although
the highest reproductive output per individual was in the coastal area. 相似文献
422.
On an 85 km stretch of coastline along the western and northwestern edge of North West Cape Peninsula, Western Australia, are numerous beaches used for nesting by the green turtle Chelonia mydas. Many other beaches in the area are not so used. Nesting beaches displayed three characteristics that distinguished them from non-nesting beaches: the salinity of the sand moisture at nesting depth was lower, the salt content of surface sand was lower, and the beaches were sheltered from prevailing winds. Several beaches on which turtles did not nest exhibited these characteristics, but possessed sand platforms of reduced elevation above sea level. These observations are discussed in relation to the question of what cues green turtles use in selecting nesting beaches. 相似文献
423.
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425.
Rosen Johannes Fichtner Wolf Rentz Otto 《Mitigation and Adaptation Strategies for Global Change》2004,9(2):121-146
Determining adequate baselinesis a major methodological problem whenquantifying emissions reductions achievedwith the project-based flexibilitymechanisms. Possible methodologies forbaseline setting may be classified intomulti-project and project-specificapproaches. While multi-project approachesprovide baselines for a series of typicalprojects within a certain geographicregion, a sector, or a load range,project-specific (orproject-by-project/single-project)approaches only cover one specific project.Project-by-project baseline approaches havebeen tested extensively within theActivities Implemented Jointly (AIJ) pilotphase; multi-project methodologies, on theother hand, have only rarely been applieddue to the (perceived) political andeconomic complexity of the issue, whichmakes the process of introducingstandardised baselines a very sensitivetask. In particular, there is a lack ofmulti-project baseline approaches takingadvantage of optimising computer modelswithin the electricity sector, even thoughother fields of research have made use ofsuch models quite successfully in the past.Experiences made in the PROBASE projectwith the calculation of standardised,aggregated multi-project baselines forJI/CDM projects using optimising energysystem models are illustrated in this paperfor South Africa, Russia, and Indonesia.Increased transparency and credibility ofstandardised approaches along withpotentially lower transaction costs areidentified as the main arguments for theiruse and further development. In addition,the text gives recommendations wheremodel-based baseline standardisation canpreferentially be applied. 相似文献
426.
For the assessment of potential risks from total exposure to both spray drift and volatilised pesticides, field experiments in barley were carried out with insecticide application in May and June 2000. Pesticide concentrations in the air at the edge of the treated plot and at various distances in downwind direction were determined. The concentrations at 10 m distance were 0.29 and 0.58 microg/m(3) (lindane), 0.07 and 0.12 microg/m(3) (parathion) or <0.02 and 0.04 microg/m(3) (pirimicarb) after 1 d. To quantify the exposure of aquatic ecosystems, water containers simulating surface waters were placed in downwind direction of the plot at distances of 10 and 50 m. Lindane as the most volatile and most persistent of the investigated active substances showed the highest entries in surface water with 35 and 153 microg/m(2) after 1 d at a distance of 10 m, attributable to a larger extent to deposition of volatilised compound than to spray drift when drift reducing nozzles were used. Similar results were obtained for parathion, but at a lower level. Mainly due to its photolytic instability in water, pirimicarb decayed in surface water, where a maximum deposition was measured 2 h after application. 相似文献
427.
Karl-Werner Schramm Petra Marth Alexander Wolf Klaus Hahn Konstantin Oxynos Johannes Schmitzer und Antonius Kettrup 《Umweltwissenschaften und Schadstoff-Forschung》1999,11(5):277-280
Zusammenfassung Lipidbezogene Verteilungskoeffizienten (KLM/L) zwischen Muskelkonzentrationen-(CML) und Leberkonzentrationen (CLL) zweier Friedfischarten Brassen (Abramis brama) und Aalmutter (Zoarces viviparus) ergeben theoriekonform (KLM/L=CML/CLL=1) nominale Werte um 1 für persistente (hochchlorierte PCB) und Werte über 1 für metabolisierbare lipophile Umweltchemikalien
wie chlorierte Cyclohexane oder DDT.
相似文献
428.
Adverse reactions of the skin to light comprise a number of different dermatologic conditions. In light-‘allergies’ in the narrower sense non-ionised electromagnetic radiation (ultraviolet (UV)-A/-B radiation or visible light) provokes an immunologic or allergic skin reaction. These include solar urticaria, an, immunoglobulin E-mediated, immediate-type allergic photoreaction, photoallergic contact dermatitis and photoallergic (drug) exanthema, which are cell-mediated, delayed-type allergic photoreactions due to photosensitization, chronic actinic dermatitis and polymorphic light eruption. Beyond it there are nonimmunologic photosensitive and photoaggravated skin diseases, like exogenous and endogenous phototoxicity, xeroderma pigmentosum, which is based on a genetic defect, or the autoimmune disease lupus erythematosus. 相似文献
429.
430.