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111.
One of the challenges faced by local governments in the work with municipal climate action plans concerns accounting for the greenhouse gas (GHG) emissions—what emissions should be targeted, development of emissions over time, and how to effectively measure the success of local climate action. In this paper, we present challenges in developing a GHG emissions inventory related to the provision of municipal services. We argue that a consumption-based perspective, illustrated through the use of the carbon footprint (CF), rather than more conventional production-based inventory, provides a more useful and less misleading indicator. We present an analysis of the CF of municipal services provided by the city of Trondheim. The use of data directly from the city's accounting system ensures a reliable calculation of indirect emissions, and, with some minor modifications, also accurate data on direct emissions. Our analysis shows that approximately 93 percent of the total CF of municipal services is indirect emissions, located in upstream paths, underlining the need of introducing consumption-based indicators that takes into account upstream GHG emissions.  相似文献   
112.
We describe the development of the fish community in the acidified and limed river Litleåna in southern Norway, and describe how chemical restoration, compensatory introductions of exotics, and accidental invasion of exotics interact to influence the population of the naturally occurring brown trout (Salmo trutta). The river Litleåna is a tributary to the river Kvina in Vest-Agder County, southern Norway. During the years 1996–2004, annual mean pH was 4.9–5.0 and 6.1–6.4 above and below the liming facility, which was installed in 1994. Originally, brown trout was the only fish species in the river, but brook trout (Salvelinus fontinalis) have been intentionally introduced, whereas European minnow (Phoxinus phoxinus) was introduced by accident. Fish densities were recorded by means of electrofishing annually over the ten year period 1995–2004. Although close to extinction before liming was initiated, brown trout fry densities increased from 1995 to 1999, with subsequent varying densities. There has been a simultaneous major increase in the occurrence and density of European minnow since 1997. Our results show that both brown trout and European minnow increase after liming. Minnow densities are negatively affected by low pH episodes in the river. The growth rates of brown trout fry are negatively correlated to minnow densities, indicating competition between the species. Brook trout densities have decreased since liming started, and during the brown trout recovery.  相似文献   
113.
Abstract: To evaluate anthropogenic sedimentation in United States (U.S.) Pacific Northwest coastal streams, we applied an index of relative bed stability (LRBS*) to summer low flow survey data collected using the U.S. Environmental Protection Agency’s Environmental Monitoring and Assessment Program field methods in a probability sample of 101 wadeable stream reaches. LRBS* is the log of the ratio of bed surface geometric mean particle diameter (Dgm) to critical diameter (D*cbf) at bankfull flow, based on a modified Shield’s criterion for incipient motion. We used a formulation of LRBS* that explicitly accounts for reductions in bed shear stress that result from channel form roughness due to pools and wood. LRBS* ranged from ?1.9 to +0.5 in streams within the lower quartile of human riparian and basin disturbance, and was substantially lower (?4.2 to ?1.1) in streams within the upper quartile of human disturbance. Modeling results suggest that the expected range of LRBS* in streams without human disturbances in this region might be generally between ?0.7 and +0.5 in either sedimentary or volcanic lithology. However, streams draining relatively soft, erodible sedimentary lithology showed greater reductions in LRBS* associated with disturbance than did those having harder, more resistant volcanic (basalt) lithology with similar levels of basin and riparian disturbance. At any given level of disturbance, smaller streams had lower LRBS* than those with larger drainages. In sedimentary lithology (sandstone and siltstone), high‐gradient streams had higher LRBS* than did low‐gradient streams of the same size and level of human disturbance. High gradient streams in volcanic lithology, in contrast, had lower LRBS* than low‐gradient streams of similar size and disturbance. Correlations between Dgm and land disturbance were stronger than those observed between D*cbf and land disturbance. This pattern suggests that land use has augmented sediment supplies and increased streambed fine sediments in the most disturbed streams. However, we also show evidence that some of the apparent reductions in LRBS*, particularly in steep streams draining small volcanic drainages, may have resulted in part from anthropogenic increases in bed shear stress. The synoptic survey methods and designs we use appear adequate to evaluate regional patterns in bed stability and sedimentation and their general relationship to human disturbances. More precise field measurements of channel slope, cross‐section geometry, and bed surface particle size would be required to use LRBS* in applications requiring a higher degree of accuracy and precision, such as site‐specific assessments at individual streams.  相似文献   
114.
This paper presents a case study from Jumla District, Nepal, investigating local management systems and ecological sustainability of commercial collection of a medicinal plant, spikenard (Nardostachys grandiflora DC, Valerianaceae), growing in alpine meadows. Interviews were undertaken with local collectors, traders, and district forest office staff, and the dynamics of people–plant interactions are analyzed using the Oakerson model. In all, 110 sample plots 1m square were laid out in three areas with differing collection and grazing pressures for recording of floristic composition and abundance of spikenard root biomass. Comparisons show significantly more root biomass in uncollected than collected areas with local management and the interpretation of differences in abundance is discussed. The combination of qualitative and quantitative investigations can provide a framework for the study of people–plant interactions, and this study can serve as first step in a compilation of cases to create a more detailed picture of local management systems of Nepali nontimber forest products in general and commercially collected medicinal and aromatic plants in particular.  相似文献   
115.
