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341.
M. A. Ferman G. T. Wolff N. A. Kelly 《Journal of the Air & Waste Management Association (1995)》2013,63(10):1074-1082
In order to investigate the nature and sources of regional haze, the General Motors mobile Atmospheric Research Laboratory was used in the summer of 1980 to monitor ambient air quality in the Shenandoah Valley of northern Virginia. On the average, 92% of the total light extinction was due to scattering by particles; the remainder was due to scattering by gases and absorption by gases and particles. Sulfate aerosols were the most Important visibility-reducing species. Averaging 55% of the fine participate mass, sulfates (and associated water) accounted for 78% of the total light extinction. The second most abundant fine particulate, accounting for 29% of the fine mass, was carbon—most of which was organic. Most of the remaining particulate mass and extinction were due to crustal materials. It is estimated that 78–86% of the total light extinction was caused by anthropogenic aerosol, most of which originated in major source areas of the midwest. 相似文献
342.
Martin A. Cohen P. Barry Ryan 《Journal of the Air & Waste Management Association (1995)》2013,63(3):328-329
Abstract Solutions are given for plume rise assuming a power-law wind speed profile in a stably stratified layer for point and finite sources with initial vertical momentum and buoyancy. For a constant wind speed, these solutions simplify to the conventional plume rise equations in a stable atmosphere. In a shear layer, the point of maximum rise occurs further downwind and is slightly lower compared with the plume rise with a constant wind speed equal to the wind speed at the top of the stack. If the predictions with shear are compared with predictions for an equivalent average wind speed over the depth of the plume, the plume rise with shear is higher than plume rise with an equivalent average wind speed. 相似文献
343.
William F. Ryan 《Journal of the Air & Waste Management Association (1995)》2016,66(6):576-596
Air quality forecasting is a recent development, with most programs initiated only in the last 20 years. During the last decade, forecast preparation procedure—the forecast rote—has changed dramatically. This paper summarizes the unique challenges posed by air quality forecasting, details the current forecast rote, and analyzes prospects for future improvements. Because air quality forecasts must diagnose and predict several pollutants and their precursors in addition to standard meteorological variables, it is, compared with weather forecasts, a higher-uncertainty forecast. Forecasters seek to contain the uncertainty by “anchoring” the forecast, using an a priori field, and then “adjusting” the forecast using additional information. The air quality a priori, or first guess, field is a blend of past, current, and near-term future observations of the pollutants of interest, on both local and regional scales, and is typically coupled with predicted air parcel trajectories. Until recently, statistical methods, based on long-term training data sets, were used to adjust the first guess. However, reductions in precursor emissions in the United States, beginning in the late 1990s and continuing to the present, eroded the stationarity assumption for the training data sets and degraded forecast skill. Beginning in the mid-2000s, output from modified numerical air quality prediction (NAQP) models, originally developed to test pollution control strategies, became available in near real time for forecast support. The current adjustment process begins with the analyses and postprocessing of individual NAQP models and their ad hoc ensembles, often in concert with new statistical techniques. The final adjustment step uses forecaster expertise to assess the impact of mesoscale features not resolved by the NAQP models. It is expected that advances in model resolution, chemical data assimilation, and the formulation of emissions fields will improve mesoscale predictions by NAQP models and drive future changes in the forecast rote.
Implications: Routine air quality forecasts are now issued for nearly all the major U.S. metropolitan areas. Methods of forecast preparation—the forecast rote—have changed significantly in the last decade. Numerical air quality models have matured and are now an indispensable part of the forecasting process. All forecasting methods, particularly statistically based models, must be continually calibrated to account for ongoing local- and regional-scale emission reductions. 相似文献
344.
Hjalmar Laudon Lenka Kuglerová Ryan A. Sponseller Martyn Futter Annika Nordin Kevin Bishop Tomas Lundmark Gustaf Egnell Anneli M. Ågren 《Ambio》2016,45(2):152-162
Protecting water quality in forested regions is increasingly important as pressures from land-use, long-range transport of air pollutants, and climate change intensify. Maintaining forest industry without jeopardizing sustainability of surface water quality therefore requires new tools and approaches. Here, we show how forest management can be optimized by incorporating landscape sensitivity and hydrological connectivity into a framework that promotes the protection of water quality. We discuss how this approach can be operationalized into a hydromapping tool to support forestry operations that minimize water quality impacts. We specifically focus on how hydromapping can be used to support three fundamental aspects of land management planning including how to (i) locate areas where different forestry practices can be conducted with minimal water quality impact; (ii) guide the off-road driving of forestry machines to minimize soil damage; and (iii) optimize the design of riparian buffer zones. While this work has a boreal perspective, these concepts and approaches have broad-scale applicability. 相似文献
345.
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347.
The strategic use of science in regional policy-making forums often assumes collaborative interactions between stakeholders. However, other types of stakeholder interactions are possible. This paper uses the ecology of games to frame an investigation into stakeholder participation in the policy networks for regional climate change planning for South East Queensland, Australia. We tracked organisational participation in policy forums between 2008 and 2012. We then used a novel bipartite network theoretical approach to identify participation by different types of organisations across shared multiple forums, which we argue prefaces: cooperation, collaboration, support or advocacy. Network analysis was then combined with semi-structured interviews to access how scientific information was utilised across the regional network. Our results suggest that stakeholder interactions were predominately used to advocate for organisational agendas. Advocacy artificially narrows the scope of possible policy options and represents a biased, selective use of information. While advocacy is an important part of policy process, as a counter balance, explicit efforts are needed to recurrently expand the scope of policy options. 相似文献
348.
Joseph H. Rustick David S. Kosson Steven L. Krahn Michael T. Ryan Craig H. Benson James H. Clarke 《补救:环境净化治理成本、技术与工艺杂志》2015,26(1):69-91
Near surface disposal facility design and management are examined and compared using a systems approach that defines facility performance as a function of three components (or subsystems): the disposal facility design (cover systems and bottom liners); the properties of the waste (waste composition, waste form and waste package); and the site‐specific environmental features (climate, geology, and hydrology). We report an evaluation of five DOE near surface disposal facility case studies, selected to provide a “representative” sample that included disposal sites with a range of waste and environmental characteristics across the DOE. The facilities selected were the Savannah River E‐Area Engineered Trenches, Hanford Integrated Disposal Facility, Idaho Radioactive Waste Management Complex, Oak Ridge Environmental Management Waste Management Facility, and Nevada National Security Site Area 5. ©2015 Wiley Periodicals, Inc. 相似文献
349.
Derek Armitage Rob C. de Lo? Michelle Morris Tom W. D. Edwards Andrea K. Gerlak Roland I. Hall Dave Huitema Ray Ison David Livingstone Glen MacDonald Naho Mirumachi Ryan Plummer Brent B. Wolfe 《Ambio》2015,44(5):353-366
In this policy perspective, we outline several conditions to support effective science–policy interaction, with a particular emphasis on improving water governance in transboundary basins. Key conditions include (1) recognizing that science is a crucial but bounded input into water resource decision-making processes; (2) establishing conditions for collaboration and shared commitment among actors; (3) understanding that social or group-learning processes linked to science–policy interaction are enhanced through greater collaboration; (4) accepting that the collaborative production of knowledge about hydrological issues and associated socioeconomic change and institutional responses is essential to build legitimate decision-making processes; and (5) engaging boundary organizations and informal networks of scientists, policy makers, and civil society. We elaborate on these conditions with a diverse set of international examples drawn from a synthesis of our collective experiences in assessing the opportunities and constraints (including the role of power relations) related to governance for water in transboundary settings. 相似文献