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141.
Gina M. Garland Emma SuddickMartin Burger W.R. HorwathJohan Six 《Agriculture, ecosystems & environment》2011,144(1):423-428
Knowing underlying practices for current greenhouse gas (GHG) emissions is a necessary precursor for developing best management practices aimed at reducing N2O emissions. The effect of no-till management on nitrous oxide (N2O), a potent greenhouse gas, remains largely unclear, especially in perennial agroecosystems. The objective of this study was to compare direct N2O emissions associated with management events in a cover-cropped Mediterranean vineyard under conventional tillage (CT) versus no-till (NT) practices. This study took place in a wine grape vineyard over one full growing season, with a focus on the seven to ten days following vineyard floor management and precipitation events. Cumulative N2O emissions in the NT system were greater under both the vine and the tractor row compared to CT, with 0.15 ± 0.026 kg N2O-N ha−1 growing season−1 emitted from the CT vine compared to 0.22 ± 0.032 kg N2O-N ha−1 growing season−1 emitted from the NT vine and 0.13 ± 0.048 kg N2O-N ha−1growing season−1 emitted from the CT row compared to 0.19 ± 0.019 kg N2O-N ha−1 growing season−1 from the NT row. Yet these variations were not significant, indicating no differences in seasonal N2O emissions following conversion from CT to NT compared to long-term CT management. Individual management events such as fertilization and cover cropping, however, had a major impact on seasonal emissions, indicating that management events play a critical role in N2O emission patterns. 相似文献
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143.
In running our increasingly complex business systems, formal risk analyses and risk management techniques are becoming more important part to managers: all managers, not just those charged with risk management. It is also becoming apparent that human behaviour is often a root or significant contributing cause of system failure. This latter observation is not novel; for more than 30 years it has been recognised that the role of human operations in safety critical systems is so important that they should be explicitly modelled as part of the risk assessment of plant operations. This has led to the development of a range of methods under the general heading of human reliability analysis (HRA) to account for the effects of human error in risk and reliability analysis. The modelling approaches used in HRA, however, tend to be focussed on easily describable sequential, generally low-level tasks, which are not the main source of systemic errors. Moreover, they focus on errors rather than the effects of all forms of human behaviour. In this paper we review and discuss HRA methodologies, arguing that there is a need for considerable further research and development before they meet the needs of modern risk and reliability analyses and are able to provide managers with the guidance they need to manage complex systems safely. We provide some suggestions for how work in this area should develop. But above all we seek to make the management community fully aware of assumptions implicit in human reliability analysis and its limitations. 相似文献
144.
Alfonso Rodríguez-Vila Emma F. Covelo Rubén Forján Verónica Asensio 《Environmental science and pollution research international》2014,21(19):11293-11304
The soils at a depleted copper mine in Touro (Galicia, Spain) are chemically degraded. In order to determine the effect of amendments and vegetation on the chemical characteristics of a mine soil and on the plant uptake of metals, a greenhouse experiment was carried out for 3 months. A settling pond soil was amended with different percentages of a compost and biochar mixture and vegetated with Brassica juncea L. The results showed that the untreated settling pond soil was polluted by Cu. Amendments and planting mustards decreased the pseudototal concentration of this metal, reduced the extreme soil acidity and increased the soil concentrations of C and TN. Both treatments also decreased the CaCl2-extractable Co, Cu and Ni concentrations. However, the amendments increased the pseudototal concentration of Zn in the soil, provided by the compost that was used. The results also showed that mustards extracted Ni efficiently from soils, suggesting that B. juncea L. is a good phytoextractor of Ni in mine soils. 相似文献
145.
The field of prenatal screening and diagnosis for fetal anomalies has been marked by a rapid succession of technological advances, including most notably, chromosomal microarray analysis, and next generation sequencing. Despite the diagnostic advantages of these technologies, their incorporation into prenatal testing has created additional challenges of revealing genomic variants of unknown or uncertain significance, and secondary findings. While detailed posttest counseling about uncertain variants is best performed by medical geneticists, many of the screening and diagnostic tests that lead to this information are actually ordered by general maternity health care professionals (HCPs), such as obstetricians, midwives, and family physicians. Maternity HCPs support pregnant women through to the conclusion of their pregnancy and the postpartum period, and thus are close observers of the psychosocial impart of fetal genomic uncertainty on women and their families. While there have been many studies exploring the handling of genomic uncertainty by genetics HCPs, there has been relatively less attention paid to maternity HCPs without speciality training in genetics. This review explores the current literature surrounding nongenetic maternity HCPs' views and experiences of genomic uncertainty and returning uncertain results in the prenatal setting. 相似文献
146.
