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   93篇
  免费   7篇
安全科学   21篇
环保管理   25篇
综合类   26篇
基础理论   12篇
环境理论   1篇
污染及防治   1篇
评价与监测   8篇
社会与环境   6篇
  2023年   1篇
  2022年   2篇
  2021年   1篇
  2020年   4篇
  2019年   3篇
  2018年   3篇
  2017年   3篇
  2016年   4篇
  2015年   4篇
  2014年   6篇
  2013年   9篇
  2012年   10篇
  2011年   9篇
  2010年   5篇
  2009年   6篇
  2008年   2篇
  2007年   5篇
  2006年   5篇
  2005年   4篇
  2004年   1篇
  2003年   3篇
  2002年   3篇
  2001年   1篇
  2000年   2篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1978年   1篇
排序方式: 共有100条查询结果,搜索用时 31 毫秒
51.
ABSTRACT: Arizona's water pollution control program is based on authorties of Arizona Revised Statutes and Public Law 92–500, the Federal Water Pollution Control Act Amendments of 1972. The primary areas of this program are monitoring, facility inspections, plan review, planning, discharge permits and grants for the construction of publicly-owned waste water treatment facilities. The discharge permit program deals with control of point-source discharges and is administered by the United States Environmental Protection Agency. The planning and construction grants programs are administered by the State Water Quality Control Council and are implemented by the Bureau of Water Quality Control, which serves as staff to the Council. There are several challenges that face the State in this program. First is the adaptation of the “eastern law” to deal with Arizona's water quality problems. Second is to address problems caused by a long history of “laissez-faire” environmental quality management. Third is a mutual cooperation and coordination among the many entities involved in water resources management. Areas of particular interest in the State's program is the process setting water quality standards and the involvement of people of diversified backgrounds in the field of areawide planning under Section 208 of the Federal Water Pollution Control Act, which is primarily concerned with non-point sources of water pollution.  相似文献   
52.
This article examines the relationship between increased metal mining and sustainable development in the eastern section of the Amazonian state of Pará in Brazil. Since the early 1980s, mining has grown rapidly in Pará and local mining operations have become global leaders in the production of iron, manganese, bauxite, aluminum, gold, copper and — in the near future — nickel. To stay in tune with global standards, these companies have committed themselves to the principles of sustainability and have obtained certification for both social and environmental aspects of their activities. The article looks into whether such certification is linked to sustainable development of the relatively poor regions where these companies operate. The main findings are that: (1) there is a visible association between certification and improved performance by the companies, but not with the development of nearby areas; and (2) social‐environmental certification processes place more emphasis on ecological variables than on social ones.  相似文献   
53.
电力施工是高强度露天作业,流动性和机动性比较强,往往出现习惯性违章作业,所以必须加强各项安全管理工作。本文从提高企业核心竞争力和加强企业内部综合管理水平两个方面论述了实施管理体系认证工作的必要性,并指出企业实施管理体系认证过程中的不正确看法,提出体系认证工作中应重点做好危险辨识、建立体系文件等方面的工作,企业通过实施管理体系认证工作后,可以掌握先进的工作思路、形成良好的习惯,建立现代管理模式,使体系认证工作切实起到稳定企业的安全生产的局面。  相似文献   
54.
显示触控系统人为因素适航符合性验证技术   总被引:1,自引:0,他引:1  
为解决传统人为因素适航符合性验证技术对先进驾驶舱显示触控系统设计的不适用性问题,首先,详细阐述显示触控系统的技术特点;然后,依据相关适航条款,确定显示触控系统在人为因素适航审定中需重点考虑的要素和审定计划的条理性方法;最后,结合符合性验证可能产生的问题,给出显示触控系统人为因素符合性验证要求及实现方法.结果 表明:人为...  相似文献   
55.
Abstract:  Many tropical forests have been converted for agri- or silviculture or a combination of both (agroforestry). Conservation at a landscape scale requires an understanding of the distribution and abundance of native biodiversity in these converted natural ecosystems, of which the knowledge is especially poor for African agroecosystems. We compared species density and species composition of four plant groups (trees and shrubs, epiphytic vascular plants, mosses, and liverworts) among three arboreal land-use types in southwestern Ethiopia (montane rainforest fragments, shade-tree coffee home gardens, and exotic tree plantations). Species density was significantly higher in forests than in coffee home gardens for all plant groups and in exotic tree plantations for all groups except mosses. Home gardens had more vascular epiphytic species than plantations, whereas the reverse was true for mosses and liverworts. The species composition of the forest plots was sometimes more similar to home-garden plots than plantation plots and sometimes vice versa. Fifteen forest plots had, however, cumulatively more species than a random selection of 15 nonforest (coffee home garden and plantation) plots, even if the 2 plot types complemented each other in terms of habitats for forest plants. Tree plantations dominated by Eucalyptus had many small trees and shrubs in common with forests, whereas plantations with Cupressus were important substrates for forests mosses and liverworts. Our results illustrate the importance of undisturbed forests habitats for conservation of species at a landscape scale and that different human-made land-use types may complement each other in their capacity as additional habitats for forest species.  相似文献   
56.
