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   736篇
  免费   75篇
  国内免费   44篇
安全科学   137篇
废物处理   9篇
环保管理   213篇
综合类   301篇
基础理论   47篇
污染及防治   33篇
评价与监测   39篇
社会与环境   41篇
灾害及防治   35篇
  2024年   1篇
  2023年   10篇
  2022年   27篇
  2021年   26篇
  2020年   24篇
  2019年   22篇
  2018年   13篇
  2017年   19篇
  2016年   20篇
  2015年   21篇
  2014年   18篇
  2013年   30篇
  2012年   46篇
  2011年   47篇
  2010年   43篇
  2009年   43篇
  2008年   29篇
  2007年   62篇
  2006年   34篇
  2005年   35篇
  2004年   32篇
  2003年   35篇
  2002年   17篇
  2001年   39篇
  2000年   27篇
  1999年   22篇
  1998年   14篇
  1997年   13篇
  1996年   9篇
  1995年   19篇
  1994年   18篇
  1993年   3篇
  1992年   7篇
  1991年   2篇
  1990年   2篇
  1989年   4篇
  1988年   2篇
  1987年   1篇
  1986年   1篇
  1983年   1篇
  1982年   1篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   3篇
  1976年   1篇
  1973年   3篇
  1972年   1篇
  1971年   1篇
排序方式: 共有855条查询结果,搜索用时 78 毫秒
581.
ABSTRACT: Societal trends indicate an increased need for university water researchers to develop and improve working relationships with state legislatures to help ensure that water related legislation is based on sound water resources information. Recommendations for providing technical support to state legislatures on water resources issues include: the necessity for researchers to take the initiative; the importance of researchers capitalizing on existing linkages; the need to maintain a continuous link between key legislators, legislative staff, and researchers; and the need for researchers to provide comprehensible information in a timely manner.  相似文献   
582.
ABSTRACT: New Hampshire's riparian water law, first modified judicially, has been more drastically changed by recent legislative and administrative action. As it stands, however, the judicially enforced doctrine of reasonable use appears to be utterly inadequate to handle increasing water demands. The protection of the public interest has imposed substantial limitations on the use of riparian water rights, all under the guise of the exercise of the police power, i.e., the protection of the public health, safety, and welfare. The efficient use of the state's water resources has been further crippled by the widespread and indiscriminate exercise of eminent domain. As a result, the state is now considering the imposition of a permit system that has the potential to streamline the allocation of water. Such a system should take into consideration the public interest factors that have recently frustrated the exercise of riparian rights and the effective use of the state's water resources.  相似文献   
583.
江西洪涝灾害的时空分布规律   总被引:4,自引:2,他引:2  
黄国勤 《灾害学》1999,14(1):60-64
洪涝灾害是江西农业灾害的主要文种之一,也是全省农业及经济持续发展的重要制约因素之一.本文通过对全省85个县(市)近50a洪涝灾害资料的统计、对比和分析,揭示了江酉洪涝灾害的时空分布规律,为全省制定防洪减涝对策和措施提供了重要决策依据.  相似文献   
584.
郭增建  秦保燕 《灾害学》1996,11(2):28-31
介绍了倍九律的科学内函以及在地震预报实际应用中的几个主要方面;进而对1983年5月26日日本海中部Ms=7.7级大震前的无震应变前兆的倍九天特征进行了分析,同时探讨了倍九律在日本海地区预报强余震的可参考性。  相似文献   
585.
古建筑火灾会造成重大财产和文化损失,一直是我国消防工作中的重点和难点问题。我国古建筑消防相关法规与技术体系建设起步较晚,发展速度较慢。近年来我国文物保护部门与消防部门加强对古建筑消防法规与技术体系建设,颁布了一系列法规与规范,为我国古建筑消防事业发展提供了法律和技术依据。本文对我国古建筑火灾特点进行分析,阐述了我国古建筑消防法规与技术规范发展历程,并对其中存在制度单一,灵活性差;发展滞后,内容不完善;体系封闭,社会参与不足等问题进行了分析与探讨,为进一步研究提供了一定的参考价值。  相似文献   
586.
我国煤矿安全生产事故呈现逐年大幅度下降的趋势,对比中美煤炭百万吨死亡率,显示,我国与美国相比还存在比较大的差距。继而,通过分析中美煤矿安全监察执法的特点,发现,中美在安全监察执法、职业培训、执法人员权责、煤矿监管监察技术方面存在不同,并针对这几方面提出了进一步完善我国煤矿安全监察工作的建议,可为完善我国安全监察执法体系提供参考和借鉴。  相似文献   
587.
Objective: Road crashes are considered as the eighth leading causes of death. There is a wide disparity in crash severity and law enforcement efficiency among low-, medium-, and high-income countries. It would be helpful to review the crash severity trends in these countries, identify the vulnerable road users, and understand the law enforcement effectiveness in devising efficient road safety improvement strategies.

