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71.
在资料调研的基础上,通过对美国、欧洲和日本机动车污染物排放限值的严化过程分析,讨论了我国严化机动车排放标准的紧迫性。该文建议我国应根据当前对车辆排污控制的需求,车用无铅汽油的发展进程,以及已具备的排污控制技术条件,参照欧洲91/441/EEC排放规程,尽快制定适应我国轻型车辆发展和环境保护战略要求的轻型车污染排放标准。 相似文献
72.
The ability of Section 404 of the Clean Water Act to act as an effective, efficient, and equitable land-use planning tool
was assessed through a survey of Section 404 permits in Wisconsin. In a six-month period of permitting, the 404 program reduced
wetland losses in the state by 15%. Several factors were examined that may affect permit decisions; these factors are water
dependency, alternatives, project type, wetland type, and public or agency comments. Only the water dependency of the project
had a statistically significant effect on permit decisions, although development projects that were perceived to provide public
good were more likely to be permitted. Environmental impacts of a proposed fill project were not adequately assessed in any
of the permit decisions. Because of the way Section 404 is interpreted and administered by the US Army Corps of Engineers,
increasing net benefits and achieving an equitable distribution of those benefits is difficult. The corps does not perform
any functional evaluations of wetlands nor do they attempt to measure economic value and environmental impacts. In addition,
the 404 review process is, in effect, inaccessible to the public. The de facto interpretations of the Section 404 regulations
and a lack of program funding and trained personnel all contribute to the program's ineffectiveness. 相似文献
73.
74.
This article is an extension and application of Preston and Bedford (1988), especially as relevant to bottomland hardwood (BLH) forests of the southeastern United States. The most important cumulative effects in BLH forests result from incremental forest loss (nibbling) and from synergisms resulting from this nibbling. Present regulatory procedures are ineffective in preventing incremental forest loss because of the focus on permit site evaluation, rather than on large landscapes. Three examples are given to illustrate the need for a landscape focus. This perspective requires preplanning or goal-setting to establish the desired conditions to be maintained in the regulated landscape unit.Spatial and temporal scales are of particular concern for landscape impact assessment. Natural drainage basins of about 106 ha, as identified in U.S. Geological Survey hydrologic units, appear to appropriate spatial units: they have fairly natural boundaries, are of sufficient size to support populations of large, wide-ranging mammals, and are compatible with existing maps and databases. Time scales should be sufficiently long to include recovery of wetland ecosystems from human perturbations. In practice, available data sets limit analysis to no longer than 50 yr. Eight indicators of landscape integrity are identified, based on generally available long-term data sets.Linking technical information concerning cumulativeeffects on landscapes to the evaluation of cumulativeimpacts in regulatory programs (i.e., goal-setting) is a serious issue that can benefit from precedents found in the field of epidemiology, and in the establishment of clean air and clean water standards. We suggest that reference data sets must be developed, relating BLH function to structure (forest area). These can be used to set goals for individual watersheds, based on their present conditions and the magnitude and type of perceived development pressures. Thus the crucial steps in establishing a successful program appear to be (1) establish study unit boundaries, (2) assess the condition of study unit landscape integrity, (3) set goals, and (4) consider the impacts of permit proposals with both goals and the existing condition of the study unit landscape in mind. 相似文献
75.
Melaleuca quinquenervia, is expanding rapidly throughout seasonally wet areas of southern Florida (USA), including the littoral zone of Lake Okeechobee.
Natural resource managers are concerned that a lower lake level regulation schedule under consideration for Lake Okeechobee,
while potentially beneficial to overall ecosystem health, might increase the rate of Melaleuca expansion. To investigate this possibility, Melaleuca saplings (harvested from the littoral zone) and 7-week-old seedlings (grown from harvested seeds) were subjected to various
hydroperiod treatments in replicated mesocosms. Hydroperiod treatments were selected based on a simulation of historical water
level variations. Saplings grew taller under longer hydroperiods with fluctuating water levels, including periods of submersion.
Time since germination affected the response of seedlings to inundation. Submersed 7-week-old seedlings grew slower and had
less biomass than submersed 12-week-old seedlings, yet mortality was low at both ages. Melaleuca's plasticity allows it to adapt to hypoxic, aquatic conditions by means of aquatic heterophylly and adventitious roots. Algae
and drought also increased mortality. Based on faster growth of Melaleuca under longer hydroperiods and its adaptability to seasonal flooding, a lower lake regulation schedule may not stimulate its
expansion. Therefore, water levels should not be manipulated only to control Melaleuca. Control of Melaleuca should continue using current practices such as manual removal or chemical treatment. 相似文献
76.
77.
面对国际社会知识与经济的迅猛发展,特别是伴随我国自主创新、努力掌握环境保护核心与关键技术以及知识产权保护战略决策的实施,国际环境技术转移的知识产权保护法律调整问题也不断扩大其内涵。针对我国运用知识产权参与国际竞争的能力与经验的欠缺,本文从多方位关注和介绍国际环境技术转移中知识产权保护的有关法律规制,以对我国重构国际环境技术转移知识产权保护体系有所裨益。 相似文献
78.
79.
Thomas Hruby 《Environmental management》2009,43(6):1219-1243
Regulators protecting riparian areas need to understand the integrity, health, beneficial uses, functions, and values of this
resource. Up to now most methods providing information about riparian areas are based on analyzing condition or integrity.
These methods, however, provide little information about functions and values. Different methods are needed that specifically
address this aspect of riparian areas. In addition to information on functions and values, regulators have very specific needs
that include: an analysis at the site scale, low cost, usability, and inclusion of policy interpretations. To meet these needs
a rapid method has been developed that uses a multi-criteria decision matrix to categorize riparian areas in Washington State,
USA. Indicators are used to identify the potential of the site to provide a function, the potential of the landscape to support
the function, and the value the function provides to society. To meet legal needs fixed boundaries for assessment units are
established based on geomorphology, the distance from “Ordinary High Water Mark” and different categories of land uses. Assessment
units are first classified based on ecoregions, geomorphic characteristics, and land uses. This simplifies the data that need
to be collected at a site, but it requires developing and calibrating a separate model for each “class.” The approach to developing
methods is adaptable to other locations as its basic structure is not dependent on local conditions. 相似文献