During the last decade, forest certification has gained momentum as a market-based conservation strategy in tropical forest countries. Certification has been promoted to enhance forest management in countries where governance capacities are insufficient to adequately manage natural resources and enforce pertinent regulations, given that certification relies largely on non-governmental organisations and private businesses. However, at present there are few tropical countries with large areas of certified forests. In this study, we conducted semi-structured stakeholder interviews in Ecuador and Bolivia to identify key framework conditions that influence the costs and benefits for companies to switch from conventional to certified forestry operations. Bolivia has a much greater relative area under certified forest management than Ecuador and also significantly more certified producers. The difference in the success of certification between both countries is particularly notable because Bolivia is a poorer country with more widespread corruption, and is landlocked with less access to export routes. Despite these factors, several characteristics of the Bolivian forest industry contribute to lower additional costs of certified forest management compared to Ecuador. Bolivia has stronger government enforcement of forestry regulations a fact that increases the cost of illegal logging, management units are larger, and vertical integration in the process chain from timber extraction to markets is higher. Moreover, forestry laws in Bolivia are highly compatible with certification requirements, and the government provides significant tax benefits to certified producers. Results from this study suggest that certification can be successful in countries where governments have limited governance capacity. However, the economic incentives for certification do not only arise from favourable market conditions. Certification is likely to be more successful where governments enforce forestry laws, provide financial incentives for certified forestry, and provide land tenure security, and where large-scale and vertically integrated forestry operations are commercially feasible. For this reason, at present, there are few developing countries where forest certification is likely to achieve widespread success.  相似文献   
57.
民用飞机闪电分区适航验证技术研究进展   总被引:1,自引:0,他引:1  
闪电是自然界常见的一种物理现象,据统计,全世界每秒可发生几百次闪电.雷击的结果或多或少都会影响飞行安全,对闪电效应的分析是评估闪电防护的基础.本文介绍了闪电对飞机的危害和闪电分区技术的相关概念,综述了近年来国内外有关飞机闪电分区适航验证技术应用的研究成果及其发展前景.指出我国在飞机闪电分区技术研究方面主要存在以下问题:一是闪电防护分区技术相关适航规章与文件体系还尚未完善;二是闪电分区技术研究手段单一,集中在实物试验方面,尚未针对性开展仿真及数值分析技术研究.最后,结合闪电防护发展中存在的问题及其最新研究成果,提出了仿真模拟应与实物试验并重的设想,为飞机适航验证技术的发展提供参考.  相似文献   
58.
Sustainable practices at construction sites should be considered from the start of the project, meaning during the design phase. A model for the implementation of sustainability at a site is an important management tool, and its adoption can indicate good practices and propose an assessment of local conditions. Thus, the main contribution of this article is to propose a practical model to evaluate the level of implementation of sustainable practices at construction sites. The model was based on sustainability certifications and validated at six construction sites in Brazil. The results indicate that construction companies that possess environmental certifications have better levels of implementation of good practices at their work sites. However, it was noted that it is not necessary for a company to obtain an environmental certification; rather, it is necessary for sustainability strategies to become corporate culture.  相似文献   
59.
安全系统的功能安全是基于整体安全生命周期的风险控制与管理,是安全管理学和安全监控技术的新发展。有效的开展功能安全相关工作是进一步落实科技兴安战略和预防为主方针的必然要求,对于减低安全生产事故风险,提高安全监控监管监察效能,缩小安全技术差距具有重要意义。实施功能安全相关工作需要各行业协调行动,从战略高度进行综合分析、宏观设计、统筹安排和合理规划。对功能安全研究与应用、安全生产法规标准、产业发展、科研试验、人才队伍等方面进行了探讨,在加大功能安全相关研发投入,增强科技扶持力度,提高功能安全准入门槛,建设功能安全认证服务机构,发展功能安全产业,培养功能安全专业人才等方面提出了相应的建议措施。  相似文献   
60.
Forest degradation in the tropics is often associated with roads built for selective logging. The protection of intact forest landscapes (IFL) that are not accessible by roads is high on the biodiversity conservation agenda and a challenge for logging concessions certified by the Forest Stewardship Council (FSC). A frequently advocated conservation objective is to maximize the retention of roadless space, a concept that is based on distance to the nearest road from any point. We developed a novel use of the empty‐space function – a general statistical tool based on stochastic geometry and random sets theory – to calculate roadless space in a part of the Congo Basin where road networks have been expanding rapidly. We compared the temporal development of roadless space in certified and uncertified logging concessions inside and outside areas declared IFL in 2000. Inside IFLs, road‐network expansion led to a decrease in roadless space by more than half from 1999 to 2007. After 2007, loss leveled out in most areas to close to 0 due to an equilibrium between newly built roads and abandoned roads that became revegetated. However, concessions in IFL certified by FSC since around 2007 continuously lost roadless space and reached a level comparable to all other concessions. Only national parks remained mostly roadless. We recommend that forest‐management policies make the preservation of large connected forest areas a top priority by effectively monitoring – and limiting – the occupation of space by roads that are permanently accessible.  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