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181.
Differences between scientist and policy-maker response types and times, or the “how” and “when” of action, constrain effective
water resource management in suburbanizing watersheds. Policy-makers are often rushed to find a single policy that can be
applied across an entire, homogeneous, geopolitical region, whereas scientists undertake multiyear research projects to appreciate
the complex interactions occurring within heterogeneous catchments. As a result, watershed management is often practiced with
science and policy out of synch. Meanwhile, development pressures in suburban watersheds create changes in the social and
physical fabric and pose a moving target for science and policy. Recent and anticipated advances in the scientific understanding
of urbanized catchment hydrology and pollutant transport suggest that management should become increasingly sensitive to spatial
heterogeneities in watershed features, such as soil types, terrain slopes, and seasonal watertable profiles. Toward this end,
policy-makers should encourage funding scientific research that characterizes the impacts of these watershed heterogeneities
within a geopolitical zoning and development framework. 相似文献
182.
Public involvement is recognized by legislators, practitioners, academics, nongovernment organizations and, most importantly,
affected communities, as a fundamental component of environmental assessment (EA) processes. Experience with public involvement
in EA has proven, however, that despite good intentions, there are formidable barriers to participation. This paper examines
this issue, largely through a case study of a new Can$120 million hog processing facility in Brandon, Canada. Primary data
were collected in three phases, using multiple methodological techniques, including document review, qualitative interviews,
and a mail questionnaire. Results included a diverse list of barriers to involvement, grouped into two primary categories:
structural and individual. A significant structural barrier was a belief that becoming involved would not make a difference
as the ultimate decision in the case was a foregone conclusion. An important individual barrier was that people did not know
about the EA. Finally, the results indicated that lack of interest was not an important reason for nonparticipation. 相似文献
183.
Power line rights-of-way provide a major portion of the shrub habitat in New York. Since this habitat type is on the decline,
many of the birds dependent on shrub habitat are also declining. The methods used to control right-of-way vegetation could
therefore have serious impacts on several birds of conservation concern. Since New York is increasingly using selective herbicide
treatments in vegetation management, we sought to investigate the potential impacts of these treatments on nesting birds.
The study looked at plots in two adjacent rights-of-way before and after a selective herbicide treatment in one of the rights-of-way.
We investigated three bird species: alder flycatcher (Empidonax alnorum), chestnut-sided warbler (Dendroica pensylvanica), and gray catbird (Dumetella carolinensis). All three species exhibited a preference for shrub vegetation around nest sites. The selective herbicide treatment did
not significantly decrease that shrub vegetation, and neither the density nor the nesting success of the three species declined
following the treatment. We conclude that selective herbicide vegetation management encourages the development of shrub habitat
without negatively impacting the birds nesting in the habitat. 相似文献
184.
Mineralogical compositions and their spatial distributions are important initial conditions for reactive transport modeling. However, popular Kd-based "reactive" transport models only require contaminant concentrations in the pore fluids as initial conditions, and minerals implicitly represent infinite sources and sinks in these models. That situation results in a general neglect of mineralogical characterization in site investigations. This study uses a coupled multi-component reactive mass transport model to predict the natural attenuation of a ground water plume at a uranium mill tailings site in western USA. Numerous ground water geochemistry data are available at this site, but mineralogical data are sketchy. Even given the well-defined pore fluid chemistry, variations of secondary mineral species and mineral abundances in the aquifer resulted in significantly different modeling outcomes. Results show that the amount of calcite in the aquifer determines the distances of plume migration. The possible presence of jurbanite, an aluminum sulfate phase, can store acidity temporarily but cause more severe contamination on a later date. The surfaces of iron oxyhydroxides can store significant amounts of sulfate and protons and serve as a second source for prolonged contamination. These simulations under field conditions illustrate that mineralogical compositions are an essential requirement for accurate prediction of contaminant fate and transport. 相似文献
185.
The purpose of this research was to explore the concept of an environmental racism claim through the use of several environmental
management tools. The EPAs Toxics Release Inventory, Cumulative Exposure Project, and the Los Angeles County Department of
Health Services' Hot Zone Census Tract Assessment were combined with racial and socioeconomic data to test claims that minorities
in South Central Los Angeles are disproportionately exposed to environmental lead. Multivariate analysis indicated that race
is strongly associated with the number of cases of elevated blood lead levels in South Central, irrespective of poverty status.
Proximity to point sources, a common focal point for studies of environmental racism, was not a contributing factor to health
outcomes. Proximity to transportation corridors was consistently the strongest indicator of environmental lead exposure, while
median home values were significantly and positively related to elevated blood lead levels. Implications for environmental
justice advocates and social and environmental scientists are discussed. 相似文献
186.
It is now widely accepted that members of the public should be involved in environmental decision-making. This has inspired
many to search for principles that characterize good public participation processes. In this paper we report on a study that
identifies discourses about what defines a good process. Our case study was a forest planning process in northern New England
and New York. We employed Q methodology to learn how participants characterize a good process differently, by selecting, defining,
and privileging different principles. Five discourses, or perspectives, about good process emerged from our study. One perspective
emphasizes that a good process acquires and maintains popular legitimacy. A second sees a good process as one that facilitates
an ideological discussion. A third focuses on the fairness of the process. A fourth perspective conceptualizes participatory
processes as a power struggle—in this instance a power play between local landowning interests and outsiders. A fifth perspective
highlights the need for leadership and compromise. Dramatic differences among these views suggest an important challenge for
those responsible for designing and carrying out public participation processes. Conflicts may emerge about process designs
because people disagree about what is good in specific contexts. 相似文献
187.
