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931.
Acceptability and personal outcome expectations (i.e., the extent to which one expects to be better or worse off) of transport pricing policies were examined in relation to the expected effects of these policies on one’s own car use, congestion and environmental problems. Car users who commuted frequently by car and experienced congestion on a regular basis evaluated two pricing measures, which were mainly aimed at either decreasing congestion (by tolling at congested areas) or environmental problems (by a differential kilometre charge based on car mass). For the policy mainly aimed to reduce congestion, acceptability was higher and personal outcome expectations were more positive when respondents expected reductions in congestion when the policy was implemented. The policy aimed to reduce environmental problems was more acceptable and respondents expected to be better off in general when they expected reductions in environmental problems after its implementation. Expectations, both about a decrease in congestion and environmental problems were related to respondents’ personal outcome expectations of the policy mainly aimed to decrease environmental problems. We conclude that the acceptability of transport pricing policies are not necessarily low because car users expect negative effects on their car use, but rather because they are not be convinced that transport pricing policies will reduce congestion and environmental problems.  相似文献   
932.
Dosskey, Michael G., Philippe Vidon, Noel P. Gurwick, Craig J. Allan, Tim P. Duval, and Richard Lowrance, 2010. The Role of Riparian Vegetation in Protecting and Improving Chemical Water Quality in Streams. Journal of the American Water Resources Association (JAWRA) 46(2):261-277. DOI: 10.1111/j.1752-1688.2010.00419.x Abstract: We review the research literature and summarize the major processes by which riparian vegetation influences chemical water quality in streams, as well as how these processes vary among vegetation types, and discuss how these processes respond to removal and restoration of riparian vegetation and thereby determine the timing and level of response in stream water quality. Our emphasis is on the role that riparian vegetation plays in protecting streams from nonpoint source pollutants and in improving the quality of degraded stream water. Riparian vegetation influences stream water chemistry through diverse processes including direct chemical uptake and indirect influences such as by supply of organic matter to soils and channels, modification of water movement, and stabilization of soil. Some processes are more strongly expressed under certain site conditions, such as denitrification where groundwater is shallow, and by certain kinds of vegetation, such as channel stabilization by large wood and nutrient uptake by faster-growing species. Whether stream chemistry can be managed effectively through deliberate selection and management of vegetation type, however, remains uncertain because few studies have been conducted on broad suites of processes that may include compensating or reinforcing interactions. Scant research has focused directly on the response of stream water chemistry to the loss of riparian vegetation or its restoration. Our analysis suggests that the level and time frame of a response to restoration depends strongly on the degree and time frame of vegetation loss. Legacy effects of past vegetation can continue to influence water quality for many years or decades and control the potential level and timing of water quality improvement after vegetation is restored. Through the collective action of many processes, vegetation exerts substantial influence over the well-documented effect that riparian zones have on stream water quality. However, the degree to which stream water quality can be managed through the management of riparian vegetation remains to be clarified. An understanding of the underlying processes is important for effectively using vegetation condition as an indicator of water quality protection and for accurately gauging prospects for water quality improvement through restoration of permanent vegetation.  相似文献   
933.
Many regions worldwide are experiencing rapid urbanization, and often along with growth in the local economy and population comes worsening air quality. Such regions typically find that addressing the additional challenge of polluted air is difficult. This paper reports the results of an assessment of the present health and related economic costs of poor air quality in the San Joaquin Valley of California. Further, it suggests how such assessments can support strategies to pursue pollution reductions that offer the largest near-term gains, by rigorously modeling the associations between pollution levels, demographic groups, and recognized adverse health effects.  相似文献   
934.
In Chinese cities, air pollution has become a serious and aggravating environmental problem undermining the sustainability of urban ecosystems and the quality of urban life. Besides technical solutions to abate air pollution, urban vegetation is increasingly recognized as an alternative ameliorative method by removing some pollutants mainly through dry deposition process. This paper assesses the capability and monetary value of this ecosystem service in Guangzhou city in South China. The results indicated an annual removal of SO(2), NO(2) and total suspended particulates at about 312.03Mg, and the benefits were valued at RMB90.19 thousand (US$1.00=RMB8.26). More removal was realized by recreational land use due to a higher tree cover. Higher concentration of pollutants in the dry winter months induced more removal. The lower cost of pollution abatement in China generated a relatively subdued monetary value of this environmental benefit in comparison with developed countries. Younger districts with more extensive urban trees stripped more pollutants from the air, and this capacity was anticipated to increase further as their trees gradually reach final dimensions and establish a greater tree cover. Tree cover and pollutant concentration constitute the main factors in pollutant removal by urban trees. The efficiency of atmospheric cleansing by trees in congested Chinese cities could be improved by planting more trees other than shrubs or grass, diversifying species composition and biomass structure, and providing sound green space management. The implications for greenery design were discussed with a view to maximizing this ecosystem service in Chinese cities and other developing metropolises.  相似文献   
935.
