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661.
Andrew Simon Lauren Klimetz 《Journal of the American Water Resources Association》2008,44(5):1270-1283
Abstract: Sediment is listed as one of the leading causes of water‐quality impairments in surface waters of the United States (U.S.). A water body becomes listed by a State, Territory or Tribe if its designated use is not being attained (i.e., impaired). In many cases, the prescribed designated use is aquatic health or habitat, indicating that total maximum daily loads (TMDL) targets for sediment should be functionally related to this use. TMDL targets for sediment transport have been developed for many ecoregions over the past several years using suspended‐sediment yield as a metric. Target values were based on data from “reference” streams or reaches, defined as those exhibiting geomorphic characteristics of equilibrium. This approach has proved useful to some states developing TMDLs for suspended sediment, although one cannot conclude that if a stream exceeds the target range, the aquatic ecosystem will be adversely impacted. To address this problem, historical flow‐transport and sediment‐transport data from hundreds of sites in the Southeastern U.S. were re‐examined to develop parameters (metrics) such as frequency and duration of sediment concentrations. Sites determined as geomorphically stable from field evaluations and from analysis of gauging‐station records were sorted by ecoregion. Mean‐daily flow data obtained from the U.S. Geological Survey were applied to sediment‐transport rating relations to determine suspended‐sediment load for each day of record. The frequency and duration that a given concentration was equaled or exceeded were then calculated to produce a frequency distribution for each site. “Reference” distributions were created using the stable sites in each ecoregion by averaging all of the distributions at specified exceedance intervals. As with the “reference” suspended‐sediment yields, there is a broad range of frequency and duration distributions that reflects the hydrologic and sediment‐transport regimes of the ecoregions. Ecoregions such as the Mississippi Valley Loess Plains (#74) maintain high suspended sediment concentrations for extended periods, whereas coastal plain ecoregions (#63 and 75) show much lower concentrations. 相似文献
662.
Andrew Challinor 《Environmental Science & Policy》2009,12(4):453-465
In order for climate forecasting to be used in developing adaptation options, the forecasts should be able to affect decisions made by stakeholders in a manner that improves outcomes. The implications of this requirement for forecasting are presented under five headings: relevance, reliability, stakeholder engagement, holism and accuracy. These characteristics are elucidated through a particular focus on the use of ensemble climate and crop simulations. Resulting recommendations, including comments on mainstreaming and seamlessness, are described using the concepts of quality and value.Adaptation options can be developed using climate forecasts on a range of timescales, from days to decades. Using the five identified characteristics, two cases are presented: (i) options based on large-area seasonal crop yield forecasting are discussed, and (ii) genotypic adaptation based on long-term climate change projections is examined. For the latter, novel analyses of existing large-area groundnut simulations are used to assess the magnitude and spatial extent of the impact of changes in the mean and variability of temperature, rainfall and humidity. The genotypic properties required to ameliorate negative impacts are then assessed and compared to observations. The processes examined act on most annual crops, making the method, and to some extent the results, broadly relevant. 相似文献
663.
Governments make increasing use of private certification and testing infrastructures as an alternative for traditional regulatory arrangements in several areas including occupational safety and health (OSH).This research, commissioned by the Dutch Inspectorate for Work and Income (IWI), concerns an analysis of risk control of four certification and testing regimes (CTRs) in the Netherlands, three mandatory regimes and one non-mandatory regime. The aim was to create a better understanding of problems that may arise in the risk control through such regimes and to identify critical processes and factors that can affect the risk control process.The results of this research are reported in two papers in this special issue (see also Zwetsloot et al., this issue). This one presents an analysis of the risk control at the regulatory level, and its associated critical factors and processes. These critical factors are clustered in four essential processes: the regulatory choice for a CTR, the definition of requirements for the auditing or inspection regime, the certification and testing processes as such, and the processes needed for the self-correcting or learning capability of the CTR. Jointly, these factors and processes form a framework for both the design and the evaluation of such regimes. The case studies clearly demonstrate that these critical factors may undermine the effectiveness of such regulatory practices. We propose that a further development of our framework should be used in the (re)design process for proposed and existing CTRs, and in the process of independent evaluation of such regimes. 相似文献
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Mustafa Mokrech Susan Hanson Robert J. Nicholls Judith Wolf Mike Walkden Corentin M. Fontaine Sophie Nicholson-Cole Simon R. Jude James Leake Peter Stansby Andrew R. Watkinson Mark D. A. Rounsevell Jason A. Lowe Jim W. Hall 《Journal of Coastal Conservation》2011,15(3):325-335
The threat of sea-level rise and climate change means that coastal managers are being increasingly asked to make long-term assessments of potential coastal impacts and responses. In the UK, shoreline management planning (for flood and erosion hazards) and spatial planning now takes a 100 year perspective. An integrated framework across a wide range of physical and social issues is required for the assessment of coastal impacts and consequently for making sound management decisions. This paper provides an overview of the development of the ‘Tyndall Coastal Simulator’ including the underlying philosophy that is being followed. The Simulator is based on a series of linked climate models (CM) within a nested framework which recognises three spatial scales: (i) the global (GCM) scale; (ii) the regional scale and (iii) the Simulator Domain (a physiographic unit, such as a coastal sub-cell). Within the nesting, the larger scale provides the boundary conditions for the smaller scale. The models feed into each other and describe a range of relevant processes: sea level, tides, surges, waves, sediment transport and coastal morphology. Different climate scenarios, as well as the range of uncertainty, are being explored. Communication of results is a major issue and the Simulator includes a dedicated GIS-based user interface that allows a wide range of queries of model outputs. The paper demonstrates the possibility of developing an integrated framework that is multi-scale and capable of linking various models in order to simulate complex coastal processes and consequently allowing long-term assessments that are useful for setting future management plans. 相似文献
667.
