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901.
The associations between blood organohalogen contaminant (OHC) concentrations and thyroid gland histology were studied in 10 adult female glaucous gulls (Larus hyperboreus) from the Norwegian Arctic (Bjørnøya) during the incubation period. This histological investigation was undertaken as previous glaucous gull studies from the same area reported negative relationships between circulating OHC concentrations and thyroid hormone levels. Organohalogen concentrations have previously been associated with altered blood plasma thyroid hormone concentrations, as a result of parenchymal thyroid gland alterations and perturbation of the hypothalamic-pituitary-thyroid (HPT)-axis. In this study, PCB (range: 186–1027 ng g?1ww), DDT (77–203 ng g?1ww) and chlordane (18–65 ng g?1ww) concentrations dominated the blood plasma OHC profile in incubating female glaucous gulls. High density of small follicles accompanied by follicular epithelial cell proliferations was seen in thyroid glands in seven of 10 gulls. Focal thyroiditis and nodular hyperplasia were found in two birds. No significant differences in plasma OHC concentrations were noted between gulls exhibiting high density of small follicles and cell proliferations and those birds not showing histological changes. Based on these findings, data suggest that the histological changes in thyroid glands of OHC-contaminated female glaucous gulls may be due to natural variance, although an OHC-induced thyroid stimulating hormone (TSH) perturbation resulting in epithelial cell hyperplasia and increased follicular density cannot be ruled out and remains to be verified. Hence, a large-scale histological study is required, in order to elaborate the potential linkage between changes in thyroid gland histology, OHC exposure and regulation of the HPT-axis in the Arctic-breeding glaucous gull.  相似文献   
902.
Concentrations of organochlorine (OC) contaminants and histomorphology of liver, kidney, and thyroid tissues were studied in nine adult and one subadult glaucous gulls (Larus hyperboreus) collected at Svalbard on 2 August 2011. Concentrations of liver polychlorinated biphenyls (PCB; range: 150–2820?ng?g?1 ww), dichlorodiphenyltrichloroethane (DDT; range: 58–724?ng?g?1 ww), and chlordanes (CHL; range: 11–126?ng?g?1 ww) dominated the OC profile followed by hexachlorobenzene (HCB; range: 11–42?ng?g?1 ww), mirex (range: 2–52?ng?g?1 ww), and β-hexachlorocyclohexane (β-HCH; range: 1–7?ng?g?1 ww). Histological examination of the liver showed mononuclear cell infiltrations and granulomas in 10 and 6 gulls, respectively, while intense intrahepatic lipid accumulation (steatosis) was found in two and focal necrosis in one gull. In kidney, glomerular sclerosis and adhesions was found in five and one gull, respectively. Thickening of the glomerular basement membranes and tubular necrosis was found in four and seven gulls, respectively, while mononuclear cell infiltrations were found in two individuals. In the thyroid gland, a high density of small follicles accompanied by follicular epithelial cell proliferation was observed in five glaucous gulls. Gulls with hepatic steatosis had significantly higher ΣDDT levels than the gulls without hepatic steatosis and a similar trend was found for ΣPCB. When normalizing OC concentrations for lipid content in liver, gulls with lipid granulomas had significantly lower β-HCH and significantly higher mirex levels, respectively, than gulls without lipid granulomas. Also; gulls with thickening of the glomerular basement membranes had non-significantly higher ΣPCB levels than gulls without. The histological findings were similar to those of controlled laboratory studies and OC-contaminated wildlife (e.g., polar bears; Ursus maritimus) and the data of this study therefore suggest that OC exposure may be a co-factor in the development of organ alterations in glaucous gulls. However, other environmental factors such as age, element exposure, and infectious micropathogens cannot be ruled out as co-factors, and it is uncertain if the tissue changes found exert adverse health effects on the population of Svalbard glaucous gulls.  相似文献   
903.
East Greenland polar bears (Ursus maritimus) are among the mammals with the highest bioaccumulated concentrations of organohalogen contaminants (OHCs). Since Greenlanders in this region ingest significant quantities of adipose tissue from polar bears and also ringed seals (Pusa hispida), initial conservative estimates of the daily oral exposure to this chemical cocktail are thus presented. The tolerable daily intake was exceeded approximately five-fold for polychlorinated biphenyls and chlordane pesticides and metabolites, while the estimated daily toxic equivalent (TEQ) (based on the 2,3,7,8-tetrachlorodibenzo-rho-dioxin toxicity equivalence factors) for East Greenland subsistence hunters was three- to ten-fold higher than the WHO ∑TEQ guidelines even though the estimations were conservative. The daily oral OHC exposure from polar bear and ringed seal blubber consumption is markedly high and needs to be reduced in order to remove this co-factor with respect to the influence on the development of chronic diseases. Furthermore, it is warranted that a physiologically based pharmacokinetic model for Greenlander's exposure to OHCs is constructed and that risk quotients calculated to estimate the threats to health for East Greenland subsistence hunters.  相似文献   
904.
Abstract

Airborne particulate matter PM2.5 was collected in an industrial, a low-density, and a high-density residential area of Lagos from December 2010 to November 2011, and elemental composition was determined by proton-induced X-ray emission. Across the months, mass concentrations ranged from 13 to 237?µg?m?3, exceeding the World Health Organization guideline value of 10?µg?m?3. Data on 24 elements were obtained, with maximum values during Harmattan season months; source identification and apportionment studies by positive matrix factorization suggested that petroleum oil combustion (70%) was the major source of PM2.5 and could pose a great hazard to Lagos receptors.  相似文献   
905.
