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101.
Spain's Programa AGUA was proposed in 2004 as a replacement for the Spanish National Hydrological Plan and represented a fundamental policy shift in national water management from large inter-basin water transfers to a commitment to desalination. Twenty-one desalination facilities are planned for six provinces on the Spanish Mediterranean coast to supplement their water needs. These include the province of Almería that for the last 30 years has endured a net water abstraction overdraft leading to serious reservoir depletion and groundwater imbalances. Rising water use is a result of increasing demand to support irrigated agriculture (e.g. greenhouse horticulture) and for domestic needs (e.g. rapid urban growth and tourism development), which has led observers to question Almería's long-term water sustainability. Desalinated water alone is unlikely to be sufficient to make up these water deficits and water-users will have to accept a move to full-price water recovery by 2010 under the European Union (EU) Water Framework Directive of which Spain is a signatory. Anticipated water efficiencies resulting from higher water tariffs, increasing water reuse and water infrastructure improvements (including inter-basin transfers), in conjunction with increasing use of desalinated water, are expected to address the province's current water overdraft. However, Almería will need to balance its planned initiatives against long-term estimates of projected agricultural and domestic development and the environmental consequences of adopting a desalination-supported water future.  相似文献   
102.
Marsh KJ  Wallis IR  McLean S  Sorensen JS  Foley WJ 《Ecology》2006,87(8):2103-2112
Most herbivores eat more and survive better when they have access to a variety of foods. One explanation involves the detoxification of plant secondary metabolites (PSMs). By feeding from a variety of plants that contain different classes of PSMs, animals can use multiple detoxification pathways and presumably consume more food. Although popular, this theory is difficult to test because it requires knowledge of the detoxification pathways of each PSM in the diet. We established that common brushtail possums (Trichosurus vulpecula) use various combinations of oxidation, hydrolysis, and conjugation with glucuronic acid (GA) or glycine to detoxify six PSMs. Compared to their ingestion of a single PSM, possums ate more when offered a choice between two diets containing PSMs that require apparently independent detoxification pathways (benzoate and 1,8-cineole, benzoate and p-cymene, benzoate and orcinol, benzoate and salicin, or orcinol and 1,8-cineole). However, possums still did not eat as much of these diets as they did of a basal diet free of PSMs. This suggests that detoxification pathways are never independent, but are separated instead by degrees. In contrast, possums offered a choice of two PSMs that require competing detoxification pathways (1,8-cineole and p-cymene, 1,8-cineole and salicin, or orcinol and salicin) ate no more than when offered diets containing one of the compounds. There was an exception: even though both rutin and orcinol are detoxified via conjugation with GA, the feeding behavior of possums did not suggest competition for detoxification pathways. This implies that the supply of GA is not limiting. This study provides the first convincing evidence that herbivorous mammals can eat more by selecting mixed diets with a diversity of PSMs that make full use of their detoxification potential. It also emphasizes that other behavioral and physiological factors, such as transient food aversions, influence feeding behavior.  相似文献   
103.
This paper addresses the interactions between the AIDS epidemic and climate change in southern Africa, particularly as they impact on food security. An assessment was undertaken through a comprehensive literature review. Understanding the underlying causes of regional food insecurity inevitably means understanding the role of the AIDS epidemic and increasingly climate change amongst other stressors. AIDS cuts through household and community level capacity, as well as the capacity of key facilitators of the adaptation process including state extension services and civil society organisations. The main argument of the paper is that adaptation to climate change must explicitly factor in the existing and long-term effects of the epidemic. While calls for embracing adaptation abound, little is being done to assess and strengthen the organisational capacity of institutions, which should play leading roles in any attempt to help prepare for a changing climate. In particular the capacity of key agencies has been undermined by the AIDS epidemic. This reiterates the need for a multisectoral approach and building bridges between agriculture and health sectors to ensure longer term support to livelihoods where HIV and hunger coexist, often overlaid by climate change.  相似文献   
104.
