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661.
Liane Nakamura Stephen M. Born 《Journal of the American Water Resources Association》1993,29(5):807-821
ABSTRACT: Since the 1970s, there has been extensive experimentation with new approaches to water and land resources management at the state and local levels. There is a critical need to document, assess, and synthesize lessons learned from the nation's recent experience with subnational institutional changes in environmental management. This paper examines institutional changes aimed at more integrated water and related resources management at the substate level of government. We describe innovative institutional changes in a case study of Dane County, Wisconsin, and assess the implementation and preliminary consequences of these changes. Dissatisfaction with watershed and lake management results and perceptions of institutional inadequacy led to significant changes in the structure and rules for county resources management. A new entity was created to focus watershed management responsibilities. The scope of authority and powers were expanded. However, these changes all occurred within the framework of a general purpose unit of government. The new institutional arrangements have achieved a number of milestones, although it is premature to fully assess resource outcomes. The substantive changes, implementation tactics, and overall experience in Dane County's reforms - especially with regard to addressing intergovernmental tensions and decentralized management, limited authorities and funding, and public and constituency support - have useful implications for other substate efforts at more comprehensive and integrated water resources management. 相似文献
662.
663.
The USA and Canada are each considering measures to reduce general exposure to asbestos. Product bans and workplace exposure rules may each reduce general exposure by reducing domestic asbestos demand. The effectiveness of demand-reducing measures will depend upon the elasticity of asbestos supply to the domestic market. This paper provides calculations of this elasticity for three fibre grade groupings, using a framework that recognizes international trade in asbestos and the joint product nature of most asbestos fibre production. The results suggest that reductions in North American demand result in relatively substantial changes in asbestos use but very small changes in price. 相似文献
664.
James W. Mercer Barry H. Lester Stephen D. Thomas Ronald L. Bartel 《Journal of the American Water Resources Association》1986,22(6):951-965
ABSTRACT: Volusia County, in east central Florida, comprises approximately 1,200 square miles situated between the St. Johns River and the Atlantic Ocean. Most of the County is underlain by a three-aquifer system. Population centers in Volusia County, which create a large water demand, are located near the coast. Saltwater intrusion into the ground water near these population centers has led to relocation of public water supply wells further inland. Regional management of the county's water resources commissioned construction of a three-dimensional computer model of the county. Predevelopment simulation results were used as initial conditions for the development simulations, which included well discharge data. The predevelopment model calibration consisted of reproducing field-determined potentiometric surfaces. As part of the calibration process, sensitivity analyses were performed on boundary conditions, recharge rates, permeability, and leakage properties. Results of the model study indicate the utility of computer models as a management tool for the complex ground-water system in Volusia County. 相似文献
665.
666.
S. Lawrence. Dingman Stephen C. Lawlor 《Journal of the American Water Resources Association》1995,31(2):243-256
ABSTRACT: This study systematically develops, validates, and compares alternative approaches for estimating quantiles of the distribution of annual minimum seven-day-average flows (7Q) for ungaged, unregulated drainage basins in New Hampshire and Vermont via regression on map-measurable drainage-basin characteristics. At 47 gaging stations in the region, the hypotheses that 7Q is log normally distributed and serially independent are not rejected, and the regional average spatial correlation is R= 0.35. Step-forward examination of a suite of potential predictor variables revealed that logarithm of drainage area, mean elevation, and fraction of basin covered with sand and gravel deposits are significant predictors of quantiles of 7Q. The regression equations were incorporated into four approaches to estimate the 7Q value with a nonexceedence probability of 0.1, 7Q10. Comparison of observed values and values predicted via a delete-one jackknife resampling validation indicates that one of the approaches gives estimates with acceptable bias and precision, with median relative error of 33 percent and prediction error of 64 percent. This is equivalent to the precision obtainable with only one to two years of gaging records. In spite of this limited precision, the approaches developed herein are useful for predicting 7Q quantiles at ungaged sites. Further improvement in precision will likely be possible only by exploiting the spatial correlation of annual 7Q. 相似文献
667.
