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771.
The Countryside Council for Wales (CCW) is developing a management framework with the primary aim of restoring favourable
conservation status to the sand dune resource of Wales. It will take onboard the requirements of both national and international
conservation legislation and will also help CCW integrate its responsibilities for biodiversity, geodiversity, landscape,
access and recreation for this habitat. In order to achieve certain conservation goals it will be necessary to have in place
a variety of different types of management ranging from non- or minimal intervention through to intensive single species management
and habitat re-creation. However, it will not provide a comprehensive framework for all aspects of site management, but only
those that are deemed to be of strategic importance, and have significance within an all-Wales perspective for their nature
conservation importance. 相似文献
772.
773.
David W. Neumann Edith A. Zagona Balaji Rajagopalan 《Journal of the American Water Resources Association》2006,42(5):1275-1284
ABSTRACT: Warm summer stream temperatures due to low flows and high air temperatures are a critical water quality problem in many western United States river basins because they impact threatened fish species’habitat. One way to alleviate this problem is for local and federal organizations to purchase water rights to be used to increase flows, hence decrease temperatures. Presented is a Decision Support System (DSS) that can be used in an operations mode to effectively use water acquired to mitigate warm stream temperatures. The DSS uses a statistical model for predicting daily stream temperatures and a rule‐based module to compute reservoir releases. Water releases are calculated to meet fish habitat temperature targets based on the predicted stream temperature and a user specified confidence of the temperature predictions. Strategies that enable effective use of a limited amount of water throughout the season have also been incorporated in the DSS. The utility of the DSS is demonstrated by an example application to the Truckee River near Reno, Nevada, using hypothetical operating policy and 1988 through 1994 inflows. Results indicate that the DSS could substantially reduce the number of target temperature violations (i.e., stream temperatures exceeding the target temperature levels detrimental to fish habitat). 相似文献
774.
775.
ABSTRACT: The Basin Characteristics System (BCS) has been developed to quantify characteristics of a drainage basin. The first of four main BCS processing steps creates four geographic information system (GIS) digital maps representing the drainage divide, the drainage network, elevation contours, and the basin length. The drainage divide and basin length are manually digitized from 1:250,000-scale topographic maps. The drainage network is extracted using GIS software from 1:100,000-scale digital line graph data. The elevation contours are generated using GIS software from 1:250,000-scale digital elevation model data. The second and third steps use software developed to assign attributes to specific features in three of the four digital maps and analyze the four maps to quantify 24 morphometric basin characteristics. The fourth step quantifies two climatic characteristics from digitized State maps of precipitation data. Compared to manual methods of measurement, the BCS provides a reduction in the time required to quantify the 26 basin characteristics. Comparison tests indicate the BCS measurements are not significantly different from manual topographic-map measurements for 11 of 12 primary drainage-basin characteristics. Tests indicate the BCS significantly underestimates basin slope. Comparison-measurement differences for basin slope, main channel slope, and basin relief appear to be due to limitations in the digital elevation model data. 相似文献
776.
D. J. Schaeffer T. R. Seastedt D. J. Gibson D. C. Hartnett B. A. D. Hetrick S. W. James D. W. Kaufman A. P. Schwab E. E. Herricks E. W. Novak 《Environmental management》1990,14(1):81-93
Ecosystem responses to physical or chemical stress may vary from changes in single organisms to alteration of the structure
and function of the ecosystem. These responses to stress cannol be predicted exactly. Ecosystems repeatedly exposed to physical
and/or chemical stress can be used to study the separate and combined environmental effects of stress. Such studies also allow
the development of procedures to select test systems for the analysis of stress in ecosystems. A preliminary field survey
of six military training sites at Fort Riley, Kansas, USA, was conducted to identify and verify ecological test systems for
evaluating ecosystem responses to physical and/or chemical stress. Comparisons of these data with data collected concurrently
from Konza Prairie Research Natural Area reference sites showed that soil microarthropods, some species of macroarthropods,
small mammals, and native earthworm species were negatively affected by stress. In contrast, plant species diversity, plant
foliage biomass, soil mycorrhizae, and many soil characteristics were within the boundaries of nominal variations observed
on “pristine” Konza Prairie. Introduced European earthworms appeared to be positively affected by training activities. This
study provided a test of systematic procedures to support impact analysis, ecological toxicology, and ecosystem risk assessments.
This is paper IX in D. J. Schaeffer's “Environmental Audit” series. 相似文献
777.