Scientific information is not always effectively incorporated into decision-making processes. This phenomenon seems to hold even when the information is aligned with an articulated need, is generated according to sound scientific procedures, and is packaged with end-user preferences in mind. We propose that contextual or cultural differences contribute significantly to the misalignment in communication between those who generate information and those who seek information for improved management of natural resources. The solution is to cultivate shared understanding, which in turn relies on acknowledgment and sharing of diverse values and attitudes. This constitutes a difficult challenge in a culturally diverse environment. Whereas cultural diversity represents wealth in experiences, knowledge and perspectives it can constrain the potential to develop the shared understandings necessary for effective integration of new information. This article illustrates how a lack of shared understanding among participants engaged in a resource-management process can produce and perpetuate divergent views of the world, to the extent that information and knowledge flows are ineffective and scientific information, even when requested, cannot be used effectively. Four themes were distilled from interviews with management and scientific staff of a natural resource–management agency in South Africa. The themes are used to illustrate how divergent views embedded in different cultures can discourage alignment of effort toward a common purpose. The article then presents a sense-making framework to illustrate the potential for developing shared understandings in a culturally diverse world.  相似文献   
936.
The effect of sulfur dioxide (SO2) on the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) has been studied in an entrained-flow reactor (EFR) under simulated waste combustion conditions. A chlorination model based on conditional probability was employed to evaluate the homologue patterns of PCDDs and PCDFs. Results revealed that the presence of SO2 did not alter the formation pathway although SO2 suppressed PCDD/F formation. The prediction model of PCDF showed good agreement with the experimental data (R--0.95), whereas the prediction for PCDDs did not correlate well with the experimental data. This may be explained because potential chlorination pathways play a significant role in PCDF formation, whereas PCDDs are mainly formed through condensation reactions. Furthermore, the result indicated that the steric hindrance during formation has more effects on PCDD than on PCDF due to the symmetric molecular structures of PCDDs.  相似文献   
937.
The peroxynitrite/porphyrin biomimetic system was established to investigate the effects of peroxynitrite on benzo[a]pyrene (B[a]P) metabolism. Through the comparison of three model systems consisting of different iron porphyrins, we found that the peroxynitrite/T(p-Cl)PPFeCl system showed the highest catalytic efficiency in the metabolism of B[a]P. We analyzed the B[a]P metabolites produced from this system by RP-HPLC method and firstly identified the formation of nitrobenzo[a]pyrenes which are the special metabolites of B[a]P induced by peroxynitrite.  相似文献   
938.
We studied the responses of soil fauna to a simulated nitrogen deposition in nursery experimental plots in Subtropical China. Dissolved NH4NO3 was applied to the soil by spraying twice per month for 16 months, starting January 2003 with treatments of 0, 5, 10, 15 and 30 gN/(m2·a). Soil fauna was sampled after 6, 9, 13 and 16 months of treatment in three soil depths (0-5 cm, 5-10 cm, 10-15 cm). Soil available N increased in correspondence with the increasing N treatment, whereas soil pH decreased. Bacterial and fungal densities were elevated by the N treatment. Soil fauna increased in the lower nitrogen treatments but decreased in the higher N treatments, which might indicate that there was a threshold around 10 gN/(m2·a) for the stimulating effects of N addition. The N effects were dependent on the soil depth and sampling time. The data also suggested that the effects of the different N treatments were related to the level of N saturation, especially the concentration of NO3- in the soil.  相似文献   
939.
Riverine floods cause increasingly severe damages to human settlements and infrastructure. Ecosystems have a natural capacity to decrease both severity and frequency of floods. Natural flood regulation processes along freshwaters can be attributed to two different mechanisms: flood prevention that takes place in the whole catchment and flood mitigation once the water has accumulated in the stream. These flood regulating mechanisms are not consistently recognized in major ecosystem service (ES) classifications. For a balanced landscape management, it is important to assess the ES flood regulation so that it can account for the different processes at the relevant sites. We reviewed literature, classified them according to these mechanisms, and analysed the influencing ecosystem characteristics. For prevention, vegetation biomass and forest extent were predominant, while for mitigation, the available space for water was decisive. We add some aspects on assessing flood regulation as ES, and suggest also to include flood hazard into calculations.  相似文献   
940.
To balance trade-offs between livestock’s negative environmental impacts and their positive contributions (e.g. maintaining semi-natural grasslands, varied agricultural landscapes and crop rotations), a better understanding is needed of how the supply of ecosystem services differs across farms. We analysed a suite of indicators for non-provisioning ecosystem services on a large subset of Swedish farms (71% of farms, covering 82% of agricultural land) and related these to farm type, farm size and livestock density. The analysed indicators exhibited clear geographical patterns with hotspots especially in less productive regions. Controlling for this spatial variation we still found that small-scale and ruminant farms were associated with more varied landscapes, small-scale habitats, semi-natural grasslands and better crop sequences compared to nearby farms specialised in crop production, while farms specialising in monogastric livestock were associated with less varied landscapes and inferior crop sequences. Results for cultural ecosystem services indicated that farms with more semi-natural grassland were associated with more visitors and more likely located within designated recreation or nature conservation areas.Supplementary InformationThe online version contains supplementary material available at 10.1007/s13280-022-01726-y.  相似文献   
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