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More than 50 years of research, development, manufacture, and testing of nuclear weapons at Department of Energy (DOE) sites has left a legacy of on-site contamination that often spreads to surrounding areas. Despite substantial cleanup budgets in the last decade, the DOE's top-to-bottom review team concluded that relatively little actual cleanup has been accomplished, although milestones have been met and work packages completed. Rather than solely use regulatory constraints to direct cleanup, many people have suggested that human and ecological health should guide long-term stewardship goals of DOE-managed sites. The main questions are how ecological and human health considerations should be applied in deciding the extent of cleanup that contaminated sites should receive and how near-term and longer run considerations of costs and benefits should be balanced as cleanup decisions are made. One effort to protect ecological integrity is the designation of the largest sites as National Environmental Research Parks (NERPs). Recently, the Competitive Enterprise Institute (CEI) suggested isolating and conserving DOE sites as a policy priority because of their rich ecological diversity. A more effective long-term stewardship approach for former nuclear weapons complex sites may emerge if the guiding principles are to (1) reduce risks to human and ecological health, (2) protect cultural traditions, and (3) lower short- and long-term cleanup and remediation costs. A “net benefits” perspective that takes both near- and longer-term costs and consequences into account can help illuminate the trade-offs between expensive cleanup in the near term and the need to assure long-term protection of human health, cultural values, and high levels of biodiversity and ecological integrity that currently exist at many DOE sites.  相似文献   
133.
Abstract: Tropical forests dominated by only one or two tree species occupy tens of millions of hectares in Ammonia In many cases, the dominant species produce fruits, seeds, or oils of economic importance. Oligarchic (Gr. oligo = few, archic = dominated or ruled by) forests of six economic species, i. e., Euterpe oleracea, Grias peruviana, Jessenia bataua, Mauritia flexuosa, Myrciaria dubia, and Orbignya phalerata, were studied in Brazil and Peru Natural populations of these species contain from 100 to 3,000 conspecific adult trees/ha and produce up to 11.1 metric tons of fruit/hd/yr. These plant populations are utilized and occasionally managed, by rural inhabitants in the region. Periodic fruit harvests, if properly controlled have only a minimal impact on forest structure and function, yet can generate substantial economic returns Market-oriented extraction of the fruits produced by oligarchic forests appears to represent a promising alternative for reconciling the development and conservation of Amazonian forests.  相似文献   
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Abstract: In 1987, a proposal was made to introduce channel catfish (Ictalurus punctatus) into New Zealand for aquaculture. An environmental impact assessment in support of the proposal incorporated details of channel catfish biology, its value to people, diseases, the history of introductions elsewhere, and possible impacts on New Zealand biota should the species become established in the wild. Although information on the environmental impacts of channel catfish introduced to other countries was limited and inadequate for assessing potential effects on freshwater ecosystems in New Zealand, a permit was granted to import fertilized eggs. These were hatched in quarantine, and subject to the favorable outcome of environmental trials were to be released for aquaculture. Subsequently, the requirement for trials was abandoned and instead an independent, two-man review team (the authors) was appointed to advise the Minister of Fisheries on whether the environmental risk posed by channel catfish was acceptable. The team considered the impact assessment and additional submissions from interested parties. The team concluded that there was a high probability that fish would escape and that they would be capable of breeding and growing in a wide range of freshwater environments throughout much of New Zealand. Because channel catfish are omnivorous, they would probably prey on at least some native fish species and introduced salmonids, invertebrates including freshwater crayfish, and aquatic macrophytes. Competition to the detriment of other fishes was also considered likely. Furthermore, the low species diversity and ecological simplicity of fish communities in New Zealand could allow channel catfish opportunities not found within their natural range, as in parts of western North America where they have had significant impacts on freshwater communities. Because the evidence indicated that one or more valued species was likely to suffer a decline in abundance or distribution if channel catfish were introduced, the review team recommended that the environmental risk posed by the fish was unacceptable. The recommendation was accepted by the Minister of Fisheries and all the channel catfish held in quarantine were destroyed. This case clearly demonstrated weaknesses in the importation procedure in New Zealand and subsequently some changes have been made. In general, we recommend a four-step importation procedure comprising (1) environmental impact assessment, (2) publicity, (3) independent review, and (4) implementation. We suggest that the second step is most crucial.  相似文献   
