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Increasing knowledge about the environment has brought about a better understanding of the complexity of the issues, and more information publicly available has resulted into a steady shift from centralized decision making to increasing levels of participatory processes. The management of that information, in turn, is becoming more complex. One of the ways to deal with the complexity is the development of tools that would allow all players, including managers, researchers, educators, stakeholders and the civil society, to be able to contribute to the information system, in any level they are inclined to do so. In this project, a search for the available technology for collaboration, methods of community filtering, and community-based review was performed and the possible implementation of these tools to create a general framework for a collaborative ??Water Quality Knowledge and Information Network?? was evaluated. The main goals of the network are to advance water quality education and knowledge; encourage distribution and access to data; provide networking opportunities; allow public perceptions and concerns to be collected; promote exchange of ideas; and, give general, open, and free access to information. A reference implementation was made available online and received positive feedback from the community, which also suggested some possible improvements.  相似文献   
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Male mating biases may be a widespread feature of animal mating systems but the phenotypic consequences of these biases are often unclear, especially in species for which the operational sex ratio is strongly male-biased. In Colias butterflies, male choice is thought to be one of the factors responsible for maintaining a female-limited genetic color polymorphism, in which female wings appear either yellowish-orange or white (the “alba” variant). Previous studies have indicated that alba females of two montane Colias species mate fewer times during their lifetime, possibly as a partial consequence of this bias. Here we report the results of a field study of male mating behavior and female mating biology in Colias eurytheme, conducted under conditions of high (summer) and low (spring) population densities. Our data show that despite a substantial male bias in approaching alba vs yellowish-orange phenotypes [ratios of 0.08:1 (spring) and 0.28:1 (summer)], alba females did not contain, on average, fewer or smaller spermatophores. Not one of the 308 sampled females was virgin, but females of both phenotypes accumulated spermatophores with age, and tended to carry fewer, larger spermatophores in spring. These data suggest that significantly fewer (or lighter) spermatophores need not be an obligatory or simple consequence of a strong male bias in butterflies. We discuss these findings in light of the known, thermally and density-dependent complexities of alba reproductive biology and of the Colias mating system.  相似文献   
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The distribution of Cd, Cu, Pb and Zn in above-ground parts of corn, small grains and pulse crops was investigated. Sampled parts included grain or seed, leaves, stems, silk and husks of corn-ears, rachilla and chaff of small grains and pods of bean plants. The distribution of these elements was variable and reflected, primarily, their relative mobility between plant parts including transfer into the grain. Generally, Zn and Cu were preferentially transferred into the seed or grain, while Cd and Pb were selectively excluded from these organs. For example, the distribution pattern in ears of corn was: for Cd, husks > silk > grain; for Zn, silk > grain > husks. The selective transfer of Zn and Cu into seed or grain, in contrast to the restricted movement of Cd and Pb into these organs, may be the result of selective absorption of Zn and Cu over Cd and Pb by vascular transfer cells within the plant's reproductive tissues. The effect of soil type on Cd, Cu, Pb and Zn levels in cereal grain or pulse seed was small compared to the differences found in the concentrations of these elements between different plant organs. Thus, grain and seed crops serve as natural barriers to the movement of the potentially toxic heavy metals, Cd and Pb, into the animal/human food chain, minimising their transfer from soils while conserving Zn and Cu levels in edible portions of these crops.Soil Scientist, USDA, Soil Conservation Service, Retired.  相似文献   