Although the area of urban river sediment quality has received increasing attention over the last 10 years, the presence of contaminated sediments in urban rivers and the potential risk to public health it poses has yet to be rigorously addressed within the urban river restoration context. This is an issue of particular concern at the current time, as the opening-up of urban rivers is being strongly promoted by many legislative and non-legislative bodies as a multi-benefit approach to tackling a range of urban challenges; from decreasing the risk of flooding to increasing the quality-of-life in urbanised areas. This paper brings together these two contrasting concepts; urban rivers as pollutant sinks and sources (presentation of data on urban river sediment quality) and urban rivers as sites of flood alleviation, amenity, recreation and wildlife value (review of the drivers and initiatives behind the increasing implementation of urban river rehabilitation schemes). In light of this combined assessment, the urgent need for a risk assessment of restored urban river sites to establish whether the presence of contaminated sediments poses a risk to public health is strongly recommended. Should such a risk be demonstrated, a tiered approach to supporting the identification and pro-active management of these risks is proposed as a way to inform and enable, rather than to prevent, the safe and appropriate use of the increasing number of urban river restoration schemes being implemented.  相似文献   
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ABSTRACT: The U.S. Geological Survey is now (1975) conducting an intensive river-quality assessment of the Willamette River basin, Oregon. The objectives are to (1) define a practical framework for conducting comprehensive river-quality assessments, (2) develop and document methods for evaluating basin-development alternatives in terms of potential impacts on river quality, (3) determine the kinds and amounts of data required to adequately assess various types of river-quality problems, and (4) apply the framework, data, and methods to assess the existing or potential river-quality problems of the Willamette River basin. This paper covers objectives 2, 3, and 4 by examining the rationales behind the selection and application of methods and the design of data programs for assessing specific river-quality problems. The rationales are those developed for assessing (1) the effect of population and industrial growth and resulting waste discharges on river-dissolved oxygen, (2) the potentially harmful effects on land and river quality of accelerated erosion resulting from intensive land-use development, and (3) the potential for nuisance algal growth. The goal of the assessment program and, thus, the context of the rationales is to provide technically sound information that is appropriate and adequate for resource planning and management.  相似文献   
108.
This article is a primer on the emerging role for Information Technology (IT) in the Environmental Justice (EJ) movement. It explores current and potential uses of IT by EJ organisations fighting to protect vulnerable local environments and it addresses some of the barriers to more widespread movement efficacy via e-advocacy. We argue a chief but not insurmountable barrier is the disproportionate access to, and knowledge of, the benefits of using IT in the struggle for equitable decisions about environmental impacts.  相似文献   
109.
This article addresses the use of critical loads in optimized emission abatement strategies. Critical loads represent the maximum tolerable deposition possible without adverse impacts, a limit that is highly spatially variable. As deposition targets, critical loads cannot be satisfied at all receptors in Europe. Consequently, there is a need for alternative criteria that still relate to ecological indicators, yet that are feasible, consistent, and equitable. Two criteria are suggested: the relative critical load coverage and the relative deposition reduction. Deposition goals based on these criteria will guarantee that a specified fraction of ecosystems will attain target loads and thus will be protected from adverse environmental impacts. In areas that cannot achieve target loads with the best available control measures, deposition can be reduced to a specified fraction of the unabated level. Examples are presented that demonstrate their derivation and application of the two criteria. The criteria have been implemented in the European-scale Regional Acidification Information and Simulation (RAINS) model. Results obtained indicate that optimized emission strategies based on critical loads may be similar to emission strategies based on deposition reductions at certain levels of the two criteria. This suggests that it may not be necessary to utilize critical loads to formulate deposition targets. A second example shows the effect of excluding countries from European cost minimization. A country's participation can save costs with moderate deposition targets; however, significant costs can be imposed with low (stringent) deposition targets. These preliminary results have significant implications for multilateral negotiations.  相似文献   
110.
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