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911.
Erik Vanem 《Safety Science》2012,50(4):958-967
Ethics are concerned with distinguishing between what actions are “right” and “wrong” and what values are “good” and “bad”, etc. and there is a long academic tradition in discussing ethics and ethical theories. Risk acceptance criteria, on the other hand, distinguish between levels of risks that are acceptable and levels that are intolerable. In some sense, one may say that risk acceptance criteria distinguishes between “good” and “bad” systems and activities with regards to the risk they expose the society or elements of a society to and there is thus an obvious link between ethics and risk acceptance criteria or to risk management at large. However, there are few references in the literature that explores this link, and in this paper, the ethical foundation of fundamental principles of risk acceptance criteria will be elaborated upon.This paper considers some important principles for establishing risk acceptance criteria for safety critical systems and activities. The various principles and the philosophies behind them might at first sight seem contradictory and exclusive, but it is demonstrated how they may coexist in one and the same regulatory regime; They may complement each other in order to achieve the overall safety objectives of society. Then, some brief considerations of the ethical foundations for the principles will be given and some relevant examples of actual risk acceptance criteria will be given from the maritime industries. However, it is believed that the principles and discussions are of general interest and apply to all areas of technical risk and to safety regulations in a broader perspective.  相似文献   
912.
泾河流域枯水复杂性研究   总被引:1,自引:0,他引:1  
枯水复杂性作为枯水的重要特征,在枯水研究中具有重要的意义。论文以泾河流域张家山水文站1933—2010年的月径流序列为研究对象,基于距平法和均值标准差法对比确定月枯水序列,基于近似熵(ApEn)分析枯水的复杂性。结果表明:1)年径流在0.01水平下呈现极显著的递减趋势,流域1997年以来发生枯水的频率越来越大。张家山水文站月枯水量上界为 9 369.67×104 m3,1、2和12月径流量小于月枯水量上界的月份比例远大于其他月份的比例,故以这3个月的月枯水组成枯水序列;2)枯水序列的ApEn值为1.059 1,与同期整个月径流序列的ApEn值(1.059 7)接近,说明发生于1、2和12月的15个非枯水月份径流对枯水序列的复杂度影响不大;3)月枯水复杂度在0.05水平下呈现显著的波动递增趋势,与月枯水径流呈显著的负相关关系,但与月降水量不显著相关,表明降水不是枯水径流系统的主要输入,降水量的变化对枯水复杂度的变化不起关键作用,而径流惯性可能是引起枯水复杂度变化的重要因素。  相似文献   
913.
Little information is available about the effects of watershed attributes on long-term stream chemical responses to reduced acidic deposition. Long-term chemical data (1980-2006) for 21 stream sites from the Appalachian Mountain region and data of 8 watershed attributes of the corresponding watersheds were analyzed to study such effects. Latent growth curve modeling (LGM), a structural equation modeling (SEM) approach, was conducted to quantify stream sensitivity to reduced acidic deposition in the region, and to model the initial chemical conditions (intercepts) and changing rates (slopes) in three time periods: 1980s, 1990s, and 2000s. The modeled chemical trends were generally consistent with those trends which were detected by trend analyses in a previous study. Watershed attributes including area, mean elevation, percentage of developed land, percentage of grassland, percentages of shale and sandstone, percentage of barren land, and percentage of soil type Gilpin-Upshur-Vandalia (GUV) were found to affect stream sensitivity to the reduced acidic deposition with their importance in the respective order. The stream sensitivity in turn regulated streams’ chemical initial conditions and their changing rates in the studied watersheds. This innovative application of LGM for modeling long-term chemical trends advanced our understanding of the role of watershed attributes in regulating streams’ responses to reduced acidic deposition. This approach can be applied for evaluating streams’ responses to acidic deposition in other regions and, more broadly, for studying causal effects on long-term behaviors in other ecological and environmental science subjects.  相似文献   
914.
Understanding the environmental consequences of changing water regimes is a daunting challenge for both resource managers and ecologists. Balancing human demands for fresh water with the needs of the environment for water in appropriate amounts and at the appropriate times are shaping the ways by which this natural resource will be used in the future. Based on past decisions that have rendered many freshwater resources unsuitable for use, we argue that river systems have a fundamental need for appropriate amounts and timing of water to maintain their biophysical integrity. Biophysical integrity is fundamental for the formulation of future sustainable management strategies. This article addresses three basic ecological principles driving the biogeochemical cycle of nitrogen in river systems. These are (1) how the mode of nitrogen delivery affects river ecosystem functioning, (2) how increasing contact between water and soil or sediment increases nitrogen retention and processing, and (3) the role of floods and droughts as important natural events that strongly influence pathways of nitrogen cycling in fluvial systems. New challenges related to the cumulative impact of water regime change, the scale of appraisal of these impacts, and the determination of the impacts due to natural and human changes are discussed. It is suggested that cost of long-term and long-distance cumulative impacts of hydrological changes should be evaluated against short-term economic benefits to determine the real environmental costs.  相似文献   
915.