To evaluate the accounts of local fishermen, Landsat TM images (1986, 1993, 1999) were examined to assess potential losses
in the mangrove forests of the Teacapán–Agua Brava lagoon system, Mexico. A binary change mask derived from image differencing
of a band 4/3 ratio was employed to calculate any changes within this forested wetland. The results indicate that by 1986
approximately 18% (or 86 km2) of the mangrove area under study was either dead or in poor condition. The majority of this damage had occurred in the eastern
section of the Agua Brava basin, which coincides, with the reports of the elderly fishermen. Examination of aerial photographs
from 1970 revealed no adverse impacts in this area and would suggest, as postulated by the fishermen and other scientists,
that modifications in environmental conditions following the opening of a canal, Cuautlá canal, in 1972 may have initiated
the large-scale mortality. Although these areas of impact are still developing, the results from the satellite data indicate
that the majority of the more recent changes are occurring elsewhere in the system. Obvious in the 1999 satellite data, but
not so in the 1993, are large areas of mangrove degradation in the northern section of the Teacapán region. In the Agua Brava
basin, the more recent transformations are appearing on the western side of the basin. Since long-term records of environmental
conditions are absent, it is difficult to determine why these latest changes are occurring or even if the earlier losses were
the result of the canal. Potential agents of change that have recently been observed include a hurricane, a second canal,
and the uncontrolled expansion of the Cuautlá canal since 1994. 相似文献
188.
Lake Erie water quality has improved dramatically since the degraded conditions of the 1960s. Additional gains could be made,
but at the expense of further investment and reductions in fishery productivity. In facing such cross-jurisdictional issues,
natural resource managers in Canada and the United States must grapple with conflicting objectives and important uncertainties,
while considering the priorities of the public that live in the basin. The techniques and tools of decision analysis have
been used successfully to deal with such decision problems in a range of environmental settings, but infrequently in the Great
Lakes. The objective of this paper is to illustrate how such techniques might be brought to bear on an important, real decision
currently facing Lake Erie resource managers and stakeholders: the choice of new phosphorus loading targets for the lake.
The heart of our approach is a systematic elicitation of stakeholder preferences and an investigation of the degree to which
different phosphorus-loading policies might satisfy ecosystem objectives. Results show that there are potential benefits to
changing the historical policy of reducing phosphorus loads in Lake Erie. 相似文献
189.
The production of large quantities of wastes globally has created a commercial activity involving the transfrontier shipments
of hazardous wastes, intended to be managed at economically attractive waste-handling facilities located elsewhere. In fact,
huge quantities of hazardous wastes apparently travel the world in search of “acceptable” waste management facilities. For
instance, within the industrialized countries alone, millions of tonnes of potentially hazardous waste cross national frontiers
each year on their way for recycling or to treatment, storage, and disposal facilities (TSDFs) because there is no local disposal
capacity for these wastes, or because legal disposal or reuse in a foreign country may be more environmentally sound, or managing
the wastes in the foreign country may be less expensive than at home. The cross-boundary traffic in hazardous wastes has lately
been under close public scrutiny, however, resulting in the accession of several international agreements and laws to regulate
such activities. This paper discusses and analyzes the most significant control measures and major agreements in this new
commercial activity involving hazardous wastes. In particular, the discussion recognizes the difficulties with trying to implement
the relevant international agreements among countries of vastly different socioeconomic backgrounds. Nonetheless, it is also
noted that global environmental agreements will generally be a necessary component of ensuring adequate environmental protection
for the world community—and thus a need for the careful implementation of such agreements and regulations. 相似文献
190.
The Concept of Habitat Diversity Between and Within Ecosystems Applied to River Side-Arm Restoration 总被引:3,自引:0,他引:3
Amoros C 《Environmental management》2001,28(6):805-817
Since returning an ecosystem to its pristine state may not be realistic in every situation, the concept of habitat diversity is proposed to help decision-makers in defining realistic restoration objectives. In order to maintain habitat diversity and enhance the long-term success of restoration, process-oriented projects should be preferred to species-oriented ones. Because the hydrogeomorphological processes that influence biodiversity operate at different spatiotemporal scales, three scales are considered: river sectors, floodplain waterbodies, and mesohabitats within each waterbody. Based on a bibliographical review, three major driving forces are proposed for incorporation into the design of restoration projects: (1) flow velocity and flood disturbances, (2) hydrological connectivity, and (3) water supply. On the sector scale, increased habitat diversity between waterbodies can be achieved by combining various intensities of these driving forces. On the waterbody scale, increased habitat diversity within the ecosystem can be achieved by varying water depth, velocity, and substrate. The concept is applied to a Rhône River sector (France) where three terrestrialized side arms will be restored. Two were designed to be flood scoured, one having an additional supply of groundwater, the other being connected to the river at both ends. The third cannot be scoured by floods because of upstream construction and would be supplied by river backflow through a downstream connection. Habitat diversity within the ecosystem is exemplified on one side arm through the design of a sinuous pathway combined with variation of water depth, wetted width, and substrate grain size. Self-colonization of the side arms is expected owing to the restoration of connectivity to upstream sources of potential colonizers. 相似文献