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191.
Stayers versus movers: Social capital and early career imprinting among young professionals 下载免费PDF全文
We investigate what interfirm career mobility patterns would emerge if individuals are motivated by the job rewards they obtain as a function of their experience in organizations. We articulate two career strategies that individuals employ to navigate their early careers—commitment to a single employer and “job hopping” between different employers. Each strategy generates social capital (an individual's structure of social relations) but of a different kind. Embeddedness in the same organization over time develops a strong local identity and reputation within the firm. Boundary spanning through experience in different organizations creates opportunities for connecting people and ideas and for knowledge transfer between firms. We posit and present evidence that the choice between these two strategies is conditioned by social experience at the onset of one's career—the length of tenure with the first employer—which sorts individuals into “stayers” and “movers.” 相似文献
192.
Jennifer Ann McGetrickTania BubelaDavid S.Hik 《环境影响评价》2018,(2):97-98
无论从程序上还是内容上,公众参与对开展可持续的环境评价都是必不可少的。听证会是公众参与最便捷的途径,但其也面临着各方的政治压力,需快速有效地开展。听证会记录的保存为研究环评公众参与提供了最原始的数据,但数据分析需要大量的时间和精力,不利于开展经常需要的深度定性分析。自动内容分析技术提供了分析听证会记录的快速、可复制、可归纳的系统方法,包括计算机编程脚本的重要开发和应用,能合成大量的文档信息。此文通过加拿大西北部麦肯齐山谷Prairie Creek(EA0809-002;2008—2011)和Nico(EA0809-004;2009—2013)两个听证会案例研究,证实了此技术的潜在功用。通过对分析结果的解读,对自动内容分析技术进行了评估,并预估了将其广泛应用于环境评价研究和实践的可能性。 相似文献
193.
194.
Ambio - In recent years, private land conservation has increased in profile among policymakers and academics. Conservation initiatives on privately owned land help to mitigate global biodiversity... 相似文献
195.
James Littler Jennifer N. Geroni Devin J. Sapsford Richard Coulton Anthony J. Griffiths 《Chemosphere》2013,90(4):1533-1538
Hydrous ferric oxide (here termed ‘ochre’) sludge, an abundant waste product produced from the treatment of acid mine drainage (AMD), was used in this study for the removal of phosphorus (in the form of phosphate ions) from contaminated waters. The phosphorus uptake capacities of both raw and pelletized AMD solids were compared using batch and column tests. Addition of a cement binder to the AMD solids during pellet production led to significantly increased P-loading of the resultant solids compared to the raw sludge. Additionally, the pellets were found to continue to remove P in tests up to 7 d in duration whereas the unbound AMD sludge appeared to approach equilibrium with phosphate solution after approximately 60 min of contact time. In line with previous studies P uptake by the AMD solids was found to be primarily via adsorption. By contrast calcium phosphate precipitation was found to be the dominant removal mechanism for the cement-bound ochre pellets with a relatively small proportion of removal attributable to the AMD solids. SEM–EDX analysis of the surface of used pellets showed a Ca:P molar ratio close to that of hydroxyapatite (HAP). Continuous column tests on these pellets showed a rapid decrease in P removal capacity by the pellets over time, attributable to the formation of a passivating HAP surface layer. 相似文献
196.
McNulty SG Cohen EC Moore Myers JA Sullivan TJ Li H 《Environmental pollution (Barking, Essex : 1987)》2007,149(3):281-292
Concern regarding the impacts of continued nitrogen and sulfur deposition on ecosystem health has prompted the development of critical acid load assessments for forest soils. A critical acid load is a quantitative estimate of exposure to one or more pollutants at or above which harmful acidification-related effects on sensitive elements of the environment occur. A pollutant load in excess of a critical acid load is termed exceedance. This study combined a simple mass balance equation with national-scale databases to estimate critical acid load and exceedance for forest soils at a 1-km(2) spatial resolution across the conterminous US. This study estimated that about 15% of US forest soils are in exceedance of their critical acid load by more than 250eqha(-1)yr(-1), including much of New England and West Virginia. Very few areas of exceedance were predicted in the western US. 相似文献
197.
Jae-Won Yoo Yong-Woo Lee Jennifer L. Ruesink Chang-Gun Lee Chang-Soo Kim Mi-Ra Park Kon-Tak Yoon In-Seo Hwang Jun-Ho Maeng Rutger Rosenberg Jae-Sang Hong 《Environmental monitoring and assessment》2010,170(1-4):141-157
The coast of the Korean peninsula experiences a range of human impacts, including pollution, shipping, reclamation, and aquaculture, that have motivated numerous local studies of macrobenthic organisms. In this paper, 1,492 subtidal stations were compiled from 23 studies (areas) to evaluate environmental quality on a broader scale. A common index in biomonitoring, Shannon–Wiener evenness proportion (SEP), could not incorporate azoic or single-species samples. This shortcoming was overcome by developing an inverse function of SEP (ISEP), which was positively correlated with independent measures of water quality available for nine sites and was not biased by the size of the sampling unit. Additionally, at Shihwa Dike, where samples were collected before and after reinstating a tidal connection with the ocean, ISEP values improved over time, as expected. Thus, it is now possible to assign Korean subtidal sites to seven ISEP “grades” and to use their values and trends to guide coastal management. 相似文献
198.
