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251.
Faced with an intermittent but potent threat, animals exhibit behavior that allows them to balance foraging needs and avoid predators and over time, these behaviors can become hard-wired adaptations with both species trying to maximize their own fitness. In systems where both predator and prey share similar sensory modalities and cognitive abilities, such as with marine mammals, the dynamic nature of predator-prey interactions is poorly understood. The costs and benefits of these anti-predator adaptations need to be evaluated and quantified based on the dynamic engagement of predator and prey. Many theoretic models have addressed the complexity of predator-prey relationships, but few have translated into testable mechanistic models. In this study, we developed a spatially-explicit, geo-referenced, individual-based model of a prototypical adult dusky dolphin off Kaikoura, New Zealand facing a more powerful, yet infrequent predator, the killer whale. We were interested in two primary objectives, (1) to capture the varying behavioral game between a clever prey and clever predator based on our current understanding of the Kaikoura system, (2) to compare evolutionary costs vs. benefits (foraging time and number of predator encounters) for an adult non-maternal dusky dolphin at various levels of killer whale-avoidance behaviors and no avoidance rules. We conducted Monte Carlo simulations to address model performance and parametric uncertainty. Mantel tests revealed an 88% correlation (426 × 426 distance matrix, km2) between observed field sightings of dusky dolphins with model generated sightings for non-maternal adult dusky dolphin groups. Simulation results indicated that dusky dolphins incur a 2.7% loss in feeding time by evolving the anti-predator behavior of moving to and from the feeding grounds. Further, each evolutionary strategy we explored resulted in dolphins incurring an additional loss of foraging time. At low killer whale densities (appearing less than once every 3 days), each evolutionary strategy simulated converged towards the evolutionary cost of foraging, that is, the loss in foraging time approached the 2.7% loss experienced by evolving near shore-offshore movement behavior. However, the highest level of killer whale presence resulted in 38% decreases in foraging time. The biological significance of these losses potentially incurred by a dusky dolphin is dependent on various factors from dolphin group foraging behavior and individual energy needs to dolphin prey availability and behavior.  相似文献   
252.
SUMMARY

In order to use the planet's ecological life-support systems sustainably, damage to them must be both prevented and repaired. However, repair requires awareness of damage which, in this case, mandates a high level of ecological literacy. Prevention of ecological damage will only be successful on a planetary scale if human society endorses precautionary practices that reduce the probability of ecosystem damage. Society is beginning to endorse precautionary practices to protect human health, which is no longer regarded as merely absence of symptoms of disease and malfunction. Health is regarded as a robust function — an approach toward optimal conditions. Similar views are beginning to emerge regarding ecosystem health, and a close link between human and ecosystem health is gaining increased recognition. However, to achieve health, ecological ‘wounds’ must be repaired, which is impossible until society ‘sees’ the wounds. After this recognition, society must become more literate on the attributes of ecosystem health. The methods and procedures are in place, but they will not be used effectively until a major paradigm shift occurs.  相似文献   
253.
The failure of food security and livelihood interventions to adapt to conflict settings remains a key challenge in humanitarian responses to protracted crises. This paper proposes a social capital analysis to address this policy gap, adding a political economy dimension on food security and conflict to the actor‐based livelihood framework. A case study of three hillsides in north Burundi provides an ethnographic basis for this hypothesis. While relying on a theoretical framework in which different combinations of social capital (bonding, bridging, and linking) account for a diverse range of outcomes, the findings offer empirical insights into how social capital portfolios adapt to a protracted crisis. It is argued that these social capital adaptations have the effect of changing livelihood policies, institutions, and processes (PIPs), and clarify the impact of the distribution of power and powerlessness on food security issues. In addition, they represent a solid way of integrating political economy concerns into the livelihood framework.  相似文献   
254.
《Environmental Hazards》2013,12(5):414-433
ABSTRACT

The paper updates normalisation of the Insurance Council of Australia’s Disaster List in the light of debate about the contribution of global warming to the rising cost of natural disasters. Normalisation estimates losses from historical events in a common year, here ‘season’ 2017 defined as the 12-month period from 1 July 2017. The number and nominal cost of new residential dwellings are key normalising factors and post-1974 improvements in construction standards in tropical cyclone-prone parts of the country are explicitly allowed for. 94% of the normalised losses arise from weather-related perils – bushfires, tropical cyclones, floods and severe storms – with the 1999 Sydney hailstorm the most costly single event (AUD5.6 billion). When aggregated by season, there is no trend in normalised losses from weather-related perils; in other words, after we normalise for changes we know to have taken place, no residual signal remains to be explained by changes in the occurrence of extreme weather events, regardless of cause. In sum, the rising cost of natural disasters is being driven by where and how we chose to live and with more people living in vulnerable locations with more to lose, natural disasters remain an important problem irrespective of a warming climate.  相似文献   
255.