区域管制在实现国家资源安全过程中的作用研究   总被引:2,自引:0,他引:2  
本文分析了国家资源安全的特点 ,提出区域管制是实现国家资源安全的重要手段。认为建立资源市场 ,对自然资源进行资产化管理 ,制定资源开发利用技术标准 ,实行资源开发许可审批制度 ,采取激励政策 ,建立安全押金制度是实现国家资源安全的重要途径  相似文献   
916.
气象水文要素对流域产沙量和输沙量影响研究   总被引:1,自引:0,他引:1  
选取年降雨量和流量等气象水文要素作因子,应用B-P神经网格,建立渠江流域毛坝、车林两站的年均含沙量和输沙量的预测模型。其模型拟合合格率达90%以上,预留预测检验合格率达80%以上。  相似文献   
917.
Ecology and culture comprise interacting components of landscapes. Understanding the integrative nature of the landscape is essential to establish methods for sustainable management. This research takes as a unifying theme the idea that ecological and cultural issues can be incorporated through management. As a first step in developing integrative management strategies, information must be collected that compares and contrasts ecological and cultural issues to identify their areas of intersection. Specifically how can local cultural knowledge enable water resource management that reflects cultural and ecological values? This research examines Native American cultural knowledge for setting water resource management priorities in the Wind River Indian Reservation in central Wyoming. A cross-cultural approach is adopted to assess the relationship between indigenous cultural knowledge and Euro-American perspectives through a comparative examination of the Wind River Water Code and Wyoming Water Law. This research indicates that cultural perspectives provide a rich arena in which to examine management issues. Understanding and identifying cultural practices may be an important first step in collaborative resource management between different cultural groups to prevent conflict and lengthy resolution in court.  相似文献   
918.
As part of a comparative watershed project investigating land-cover/land-use disturbance gradients for streams in the western Lake Superior Basin, we examined general relationships between landscape character and fish assemblage structure and function. We also examined the shape of those relationships to identify discontinuity thresholds where small changes in landscape character were associated with marked shifts in the fish assemblages. After completing a geographic analysis of second- and third-order watersheds in the western Lake Superior drainage, we randomly selected 48 streams along mature forest and watershed storage gradients in 2 hydrogeomorphic regions as our study sites. During the summers of 1997 and 1998, we used electrofishing to sample fish assemblages from each stream. Each of the landscape factors was significantly associated with fish assemblage structure and function based on analysis of covariance. Watershed storage was related to the greatest number of fish assemblage characteristics, but hydrogeopmorphic region and mature forest cover were strongly associated as well. The hydrogeomorphic region also mediated relationships between watershed character and fish assemblages. Discontinuity thresholds for our fish assemblages averaged 11% for watershed storage and 50% for watershed mature forest cover based on piecewise regression analysis. Although many of the landscape–fish relationships might have been manifest through effects on in-stream habitat, our results highlight the importance of management and land-use planning decisions at the watershed and landscape scales.Published online  相似文献   
919.
Watershed management requires integration of social and ecological understanding. Participatory approaches to planning and management incorporate stakeholder knowledge and understanding. An action research strategy using focus groups with Michigan State University operations units helped generate a soft systems model of watershed impacts of organizational decision-making regarding road de-icing. The results reveal tensions and inconsistencies between the mission and operation of the institution. These tensions are exacerbated by inadequate communication among various elements of the campus watershed management system. The action research approach facilitated the researchers understanding of the complex institutional system and helped identify possible areas for making improvements. Specifically, the researchers were able to facilitate improvement in some linkages between scientists developing campus watershed models and the operations staff responsible for handling many of the inputs being modeled.  相似文献   
920.
Resolving Conflict and Building Cooperation in the National Estuary Program   总被引:1,自引:1,他引:0  
Since its beginning in 1987, researchers and policymakers have touted the US Environmental Protection Agency National Estuary program (NEP) as one of the leading examples of collaborative institutions designed to resolve conflict and build cooperation at the watershed level. Using the NEP as an example, I summarize the advantages and disadvantages of collaborative institutions. Using data gathered from focused surveys of policy elites in 22 estuaries, I estimate statistical models that show the NEP does a better job of resolving conflict and building project-level cooperation than similar estuaries without the NEP. I also describe the activities of the NEP mentioned by respondents as contributing to this outcome.  相似文献   
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