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881.
Strange E Galbraith H Bickel S Mills D Beltman D Lipton J 《Environmental management》2002,29(2):290-300
The amount of ecological restoration required to mitigate or compensate for environmental injury or habitat loss is often
based on the goal of achieving ecological equivalence. However, few tools are available for estimating the extent of restoration
required to achieve habitat services equivalent to those that were lost. This paper describes habitat equivalency analysis
(HEA), a habitat-based “service-to-service” approach for determining the amount of restoration needed to compensate for natural
resource losses, and examines issues in its application in the case of salt marsh restoration. The scientific literature indicates
that although structural attributes such as vegetation may recover within a few years, there is often a significant lag in
the development of ecological processes such as nutrient cycling that are necessary for a fully functioning salt marsh. Moreover,
natural variation can make recovery trajectories difficult to define and predict for many habitat services. HEA is an excellent
tool for scaling restoration actions because it reflects this ecological variability and complexity. At the same time, practitioners
must recognize that conclusions about the amount of restoration needed to provide ecological services equivalent to those
that are lost will depend critically on the ecological data and assumptions that are used in the HEA calculation. 相似文献
882.
Fuzzy decision analysis for integrated environmental vulnerability assessment of the mid-Atlantic Region 总被引:20,自引:0,他引:20
Tran LT Knight CG O'Neill RV Smith ER Riitters KH Wickham J 《Environmental management》2002,29(6):845-859
A fuzzy decision analysis method for integrating ecological indicators was developed. This was a combination of a fuzzy ranking
method and the analytic hierarchy process (AHP). The method was capable of ranking ecosystems in terms of environmental conditions
and suggesting cumulative impacts across a large region. Using data on land cover, population, roads, streams, air pollution,
and topography of the Mid-Atlantic region, we were able to point out areas that were in relatively poor condition and/or vulnerable
to future deterioration. The method offered an easy and comprehensive way to combine the strengths of fuzzy set theory and
the AHP for ecological assessment. Furthermore, the suggested method can serve as a building block for the evaluation of environmental
policies. 相似文献
883.
Serveiss VB 《Environmental management》2002,29(2):145-154
Considerable progress in addressing point source (end of pipe) pollution problems has been made, but it is now recognized
that further substantial environmental improvements depend on controlling nonpoint source pollution. A watershed approach
is being used more frequently to address these problems because traditional regulatory approaches do not focus on nonpoint
sources. The watershed approach is organized around the guiding principles of partnerships, geographic focus, and management
based on sound science and data. This helps to focus efforts on the highest priority problems within hydrologically-defined
geographic areas. Ecological risk assessment is a process to collect, organize, analyze, and present scientific information
to improve decision making. The U.S. Environmental Protection Agency (EPA) sponsored three watershed assessments and found
that integrating the watershed approach with ecological risk assessment increases the use of environmental monitoring and
assessment data in decision making. This paper describes the basics of the watershed approach, the ecological risk assessment
process, and how these two frameworks can be integrated. The three major principles of watershed ecological risk assessment
found to be most useful for increasing the use of science in decision making are (1) using assessment endpoints and conceptual
models, (2) holding regular interactions between scientists and managers, and (3) developing a focus for multiple stressor
analysis. Examples are provided illustrating how these principles were implemented in these assessments. 相似文献
884.
California and other regions in the United States are becoming more populated and ethnically diverse, and thus, ecological
impacts on the wildland–urban interface are a significant policy concern. In a socioeconomic assessment focused on the geographic
regions surrounding four national forests in southern California, population projections are being formulated to assist in
the update of forest plans. In southern California, the projected trend of explosive population growth combined with increased
ethnic and racial diversity indicates four challenges for environmental management. First, patterns of recreation use on wildlands
are likely to change, and management of these areas will have to address new needs. Second, as land-management agencies face
changing constituencies, new methods of soliciting public involvement from ethnic and racial groups will be necessary. Third,
growth in the region is likely to encroach upon wildland areas, affecting water, air, open space, and endangered species.
Fourth, in order to address all these concerns in a climate of declining budgets, resource management agencies need to strengthen
collaborative relationships with other agencies in the region. How environmental managers approach these changes has widespread
implications for the ecological sustainability of forests in southern California. 相似文献
885.
Community involvement is fundamental to the management of multijurisdictional river basins but, in practice, is very difficult
to achieve. The Murray-Darling basin, in Australia, and the Mekong River basin in Southeast Asia are both cooperatively managed
multijurisdictional river basins where the management authorities have expressed an aim of community involvement. In the Murray-Darling
basin vigorous efforts have promoted a culture of community consultation throughout each of the state jurisdictions involved,
although true participation has not necessarily been achieved. In the Mekong basin the community is much more diverse and
the successes so far have been largely at the local level, involving action in subsections of the basin. These case studies
suggest that community involvement in the form of community consultation across large multijurisdictional river basins is
achievable, but more comprehensive participation is not necessarily possible. 相似文献
886.
分析探讨了浙江鄞县42级地震及历史上浙北中强震前的地震空区现象,认为孕震空区可能是浙北中等及中强震的中期前兆,并提出浙北孕震空区的特征及判别方法。 相似文献
887.