Results from a 1995 survey of utility company biologists indicate that aquatic biodiversity is an emerging and poorly understood issue. As a result, there is some confusion about what aquatic biodiversity actually is, and how we can best conserve it. Only one fourth (24%) of the respondents said their company has a stated environmental policy that addresses biodiversity. Many respondents indicate that over the years they have not specifically managed for biodiversity, but have been doing that through their efforts to assure balanced indigenous populations. While regulations are still the major driver for biological work, an increasing number of companies are involved in voluntary partnerships in managing water resources. Of these voluntary partnerships, 70% have biodiversity as a goal. Biodiversity is becoming an increasingly common subject of study, and a vast majority (75%) of the respondents suggested it should be a goal for utility resource management. Conservation of aquatic biodiversity is a complex task, and to date most aquatic efforts have been directed toward fish and macroinvertebrates. Ecological research and technological development performed by the utility industry have resulted in a number of successful biopreservation and biorestoration success stories. A common theme to preserving or enhancing aquatic biodiversity is preserving aquatic habitat. Increasingly, ecosystem management is touted as the most likely approach to achieve success in preserving aquatic biodiversity. Several utilities are conducting progressive work in implementing ecosystem management. This paper presents the potential interactions between power plants and biodiversity, an overview of aquatic biodiversity preservation efforts within the electric utility industry, more detail on the results of the survey, and recent initiatives in ecosystem management. 相似文献
778.
David J. Marcogliese Christian Blaise Daniel Cyr Yves de Lafontaine Michel Fournier Fran?ois Gagné Christian Gagnon Christiane Hudon 《Ambio》2015,44(4):257-274
The St. Lawrence River (SLR) is the second largest waterway in North America. The discharge of the City of Montreal wastewater treatment plant (WWTP) represents the largest volume of treated wastewaters being released into the river. It also ranks as the largest sewage treatment plant of its kind in North America. Over the last decade, intensive multidisciplinary research has focused on assessing the impacts of Montreal wastewater effluents on the SLR. We describe the major findings of these investigations, including the determination of the fate of contaminants, bioaccumulation in fish and invertebrates, ecotoxicological measurements of aquatic animal health, evaluation of endocrine disruption, parasitism in fish, and combined effects of multiple stressors on the SLR. Impacts of the effluents from the WWTP on aquatic organisms from the SLR are both toxicological and ecological, demonstrating the need for an integrated view of the impacts of municipal effluents on aquatic ecosystems. 相似文献
779.
本文作者主要研究了腐殖酸对聚乙烯吡咯烷酮包覆的纳米银颗粒(polyvinylpyrrolidone-coated AgNPs)毒性的影响,受试生物涵盖了水生系统不同的营养级别,包括藻类(Raphidocelis subcapitata)、水蚤类(Chydorus sphaericus)以及淡水鱼类(Danio rerio)。结果显示,腐殖酸可降低AgNPs对本研究中所有水生生物的毒性,并具有明显的剂量效应关系。原因为:1)腐殖酸使AgNPs表面带有更多负电荷,这阻碍了AgNPs与藻细胞的接触,使毒性降低;2)腐殖酸抑制了AgNPs中Ag+的溶出,而本研究显示自由Ag+的毒性高于团聚的纳米银颗粒。
精选自Zhuang Wang, Joris T.K. Quik, Lan Song, Evert-Jan Van Den Brandhof, Marja Wouterse and Willie J.G.M. Peijnenburg. Humic substances alleviate the aquatic toxicity of polyvinylpyrrolidone-coated silver nanoparticles to organisms of different trophic levels. Environmental Toxicology and Chemistry: Volume 34, Issue 6, pages 1239–1245, June 2015.
DOI: 10.1002/etc.2936
详情请见http://onlinelibrary.wiley.com/doi/10.1002/etc.2936/full 相似文献
780.
《Environmental Hazards》2013,12(4):313-328
Risk communication plays an increasingly central role in flood risk management, but there is a variety of conflicting advice about what does – and should – get transmitted, why, how, and to whom. The aim of this paper is to elucidate the underlying normative and conceptual models on which those competing assessments of ‘good’ risk communication depend. To that end, the paper identifies four broad models, or approaches, to risk communication: a risk message model of information transfer; a risk instrument model of behavioural change; a risk dialogue model of participatory deliberation; and a risk government model of self-regulation and normalization. These models differ in their theoretical and disciplinary origins and associated philosophical and political commitments, and consequently they define the basic purpose, practice, and future prospects of flood risk communication in quite different ways. Unless these different models of ‘good’ risk communication are acknowledged and understood, efforts to identify best practice for flood risk management are likely to produce inconsistent, if not contradictory, recommendations. 相似文献