SUMMARY

Sustainable development is a global challenge to science and society. In politics and economics the concepts for establishing a sustainable society are numerous, nonetheless necessary interdisciplinary approaches are still marginalised. Trying to foster a deeper communication between biology and social science, an evolutionary perspective on sustainable development is offered. Subsequently, the role of variability and diversity in evolution is highlighted. Hereby, special attention is devoted, among other things, to the links between variability and stability in the long term. Next, selection and variability are emphasised in the cultural context. This is followed by general implications for sustainability. In contrast to strategies aiming at short-term optimisation and economic efficiency, we argue that the conditions and circumstances maintaining variability and momentary sub-optimal alternatives are highly relevant for a socio-economic system that is heading for sustainable development.  相似文献   
906.
The ongoing process of ocean acidification already affects marine life, and according to the concept of oxygen and capacity limitation of thermal tolerance, these effects may be intensified at the borders of the thermal tolerance window. We studied the effects of elevated CO2 concentrations on clapping performance and energy metabolism of the commercially important scallop Pecten maximus. Individuals were exposed for at least 30 days to 4 °C (winter) or to 10 °C (spring/summer) at either ambient (0.04 kPa, normocapnia) or predicted future PCO2 levels (0.11 kPa, hypercapnia). Cold-exposed (4 °C) groups revealed thermal stress exacerbated by PCO2 indicated by a high mortality overall and its increase from 55 % under normocapnia to 90 % under hypercapnia. We therefore excluded the 4 °C groups from further experimentation. Scallops at 10 °C showed impaired clapping performance following hypercapnic exposure. Force production was significantly reduced although the number of claps was unchanged between normocapnia- and hypercapnia-exposed scallops. The difference between maximal and resting metabolic rate (aerobic scope) of the hypercapnic scallops was significantly reduced compared with normocapnic animals, indicating a reduction in net aerobic scope. Our data confirm that ocean acidification narrows the thermal tolerance range of scallops resulting in elevated vulnerability to temperature extremes and impairs the animal’s performance capacity with potentially detrimental consequences for its fitness and survival in the ocean of tomorrow.  相似文献   
907.
This paper explores the characteristics of 238 patents on 90 inventions contributed by major multinational innovators to the “Eco-Patent Commons”, which provides royalty-free access to third parties to patented innovations on green technologies. We compare the pledged patents to other patents in the same technologies or held by the same multinationals to investigate the motives of the contributing firms as well as the potential for such commons to encourage innovation and diffusion of climate change related technologies. We find pledged patents to protect environmentally friendly technologies and to be of similar value as the average patent in a pledging firm's patent portfolio but of lower value than other patents in their class. Our analysis of the impact of the patent commons on diffusion of patented technologies suggests that making patents accessible royalty-free did not result in any significant increase in diffusion as measured by citing patents. This study, therefore, indirectly provides evidence on the role of patents in the development and diffusion of green technologies.  相似文献   
908.
Earthworms highly increase ciprofloxacin mineralization in soils   总被引:1,自引:0,他引:1  
This report shows that earthworms increase up to eight times the mineralization of the antibiotic ciprofloxacin in soils. Antibiotics are extensively used and disseminated in environmental compartments. Antibiotics may enter food chains and thus induce resistance in environmental and human commensal bacteria. The antibiotic ciprofloxacin is suspected to induce significant adverse effects on soil microbial processes, with possible consequences on soil functions. Nevertheless, little is known concerning the fate of ciprofloxacin in soils. Here, we studied the mineralization and distribution of the [2-14C]-ciprofloxacin in soil–plant–water systems where ciprofloxacin was applied by amendment of spiked pig slurry. Results show that a very weak microbial mineralization of the antibiotic, lower than 0.01 %, occurred after 84 days of incubation. By contrast, the addition of earthworms increased from 5 to 8 times ciprofloxacin mineralization during the following 84 days incubation. In addition, earthworm activity induced the transfer of 40 % of radioactive compounds from the upper to the lower layer of soil, modifying the distribution of the antibiotic within the soil profile. We conclude that earthworms can be used efficiently to mineralize ciprofloxacin and modify its distribution in soils. As a consequence, earthworms change the exposure of soil organisms to ciprofloxacin, and, in turn, the eco-toxicological impact of the antibiotic.  相似文献   
909.
The effect of sheep grazing on species richness, higher order diversity measures, inequality, species composition, functional diversity and allometric relationships at a coastal dune heathland site was investigated. After a prescribed fire in 2002, the site was divided into two parts, where one of the parts was unmanaged and the other part was fenced and grazed by sheep. Sheep grazing had a positive effect on species richness as well as a significant positive effect on the functional diversity at the coastal dune heathland site. Generally, the cover of dwarf shrubs was negatively affected by grazing, whereas the cover of sedges and grasses was positively affected by grazing. There is a need for comparative investigations of the effect of different management methods not only on floristic biodiversity, but on all relevant kinds of biodiversity as well as on soil structure, soil chemistry and habitat micro- and macrostructure. Consequently, we advocate the initiation of an international systematic investigation of the effect of different management methods.  相似文献   
910.
In this theory-driven literature review we examine how leadership and emerging research in positive organizational behaviour (POB) may inform our understanding of human mechanisms that affect safety outcomes. According to authentic leadership theory, leader self-awareness and self-regulation processes are vital mechanisms in the leader-follower exchange. From emerging research on authentic leadership, we propose that production management values, attitudes, and behaviour are linked to safety climate and safety outcomes in safety critical organizations (SCOs). According to recent developments in management theory, “psychological capital” is comprised of four distinct aspects that can be linked to desirable organizational outcomes and sustained high quality performance in individual workers. From this we offer a research model and five research propositions implicating that authentic leadership directly affects safety outcomes via promoting positive safety climate perceptions. Furthermore, we propose a second path where psychological capital mediates the relationship between authentic leadership, safety climate and safety outcomes in SCOs.  相似文献   
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