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101.
Current economic assessment implies that there are considerable quantities of uranium available for use in present thermal reactors, albeit at very high costs. However, this method of appraisal contains a fundamental contradiction concerning the relationship between the price of electricity and the cost of uranium concentrate. Derivation of real costs with the technique of energy analysis is used to correct this basic inconsistency. This approach demonstrates that the amount of economically recoverable uranium is substantially less than previously expected. Consequently, if current forecasts of nuclear power growth are achieved then serious shortages of uranium will occur in the foreseeable future.  相似文献   
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The Countryside Commission's report A Better Future for the Uplands puts forward a new strategy for public intervention in the uplands of England and Wales. The aim of the report is to integrate rural policies and to promote higher environmental priorities in rural areas. This paper considers the degree to which the report is successful in planning to achieve these ends. The paper is specifically concerned with the planning methodology on which the report is based. The paper argues for an approach to rural planning which permits the consideration of more radical solutions to rural problems, along with the application of a more systematic planning methodology, in order to assist in the choice of an appropriate direction for planned change.  相似文献   
105.
The impact of disturbance from construction work around Cardiff Bay, south Wales, on the densities and feeding behavior of seven waterbird species was studied over an 11-year period. Construction of a barrage across the mouth of the bay has subsequently resulted in its impoundment; other major works included the construction of a bridge carrying a divided highway. Construction work disturbance significantly reduced the densities of five species—green-winged teal (Anas crecca), Eurasian oystercatcher (Haematopus ostralegus), dunlin (Calidris alpina), Eurasian curlew (Numenius arquata), and common redshank (Tringa totanus)—on adjacent intertidal mudflats, and thus the overall carrying capacity of the bay. Construction work also reduced the feeding activity of Eurasian oystercatcher, dunlin, and common redshank on these mudflats. The possible impact of the loss of birds from these mudflats upon the populations that the bay supported is discussed. Evidence from other local studies suggests that the displacement of common redshank from these mudflats did not contribute to a decline in this species.  相似文献   
106.
Summary Eciton burchelli workers frequently form groups to retrieve large prey items. Such groups have a definite structure. There is a constant relationship between total ant dry weight and prey item dry weight for both individual porters and groups, and this relation is such that a larger weight of ant or ants can carry disproportionately heavy items. Furthermore, all prey items are carried at a standard retrieval speed. This means that groups are superefficient; they can carry items that are so large that if they were fragmented the original members of the group would be unable to carry all the fragments. Groups also have a distinct caste distribution. There is a significant tendency for each group to have a single submajor, the specialist porter caste in Eciton burchelli. These findings which were verified by experiments suggest that groups fulfill the criteria of efficient teams. The biomechanics are proposed to explain the superefficiency of groups. The organization of co-operation is considered as is the role of teams in the economy of these societies. Colony caste profiles can only be understood by examining the role of teams which form a plastic supercaste.  相似文献   
107.
This study proposes that the perceived legitimacy of minor illness as a reason for absence varies according to the nature of the illness, sex, job grade/socio‐economic status and age. A measure of perceived legitimacy was constructed which incorporated illnesses commonly given as reasons for short‐term absence. Thirteen hundred civil servants provided data on an employee survey. Absence frequency data were collected for 115 of these respondents over a 55‐month period. General support was found for four of the five study hypotheses. Contrary to one hypothesis, it was found that men legitimize minor illnesses as reasons for absence more than women. Clusters of minor illnesses were identified using a factor analysis. The implications for management responses to absence and for further research into the perception of minor illness are considered. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   
108.
Conservation science needs more high-quality impact evaluations, especially ones that explore mechanisms of success or failure. Randomized control trials (RCTs) provide particularly robust evidence of the effectiveness of interventions (although they have been criticized as reductionist and unable to provide insights into mechanisms), but there have been few such experiments investigating conservation at the landscape scale. We explored the impact of Watershared, an incentive-based conservation program in the Bolivian Andes, with one of the few RCTs of landscape-scale conservation in existence. There is strong interest in such incentive-based conservation approaches as some argue they can avoid negative social impacts sometimes associated with protected areas. We focused on social and environmental outcomes based on responses from a household survey in 129 communities randomly allocated to control or treatment (conducted both at the baseline in 2010 and repeated in 2015–2016). We controlled for incomplete program uptake by combining standard RCT analysis with matching methods and investigated mechanisms by exploring intermediate and ultimate outcomes according to the underlying theory of change. Previous analyses, focused on single biophysical outcomes, showed that over its first 5 years Watershared did not slow deforestation or improve water quality at the landscape scale. We found that Watershared influenced some outcomes measured using the survey, but the effects were complex, and some were unexpected. We thus demonstrated how RCTs can provide insights into the pathways of impact, as well as whether an intervention has impact. This paper, one of the first registered reports in conservation science, demonstrates how preregistration can help make complex research designs more transparent, avoid cherry picking, and reduce publication bias.  相似文献   
109.
A study has been carried out to assess the contribution of Polycyclic Aromatic Hydrocarbons (PAHs) from asphalt plant operation, utilising Benzo(a)pyrene (BaP) as a marker for PAHs, to the background air concentration around asphalt plants in the UK. The purpose behind this assessment was to determine whether the use of published BaP emission factors based on the US Environmental Protection Agency (EPA) methodology is appropriate in the context of the UK, especially as the EPA methodology does not give BaP emission factors for all activities. The study also aimed to improve the overall understanding of BaP emissions from asphalt plants in the UK, and determine whether site location and operation is likely to influence the contribution of PAHs to ambient air quality. In order to establish whether the use of US EPA emissions factors is appropriate, the study has compared the BaP emissions measured and calculated emissions rates from two UK sites with those estimated using US EPA emission factors. A dispersion modelling exercise was carried out to show the BaP contribution to ambient air around each site. This study showed that, as the US EPA methodology does not provide factors for all emission sources on asphalt plants, their use may give rise to over- or under-estimations, particularly where sources of BaP are temperature dependent. However, the contribution of both the estimated and measured BaP concentrations to environmental concentration were low, averaging about 0.05 ng m(-3) at the boundary of the sites, which is well below the UK BaP assessment threshold of 0.25 ng m(-3). Therefore, BaP concentrations, and hence PAH concentrations, from similar asphalt plant operations are unlikely to contribute negatively to ambient air quality.  相似文献   
110.
Wamsler C  Lawson N 《Disasters》2012,36(1):28-53
Climate change and disasters pose a serious risk to sustainable development. In the South, local coping strategies are an important element of adaptation to climate and disaster risk. Such strategies have emerged because of the limited assistance provided by urban actors and associated social security and governance systems. In the North, in contrast, local coping strategies are comparatively poorly developed. However, the extent of the changing climatic conditions is also reducing the capacity of Northern institutions to deal with climatic extremes and variability, which emphasises the need for more local-level engagement in the North. This paper analyses the differences in local and institutional responses to climate change and disasters in a Southern and a Northern city (San Salvador, El Salvador, and Manchester, United Kingdom, respectively), and highlights how the lessons learned might be translated into an improved distributed governance system; that is, an 'integrated engagement model', where local and institutionalised responses support rather than hinder each other, as is currently the case.  相似文献   
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