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241.
Although pesticide regulatory tools are mainly based on individual substances, aquatic ecosystems are usually exposed to multiple pesticides from their use on the variety of crops within the catchment of a river. This study estimated the impact of measured pesticide mixtures in surface waters from 2002 and 2008 within three important Portuguese river basins(‘Mondego', ‘Sado' and ‘Tejo') on primary producers, arthropods and fish by toxic pressure calculation. Species sensitivity distributions(SSDs), in combination with mixture toxicity models, were applied. Considering the differences in the responses of the taxonomic groups as well as in the pesticide exposures that these organisms experience, variable acute multi-substance potentially affected fractions(ms PAFs) were obtained. The median msP AF for primary producers and arthropods in surface waters of all river basins exceeded 5%, the cut-off value used in the prospective SSD approach for deriving individual environmental quality standards. A ranking procedure identified various photosystem II inhibiting herbicides, with oxadiazon having the relatively largest toxic effects on primary producers, while the organophosphorus insecticides, chlorfenvinphos and chlorpyrifos, and the organochloride endosulfan had the largest effects on arthropods and fish, respectively. These results ensure compliance with European legislation with regard to ecological risk assessment and management of pesticides in surface waters.  相似文献   
242.
Landslide Vulnerability Criteria: A Case Study from Umbria,Central Italy   总被引:9,自引:0,他引:9  
Little is known about the vulnerability to landslides, despite landslides causing frequent and widespread damage to the population and the built-up environment in many areas of the world. Lack of information about vulnerability to landslides limits our ability to determine landslide risk. This paper provides information on the vulnerability of buildings and roads to landslides in Umbria, central Italy. Information on 103 landslides of the slide and slide-earth flow types that have resulted in damage to buildings and roads at 90 sites in Umbria is used to establish dependencies between the area of the landslide and the vulnerability to landslides. The dependencies obtained are applied in the hills surrounding the town of Collazzone, in central Umbria, an area for which a detailed landslide inventory map is available. By exploiting the landslide inventory and the established vulnerability curves, the geographical distribution of the vulnerability to landslides is mapped and statistics of the expected damage are calculated. Reliability and limits of the vulnerability thresholds and of the obtained vulnerability assessment are discussed.  相似文献   
243.
INTRODUCTION: Although Musculoskeletal Disorders (MSD) represent a common occupational problem, few epidemiological studies have investigated MSD risk factors among Asian nurses, particularly those in Japan. METHOD: We administered a modified Japanese-language version of the Standardized Nordic Questionnaire to 1,162 nurses from a large teaching hospital. MSD categories focused on the neck, shoulder, upper back, and lower back regions. RESULTS: A total of 844 completed questionnaires were analyzed (response rate: 72.6%). The 12-month period-prevalence of MSD at any body site was 85.5%. MSD was most commonly reported at the shoulder (71.9%), followed by the lower back (71.3%), neck (54.7%), and upper back (33.9%). Alcohol consumption, tobacco smoking, and having children were shown to be significant risk factors, with adjusted Odds Ratios of 1.87 (95%CI: 1.17-2.96), 2.45 (95%CI: 1.43-4.35), and 2.53 (95%CI: 1.32-4.91), respectively. Workplace risk factors included manually handling patients (OR: 2.07 to 11.97) and undertaking physically laborious work (OR: 2.09 to 2.76). Nurses reporting pre-menstrual tension were 1.66 and 1.94 times more likely to suffer from lower back and upper back MSD, respectively. High mental pressure was also identified as a significant risk factor for MSD of the neck (OR: 1.53) and shoulder (OR: 2.07). IMPACT ON INDUSTRY: The complex nature of MSD risk factors identified during this study suggests that remediation strategies which focus only on manual handling tasks would probably be suboptimal in reducing MSD among nurses. Therefore, to help alleviate their considerable MSD burden, a greater emphasis will need to be placed on job satisfaction, work organization, and occupational stress, as well as the more traditional hazard reduction strategies such as manual handling, work tasks, and other occupational factors.  相似文献   
244.
Nanotechnology is a major innovative scientific and economic growth area, which may present a variety of hazards for environmental and human health. The surface properties and very small size of nanoparticles and nanotubes provide surfaces that may bind and transport toxic chemical pollutants, as well as possibly being toxic in their own right by generating reactive radicals. There is a wealth of evidence for the harmful effects of nanoscale combustion-derived particulates (ultrafines), which when inhaled can cause a number of pulmonary pathologies in mammals and humans. However, release of manufactured nanoparticles into the aquatic environment is largely an unknown. This review addresses the possible hazards associated with nanomaterials and harmful effects that may result from exposure of aquatic animals to nanoparticles. Possible nanoparticle association with naturally occurring colloids and particles is considered together with how this could affect their bioavailability and uptake into cells and organisms. Uptake by endocytotic routes are identified as probable major mechanisms of entry into cells; potentially leading to various types of toxic cell injury. The higher level consequences for damage to animal health, ecological risk and possible food chain risks for humans are also considered based on known behaviours and toxicities for inhaled and ingested nanoparticles in the terrestrial environment. It is concluded that a precautionary approach is required with individual evaluation of new nanomaterials for risk to the health of the environment. Although current toxicity testing protocols should be generally applicable to identify harmful effects associated with nanoparticles, research into new methods is required to address the special properties of nanomaterials.  相似文献   
245.