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Harnessing the economic potential of the oceans is key to combating poverty, enhancing food security, and strengthening economies. But the concomitant risk of intensified resource extraction to migratory species is worrying given these species contribute to important ecological processes, often underpin alternative livelihoods, and are mostly already threatened. We thus sought to quantify the potential conflict between key economic activities (5 fisheries and hydrocarbon exploitation) and sea turtle migration corridors in a region with rapid economic development: southern and eastern Africa. We satellite tracked the movement of 20 loggerhead (Caretta caretta) and 14 leatherback (Dermochelys coriacea) turtles during their postnesting migrations. We used movement‐based kernel density estimation to identify migration corridors for each species. We overlaid these corridors on maps of the distribution and intensity of economic activities, quantified the extent of overlap and threat posed by each activity on each species, and compared the effects of activities. These results were compared with annual bycatch rates in the respective fisheries. Both species’ 3 corridors overlapped most with longline fishing, but the effect was worse for leatherbacks: their bycatch rates of approximately 1500/year were substantial relative to the regional population size of <100 nesting females/annum. This bycatch rate is likely slowing population growth. Artisanal fisheries may be of greater concern for loggerheads than for leatherbacks, but the population appears to be withstanding the high bycatch rates because it is increasing exponentially. The hydrocarbon industry currently has a moderately low impact on both species, but mining in key areas (e.g., Southern Mozambique) may undermine >50 years of conservation, potentially affecting >80% of loggerheads, 33% of the (critically endangered) leatherbacks, and their nesting beaches. We support establishing blue economies (i.e., generating wealth from the ocean), but oceans need to be carefully zoned and responsibly managed in both space and time to achieve economic (resource extraction), ecological (conservation, maintenance of processes), and social (maintenance of alternative livelihood opportunities, alleviate poverty) objectives.  相似文献   
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ABSTRACT: The indexed sequential hydrologic modeling (ISM) methodology is utilized by the Western Area Power Administration as the basis for risk-based estimation of project-dependable hydropower capacity for several federally owned/operated projects. ISM is a technique based on synthetic generation of a series of overlapping short-term inflow sequences obtained directly from the historical record. The validity of ISM is assessed through application to the complex multireservoir hydropower system of the Colorado River basin for providing risk estimates associated with determination of reliable hydrogeneration capacity. Performance of ISM is compared with results from stochastically generated streamflow input data to the Colorado River Simulation System (CRSS). Statistical analysis and comparison of results are based on monthly power capacity, energy generation, and downstream water deliveries. Results indicate that outputs generated from ISM synthetically generated sequences display an acceptable correspondence with those obtained from stochastically generated hydrologic data for the Colorado River Basin.  相似文献   
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ABSTRACT: In Virginia, as in many states, priority to streamflow is held by riparian landowners who are predominantly agricultural users. The streamfiow may also have a high potential value to non-agricultural users who do not have riparian rights. The potential benefits of transferring streamfiow priority rights from agricultural to non-agricultural use were evaluated using simulation for an eastern Virginia watershed. Lowering irrigators' priority to streamflow reduced crop yields and irrigated returns in some years because of inadequate water supplies. However, the transfer of priorities increased the likelihood that the urban reservoir would be able to withdraw water from the stream without interruption. As a result, priority trades reduced the size of reservoir needed to meet a given water requirement by municipal users. The resulting savings in reservoir construction and maintenance costs more than offset the losses to irrigators. Net savings could be achieved even if the reservoir were required to release water periodically to maintain a minimum level of instream flow. The conclusion is that the state should encourage trading of access to streamflow in order to increase the use efficiency of streamfiows. Alternative means by which the state can facilitate water exchanges are discussed.  相似文献   
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/ The Council on Environmental Quality's (CEQ's) principal aims in implementing the National Environmental Policy Act (NEPA) are (1) to reduce paperwork, (2) to avoid delay, and most importantly (3) to produce better decisions that protect, restore, and enhance the environment. This paper presents four strategies for improving the NEPA process along with tools that can be used to implement each strategy. The tools include guidelines for project management and problem definition, tips for acquiring existing information and identifying issues of public concern, worksheets on how to identify and analyze potential impacts on resources, ideas for enhancing NEPA documents, and a NEPA process checklist. The tools can be used at various stages of the NEPA process and provide a toolbox of guidelines and techniques to improve implementation of the NEPA process by focusing the pertinent information for decisionmakers and stakeholders. KEY WORDS: National Environmental Policy Act; NEPA; Environmental impact assessment; Ecosystem management  相似文献   
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