Nelson J. ODriscoll Emma Vost Erin Mann Sara Klapstein Robert Tordon Matthew Lukeman 《环境科学学报(英文版)》2021,33(5):347-350
147.
A qualitative tool combining an interaction matrix and a GIS to map vulnerability to traffic induced air pollution 总被引:1,自引:0,他引:1
Local authorities and transport planners need fast and straightforward tools to perform their preliminary air quality assessments. Such tools are required to provide an initial impression of the local air quality and to highlight areas requiring a more rigorous investigation. This paper presents a technique to develop such a tool, for performing an initial assessment of air quality due to traffic in an urban area. The technique combines an interaction matrix methodology as developed for rock engineering systems, with Geographical Information System (GIS) map overlaying. This interaction matrix methodology incorporates a total system approach, which identifies the main parameters and quantifies the interactions between them. Weighting values for these parameters are obtained either through parametric studies, using numerical modelling, or from engineering judgement. These weightings are applied to spatial datasets for a study area using a GIS. The GIS results are presented in the form of a vulnerability map, which highlights the areas susceptible to poor air quality. This visual interpretation of the results is ideal for local authorities, who have to report to a wide range of non-specialists in the field, for example, planners, councillors and the public. The vulnerability map compares favourably with pollutant concentration patterns, obtained from an advanced dispersion model. 相似文献
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149.
Many animals, including gregarious caterpillars, begin life in groups and become increasingly solitary as they grow larger. These ontogenetic changes in social behaviour suggest that the costs and benefits of grouping change with increasing individual size. Forest tent caterpillar (Malacosoma disstria) colonies exhibit complex social behaviour during the early larval instars, using pheromone trails to move together between temporary bivouacs and feeding sites, and break up as the caterpillars grow. We demonstrate changes in individual responses to cues from conspecifics that explain changes in aggregation during caterpillar development. We used Markov chain analysis to test the influence of pheromone trails and colony-mates on an individual caterpillars tendency to switch between quiescence, searching, walking and spinning. Pheromone-laden silk trails increased the tendency to begin locomotion, whereas colony-mates increased switching from activity to quiescence. Trails also influenced the form taken by locomotor behaviour, and promoted directed walking over searching. Social cues thus increase the efficiency of individual locomotion. Younger larvae were more quiescent and more reluctant to walk in the absence of trails than were older insects. An increase in independent locomotion as the larvae grow provides a mechanism to explain colony break-up and points to an ontogenetic shift in the internal processes driving behaviour. Scaling relationships suggest that many of the benefits associated with group-living in caterpillars decrease as individuals grow larger, providing an adaptive explanation for observed ontogenetic changes in social behaviour.Communicated by N. Wedell 相似文献
150.
Emma?J?Stokes Richard?J?ParnellEmail author Claudia?Olejniczak 《Behavioral ecology and sociobiology》2003,54(4):329-339
This paper presents data on the dispersal patterns and reproductive success of western lowland gorilla females from a long-term study at Mbeli Bai in the Nouabalé-Ndoki National Park, Republic of Congo. We find that female natal and secondary transfer is common. Female immigration rates are negatively related to group size, and emigration rates are positively related to group size, with the net result that larger groups are losing females and smaller groups are gaining females. Furthermore, females transferring between known groups show a preference for significantly smaller groups. However, there is no effect of group size on female reproductive success. Male protection and male quality are considered important in determining female transfer decisions. The case for infanticide is argued and females exhibit strategies that appear to minimise the probability of infanticide following the death of the silverback. Exclusively single-male groups and group formation through female acquisition by solitary males may bias female transfer to lone silverbacks and small groups. The effects of group size on female dispersal and reproductive success are not wholly consistent with an argument for increased foraging costs, and group size effects are more parsimoniously explained by demographic factors. Male protection from intra-group aggression is the most likely factor underlying grouping patterns across gorilla taxa, but differences in population structure and male reproductive strategies may account for inter-specific variation. We stress the need for intra-specific comparisons and more complete data sets on western lowland gorilla feeding behaviour.Communicated by S. Boinski 相似文献