首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   111篇
  免费   3篇
  国内免费   1篇
安全科学   11篇
废物处理   1篇
环保管理   51篇
综合类   15篇
基础理论   24篇
污染及防治   4篇
评价与监测   4篇
社会与环境   4篇
灾害及防治   1篇
  2023年   2篇
  2022年   1篇
  2021年   2篇
  2020年   2篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2016年   5篇
  2015年   1篇
  2014年   1篇
  2013年   3篇
  2012年   6篇
  2011年   17篇
  2010年   3篇
  2009年   11篇
  2008年   4篇
  2007年   2篇
  2006年   6篇
  2005年   4篇
  2004年   4篇
  2003年   5篇
  2002年   2篇
  2000年   3篇
  1999年   1篇
  1998年   2篇
  1997年   2篇
  1995年   2篇
  1994年   1篇
  1992年   1篇
  1990年   2篇
  1989年   2篇
  1987年   1篇
  1986年   1篇
  1985年   2篇
  1984年   2篇
  1983年   1篇
  1980年   2篇
  1977年   1篇
  1976年   1篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
排序方式: 共有115条查询结果,搜索用时 15 毫秒
41.
Abstract:  Many endangered species depend on certain types of agricultural or other forms of human land use. To conserve such species, schemes are set up in which land users receive payments for voluntarily managing their land in a biodiversity-enhancing manner. We developed a model-based framework for designing cost-effective payment schemes that generate spatiotemporal habitat heterogeneity to maximize the survival of multiple species under budget constraints. The framework integrates ecological and economic knowledge and consists of the derivation of an ecological benefit function and a budget function that are then combined to determine the cost-effective degree of spatiotemporal habitat heterogeneity. The ecological benefit function considers the timing of conservation measures, the induced habitat dynamics, and different degrees of substitutability among species. The budget function considers that the conservation agency may lack information about land users' individual conservation costs and personal attitudes and that land users can choose among different conservation measures. We applied the framework to a case study of grassland management, where the survival of three endangered species protected by the EU Habitats Directive depends on different types of land use. The lack of information available to the agency and the choice options of land users reduced the amount of conservation that can be financed with a given budget. Neglecting such findings may lead to an overestimation of the benefits of conservation programs.  相似文献   
42.
Abstract: Current networks of protected areas are biased in many countries toward landscapes of low productivity. Voluntary conservation incentives have been suggested as a socially acceptable way to supplement existing networks with more productive, privately owned areas of high priority for nature conservation. The limited resources committed to nature conservation demand cost‐efficiency. Efficiency, however, depends not only on costs incurred to society from alternative ways of maintaining biodiversity but also on ecological values that can be captured. We examined the ecological efficiency of the new market‐based voluntary program to preserve forest habitats on private land in southwestern Finland. We compared sites that have become protected (10‐year contracts) in the program with managed forests, with sites that have been negotiated for protection for which no contract has been signed, and with the most ecologically valuable privately owned sites in the region that have not been offered for protection by forest owners. We surveyed sites for the amount of dead wood, wood‐decomposing fungi, and epiphytic lichens to evaluate their ecological quality. Contracted sites had more features important for overall biodiversity than managed forests and negotiated sites with no contract. These results indicate that procedures used during site selection and negotiations were appropriate and not opportunistic. The contracted sites were also as valuable in ecological terms as the best, still‐unprotected, privately owned forests in the region that have not been offered for protection. We conclude that voluntary conservation programs have the potential to yield ecologically valuable sites for protection if the site‐selection procedures are appropriate. Reliance on completely voluntary programs, however, may entail uncertainties and inadequacies, for example, in terms of spatial configuration and persistence of the ecological values. Thus, such programs may often need to be supplemented with alternative methods such as land purchase to achieve an ecologically effective network of protected sites.  相似文献   
43.
The article quantifies the size of ‘hidden’ social costs that are incurred by forestry offsets in the voluntary market that promise to offset present emissions sometime in the future. It does this by estimating the difference between the social costs of carbon (C) emitted and of costs offset by removal of C from the atmosphere by reforestation/afforestation. All current attempts to make forestry offsets more reliable focus on quality control rather than the mismatch of the timing of emissions and their offset. Recommendations that follow from the analysis are twofold. First, that markets for carbon dioxide equivalent (CO2e) removals by voluntary offsets should be confined to the annual incremental removals actually achieved. Second, the promoters of voluntary offsets projects should declare the annual stream of carbon credits and debits expected so that buyers can place a present value on such projects.  相似文献   
44.