The expansion of protected areas is a critical component of strategies to promote the continued existence of biodiversity (i.e., life at all levels of biological organization) as climate changes, but scientific, social, and economic uncertainties associated with climate change are some of the major obstacles preventing such expansion. New models of climate change and species distribution and new methods of conservation planning now make it possible to explore the uncertainties associated with climate changes and species responses. Yet few reliable estimates of the costs of expanding protected areas and methods for determining these costs exist, largely because of the many (and uncertain) determinants of these costs. We developed a cost-accounting model to estimate the range in costs of various options for expanding protected areas and to explore the variables that drive these costs. Model development was informed by an existing plan to expand protected areas in the Cape Floristic Region of South Africa to address species conservation under a scenario of climate change. The 50-year present value of total costs varied from US$260 million ($1077/ha) for an off-reserve option that involves agreements with landowners and no compensation of forgone production and associated revenue to $1020 million ($4228/ha) for an on-reserve option that involves land acquisition and protection. The costs of acquiring land or compensating landowners for forgone production and development opportunities were the major drivers of the total costs across all options because most of the area identified in the protected-area expansion plan consisted of urban and high-quality agricultural lands. Total costs were also affected by changes in protected area extent and discount rate. Model-generated outputs such as these may be useful for informing implementation strategies and the allocation of future efforts in monitoring, data collection, and model development.  相似文献   
256.
Any opinions and conclusions expressed herein are those of the author(s) and do not necessarily represent the views of the U.S. Census Bureau or the U.S. Environmental Protection Agency. All results have been reviewed to ensure that no confidential information is disclosed. We thank Wang Jin and Shital Sharma for excellent research assistance; we also thank Jim Davis at the Boston Research Data Center for his continued help, and Reed Walker and participants at the 2011 AERE Summer Conference and the Environmental Economics seminar at Harvard University?s Kennedy School for helpful comments. Any remaining errors are ours.  相似文献   
257.
依据资本观、能力观等相关理论,构建了以情绪智力为中介变量的施工企业内社会资本与安全绩效关系的理论模型,并以156家施工企业为调查对象而获取的数据进行多元回归分析。研究结果表明:员工情绪智力在施工企业内社会资本的结构维度、关系维度与安全绩效之间起到完全中介作用,在认知维度与安全绩效之间起到部分中介作用。因此,施工企业应该重视企业内社会资本的积累,同时加强员工情绪智力的提升,提高安全绩效。  相似文献   
258.
This paper analyzes the economic implications of an environmental policy when we account for the life expectancy of heterogeneous agents. In a framework in which everyone suffers from pollution but health status also depends on individual human capital, we find that the economy may be stuck in a trap in which inequality rises steadily, especially when the initial pollution intensity of production is too high. We emphasize that such inequality is in the long run costly for the economy in terms of health and growth. Therefore, we study whether a tax on pollution associated with an investment in pollution abatement can be used to address this situation. We show that a stricter environmental policy may allow the economy to escape from the inequality trap while enhancing the long-term growth rate when the initial inequality in human capital is not too large.  相似文献   
259.
Energy efficiency plays an important role in reducing the carbon externality from buildings, but economic analyses of more efficient, green building have thus far ignored input costs. This paper finds that the average marginal cost of green-labeled construction projects is smaller than the value premiums documented in the literature. However, design fees, representing just a fraction of development costs but paid largely up-front, are significantly higher for green construction projects. These projects also take longer to complete. The results provide some insight into the market barriers and market failures that may explain the relatively slow adoption of otherwise economically rational green construction practices.  相似文献   
260.
Home buyout programs facilitate the permanent relocation of residents away from areas considered to be at risk from future hazards, though few studies have examined the impacts of home buyout programs on affected households and communities beyond the program implementation period. In this paper, we examine between-neighborhood variation in key recovery indicators for three neighborhoods that followed different paths to recovery after Hurricane Sandy: one that rebuilt in situ, one that participated in a buyout and relocated, and one located immediately adjacent to the buyout zone. Three years post-disaster, buyout participants are faring worse in terms of place attachment and social capital compared to residents in the other two neighborhoods, while the neighborhood adjacent to the buyout zone is also showing signs of decline. These findings suggest that the social costs of buyouts extend well into the recovery period, and that the place-based ties and social networks that would typically help individuals cope with disaster impacts and persevere through adversity may be diminished for buyout participants, ultimately hindering their recovery. We conclude with a discussion of the implications of buyouts on participating and affected communities, as well as implications for research and policy.  相似文献   
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