This paper evaluates how geographical theories of scale can give a more robust understanding of the governance of complex environmental risks. We assess the case of fisheries in Iwaki City, Fukushima Prefecture in Japan following the 2011 nuclear disaster. Fisheries in Iwaki and Fukushima more widely are operating on a trial basis as understanding of the marine radiation situation becomes clearer, however questions remain over whether consumers will buy produce and to what extent full-scale fisheries will resume. Based on empirical fieldwork undertaken in Fukushima plus supporting documentary analysis, we construct a scalar account of post-disaster Iwaki fisheries. We use this to argue that framing post-disaster fisheries governance at the municipal scale rather than the prefectural scale has opened up opportunities for enacting the more two-way forms of risk governance that contemporary environmental issues may require. We also argue locally-situated ‘experts’ (e.g. fisheries extension officers and citizen science groups) play a key role in negotiating citizens’ and fishers’ relationships with larger-scale scientific discourses due to their ability to work across scales, despite having less techno-scientific expertise than their national-level counterparts. In turn, we suggest that in governance of complex environmental issues, policymakers ought to (a) consider how community-level expectations may differ from risk governance processes developed at larger scales; (b) identify key institutions or figures who can work across scales and support them accordingly; and (c) show cognisance to the social effects that may arise from spatial demarcation of environmental problems.  相似文献   
246.
Italy is a country highly vulnerable to floods and landslides. The present study aims to investigate disaster preparedness and perception of flood risk in a group of people living in an alpine valley in the north of Italy. Four hundred seven adult residents in nine communities exposed to hydrogeological risk were interviewed by using a structured questionnaire. Participants were asked about the adoption of a set of protective behaviors that can prevent negative consequences of floods. Perception of flood risk was assessed by means of a one-dimensional scale that was developed and validated by the authors. Items included in this scale asked participants to estimate likelihood of occurrence of different flood consequences and to express feelings of worry associated to them. Socio-demographic and experiential information on respondents were also collected. Overall, results showed that most of respondents were fairly well prepared to deal with a future flood disaster. Correlational and regression analyses indicated that disaster preparedness was positively associated with risk perception. In accordance with literature, there was not a significant relation between likelihood judgments and adoption of protective behaviors, while feelings of worry were associated with disaster preparedness. Authors interpret their results in relation to the socio-environmental characteristics of the studied communities. Theoretical, empirical and practical implications of the findings are also discussed.  相似文献   
247.
Managing fishing threats to populations of endemic, threatened Hector’s and Māui dolphins around New Zealand is a complex and controversial issue, underpinned by uncertain scientific knowledge. As such, it can be argued that it falls into the realm of post-normal science, which advocates transparency about uncertainties and stakeholder peer review of knowledge feeding into decision-making. This paper focuses on selected examples of modelling and risk assessment research relating to Hector’s and Māui dolphin threat management. It explores how knowledge is developed, shared and utilised by decision-makers, finding that uncertain scientific knowledge may be shared in ways that make it appear more certain, with some of the subjectivities involved in knowledge production hidden from view. Interviews with stakeholders illustrate how some stakeholders are aware of the subjectivities involved when uncertain knowledge underpins decision-making, so a lack of transparency may be leading to erosion of social trust in decisions made. This in turn can lead to a lack of support for dolphin conservation measures from key stakeholders such as the commercial fishing industry. The paper concludes that while moves towards increasing transparency and stakeholder involvement are apparent, a deeper embrace of post-normal science approaches to knowledge production and dissemination would contribute to effective dolphin threat management in New Zealand.  相似文献   
248.
泥石流危险范围的模型实验预测法   总被引:6,自引:1,他引:6  
泥石流危险范围的模型实验预测旨在确定一次泥石流可能堆积泛滥的最大范围.通过泥石流不同冲出量、堆积区坡度和容重的31次模型实验,获取了泥石流堆积面积.最大堆积长度、宽度和厚度的实验数据.采用量纲分析方法,建立了一次泥石流危险范围的预测模型,并由实验资料确定了模型的修正系数.在云南和甘肃的应用实践表明,预测模型精度高,适用范围广,可在我国泥石流危险范围预测预报中使用.  相似文献   
249.
The linear dose-response model is considered a conservative, nonthreshold relationship. This is based on a confusion between the sufficient condition (that is, zero slope at zero dose) and the necessary condition (that is, response distinguishable from zero). Once the threshold is properly defined, it is shown that the linear model predicts thresholds for radiation data in good agreement with experimental results.  相似文献   
250.
Rockfalls are a common type of fast-moving slope failures, and in many countries they represent the primary cause of landslide fatalities. We present a methodology to ascertain rockfall hazard and to determine the associated risk along transportation networks. The proposed methodology is based on the combined analysis of the recurrence of rockfall events, determined from historical information, the frequency-volume statistics of rockfalls, obtained from inventories of recent rockfall triggering events, and the results of a physically based, spatially distributed rockfall simulation model used to determine rockfall hazard. The available information on rockfall hazard is combined in a Geographic Information System with a map of the transportation network to identify the road sections potentially subject to rockfalls. Information on the location and type of rockfall defensive measures, including revetment nets, elastic fences, concrete walls, and artificial tunnels, is used to estimate the efficacy of the defensive structures and to determine the level of the residual rockfall risk along the roads. To illustrate the methodology, we discuss an application in a 48-km2 area in the Nera River valley, in the Umbria Region of central Italy, where rockfalls are abundant, and where considerable investments were recently made to mitigate rockfall risk. Note: This version was published online in June 2005 with the cover date of August 2004.  相似文献   
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