全文获取类型
收费全文 | 752篇 |
免费 | 6篇 |
国内免费 | 34篇 |
专业分类
安全科学 | 64篇 |
废物处理 | 43篇 |
环保管理 | 179篇 |
综合类 | 93篇 |
基础理论 | 237篇 |
污染及防治 | 78篇 |
评价与监测 | 57篇 |
社会与环境 | 30篇 |
灾害及防治 | 11篇 |
出版年
2023年 | 6篇 |
2022年 | 1篇 |
2021年 | 11篇 |
2020年 | 8篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 9篇 |
2016年 | 10篇 |
2015年 | 23篇 |
2014年 | 19篇 |
2013年 | 26篇 |
2012年 | 14篇 |
2011年 | 71篇 |
2010年 | 53篇 |
2009年 | 68篇 |
2008年 | 56篇 |
2007年 | 47篇 |
2006年 | 39篇 |
2005年 | 36篇 |
2004年 | 16篇 |
2003年 | 29篇 |
2002年 | 39篇 |
2001年 | 35篇 |
2000年 | 26篇 |
1999年 | 27篇 |
1998年 | 12篇 |
1997年 | 14篇 |
1996年 | 13篇 |
1995年 | 7篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1992年 | 6篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 11篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1978年 | 1篇 |
1977年 | 1篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有792条查询结果,搜索用时 15 毫秒
721.
E.?HolzbecherEmail author A.?Knappe A.?Pekdeger 《Environmental Modeling and Assessment》2005,10(1):1-8
Surface water from rivers or lakes, infiltrating through porous media, is increasingly used as a source of public water supply. During bank filtration the water chemistry is substantially changed by various processes such as biodegradation, sorption and mixing with ambient groundwater, but the details of this natural attenuation are not yet entirely understood. In order to gain a better understanding, the degradation of an organic substance (DTPA) is examined here using various model approaches for steady state conditions. Models are fitted on data from an experimental study under near-field conditions. The results show advantages and disadvantages of the different model approaches and provide a guideline for the modelling of other organic substances under different but similar conditions. 相似文献
722.
Air pollution due to small scale industries have been found tocause serious occupational health hazards and adverse effects on vegetation and heritage. The study for air pollution impactassessment for brick kiln industries was undertaken. The stackmonitoring exercise was carried out to estimate the pollution level of SPM, SO2, and NOx. The ambient air quality was also measured in the vicinity of brick kilns to assess the impact of stack emission on ground level concentration. Characterisation of SPM for toxic metals were studied. Modelling exercise was carried to predict the impact of emission of brick kiln on surrounding environment. To minimise the emission level and ground level concentration, airpollution mitigation measures are suggested. 相似文献
723.
The distribution of fly ash that is discharged in the form of slurry from a power plant situated on the southern coast of the Black Sea was simulated with a transport model that used the velocity fields produced by isopycnic modelling. It is shown that a significant amount of ash is deposited in the vicinity of the discharge location. The ash remaining in the water column settles in a manner dependent on the direction and intensity of the local current regime. Generally, summer and spring are found to be seasons when the circulation is weak and the ash dispersion is confined to the shore. The model results are conditional upon obtaining observational data for validation. 相似文献
724.
S. A. Power M. R. Ashmore A. C. Terry S. J. M. Caporn M. G. Pilkington D. B. Wilson C. G. Barker J. A. Carroll N. Cresswell E. R. Green G. W. HEIL 《Water, Air, & Soil Pollution: Focus》2004,4(6):259-267
The results from three long-term field manipulation studies of the impacts of increased nitrogen deposition (0–120 kg N ha–1 yr–1) on lowland and upland heathlands in the UK were compared, to test if common responses are observed. Consistent increases in Calluna foliar N content and decreases in litter C:N ratios were found across all sites, while increases in N leaching were not observed at any site over the range 0–80 kg ha–1 yr–1. However, the response of Calluna biomass did vary between sites, possibly reflecting site differences in nutrient status and management histories. Five versions of a simulation model of heathland responses to N were developed, each reflecting different assumptions about the fate and turnover of soil N. Model outputs supported the deduction from mass balance calculations at two of the field sites that N additions have resulted in an increase in immobilisation; the latter was needed to prevent the model overestimating measured N leaching. However, this version of the model significantly underestimated Calluna biomass. Model versions, which included uptake of organic N by Callunaand re-mobilisation of N from the soil organic store provided some improvement in the fit between modelled and field biomass data, but re-mobilisation also led to an overestimation of N leaching. Quantification of these processes and their response to increased N deposition are therefore critical to interpreting experimental data and predicting the long-term impacts of atmospheric deposition on heathlands and moorlands. 相似文献
725.
726.
727.
Vondracek B Blann KL Cox CB Nerbonne JF Mumford KG Nerbonne BA Sovell LA Zimmerman JK 《Environmental management》2005,36(6):775-791
We synthesized nine studies that examined the influence of land use at different spatial scales in structuring biotic assemblages
and stream channel characteristics in southeastern Minnesota streams. Recent studies have disagreed about the relative importance
of catchment versus local characteristics in explaining variation in fish assemblages. Our synthesis indicates that both riparian-
and catchment-scale land use explained significant variation in water quality, channel morphology, and fish distribution and
density. Fish and macroinvertebrate assemblages can be positively affected by increasing the extent of perennial riparian
and upland vegetation. Our synthesis is robust; more than 425 stream reaches were examined in an area that includes a portion
of three ecoregions. Fishes ranged from coldwater to warmwater adapted. We suggest that efforts to rehabilitate stream system
form and function over the long term should focus on increasing perennial vegetation in both riparian areas and uplands and
on managing vegetation in large, contiguous blocks.
Minnesota Cooperative Fish and Wildlife Research Unit is jointly sponsered by U.S. Geological Survey Biological Resources
Division, the University of Minnesota, The Minnesota Department of Natural Resources, and the Wildlife Management Institute. 相似文献
728.
Bazzani GM 《Journal of environmental management》2005,77(4):301-314
729.
Arnold L. Lum 《Environmental management》1978,2(5):423-430
Numbers of shorebirds visiting the Paiko Lagoon Wildlife Sanctuary, a small tropical estuary located on Oahu, Hawaii, are compared before and after environmental restoration of the lagoon. An attempt is made to examine both the biological impacts and policy implications of the project. The biological results indicate that shorebird abundance did not increase following restoration. On the other hand, public perceptions regarding the ecological value of the lagoon suggest that in spite of a lack of biological benefit to shorebirds, the lagoon was perceived by the public, particularly local residents, as being more ecologically valuable because it had been aesthetically improved. The discussion focuses on the interplay between scientific and non-scientific factors in natural resource decision making. 相似文献
730.
M. B. Bayer 《Journal of the American Water Resources Association》1977,13(6):1141-1152
ABSTRACT: This paper describes a modelling method which simplifies the evaluation of water quality policies for nonserial (branching) river systems. The method introduces dummy facilities at the junctions of the major tributary branches with the mainstream as replacements for the facilities and activities on the tributaries. The cost functions for the dummy facilities and the DO and BOD concentrations at the junctions as determined for each tributary are introduced into the mainstream serial system model which is then solved for the optimal values of the mainstream treatment plant efficiencies, the dummy facility effeciencies, and the tributary system DO and BOD concentrations using nonlinear programming. Given the optimum values for the dummy facility efficiencies and the values for the tributary system DO and BOD concentrations, the optimum values for the tributary treatment plant efficiencies are found using nonlinear programming. The method is applied to a river system with a mainstream and one major tributary which contain industrial and municipal organic and thermal polluters and their associated wastewater treatment plants. 相似文献