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   6360篇
  免费   200篇
  国内免费   226篇
安全科学   254篇
废物处理   96篇
环保管理   1910篇
综合类   2050篇
基础理论   659篇
环境理论   2篇
污染及防治   137篇
评价与监测   132篇
社会与环境   1395篇
灾害及防治   151篇
  2024年   8篇
  2023年   35篇
  2022年   93篇
  2021年   115篇
  2020年   104篇
  2019年   83篇
  2018年   76篇
  2017年   133篇
  2016年   137篇
  2015年   101篇
  2014年   175篇
  2013年   406篇
  2012年   342篇
  2011年   403篇
  2010年   278篇
  2009年   273篇
  2008年   261篇
  2007年   402篇
  2006年   403篇
  2005年   335篇
  2004年   338篇
  2003年   322篇
  2002年   318篇
  2001年   266篇
  2000年   293篇
  1999年   227篇
  1998年   166篇
  1997年   140篇
  1996年   101篇
  1995年   90篇
  1994年   74篇
  1993年   70篇
  1992年   41篇
  1991年   20篇
  1990年   24篇
  1989年   8篇
  1988年   8篇
  1987年   11篇
  1986年   15篇
  1985年   4篇
  1984年   5篇
  1982年   12篇
  1981年   7篇
  1980年   10篇
  1979年   12篇
  1978年   9篇
  1977年   5篇
  1975年   4篇
  1973年   4篇
  1971年   9篇
排序方式: 共有6786条查询结果,搜索用时 875 毫秒
611.
影响安全生产状况的经济社会发展指标及灰色关联度分析   总被引:2,自引:9,他引:2  
为研究我国经济社会发展指标与安全生产状况之间的关系,首先对新中国建立以来安全生产状况的规律性作了分析研究。然后选取了与安全生产密切相关的7个经济社会发展指标,应用灰色系统理论的关联度分析法计算分析了各指标对安全生产状况的影响程度,得出该时期农业产值占GDP的比重对安全生产状况的影响最大,第三产业的影响其次,科技和教育经费的投入指标对安全生产状况的影响度较小的结论,并深入分析探讨了其内在原因。提出了我国在工业化进程中如何解决安全生产问题的意见和建议。  相似文献   
612.
安全发展理念的提出,为安全生产工作提出了新课题。本文站在安全生产监督管理部门的角度,从经济社会发展大局出发,阐述了跳出安全抓安全,通过积极主动的献计献策,争取支持,在实施产业结构调整过程中,解决安全生产深层次问题,减轻压力,从而更好地落实安全发展观、抓好安全生产工作的实践和思考。  相似文献   
613.
发展经济和保护环境是现代政府治理的主要课题。环境问题越来越严峻,对公众的影响越来越深,政府和公众的环保意识不断增强,他们不断地参与到环境保护运动中。政府和公众都是理性的经济人,他们有不同的利益诉求。由于信息交流的不顺畅,政府和公众在环境保护参与中进行着博弈。在博弈的过程中,博弈的情景不断变化,政府和公众对环境问题的认知在不断地变化,他们采取的策略也不断发生变化,他们之间的博弈从合作博弈到非合作博弈再到合作博弈,不断循环,从而达到发展经济和保护环境的双重目的。  相似文献   
614.
The study presented in this article used a combination of key informant interviews and a review and synthesis of existing country level literature to identify the major sources of land tenure insecurity in six Southern African countries: Botswana, Lesotho, Malawi, Mozambique, South Africa, and Zambia. Findings reveal that the main causes of land tenure insecurity experienced in Southern Africa include lack of land rights of minority groups, unclear or overlapping land rights, overcrowding, land alienation into leasehold, insecurity of farm workers and farm labour tenants, inappropriate and exploitative administrative practices, land encroachment and illegal settlers and limited women's land rights. The article presents a summary of land tenure security related initiatives that the study countries have or are in the process of adopting. Analysis of these initiatives shows that tenure reforms have focused on changing the law and rules but little has been done to translate new laws into implementable programs; capacity building; prioritization of resources to support tenure reform; provision of complementary policies and incentives; addressing HIV/AIDS‐land tenure related problems; and monitoring and evaluation. The paper contends that these policy issues should be addressed in order to ensure realization of land tenure security for all.  相似文献   
615.