Kari Hämekoski 《Environmental management》1998,22(4):517-520
2 (1 and 24 h), SO2 (1 and 24 h), O3 (1 h) and PM10 (24 h). The AQI is linked to the new air quality guidelines in Finland. The AQI is based on acute health effects, but long-term
effects on nature and materials are also taken into consideration. Subindices are calculated hourly for all pollutants and
for a given hour the highest subindex becomes the AQI. AQI values are currently calculated for the center of Helsinki and
for typical suburban areas. 相似文献
888.
/ Recreation satisfaction is a complex psychological construct that is difficult to define and measure. Recent approaches suggest that overall satisfaction may be a function of multiple satisfactions derived from specific elements of a recreation experience such as the situational characteristics of a recreation setting or activity and the recreationist's subjective evaluations of the experience. In this paper, a path model of whitewater boating satisfaction was tested using data from a survey of 1210 commercial and 111 private boaters on the Cheat River of West Virginia. The pathmodel included the direct and mediating effects of situational variables and the subjective evaluations of boaters and explained 52% and 54% of the variation in satisfaction of commercial and private boaters, respectively. Factors related to the satisfaction of both groups included a composite variable representing opportunities for challenge, excitement, and skill testing on the river trip; water flow levels; and crowding perceptions. In combination, water flow level and boater's perceptions of opportunities to experience challenge, excitement, and test boating skills were the most important variables for explaining satisfaction of both groups. Additional factors affecting commercial, but not private, boater satisfaction included the motive of escaping the usual demands of life and a social interaction variable. Among private boaters, perceptions of the environmental conditions also contributed to overall satisfaction. The results support the multiple satisfaction approach of previous research. River management implications are discussed.KEY WORDS: Whitewater; River recreation; Satisfaction 相似文献
889.
Miles L. Burnett 《Environmental management》1998,22(2):213-224
/ In 1990, the United States officially entered the era of pollution prevention with passage of the Pollution Prevention Act. This paper analyzes EPA's implementation of the Pollution Prevention Act from its passage in 1990 to the present. It examines the barriers EPA must overcome if it is to effectively integrate pollution prevention into its existing regulatory structure, including impediments created by statutory and organizational structure, the existing relationship between EPA and the groups it regulates, the fragmented implementation scheme of national environmental regulation, the balancing of conflicting demands advanced by powerful interests, industry's economic and technical concerns, and institutional inertia. It also examines issues such as industry commitment, the limits of prevention, and measurement concerns. The findings suggest that EPA's efforts at shifting to a pollution prevention regulatory ethic that holds primacy over pollution control are mixed. Its organizational structure, statutory authority, and incentives system still reflect a single-medium pollution control focus, appropriations for pollution prevention programs and activities are paltry compared to traditional pollution control programs, and participation in the program is voluntary. Yet, the findings also point to some promising programs that are working to institutionalize a pollution prevention regulatory ethic, and many states appear very committed to the concept.KEY WORDS: Pollution prevention; Source reduction; Pollution control; Alternative regulatory design; Barriers to implementation 相似文献
890.
Macroinvertebrate Community Structure Along the Longitudinal Gradient of an Agriculturally Impacted Stream 总被引:7,自引:0,他引:7
/ Lapwai Creek, an agriculturally impacted stream in northern Idaho, was sampled seasonally over a two-year period to determine if macroinvertebrate community composition changed along the longitudinal gradient and if changes followed predictions of the river continuum concept. Possible relationships between changes in food resource availability and community structure were also examined. Benthic invertebrates were collected at eight locations along the longitudinal gradient of Lapwai Creek using a Hess sampler. Random skewer analysis suggested there was no longitudinal gradient for either number of individuals or functional feeding group composition. Cluster analysis revealed that all locations, excluding a site receiving outflow from a small, eutrophic reservoir, had a similar community structure, further suggesting that invertebrate community composition remained consistent along the longitudinal gradient of the stream. The community was dominated at all sites, excluding the site below the reservoir, by functionalgrazers. Shredders were rare throughout Lapwai Creek, even in areas where healthy riparian vegetation still remained. Studies of other streams within the drainage basin show that many species found in the upper reaches of these streams, where agricultural impacts are low, were absent throughout the length of Lapwai Creek. Data collected concurrently with macroinvertebrates indicated that the input, storage, and transport of particulate organic matter was low throughout the stream, whereas periphyton abundance was high. The absence of longitudinal changes, despite flowing through three distinct geomorphological regions, and the grouping of all sites except one by cluster analysis for both dominant taxa and functional feeding groups suggest that agricultural alteration has influenced community structure of Lapwai Creek, resulting in a relatively homogeneous assemblage of macroinvertebrates capable of tolerating agricultural nonpoint source pollution. Additional support for this hypothesis is the high abundance of one food source, periphyton, and the small quantities of terrestrially derived organic matter. The abundance of the former and the rarity of the latter can be attributed to alteration of the drainage basin resulting from agricultural activities through inputs of fertilizers that generated high nutrient concentrations and the removal of riparian vegetation to clear more land for agriculture and provide increase access to the stream.KEY WORDS: Agriculture; Longitudinal patterns; Macroinvertebrates; Nonpoint source; River continuum 相似文献