Participatory Forest Management in Ethiopia: Learning from Pilot Projects   总被引:2,自引:0,他引:2  
Different arrangements of decentralized forest management have been promoted as alternatives to centralized and top down approaches to halt tropical deforestation and forest degradation. Ethiopia is one of the countries piloting one of these approaches. To inform future programs and projects it is essential to learn from existing pilots and experiences. This paper analyses five of the pilot participatory forest management (PFM) programs undertaken in Ethiopia. The study is based on the Forest User Group (FUG) members’ analyses of the programs using selected outcome variables: forest income, change in forest conditions, forest ownership feelings and effectiveness of FUGs as forest managing institutions. These variables were assessed at three points in time—before the introduction of PFM, during the project implementation and after the projects ended. Data were collected using group discussions, key informant interviews and transect walks through the PFM forests. The results show that in all of the five cases the state of the forest is perceived to have improved with the introduction of PFM, and in four of the cases the improvement was maintained after projects ended. Regulated access to the forests following introduction of PFM was not perceived to have affected forest income negatively. There are, however, serious concerns about the institutional effectiveness of the FUGs after projects ended, and this may affect the success of the PFM approach in the longer term.  相似文献   
116.
    
ABSTRACT: Bank erosion along a river channel determines the pattern of channel migration. Lateral channel migration in large alluvial rivers creates new floodplain land that is essential for riparian vegetation to get established. Migration also erodes existing riparian, agricultural, and urban lands, sometimes damaging human infrastructure (e.g., scouring bridge foundations and endangering pumping facilities) in the process. Understanding what controls the rate of bank erosion and associated point bar deposition is necessary to manage large alluvial rivers effectively. In this study, bank erosion was proportionally related to the magnitude of stream power. Linear regressions were used to correlate the cumulative stream power, above a lower flow threshold, with rates of bank erosion at 13 sites on the middle Sacramento River in California. Two forms of data were used: aerial photography and field data. Each analysis showed that bank erosion and cumulative effective stream power were significantly correlated and that a lower flow threshold improves the statistical relationship in this system. These correlations demonstrate that land managers and others can relate rates of bank erosion to the daily flow rates of a river. Such relationships can provide information concerning ecological restoration of floodplains related to channel migration rates as well as planning that requires knowledge of the relationship between flow rates and bank erosion rates.  相似文献   
117.
The Norwegian MEPS (musculoskeletal--visual--psychosocial--stress) study included 3 groups: data entry, data dialogue (female) and data dialogue (male). Before intervention, the data entry group reported significantly more symptoms and signs of musculoskeletal illness and had longer periods in front of the video display terminal (VDT) without a break. The ergonomic intervention consisted mainly of ergonomic information and training. After intervention, the data dialogue female group reported a significant reduction in shoulder pain in parallel with a reduction in trapezius load. Increasing the understanding in how to adjust the work stand and chair may have been contributing factors to reducing the pain level. There was a significant reduction in eye problems in all groups; the greatest reduction in eye symptoms was seen in the groups who had new optometric corrections.  相似文献   
118.
A study of the use of car and public transport among residents in 30 residential areas in Greater Oslo indicates that urban planning variables have a significant influence on the energy use per capita for local transport. Residents in local communities with a high density and a short distance to downtown Oslo travel considerably shorter distances and use considerably less energy per capita than those who live in low-density, outer areas. This is true also when the effects of other variables are neutralized. The influence of urban planning variables on the modal split is lower than on energy use. The distribution between public and private transport is influenced most of all by car ownership.  相似文献   
119.
    
The new ozone National Ambient Air Quality Standard specifies that the expected number of days per calendar year that the 1 hour average ozone concentration can exceed 0.12 ppm must be equal to or less than 1. This paper describes a method to calculate design frequency, design concentration, and the percentage concentration reduction necessary to achieve this standard. The design frequency is once per year (1/365) if daily maximum hour ozone concentrations are available at a particular site for an equal number of days in summer (April through September) and winter (October through March). An equation is used to adjust design frequency as a function of the number of summer and winter samples available. The design concentration (the ambient concentration measured at the design frequency) needs to be reduced to 0.12 ppm. Graphical and digital methods for determining the design concentration are presented. Percentage concentration reductions needed to achieve the standard are calculated for each site which has ozone concentration data available in the National Aerometric Data Bank for at least half of the days in one summer of years 1975 through 1977. The degree of reduction calculated for the site with the highest concentrations in each county is indicated by shading on a map of the United States.  相似文献   
120.
Submicron aerosol deposition to outdoor vegetation was evaluated by measuring vegetation and air concentrations of 212Pb, 214Pb, and 7Be attached to atmospheric aerosols. A biomass-normalized deposition velocity (VD), with units of m3 kg?1 s?1, was used to compare species and isotopes with respect to air-to-vegetation transfer rates. For 212Pb (t12 = 10·64 h), higher night-time air concebtrations dominate deposition, while for 214Pb (t12 = 26·8 min), deposition measurements over shorter time periods relative to changing atmospheric conditions were possible. Calculated VD values were usually higher for 214Pb, possibly reflecting wind-enhanced deposition during the afternoon period of sampling. Evergreen species, including pines, were not appreciably different from deciduous species. Most striking was the narrow range of results (factor of 6 for 34 212Pb measurements of 20 species). Beryllium-7 (t12 = 53·3 d) was used to evaluate time-integrated deposition by sampling vegetation in California near the end of dry summers. Similar deposition rates were found for this isotope. The results of the study indicated that naturally radioactive atmospheric aerosols can be used to understand the dynamics of submicron aerosol deposition to ecosystems.  相似文献   
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