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51.
Future climate change may lead to a substantial loss of biodiversity, particularly affecting mountain regions, including the Alps. Range-size reduction in high mountain plant species is predicted to be more pronounced for endemic species. Investigating the broad temporal spectrum of range shifts is important for the conservation of biodiversity, since learning how species responded to climate change in the past provides useful insights on how they might react to warming trends in the present and future. Using species distribution models and an ensemble forecasting approach, we explored how the distribution of Berardia subacaulis, a monospecific genus endemic of the south-west Alps, may be affected by past and future projected climate change. During the last interglacial, the habitat suitability of Berardia was lower than present and a progressive increase was observed from the last glacial maximum until now. In the future, Berardia appears to lose more than 80 % of its range, becoming endangered by 2050. Our results suggest that Berardia probably survived past warmer periods in situ, expanding its distributional range during cooler periods. The severe future range contraction predicted for Berardia reflects similar results for other endemic species. As Berardia represents an interesting model species to evaluate the effects of climate warming on range size and shifts, demographic and precise range monitoring may be undertaken on this species.  相似文献   
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For the first time, concentrations of the long lived radon progenies 210Pb, 210Bi and 210Po were measured in the mine atmosphere of the so called "healing gallery" in Badgastein, Austria, a region famous for its radioactive springs. These investigations were performed in order to study the radioactive equilibrium between the 210Pb-210Bi and the 210Pb-210Po pairs so as to gain more information about the aerosol-forming processes in the mine. The particle size distribution of the aerosols was determined under different ventilation conditions. Six-stage and eight-stage cascade impactors with working ranges from 0.15 to5 µm and from 0.063 to 8 µm, respectively, were used to collect the mine aerosols. These samples were analysed in the laboratory and measured by liquid scintillation spectrometry. The most surprising results were found under full ventilation, when the total activity concentrations of 210Pb, 210Bi and 210Po were 4.6, 2.0 and 16.5 mBq/m3, respectively. In this case 210Po/210Pb activity ratios ranged between 1.8ǂ.3 and 4.3ǂ.3. These unexpected results were confirmed by the eight-stage impactor samples. For the smallest particles, between 0.062 and 0.125 µm, an even higher value of 7.5 was observed. As outside sources could be excluded, such 210Po enrichments must occur during the aerosol-forming process itself inside the mine.  相似文献   
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A ring chromosome 19 was found in 14 of 20 metaphases (67 per cent) derived from amniotic fluid cell cultures following amniocentesis because of increased maternal age. Elective termination of the pregnancy revealed a hypotrophic female fetus with mild dysmorphic signs, but no congenital malformations. The case is discussed in relation to three reports in the literature of ring chromosome 19 mosaicism in a phenotypically normal girl, a mentally retarded man, and a boy with normal psychomotor development and minor dysmorphic features.  相似文献   
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The infra-red (IR) and the gas Chromatographic (GC) methods for the determination of mineral oil hydrocarbons in soils were examined in collaborative trials with regard to their accuracy and reproducibility. Natural, homogenized soils and soils spiked with mineral oil were used as standards. The soil matrix was composed relatively simply. The repeatability and reproducibility values obtained were about 5 % und 23 %, respectively. In contrast, the GC method revealed a considerably higher error range, especially by using the split/splitless technique. The degradation of mineral oil hydrocarbons in soils under different temperatures was investigated by IR throughout one year. The degradation rate at room temperature was about 25 %; at lower temperatures no degradation was detected. Thus, the spiked soils may be used as calibration standards for the mineral oil analysis.  相似文献   
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The Science of Nature - Female-only colour polymorphism is rare in birds, but occurs in brood parasitic cuckoos (Cuculidae). Obligate brood parasites leave incubation and parental care to other...  相似文献   
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Zebrafish (Danio rerio) larvae prefer the olfactory cues of kin to non-kin. We examined the potential benefits of kin preference by comparing growth rate, shoaling, and aggressive behavior in juvenile zebrafish housed in groups of either familiar kin or unfamiliar non-kin. Over an observation period of 5 days, the animals grew 33% more in kin groups; however, neither shoaling nor the frequency of aggressive interactions was different in groups of related versus unrelated individuals. Shoaling behavior increased with increasing observation time and increasing age, while aggressive behavior remained the same. We conclude that associating with kin probably creates a less stressful environment that allows for higher growth rates, which can lead to higher direct fitness based on increased survival and earlier reproduction. Kin recognition leading to kin-structured groups may therefore be under positive selection.  相似文献   
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文章以34名大学生为被试,采用2(150%,50%)×2(场独立,场依存)被试间实验设计探讨了不同认知风格大学生艾宾浩斯错觉的眼动特点。结果表明:(1)不同的认知风格对艾宾浩斯错觉判断正确量有影响,并且在眼动指标上存在差异;(2)测验成分和诱导成分之间的大小比例对艾宾浩斯错觉正确量有影响,并且在眼动指标上存在差异;(3)诱导成分和测验成分之间距离不同时对艾宾浩斯错觉正确量无显著影响,并且在眼动指标上也不存在显著差异。  相似文献   
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