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671.
Quality circles programmes are based on the assumptions that employee participation leads to valued outcomes such as intrinsic satisfaction and recognition, and that it also results in the implementation of changes which enhance productivity and satisfaction. An in-depth case study of one such programme finds that generally favourable testimonials by participants may be misleading. This programme yielded a few minor changes but little impact on productivity and attitudes in the unit as a whole. Causes for its demise are discussed.  相似文献   
672.
Residents of within 50 miles of the nuclear power plant at Three Mile Island (TMI), Pennsylvania, were surveyed in 1979, 1980, and 1982 to assess their general attitudes toward nuclear power, to assess their individual coping responses to the March 1979 accident, and to monitor changes in attitudes over the three-year period. Most respondents feel that future accidents like TMI will occur once or twice more in their lifetimes, that operating nuclear power stations should have improved safeguards and should continue operating, and that major institutions—government and utility companies—are experiencing a continued erosion of public trust.  相似文献   
673.
The effects of human trampling and firewood gathering on eight backcountry campsites in the Great Smoky Mountains were surveyed. Sample plots were classified as sitecenter, transition, firewood-gathering area, and control. The canopy in the center of the sites tended to be more open than that of control plots, with the greatest openings occurring at shelter sites in spruce-fir forest. Intensive human trampling in the center of the sites inhibited reproduction of tree species, whereas firewood gathering alone did not. In some cases where canopy opening had occurred, there was an increase in shrub and tree reproduction around the edge of the site. Reduction in the basal area of standing deadwood varied with the type of site; older growth stands were less depleted. Injuries to trees increased tenfold from control areas to the center of the campsites. Smaller fuels were more strongly impacted by trampling and little impacted by firewood gathering. Woody fuels in the 2.5- to 7.6-cm size class were preferred for firewood. A previously constructed carbon cycling model was modified to incorporate removal of firewood and litter on campsites. The model suggested that after extended removal of leaf litter, soil carbon takes 12 to 50 years to recover, but this hypothesis remains to be tested in the field.  相似文献   
674.
As a consequence of the accumulation of anthropogenic Pb in upland catchments, there has been much recent concern about the potential mobilisation and transport of Pb from the soils to receiving waters and also the possible harmful effects that this might have on aquatic biota. This paper presents the findings of a two-year study of Pb behaviour in an organic-rich upland catchment at Glensaugh in NE Scotland. Pb inputs to the catchment were characterised by direct measurements of Pb concentration and (206)Pb/(207)Pb ratios in rain water and interception. Pb outputs from the catchment were calculated from measurements on stream water samples taken from the two main streams, the Cairn Burn and Birnie Burn. The relative contribution of Pb from groundwater and throughflow, under different flow conditions (base flow and high flow), to stream waters was investigated via analysis of springs sourced from groundwater and of waters flowing through the various soil horizons (S (surface), A, B, C, and D), respectively. The outcome of intensive sampling and analysis over the two-year time period was that, even with marked reduction in Pb inputs over the past two decades, the catchment was still acting as a net sink for the current atmospheric deposition. Although the Pb isotopic signature for stream water is very similar to that for the contemporaneous rain water ((206)Pb/(207)Pb approximately 1.15-1.16), only a small portion of the rain water is transferred directly to stream water. Instead, the Pb input is transferred to the stream waters mainly via groundwater and it was also confirmed that the latter had a similar Pb isotopic signature. From the Pb isotopic measurements on throughflow waters, however, Pb being removed via the streams contained some previously deposited Pb, i.e. mobilisation of a small portion of soil-derived anthropogenic Pb was occurring. These findings are important not only with respect to the source/sink status of the catchment but also for calculation of the extent of retention of the current atmospheric Pb inputs, which must take account of the release of previously deposited Pb from the catchment soils, a process occurring mainly under high flow conditions.  相似文献   
675.
Acute ecological changes in North American boreal forests in this century are attributed to an array of factors including human activities. In the Quetico-Superior Ecotone of Northwest Ontario and Northern Minnesota warmer, drier climate conditions since mid-century have concurred with extensive manipulation of regional forests by fire suppression and clear-cut logging. Predicted effects of climate changes expected for the next century could compete with transformations in these systems over the past 10 000 yr. The degree of alteration of natural processes and patterns in North American boreal forests requires implementation of realistic strategies to ensure that sufficiently large tracts of these systems maintain their natural integrity.  相似文献   
676.
