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781.
就大气环境影响评价中理解和执行GB/T13201-91、GB3095-82的几个问题提出了看法和建议。 相似文献
782.
Ted L. Ernst Nancy C. Leibowitz Denis Roose Steve Stehman N. Scott Urquhart 《Environmental management》1995,19(1):99-113
The United States Environmental Protection Agency's Environmental Monitoring and Assessment Program (EMAP) will monitor the
nation's resources by evaluating the status and trends of selected indicators of condition using a probability-based sampling
design. The EMAP-Wetlands program will monitor the condition of the nation's wetlands. The EMAP classification system is an
aggregation of the many subclasses of the US Fish and Wildlife Service's National Wetlands Inventory (NWI) classification
system. This aggregation results in fewer wetland classes with more wetlands per class than the NWI system. Aggregation of
the NWI classification was based primarily on dominant vegetation cover, flooding regimes, dominant water source, and adjacency
to rivers and lakes. We evaluated the EMAP classification system and sampling design using NWI digital wetlands data for portions
of Illinois, Washington, North Dakota, and South Dakata. Relative numbers of wetlands, total areas, average areas, and common
versus rare classes were compared between the EMAP and NWI classification systems. As expected, the EMAP classification provided
fewer wetland polygons, each with larger areas, without altering total wetland area. Summary statistics comparing sample estimates
to true population parameters (represented by the NWI data) demonstrated the effectiveness of the EMAP sampling design with
the exception of rare EMAP classes in the selected regions. Although simple random sampling is inadequate for both large and
small wetlands, the EMAP sampling design is readily adapted to provide better estimates for these categories. Aggregating
the NWI classification to the EMAP classification provides fewer wetland classes, with more wetlands per class, for EMAP's
annual reports and statistical summaries.
The research in this report has been funded by the United States Environmental Protection Agency (EPA) under contracts 68-C8-0006
to ManTech Environmental Technology, Inc. and 68-03-3532 to The Bionetics Corporation. Mention of trade names does not constitute
endorsement or recommendation for use. 相似文献
783.
Mike Danson 《Journal of Environmental Planning and Management》1991,34(2):89-95
This paper describes the recent economic history of the Scottish economy and uses a synthesised theory of labour market segmentation and the dual economy to identify the origins of the relative decline of Scottish industry and labour over the period, critically evaluating the role of the SDA and of government policy in general. Incorporating the impacts of takeover and merger of indigenous companies, the promotion of the branch plant economy, the selective effects of emigration and training schemes, and the reliance on small and medium sized companies to regenerate the economies of city‐regions, an analysis based on the importance of the centre‐periphery relations of monopoly capitalism for the Scottish economy is undertaken. 相似文献
784.
在碱性溶液(pH10.4—11.1)中,钙离子与紫尿酸铵生成橙红色的稳定络合物,在500nm处有最大吸收,钙浓度在2.5—25μg/50ml范围内符合比尔定律,表观摩尔吸光系数为1.2×10~4L·mol~(-1)·cm~(-1),桑德尔灵敏度为0.003μg/cm~2。本法快速、准确、可靠,回收率为94—104%。 相似文献
785.
James Pipkin 《Environmental management》1996,20(6):793-797
While extinctions of individual species are part of a normal cycle, the current rate of extinctions should be a concern to us all. The maintenance of biological diversity is important for utilitarian reasons, quality of life considerations, and because biodiversity is important to sustainable regional economies. Single-species approaches are too limited to protect biodiversity at the landscape, habitat, and watershed levels. New approaches are necessary to deal with the complexity of biological diversity. The administration is using provisions in the Endangered Species Act to bring about broader multispecies habitat protection. The ecosystem approach provides a framework for ensuring that ecological considerations are taken into account, along with economic and social factors, and that all interested parties are able to participate in the decision-making process. 相似文献
786.
Piero Barazzuoli Senatro Izzo Paolo Menicori Massimiliano Micheluccini Massimo Salleolini 《Environmental management》1989,13(5):613-622
The principal aim of this research is to solve problems of water-budget estimation in particularly indeterminate conditions, of the kind that are frequently encountered in the field, in which absence or insufficiency of hydrographic instrumentation prevents the adequate evaluation of runoff.To do this we have developed techniques that are based on the method of Kennessey (1930), in which the runoff coefficient of a watershed in estimated using three physiographic variables (slope angle, permeability, and vegetation cover) and a parameter that defines the climatic conditions of the local area. Our comparison of the Kennessey method with instrumental records from a wide variety of instrumented drainage basins in central Italy shows that the method provides reliable estimates of runoff. Our analysis also indicates the best criteria for its application, as shown by the examples and results presented in this article.This research enables us to present a new application of the method, namely the runoff coefficient map, which, in addition to its specific usefulness for the evaluation of runoff, has three advantages. First, it supplies a more realistic vision of the local distribution of runoff/rainfall ratios; second, it allows one to overcome the spatial constraints imposed by the narrow frame of reference represented by the watershed; and third, it makes an important contribution to the solution of other hydrogeological problems, such as the evaluation of the amount of water required for adequate recharge of the intake areas of deep aquifers or the maintenance of geothermal processes.Hence we propose this mapping technique as a valuable practical aid to regional hydrogeologic planning. 相似文献
787.
A regional pollution history has been reconstructed for the borough of Halton (northwest England) from four urban ponds in
north Cheshire and south Merseyside, using environmental analyses of lake sediment stratigraphies. Mineral magnetism, geochemistry
and radiometric dating have produced profiles of pollution characteristics dating from the mid-nineteenth century to present
day. These pollution profiles reflect the atmospheric deposition of a range of pollutants over 150 years of intensified industry.
Distinct phases of pollution deposition and characteristics are identified reflecting: (1) intensification of industry in
the nineteenth century; (2) expansion of industry during the twentieth century; (3) post 1956 Clean Air Acts. This work promotes
the potential use of these pollution archives for use in epidemiology to better understand links between human health and
environmental pollution, especially for diseases with long latency times, where retrospective pollution exposure assessments
are important. 相似文献
788.
789.
成都市大气污染及其防治对策 总被引:1,自引:0,他引:1
本文针对成都市大气污染源进行了探讨,根据可持续发展的原则,提出针对性的解决措施。 相似文献
790.
Projecting Canadian Prairie Runoff for 2041–2070 with North American Regional Climate Change Assessment Program (NARCCAP) Data
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Jeannine‐Marie St‐Jacques Yuliya Andreichuk David J. Sauchyn Elaine Barrow 《Journal of the American Water Resources Association》2018,54(3):660-675
The South Saskatchewan River Basin (SSRB) of Alberta, Canada, is semiarid and under severe water stress due to increasing human demands. We present the first examination of projected changes in SSRB runoff from a large set of North American Regional Climate Change Assessment Program regional climate models (RCMs) plus one Coordinated Regional Climate Downscaling Experiment RCM. We used six different runoff estimation methods: total surface and subsurface runoff (total runoff), surface runoff, and four estimations based on Budyko functions. Most RCM estimations showed substantial biases and distribution differences when compared to observed data; thus bias correction was necessary. Total runoff was the best of the six variables in modeling observed runoff for each of the four SSRB subbasins. Projected total runoff for 2041–2070 shows a geographic gradient in the SSRB, with possible drying in the southern Oldman River subbasin and possible increased runoff in the northernmost Red Deer River subbasin. A shift to an earlier spring peak in runoff and drier late summer, with a need for increased irrigation, should be expected. In a first examination of the important question of projected changes in interannual variability, we show increasing magnitude. This result further adds to adaptation challenges over the course of this century in this basin, which is already largely closed to further allocation. 相似文献