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The Consistency of Extinction Risk Classification Protocols   总被引:1,自引:0,他引:1  
Abstract:  Systematic protocols that use decision rules or scores are seen to improve consistency and transparency in classifying the conservation status of species. When applying these protocols, assessors are typically required to decide on estimates for attributes that are inherently uncertain. Input data and resulting classifications are usually treated as though they are exact and hence without operator error. We investigated the impact of data interpretation on the consistency of protocols of extinction risk classifications and diagnosed causes of discrepancies when they occurred. We tested three widely used systematic classification protocols employed by the World Conservation Union, NatureServe, and the Florida Fish and Wildlife Conservation Commission. We provided 18 assessors with identical information for 13 different species to infer estimates for each of the required parameters for the three protocols. The threat classification of several of the species varied from low risk to high risk, depending on who did the assessment. This occurred across the three protocols investigated. Assessors tended to agree on their placement of species in the highest (50–70%) and lowest risk categories (20–40%), but there was poor agreement on which species should be placed in the intermediate categories. Furthermore, the correspondence between the three classification methods was unpredictable, with large variation among assessors. These results highlight the importance of peer review and consensus among multiple assessors in species classifications and the need to be cautious with assessments carried out by a single assessor. Greater consistency among assessors requires wide use of training manuals and formal methods for estimating parameters that allow uncertainties to be represented, carried through chains of calculations, and reported transparently.  相似文献   
138.
目前在中国,为环境保护目的建立“公益诉讼”制度的提法正吸引着人们极大的兴趣。特别是在2005年12月。国务院作出“关于落实科学发展观加强环境保护的决定”之后。“决定”中把推动环境公益诉讼作为长期改善中国环境保护体制的主要措施之一。就中国的公益诉讼应该采取哪种形式的问题。政府官员、学者、律师和NGO对此争论颇多。美国环境诉讼中采取的“公民诉讼(citizen suit)”制度作为诸多途径中的一种受到了特别关注。  相似文献   
139.
Abstract: Urban development is the most common form of land conversion in the United States. Using a before–after control‐impact study design, we investigated the effects of urbanization on larval and adult stages of southern two‐lined salamanders (Eurycea cirrigera) and northern dusky salamanders (Desmognathus fuscus). Over 5 years, we estimated changes in occupancy and probabilities of colonization and survival in 13 stream catchments after urbanization and in 17 catchments that were not urbanized. We also examined effects of proportion of urbanized area in a catchment and distance of the salamander population to the nearest stream on probabilities of colonization and survival. Before urbanization, adult and larval stages of the two salamander species occupied nearly all surveyed streams, with occupancy estimates ranging from 1.0 to 0.78. Four years after urbanization mean occupancy of larval and adult two‐lined salamanders had decreased from 0.87 and 0.78 to 0.57 and 0.39, respectively. Estimates of mean occupancy of larval northern dusky salamanders decreased from 1.0 to 0.57 in urban streams 4 years after urbanization; however, adult northern dusky salamander occupancy remained close to 1.0 in urban streams over 5 years. Occupancy estimates in control streams were similar for each species and stage over 5 years. Urbanization was associated with decreases in survival probabilities of adult and larval two‐lined salamanders and decreases in colonization probabilities of larval dusky salamanders. Nevertheless, proportion of impervious surface and distance to nearest stream had little effect on probabilities of survival and colonization. Our results imply that in the evaluation of the effects of urbanization on species, such as amphibians, with complex life cycles, consideration of the effects of urbanization on both adult and larval stages is required.  相似文献   
140.
Abstract: Many of the skills and resources associated with botanic gardens and arboreta, including plant taxonomy, horticulture, and seed bank management, are fundamental to ecological restoration efforts, yet few of the world's botanic gardens are involved in the science or practice of restoration. Thus, we examined the potential role of botanic gardens in these emerging fields. We believe a reorientation of certain existing institutional strengths, such as plant‐based research and knowledge transfer, would enable many more botanic gardens worldwide to provide effective science‐based support to restoration efforts. We recommend botanic gardens widen research to include ecosystems as well as species, increase involvement in practical restoration projects and training practitioners, and serve as information hubs for data archiving and exchange.  相似文献   
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