The simultaneous extraction of bromide, chloride, fluoride and sulfate was studied in soils, waste- and building materials. Acid, neutral and alkaline extractants were used; 0.01 mol l(-1) H(3)PO(4), milliQ-water and 0.01 mol l(-1) NaOH, respectively. The extracts were analysed by ion chromatography and ion selective electrode. Extracted concentrations were compared with the amount obtained by an alkaline smelt, as an approximation of the total extractable content. The results indicate that there is a significant difference in extraction behaviour between waste- and building materials and soils. Bromide and chloride were in general completely extracted from the former solid materials, but less than 10% and 50%, respectively, from soils. Fluoride is strongly bound in all investigated samples; less than 10% of the total content was extracted with any of the three extractants. The fraction of extracted sulfate varied between 4 and 87% of the total content, and was in general larger in waste- and building materials than in soils. Differences in extracted concentration between the 3 extractants occurred mainly for fluoride and sulfate. Extracted bromide was similar with all three extractants and extracted chloride showed differences for the various soil samples only. Increasing the NaOH concentration up to 1 mol l(-1) resulted mainly in an increase of extracted amount of fluoride and for soils also in extracted amounts of bromide and sulfate. Although, the results show that the composition of the solid material strongly influences the final pH of the extract and the extracted amount of investigated anions, application of Milli-Q water as an extractant might be a very fruitful option within the development of the Dutch Building Materials Decree.  相似文献   
677.
This study investigated the speciation of halogen-specific total organic halogen and disinfection byproducts(DBPs) upon chlorination of natural organic matter(NOM) in the presence of iopamidol and bromide(Br~-).Experiments were conducted with low bromide source waters with different NOM characteristics from Northeast Ohio,USA and varied spiked levels of bromide(2-30 μmol/L) and iopamidol(1-5 μmol/L).Iopamidol was found to be a direct precursor to trihalomethane(THM) and haloacetic acid formation,and in the presence of Br~-favored brominated analogs.The concentration and speciation of DBPs formed were impacted by iopamidol and bromide concentrations,as well as the presence of NOM.As iopamidol increased the concentration of iodinated DBPs(iodo-DBPs) and THMs increased.However,as Br~-concentrations increased,the concentrations of nonbrominated iodo-and chloro-DBPs decreased while brominated-DBPs increased.Regardless of the concentration of either iopamidol or bromide,bromochloroiodomethane(CHBrClI) was the most predominant iodo-DBP formed except at the lowest bromide concentration studied.At relevant concentrations of iopamidol(1 μmol/L) and bromide(2 μmol/L),significant quantities of highly toxic iodinated and brominated DBPs were formed.However,the rapid oxidation and incorporation of bromide appear to inhibit iodoDBP formation under conditions relevant to drinking water treatment.  相似文献   
678.
Many public programs have differential impacts on diverse parts of metropolitan areas. This fact has led analysts to use changes in land values as measures of the benefits of public programs. Using a model derived from theoretical urban economics, this paper demonstrates that changes in land values will only equal total benefits under very restrictive assumptions. Making concrete assumptions about consumer demand, the paper goes beyond previous work to consider the distributional impact of three different kinds of public programs: those which provide uniform benefits to every community, those which attempt to reduce intercommunity inequality, and those which generate improvements in only a subset of the region's towns.  相似文献   
679.
This paper draws upon the DISCUS (Developing Institutional and Social Capacity for Sustainable Development) research project, co-funded by the European Commission. The project was undertaken during 2001 – 2004 and involved an in-depth study of 40 European towns and cities in order to understand the institutional and social factors and conditions that might contribute to policy ‘achievement' or ‘failure' in local sustainable development policy and practice. Based on the findings of this research it proposes a conceptual framework for local sustainable development, linking the concepts of institutional capital, social capital and governance to provide a model for understanding the governing of local sustainability. The research shows that in those cases that exhibit sustainable development policy achievements, there are also greater levels of civil society activity and knowledge regarding sustainability issues, and high levels of institutional capacity. Confident local government is crucial to the development of institutional capacity and to institutional learning. One aspect of this is local authorities being equipped to address the longer-term issues and to have a strategic vision for a sustainable future.  相似文献   
680.
Science of odor as a potential health issue   总被引:2,自引:0,他引:2  
Historically, unpleasant odors have been considered warning signs or indicators of potential risks to human health but not necessarily direct triggers of health effects. However, citizen complaints to public health agencies suggest that odors may not simply serve as a warning of potential risks but that odor sensations themselves may cause health symptoms. Mal-odors emitted from large animal production facilities and wastewater treatment plants, for example, elicit complaints of eye, nose, and throat irritation, headache, nausea, diarrhea, hoarseness, sore throat, cough, chest tightness, nasal congestion, palpitations, shortness of breath, stress, drowsiness, and alterations in mood. There are at least three mechanisms by which ambient odors may produce health symptoms. First, symptoms can be induced by exposure to odorants (compounds with odor properties) at levels that also cause irritation or other toxicological effects. That is, irritation--rather than the odor--is the cause of the health symptoms, and odor (the sensation) simply serves as an exposure marker. Second, health symptoms from odorants at non-irritant concentrations can be due to innate (genetically coded) or learned aversions. Third, symptoms may be due to a co-pollutant (such as endotoxin) that is part of an odorant mixture. Objective biomarkers of health symptoms must be obtained, however, to determine if health complaints constitute health effects. One industry that is receiving much attention, worldwide, related to this subject is concentrated animal production agriculture. Sustainability of this industry will likely necessitate the development of new technologies to mitigate odorous aerial emissions. Examples of such "environmentally superior technologies" (EST) developed under the initiative sponsored through agreements between the Attorney General of North Carolina and Smithfield Foods and Premium Standard Farms are described.  相似文献   
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