J. M. Tom Pierce Andrew B. Nash Carole A. Clouter 《Environment, Development and Sustainability》2013,15(6):1645-1651
The UK Climate Change Act (CCA) mandates an 80 % reduction in CO2 emissions by 2050. It is estimated that 3.2 M tonnes pa CO2 results from travel-related NHS business. The acquisition of an electric bicycle to replace a car for both commuting and home visits allowed comparison of fuel use and CO2 emissions over a 4-year period. The switch to the use of the electric bicycle reduced the average annual petrol use by 329 l, the energy consumption by 3,140 kWh and the CO2 released by 748 kg a year. Wider adoption of electric bicycles in urban General Practice will contribute to the requirements of the CCA though to have a significant effect on the current estimated commuting-related carbon footprint of the NHS (0.76 MT pa) would require two-thirds of the workforce to abandon their cars in favour of electric bicycles. 相似文献
668.
Wiebke Saathoff Christina von Haaren René Dechow Andrew Lovett 《Regional Environmental Change》2013,13(4):825-841
Greenhouse gases (GHG) emissions from agricultural farming practice contribute significantly to European GHG inventories. For example, CO2 is emitted when grassland is converted to cropland or when peatlands are drained and cultivated. N2O emissions result from fertilization. Enabling farmers to reduce their GHG emissions requires sufficient information about its pressure–impact relations as well as incentives, such as regulations and funding, that support climate-friendly agricultural management. This paper discusses potentials to improve the supply of information on: farm-specific climate services or impacts, present policy incentives in Germany and England that support climate-friendly farm management and related adaptation requirements. Tools which have been developed for a farm environmental management software (to be added after review because of potential identification) are presented. These tools assess CO2 emissions from grassland conversion to cropland and peatland cultivation, as well as N2O emissions from nitrogen fertilization. As input data, the CO2 tool requires a classification of soil types according to soil organic carbon storage. The input data based on soil profile samples was compared with reference data from the literature. The N2O tool relies on farm data concerning fertilization. These tools were tested on three farms in order to determine their viability with respect to the availability of required data and the differentiation of results, which determines how well site-specific conservation measures can be identified. Assessing CO2 retention function of grassland conservation to cropland on the test farms leads to spatially differentiated results (~100 to ~900 potentially mitigated t CO2 ha?1). Assessed N2O emissions varied from 0.41 to 1.1 t CO2eq. ha?1 a?1. The proposed methods support policies that promote a more differentiated funding of climate conservation measures. Conservation measures and areas can be selected so that they will have the greatest mitigation effects. However, even though present policy instruments in Germany and England, such as Cross Compliance and agri-environmental measures, have the potential to reduce agricultural GHG, they do not appear to guide measures effectively or site-specifically. In order to close this gap, agri-environmental measures with the potential to support climate protection should be spatially optimized. Additionally, the wetland restoration measures which are most effective in reducing GHG emissions should be included in funding schemes. 相似文献
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Andrew T. Brei 《Journal of Agricultural and Environmental Ethics》2013,26(2):393-408
Due to the significant and often careless human impact on the natural environment, there are serious problems facing the people of today and of future generations. To date, ethical, aesthetic, religious, and economic arguments for the conservation and protection of the natural environment have made relatively little headway. Another approach, one capable of garnering attention and motivating action, would be welcome. There is another approach, one that I will call a rights approach. Speaking generally, this approach is an attempt to address environmental issues via the language and theory of legal and moral rights. Ultimately, it is our duties to our fellow humans that explain why we have duties regarding the natural environment. There are three main contenders among theories that can be called rights approaches to environmental issues. The first identifies the (alleged) human right to a healthful environment as the source of our obligations to conserve and protect nature. The second approach has it that our duties to nature arise from the rights of the constituents of nature themselves, its flora and fauna. The third approach to addressing environmental problems via rights is, I argue, the best path to environmental conservation and protection. This approach—which grounds duties toward nature on the human right to health—has the benefits of being a straightforward, uncontroversial, and simple approach to issues and problems that desperately need to be resolved. 相似文献