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   771篇
  免费   60篇
  国内免费   66篇
安全科学   85篇
废物处理   11篇
环保管理   235篇
综合类   287篇
基础理论   98篇
环境理论   1篇
污染及防治   30篇
评价与监测   29篇
社会与环境   114篇
灾害及防治   7篇
  2024年   1篇
  2023年   13篇
  2022年   28篇
  2021年   23篇
  2020年   32篇
  2019年   26篇
  2018年   25篇
  2017年   42篇
  2016年   39篇
  2015年   34篇
  2014年   34篇
  2013年   48篇
  2012年   44篇
  2011年   55篇
  2010年   18篇
  2009年   29篇
  2008年   22篇
  2007年   34篇
  2006年   31篇
  2005年   27篇
  2004年   32篇
  2003年   28篇
  2002年   37篇
  2001年   20篇
  2000年   25篇
  1999年   21篇
  1998年   24篇
  1997年   19篇
  1996年   19篇
  1995年   16篇
  1994年   10篇
  1993年   6篇
  1992年   8篇
  1991年   3篇
  1990年   1篇
  1989年   2篇
  1988年   5篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   1篇
  1980年   1篇
  1978年   2篇
  1976年   1篇
  1972年   1篇
排序方式: 共有897条查询结果,搜索用时 812 毫秒
441.
笔者简要回顾了我国安全生产工作在不同时期和不同阶段所使用的劳动保护、劳动安全卫生、职业安全卫生、职业健康安全及职业安全健康等概念 ,并对各自的研究对象和内涵进行了分析和探讨 ,提出了职业健康安全和职业安全健康应使用统一术语的建议  相似文献   
442.
罗蓉 《四川环境》2004,23(4):75-77
本文通过对我国土地现状、土地政策的特点以及土地政策与法律的区别来阐述土地政策亟需规范的必要性,并提出了相应的对策、措施,以期有助于缓解我国目前土地政策因缺乏规范、监控而造成大量土地被非法征用、开发、转让的局面。  相似文献   
443.
This article examines a number of issues connected with the development of small-scale hydroelectric power and related investments in Nepal. The micro-hydro investment scheme in Barpak village serves as a case study, and the article also presents a number of related issues discussed against the background of the evolution of micro-hydro power in Nepal. The article outlines the success of micro-hydro development, modest in relation to its enormous potential, the realization of which depends on whether a number of challenges and constraints can be overcome. The article closes with suggestions on implementing sustainable micro-hydro development in rural areas, based on the Barpak experience and the authors' other recent studies of rural energy issues in Nepal.  相似文献   
444.
古河道是一种由形态、物质组成的国土资源,各大江河冲积平原均有分布。利用古河道资源可蒸制灰砂砖,开采泥炭、砂料和地下水,发展旅游产业和多种经营,尤其是在半干旱、半湿润地区利用古河道建设地下水库,调蓄水资源,既可扩大水资源,又能综合治理旱涝碱成。  相似文献   
445.
ABSTRACT: We investigated the effect of technical clarity on success in multi-party negotiations in the Federal Energy Regulatory Commission (FERC) licensing process. Technical clarity is the shared understanding of dimensions such as the geographic extent of the project, range of flows to be considered, important species and life stages, and variety of water uses considered. The results of four hydropower licensing consultations are reported. Key participants were interviewed to ascertain the level of technical clarity present during the consultations and the degree to which the consultations were successful. Technical clarity appears to be a prerequisite for successful outcomes. Factors that enhance technical clarity include simple project design, new rather than existing projects, precise definition of issues, a sense of urgency to reach agreement, a sense of fairness among participants, and consistency in participation. Negotiators should not neglect the critical pre-negotiation steps of defining technical issues and determining appropriate studies, deciding how to interpret studies, and agreeing on responses to study results.  相似文献   
446.
