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251.
J.L. Mumford R.S. Chapman D.B. Harris X.Z. He S.R. Cao Y.L. Xian X.M. Li 《Environment international》1989,15(1-6)
Residents of Xuan Wei County in China have unusually high lung cancer mortality that cannot be attributed to tobacco use or occupational exposure. They are exposed to smoke from unvented, open pit coal or wood fires (often used for cooking and heating). The variation in lung cancer rates among communes within the county suggests that indoor combustion of smoky coal may be the prime determinant of lung cancer. To characterize the air in Xuan Wei homes, samples of air particles and semivolatile organic compounds were collected from homes located in two communes; one commune has a high rate of lung cancer, and the other has a low rate. Samples collected in the commune where the lung cancer rate is high and where smoky coal is the predominant fuel contained high concentrations of small particles with high organic content; organic extracts of these samples were mutagenic. Samples from homes in the wood-burning commune, which has a low rate of lung cancer, consisted mostly of larger particles of lower organic content and mutagenicity. The smoky coal sample was a mouse skin carcinogen and was a more potent initiator of skin tumors in comparison to the wood or smokeless coal sample. 相似文献
252.
Detritus as food for estuarine copepods 总被引:9,自引:0,他引:9
A variety of detrital foods derived from marsh plants were fed to the copepods Eurycemora affinis and Scottolana canadensis. The copepods did not survive well or produce eggs when feeding on detritus with smaller amounts of microbiota, but did well when a rich and abundant microbiota was present. Ciliated protozoans appear to be particularly important in the transfer of detrital energy to copepods.Contribution No. 703, Center for Environmental and Estuarine Studies, University of Maryland. 相似文献
253.
254.
Hydrogen production from biomass 总被引:1,自引:0,他引:1
The ‘hydrogen economy’ has received considerable attention in academic, industrial and political contexts. There are opportunities
for vast reductions in greenhouse gas emissions, increased energy security and greater overall efficiency. However, if hydrogen
is to become a fundamental energy source for electrical power generation, as well as a transportation fuel, novel generation
pathways will be necessary to meet the increase in demand. A promising means for generating hydrogen is the thermochemical
conversion of biomass to a synthesis gas, composed of a mixture of hydrogen, carbon monoxide, carbon dioxide and methane.
In order to manipulate the composition and maximise the hydrogen output, a calcium-based carbon dioxide sorbent can be utilised
in situ. The removal of carbon dioxide alters the reaction chemistry to preferentially produce hydrogen. In this work we report
on the characterisation of a likely Ca-based carbon dioxide sorbent and demonstrate the merits of hydrogen production from
biomass, with in situ carbon dioxide capture, on the basis of a thermodynamic study. Using this model we show that hydrogen
output from biomass gasification can be increased from 40%-vol to 80%-vol (dry basis) when a carbon dioxide sorbent is used. 相似文献
255.
Previous research has established that perceptions of organizational politics are associated with negative organizational outcomes. However, this may not hold true for all individuals. We offer subordinate and supervisor political skill, the ability to understand interactions at work and to use that understanding to effectively influence others, as possible moderators. Specifically, this study investigates the impact of both employees' self‐rated political skill and their managers' political skill on job satisfaction, job performance, and manager‐rated commitment. We examined these relationships in an organizational sample of 106 matched dyadic pairs and found mixed support for the joint moderating effect of self and manager political skill on the politics perceptions‐outcome relationships. Strengths, limitations, and directions for future research are discussed. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
256.
We examined whether job engagement mediated the effects of organizational justice dimensions on work behaviors and attitudes. Considering distributive and procedural justice from a motivational perspective, we proposed that job engagement would mediate these two dimensions' relations with the work outcomes of task performance, organizational citizenship behavior, and job satisfaction. We also expected this mediation effect would be magnified when senior management trust (SMT) was high. Our results showed that the simple mediation model was supported only for distributive justice. Alternatively, the indirect effect of procedural justice on work outcomes through job engagement was significant only when SMT was high. Implications of our findings and areas for future research are discussed. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
257.
Oedekoven Cornelia S. Marques Tiago A. Harris Danielle Thomas Len Thode Aaron M. Blackwell Susanna B. Conrad Alexander S. Kim Katherine H. 《Environmental and Ecological Statistics》2022,29(1):101-125
Environmental and Ecological Statistics - Various methods for estimating animal density from visual data, including distance sampling (DS) and spatially explicit capture-recapture (SECR), have... 相似文献
258.
Gavin M. Jones Berry Brosi Jason M. Evans Isabel G. W. Gottlieb Xingwen Loy Mauricio M. Núñez-Regueiro Holly K. Ober Elizabeth Pienaar Rajeev Pillay Kathryn Pisarello Lora L. Smith Robert J. Fletcher Jr. 《Conservation biology》2022,36(3):e13872
International demand for wood and other forest products continues to grow rapidly, and uncertainties remain about how animal communities will respond to intensifying resource extraction associated with woody bioenergy production. We examined changes in alpha and beta diversity of bats, bees, birds, and reptiles across wood production landscapes in the southeastern United States, a biodiversity hotspot that is one of the principal sources of woody biomass globally. We sampled across a spatial gradient of paired forest land-uses (representing pre and postharvest) that allowed us to evaluate biological community changes resulting from several types of biomass harvest. Short-rotation practices and residue removal following clearcuts were associated with reduced alpha diversity (−14.1 and −13.9 species, respectively) and lower beta diversity (i.e., Jaccard dissimilarity) between land-use pairs (0.46 and 0.50, respectively), whereas midrotation thinning increased alpha (+3.5 species) and beta diversity (0.59). Over the course of a stand rotation in a single location, biomass harvesting generally led to less biodiversity. Cross-taxa responses to resource extraction were poorly predicted by alpha diversity: correlations in responses between taxonomic groups were highly variable (−0.2 to 0.4) with large uncertainties. In contrast, beta diversity patterns were highly consistent and predictable across taxa, where correlations in responses between taxonomic groups were all positive (0.05–0.4) with more narrow uncertainties. Beta diversity may, therefore, be a more reliable and information-rich indicator than alpha diversity in understanding animal community response to landscape change. Patterns in beta diversity were primarily driven by turnover instead of species loss or gain, indicating that wood extraction generates habitats that support different biological communities. 相似文献