空间信息技术以及计算机技术的发展,给环境监控提供了先进、快速和科学的方法。其中,遥感技术由于能够快速、宏观地获得所监控区域的数据,近年来已逐渐成为环境监控系统中的重要技术手段。遥感信息是被控区域的电磁辐射能量及其结构特征与时空状态在遥感图像上的表现。今后,遥感技术、在线监控系统和地理信息系统等多种信息处理工具的结合将是环境信息监控系统发展的主要方向。  相似文献   
616.
结合国内外对航空安全文化定量和定性的研究结果,定义了航空安全文化,并阐述航空安全文化的内涵,介绍国内外航空安全文化研究的进展情况,指出了国内外航空安全文化研究的差距,进而给出我国航空安全文化的研究方向。目的在于使以后的研究越来越关注实证角度,为从人为因素角度加强航空安全提供可靠、可信的数据支持,提高飞行绩效,创造安全飞行周期新记录,最终提高航空公司的经济及社会效益。  相似文献   
617.
ABSTRACT: Methods of floodplain management are changing in the United States. There has been a gradual shift in emphasis from “flood control” to “management” of the floodplain. The complexities of multilevel governmental involvement in floodplain management demand an analysis of a new means to coordinate these efforts. It is the intent of this paper to discuss the role of the Corps of Engineers in this area and the problems the Corps has encountered in its endeavors. The occurrence of these problems indicates that there is a need to strengthen the federal role to ensure a comprehensive view of floodplain management.  相似文献   
618.
ABSTRACT: The Upper Colorado River Basin contains appreciable amounts of undeveloped fuel resources. Large quantities of oil shale, coal, and uranium have attracted recent economic and commercial interests. Development of these resources and subsequent conversion to alternative energy forms require an adequate supply of water. Water use for large scale energy development will place increasing demands on an already overstressed allocation of Colorado River water. Present water quality is at a concentration where increased salinity will result in economic detriments to holders of downstream water rights. The salt and water exchange in mining, processing, and spent fuel disposal processes has been incorporated as part of a two-level minimum cost linear programming algorithm. Mathematical simulation results provide an optimal use of Upper Colorado River water for levels of energy output such that salinity concentrations are maintained below predetermined levels.  相似文献   
619.
ABSTRACT: The objective of the study was to evaluate alternative land developments around New Hampshire lakes. Alternative development patterns, evaluated by their impacts on the lake area environment and area economy, included residential patterns, commercial patterns, and combinations of these two types. Phosphorus loading of the lake water was used as a proxy variable for changes in the lake water quality. Commercial developments yielded the highest revenues to the town and the local area. It also attracted the most lake users to the area as well as contributing the largest phosphorus loading in the lake waters. Residential developments, although contributing high revenues to the businessmen in the area, yielded less net income to the town. Phosphorus loading levels from residential developments were much lower than lake phosphorus loading by commercial developments.  相似文献   
620.
ABSTRACT: Public investments in water resource development projects are continually under scrutiny in terms of economic, environmental, and social impacts. Results of an analysis of a water development project that supplies irrigation water in Idaho are discussed in terms of the impact on income distribution and income growth 44 to 64 years after the project was initiated. Gini ratios for the rural farm population of these counties were consistently lower than they were for the United States as a whole and for the state of Idaho. In addition, income distributions tended to become more equitable over time in the water project counties. Rural farm population income growth rates were found to be similar to those for the nation as a whole. Some of the reasons for these results may be related to the tendency for income distribution to become more equitable as income increases, and the fact that average farm size is relatively small.  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