Many voluntary incentive programs for provision of forest ecosystem services (ES) have low participation rates, insufficient enrollment areas, and inefficient ecological outcomes. Understanding participation behavior in such programs has therefore become a crucial part of policy success. We synthesized a large body of literature on the behavior of nonindustrial private forest owners based on surveys of stated (intended) participation or data on actual participation in existing or hypothetical programs. Using metaregression analysis, we examined how methodological, program-characteristic, and economic-incentive variables affected participation rate estimates. Participation rates tended to be overestimated when landowner participation was elicited in hypothetical choice situations (compared with real situations) and when dichotomous choice surveys (compared with census data) were used. The marginal effect sizes were quite large, for example, a 31% increase with use of stated choices in hypothetical scenarios, and practitioners should therefore be aware of them. However, use of choice experiment surveys in a modified scenario based on existing programs had no effect on participation when all other determinants were controlled for. Participation rates decreased significantly as length of the contract increased and when there was no withdrawal option. These results suggest that perpetual contracts have a lower negative impact on participation than time-limited contracts with a duration of over 50 years. We confirmed that as compensation amounts increased, participation increased. One-time up-front payments were more effective in increasing initial participation than annual payments for contracts of over 5 years. We identified the robust determinants and the effect sizes of those determinants on landowner participation rate estimates, thereby contributing to a better understanding of forest owner behavior and offering useful insights to enable researchers and resource managers to improve the design and efficiency of new and existing forest ES programs.  相似文献   
45.
G. D. Edkins   《Safety Science》1998,30(3):275-295
A number of recent and highly publicised fatal aircraft accidents, within the Australian regional airline industry, has highlighted the need for operators of regular public transport aircraft to be more proactive in identifying and addressing aviation safety hazards. Despite this need, there are currently few proactive safety management programs that are practical, simple, cost effective and which reliably demonstrate improvements in airline safety performance. This paper outlines a new proactive airline safety program called INDICATE (Identifying Needed Defences In the Civil Aviation Transport Environment) that has been applied within the Australian regional airline industry. To evaluate the INDICATE program, a major Australian regional airline agreed to implement the program in one of its operational bases while another base was used as a control group. Five evaluation criteria were applied to determine whether the program would have a positive influence on the airline's safety performance. These criteria included airline safety culture, staff risk perception of aviation safety hazards, willingness of staff to report safety hazards, action taken on identified safety hazards and staff comments about safety management within the airline. Results from the trial suggest that the program can have a positive influence on airline safety performance, specifically: improving staff confidence in how safety is managed, increasing staff willingness to report safety hazards and incidents, improving organisational safety culture and reducing staff perceptions of the severity and likelihood of safety hazards occurring within the airline. The success of the trial has resulted in a number of Australian and International airlines adopting the program.  相似文献   
46.
47.
Recent studies have predicted that the costs and benefits of curbside recycling programs will vary considerably across municipalities. In this paper, we examine how the characteristics of municipalities are reflected in curbside recycling policies. Our analysis of Japanese municipal data reveals that municipalities implement recycling programs that fit the demographic profiles of their residents. Municipalities with a considerable number of single-recycler households tend to implement simple waste separation programs. The labor market positions of spouses have different impacts on recycling policies. We further find that the municipalities implementing comprehensive recycling programs collect plastic bottles and containers more frequently than do other municipalities. This implies that the municipalities need to take measures to effectively execute comprehensive recycling programs after implementing them.  相似文献   
48.
针对四川省甘孜州白玉县赠曲河流域开发规划进行了分析,发现在该流域实施梯级电站建设,存在淹没实物指标较大、破坏保护鱼类栖息地和淹没尾矿库等问题。论文结合当地环境条件和防护要求,从环境保护角度提出了调整规划河段范围、放弃支沟引水、调整梯级正常蓄水位和枢纽布置以及搬迁尾矿库等优化调整方案,为规划的合理实施和规划环评的开展提供了可资借鉴的参考。  相似文献   
49.
Using Japanese facility-level data, we estimate the effects of ISO 14001 certification on the promotion of more advanced practices, namely green supply chain management (GSCM). Our results show that ISO 14001 promotes GSCM practices. Facilities with environmental management systems (EMS) certified to ISO 14001 are 40% more likely to assess their suppliers' environmental performance and 50% more likely to require that their suppliers undertake specific environmental practices. Further, government programs that encourage voluntary EMS adoption indirectly promote GSCM practices. These programs increase the probabilities that facilities will assess their suppliers' environmental performance and require suppliers to undertake specific environmental practices by 7% and 8%, respectively. Combined, these findings suggest that there may be significant but previously unnoticed spillover effects of ISO 14001 and government promotion of voluntary action.  相似文献   
50.
Green clubs     
This paper treats programs in which firms voluntarily agree to meet environmental standards as “green clubs”: clubs, because they provide non-rival but excludable reputation benefits to participating firms; green, because they also generate environmental public goods. The model illuminates a central tension between the congestion externality familiar from conventional club theory and the free-riding externality familiar from the theory on private provision of public goods. We compare three common program sponsors—governments, industry, and environmental groups. We find that if monitoring of the club standard is perfect, a government constrained from regulating club size may prefer to leave sponsorship to industry if public-good benefits are sufficiently low, or to environmentalists if public-good benefits are sufficiently high. If monitoring is imperfect, an important question is whether consumers can infer that a club is too large for its standard to be credible. If they can then the government may deliberately choose an imperfect monitoring mechanism as a way of regulating club size indirectly. If they cannot then this reinforces the government's preference for delegating sponsorship.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号