We investigated the relationship between total annual flow of water in the Macquarie River and the extent of flooding in the northern part of the Macquarie Marshes and trends in waterbird populations from 1983 to 1993. The amount of water in the Macquarie River measured each year within the Macquarie Marshes explained about 86% of the variation in area flooded in the northern part of this wetland. This allowed use of long-term data on flow at Oxley, a gauge within the Macquarie Marshes, as an index to flooding. Annual flows at Oxley have decreased significantly for high and medium rainfall events in the catchment, despite no trend in rainfall between 1944 and 1993. The area flooded by large floods has contracted by at least 40–50% during the last 50 years (1944–1993). Water use has progressively increased upstream in the period, depriving the Macquarie Marshes of water: 51% of all water passing Dubbo each year, a gauge 100 km upstream, reached the Macquarie Marshes in the period 1944–1953, but by 1984–1993 this had declined to 21%. Numbers of species and density of waterbirds on the northern part of the Macquarie Marshes declined between 1983 and 1993. Three other wetlands, not affected by water abstractions, showed no declines. We believe the decline was due to wetland degradation as a result of decreased flooding. We estimated more than 88,000 waterbirds in the Macquarie Marshes in October 1984, establishing the site as an important wetland site in Australia. The extent and viability of this wetland will depend on maintaining or increasing the water supply.  相似文献   
447.
The task of regulating potentially harmful chemicals in the environment is presently hindered by the lack of appropriate concepts and methods for evaluating the effects of anthropogenic chemicals on ecosystems. Toxicity tests at the molecular and physiological levels have been used successfully as indicators of adverse effects on test organisms and have been extrapolated to humans to establish a basis for risk assessment. However, laboratory measurements of effects upon individuals do not translate readily into potential effects upon natural populations, in part because natural populations interact with other populations and with the physical environment. Even more difficult to assess are the deleterious impacts of anthropogenic chemicals on ecosystems, because of effects on species interactions, diversity, nutrient cycling, productivity, climatic changes, and other processes.Effects on ecosystems resulting from chemical stresses are outside the realm of classical toxicology, and an ecosystem-level perspective is essential for the consideration of such effects; but the science that deals with ecosystem-level effects,ecotoxicology, is still developing. This article synthesizes the topics discussed at a workshop on ecotoxicology held by the Ecosystems Research Center at Cornell University. Topics covered include: the regulatory framework in which ecotoxicological research must be applied; ecosystem modification of toxicant fate and transport; how ecosystem composition, structure, and function are influenced by chemicals; methods currently available for predicting the effects of chemicals at the ecosystem level; and recommendations on research needs to enhance the state of the science of ecotoxicology.  相似文献   
448.
针对我国煤炭行业矿难频发,尚未有效遏制的现状,从对行业现实矿难的统计数据和潜在危机的现象分析入手,运用系统理论的观点,根据煤炭行业的复杂系统特征进一步分析危机和矿难形成的原因和机理。笔者认为,煤炭系统的危机和矿难是由系统运行过程中的矛盾和风险演变而来的,行业内部结构失衡是危机形成的内在因素,造成系统处于病态运行状态、危机潜伏;能源需求的非理性是危机形成的外部因素,造成系统病态运行加剧、危机加重;矿难则是处于危机状态的煤炭系统运行过程中剧烈波动而产生的突发危机事件。根据分析和研究所得的结论,提出必须纳入煤炭内部系统、纳入国家能源系统和宏观经济系统中,对煤炭行业危机和矿难进行多层次宏观层面的调控并采取新的对策。  相似文献   
449.
美国是工业发达国家,是世界上最早建立“职业安全和卫生法”的国家之一。基于该法,美国确立以职业安全卫生监察局(OSHA)为执法机构、职业安全卫生复审委员会(OSHRC)为监督机构的职业卫生监管体系;同时,以劳工统计局(BLS)为统计主管机构,建立以“1904规范”为基础的企业雇主对其作业场所职业卫生记录和报告制度,并辅以两种形式的政府主动调查,形成了自下至上和自上至下相结合的调查统计体系。目前,我国职业卫生的调查统计体系尚未形成。因此,需要从工业发达国家的职业卫生法规、监管入手,以系统的方法和思路,分析其调查统计体系,学习工业发达国家的经验。研究结果认为美国的职业卫生统计体系具有上层法律及相关条例完备、组织体系职责分明、形成了政府主动调查与企业记录报告相结合的调查统计体系等明显的特点。  相似文献   
450.
流域管理中公众参与问题的探讨   总被引:2,自引:0,他引:2  
我国流域管理存在很多不足,缺乏公众参与就是其中一个重要问题。文章阐述了国外公众参与流域管理的实践经验。我国公众参与流域管理普遍存在的问题是:民间力量弱小,公众参与流域管理的权利缺乏法律保障,流域区居民的利益往往被忽略。文章提出:对流域管理中的公众参与应加强宣传教育,拓宽公众参与的渠道和途径;健全流域管理法律制度,明确公众参与的法律权利;建立环境公益诉讼制度;加强国际交流与合作。  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