Sedillo JL Quintana A Souza K Oshima KH Smith GB 《Journal of environmental monitoring : JEM》2008,10(6):718-723
The foundational idea for this project is that household faucet-mounted water filters may be used as bioforensic sampling devices to detect the extent of a potential bioagent release in domestic water supplies. An optimized eluent solution was determined experimentally by quantifying recoveries of microorganisms from point-of-use (POU) drinking water filters. The optimized extraction protocol was then used in mock bioagent release experiments to determine the feasibility of POU filters as bioforensic sampling devices. Bacillus atrophaeus spores, Escherichia coli and PP7 virus were exposed to filters and the number of attached organisms was determined by enumerating the unattached organisms on selective agar media. Subsequently, the filters were eluted and the percent of extracted organisms was determined based on the number of attached organisms. Two popular brands of carbon block filters retained 92%-99% of representative virus, spore and vegetative bacteria. In back-flush elutions of single filters, the most efficient eluent was identified as a combination of 1% peptone and 1% Tween-80, and extraction recovered 25.4% (+/-17.5%) of attached E. coli, 20.4% (+/-3.6%) of B. atrophaeus spores, and 9.4% (+/-5.2%) of PP7 virions (+/- standard deviations). In bioagent release studies in which filters were challenged with 100 agents mL(-1), greater than 99% of the spores were retained by the filters, and the percent of attached spores that were recovered ranged from 10.4% at day 0 to 4.3% five days after the release event (averaged from five separate experiments). In contrast, E. coli, Salmonella typhimurium and PP7 virus were rapidly inactivated in the chlorinated tap water, indicating their improbable survival in chlorinated water supplies. It is therefore concluded that household water filters can be used as microbial sampling devices for bioforensic applications in the event of a bioagent release in domestic drinking water supplies. 相似文献
199.
Brian Buma Jennifer K Costanza Kurt Riitters 《Environmental monitoring and assessment》2017,189(12):642
The scale of investigation for disturbance-influenced processes plays a critical role in theoretical assumptions about stability, variance, and equilibrium, as well as conservation reserve and long-term monitoring program design. Critical consideration of scale is required for robust planning designs, especially when anticipating future disturbances whose exact locations are unknown. This research quantified disturbance proportion and pattern (as contagion) at multiple scales across North America. This pattern of scale-associated variability can guide selection of study and management extents, for example, to minimize variance (measured as standard deviation) between any landscapes within an ecoregion. We identified the proportion and pattern of forest disturbance (30 m grain size) across multiple landscape extents up to 180 km2. We explored the variance in proportion of disturbed area and the pattern of that disturbance between landscapes (within an ecoregion) as a function of the landscape extent. In many ecoregions, variance between landscapes within an ecoregion was minimal at broad landscape extents (low standard deviation). Gap-dominated regions showed the least variance, while fire-dominated showed the largest. Intensively managed ecoregions displayed unique patterns. A majority of the ecoregions showed low variance between landscapes at some scale, indicating an appropriate extent for incorporating natural regimes and unknown future disturbances was identified. The quantification of the scales of disturbance at the ecoregion level provides guidance for individuals interested in anticipating future disturbances which will occur in unknown spatial locations. Information on the extents required to incorporate disturbance patterns into planning is crucial for that process. 相似文献
200.
Allen S. Lefohn H. Peter Knudsen Jennifer A. Logan Jeanne Simpson Chandrakant Bhumralkar 《Journal of the Air & Waste Management Association (1995)》2013,63(5):595-602
Using kriging, a statistical technique, the National Crop Loss Assessment Network (NCLAN) program estimated growing season 5-month (May-September) ambient 7-h mean O3 concentrations for each of the major crop growing areas of the United States for 1978-1982. The O3 estimates were used to predict economic benefits anticipated by lowering O3 levels in the United States. This paper reviews NCLAN’s use of kriging to estimate 7-h seasonal mean O3 concentrations for crop growing regions. Although the original kriging program used by NCLAN incorrectly calculated the diagonal elements of the kriging equations, this omission did not result in significant errors in the predicted estimates. Most of the data used in estimating the 7-h seasonal values were obtained from urban areas; the use of these data tended to underestimate the 7-h seasonal O3 concentrations in rural areas. It is recommended that only O3 data that are representative of agricultural areas and have been collected under accepted quality assurance programs be used In future kriging efforts. 相似文献