Method: The crash severity, fatality rate among various age groups, and law enforcement strategies of 10 countries representing low-income (i.e., India and Morocco), medium-income (i.e. Argentina, South Korea, and Greece), and high-income (i.e., Australia, Canada, France, the UK, and the United States) are studied and compared for a period of 5 years (i.e., 2008 to 2012). The critical parameters affecting road safety are identified and correlated with education, culture, and basic compliance with traffic safety laws. In the process, possible road safety improvement strategies are identified for low-income countries.

Results: The number of registered vehicles shows an increasing trend for low-income countries as do the crash rate and crash severity. Compliance related to seat belt and helmet laws is high in high-income countries. In addition, recent seat belt– and helmet-related safety programs in middle-income countries helped to curb fatalities. Noncompliance with safety laws in low-income countries is attributed to education, culture, and inefficient law enforcement.

Conclusion: Efficient law enforcement and effective safety education taking into account cultural diversity are the key aspects to reduce traffic-related injuries and fatalities in low-income countries like India.  相似文献   

588.
“十三五”是全面实现小康社会的关键时期,黑龙江省环境保护面临经济发展进入新常态、“龙江丝路带”战略实施、能源结构调整优化等带来的机遇,同时也面临着经济欠发达且下行,污染治理更加艰巨;环境短板突出,化解难度大;社会关注度增强,改善环境质量的压力增大等方面的挑战.“十三五”时期,全省应把握好新形势下黑龙江省环境保护面临的机遇与挑战,以改善环境质量为核心,补齐环境短板,编制好环境保护“十三五”规划,为黑龙江省全面实现小康社会奠定良好的环境基础.  相似文献   
589.
Western water infrastructure was funded in the early and mid‐20th Century through federal financing through the Bureau of Reclamation. Over the past 30 years, federal financing has been less forthcoming, which has been commensurate with an increase in the need for financing rehabilitation and replacement of western irrigation infrastructure. As federal appropriations have declined, there has been increased interest in alternative approaches to infrastructure including public–private partnerships (P3s), loan guarantees, or title transfer of federal infrastructure. However, two of these approaches — P3s and loan guarantees — are precluded by existing federal budgetary policies, particularly Office of Management and Budget (OMB) scoring practices. If the OMB changed its policies for P3s or loan guarantees, private capital could play an important role in recapitalizing aging Reclamation infrastructure.  相似文献   
590.
Separate waste collection in Italy comes under the responsibility of local authorities, provinces, while national laws set quantitative targets to be achieved over time. Overall, just a few provinces have reached the thresholds set by the latest law (Legislative Decree 152/2006) and some territorial differentiation has been detected. The aim of this paper is twofold: to verify the effectiveness of Legislative Decree 152/2006 in promoting higher levels of separate collection and to test whether institutional quality (considering the following indicators: voice and accountability, regulatory quality, rule of law and corruption) affects provinces’ efficiency in the separate collection process. For this purpose, we implement the stochastic frontier analysis (SFA). Results suggest that the effectiveness of Legislative Decree 152/2006 has been affected by provinces’ institutional quality. In particular, the presence of institutional constraints did not allow the most virtuous provinces to achieve the targets set by law.  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