Stephen E. White David E. Kromm 《Journal of the American Water Resources Association》1995,31(4):715-727
ABSTRACT: A state-local partnership exists in Colorado and Kansas with respect to management of the High Plains aquifer. This paper examines 330 irrigators' attitudes about the locus-of-control for different management activities in the High Plains-Ogallala region. Local control was preferred by most irrigators. The local district was most supported for 19 active management activities, whereas the state was favored for eight specific activities, primarily research efforts and water rights administration. Eight activities that had the potential for restricting water use were rejected in that irrigators indicated that no agency should be involved. Kansas and Colorado exhibited statistically significant preference differences for only five management options. A significantly higher percentage of those irrigators who preferred local control believed in sustainable management of the aquifer and aggressive groundwater management, and that their district served their interests. 相似文献
668.
The 1980 Washington driving while intoxicated (DWI) law was evaluated to determine its impact on the subsequent driving behavior of persons convicted of DWI. The major provisions of this law were mandatory jail sentences for conviction of DWI and a change in the definition of DWI. The law made it illegal per se for a person to drive with a blood alcohol level of .10% or more. The law was intended to reduce the drunk driving and accidents of individuals convicted of DWI as well as deter such behavior among the general driving population. The study assessed the deterrence effect of the law on convicted DWI offenders. It was found that individuals convicted under the provisions of this law had higher accident rates and drunk driving recidivism rates than individuals convicted under the previous law. These increases suggest that mandatory jail sentences may fail to deter subsequent acts of drunk driving. It was concluded that alternative legal sanctions for DWI (such as license suspensions or revocations) may be sufficiently stringent to produce both general and specific deterrence of drunk driving. 相似文献
669.
John D. Orbell Hien V. Dao Lawrence N. Ngeh Stephen W. Bigger 《The Environmentalist》2007,27(1):175-182
The use of magnetic particles in environmental remediation and wildlife rehabilitation is currently under investigation at
Victoria University, in collaboration with the Phillip Island Research Centre, Victoria, Australia. Iron powder has been shown
to be very effective for the magnetic cleansing of feathers and plumage and is almost ideal for this purpose, being non-toxic,
a non-irritant and recyclable. Detailed investigations have demonstrated that by varying particle size, particle structure
and surface texture, the efficacy of oil removal from feathers and plumage can be successfully manipulated. In this regard,
it is possible to identify a grade of iron powder whereby, within experimental error, effectively 100% removal of a variety
of fresh contaminants from different matrices, including feathers, can be achieved. Our investigations have been extended
to the application of such particles to the successful removal of tarry and weathered/tarry contamination. The results of
these investigations have indicated that, for such contaminants, removals ranging from 97–99% may be achieved. Magnetic particle
technology may also be adapted for the screening of pre-conditioning agents that can further assist in the removal of tarry
and weathered/tarry contamination from feathers. These investigations suggest that magnetic particles could have an important
role to play in environmental remediation and wildlife rehabilitation as a clean and effective technology. 相似文献
670.
Kolja Rotzoll Aly I. El‐Kadi Stephen B. Gingerich 《Journal of the American Water Resources Association》2007,43(2):334-345
Abstract: In recent years the ground‐water demand of the population of the island of Maui, Hawaii, has significantly increased. To ensure prudent management of the ground‐water resources, an improved understanding of ground‐water flow systems is needed. At present, large‐scale estimations of aquifer properties are lacking for Maui. Seven analytical methods using constant‐rate and variable‐rate withdrawals for single wells provide an estimate of hydraulic conductivity and transmissivity for 103 wells in central Maui. Methods based on constant‐rate tests, although not widely used on Maui, offer reasonable estimates. Step‐drawdown tests, which are more abundantly used than other tests, provide similar estimates as constant‐rate tests. A numerical model validates the suitability of analytical solutions for step‐drawdown tests and additionally provides an estimate of storage parameters. The results show that hydraulic conductivity is log‐normally distributed and that for dike‐free volcanic rocks it ranges over several orders of magnitude from 1 to 2,500 m/d. The arithmetic mean, geometric mean, and median values of hydraulic conductivity are respectively 520, 280, and 370 m/d for basalt and 80, 50, and 30 m/d for sediment. A geostatistical approach using ordinary kriging yields a prediction of hydraulic conductivity on a larger scale. Overall, the results are in agreement with values published for other Hawaiian islands. 相似文献