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   267篇
  免费   25篇
  国内免费   31篇
安全科学   88篇
废物处理   1篇
环保管理   44篇
综合类   85篇
基础理论   36篇
环境理论   7篇
污染及防治   11篇
评价与监测   7篇
社会与环境   20篇
灾害及防治   24篇
  2023年   3篇
  2022年   18篇
  2021年   8篇
  2020年   6篇
  2019年   9篇
  2018年   8篇
  2017年   14篇
  2016年   15篇
  2015年   19篇
  2014年   9篇
  2013年   18篇
  2012年   10篇
  2011年   12篇
  2010年   9篇
  2009年   13篇
  2008年   18篇
  2007年   16篇
  2006年   14篇
  2005年   12篇
  2004年   13篇
  2003年   7篇
  2002年   7篇
  2001年   3篇
  2000年   6篇
  1999年   6篇
  1998年   3篇
  1997年   5篇
  1996年   2篇
  1995年   1篇
  1994年   6篇
  1993年   5篇
  1992年   4篇
  1991年   3篇
  1990年   2篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   3篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1981年   3篇
  1980年   1篇
  1978年   1篇
  1977年   1篇
  1972年   2篇
排序方式: 共有323条查询结果,搜索用时 234 毫秒
271.
研究了过渡金属氧化物和稀土金属氧化物对乳化液废水催化湿式氧化工艺中的催化活性,得出:CuO的活性高于MnO2,Co3O4未表现出催化活性。CeO2、Nd2O3、Sm2O3均表现一定活性:制备了CuO/γAl2O3,Mn/γAl2O3负载型催化剂及其复合负载型催化剂,并对它们各自的催化活性和稳定性进行了研究。发现:Cu/γAl2O3负载型催化剂用于乳化液废水处理,200℃反应2h,CODCr去除率为88.4%,达到均相催化效果,比非催化提高13.0%,Mn/γAl2O3表现出负催化作用.复合负载型催化剂的活性低于Cu/γAl2O3。  相似文献   
272.
为了对生产加工过程中工艺操作人员的不安全行为进行有效监控,及时避免因操作失误带来的工艺安全事故,开展基于视线追踪技术的工艺操作人员人为失误识别研究。通过设计眼动实验方案,利用视线追踪技术采集操作者在工艺流程控制过程中各类失误模式的眼动数据,并对采集的数据进行统计,提取失误行为的眼动特征,并建立人为失误智能识别方法,利用距离函数聚类实现现场操作人员失误状态的准确识别。研究结果表明:以被试样本在不同区域的视线停留时间百分比作为特征参数,并运用欧氏距离函数分类法判别人员操作状态,对操作人员的不安全行为能够准确识别。  相似文献   
273.
针对国际上某些发达国家向发展中国家越境转移废物这一倍受关注的现象,阐述了废物贸易,尤其是非法废物贸易产生的机制和发生的后果,对目前有关废物越境转移的国际公约作了介绍,并着重探讨了中国对于非法废物贸易相应国内立法及应采取的措施。   相似文献   
274.
Peter Christoff 《环境政策》2016,25(6):1034-1057
The Anthropocene raises two interrelated problems for the Australian environment movement. The first concerns the movement’s normative and political relationship to non-human nature: climate change in particular is forcing an urgent reconsideration of how nature is to be understood and managed. The second problem concerns the implications of full recognition of the rights of First Peoples for environmental justice. These issues may lead to crises of identity, legitimacy, and effectiveness for the Australian movement. The normative bases upon which Australian environmentalists may draw in order to ‘protect nature’ in the Anthropocene are discussed. Setting aside the simple emancipatory ambition of preservationist environmentalism and the Australian movement’s earlier Romantic protectionism, a new pragmatic, pluralistic environmental politics – based on precaution, the avoidance of pain and suffering, and protection of the most vulnerable – is suggested.  相似文献   
275.
The demise of the soil fumigant, Midas, was heralded as a major environmental movement achievement, when Arysta LifeScience eventually deemed it economically non-viable and withdrew from US markets just before resolution of a lawsuit. Building on scholarship that focuses on strategy to understand how social movements sometimes win, we show how activist tactics were able to exploit the missteps of their opponents. These included the unreasonable expectations of Arysta for grower adoptions, the foibles of the director of California's Department of Pesticide Regulation in registering the chemical, and the reluctance of California's strawberry industry to discontinue use of methyl bromide. Although activist tactics, such as public comments and protests, had only a modest impact on the regulatory process, they had a major impact on grower adoptions of the chemical. This, together with a lawsuit that was not going well for the defendants, ultimately led to the withdrawal. Still, there was a great deal of luck involved, especially in the lawsuit in which the judge made rulings and statements favourable to the plaintiffs. Here, ‘scientization’, worked in favour of the movement rather than the industry.  相似文献   
276.
某大型超市火灾危险性评估研究   总被引:6,自引:0,他引:6  
某大型超市具有人员活动集中、火灾荷栽密度较大以及疏散距离超长等特点,超出现有建筑防火规范要求,给判断是否安全带来不确定性。该文利用性能化设计方法研究了该超市在设定火灾条件下烟气填充以及人员疏散情况,并通过安全疏散时间判据来分析人员是否能够全部疏散。研究结果表明:在满足设定的火灾条件下,该超市的保护人员和财产的安全目标是可以达到的。  相似文献   
277.
Fragmentation of the boreal forest by linear features, including seismic lines, has destabilized predator–prey dynamics, resulting in the decline of woodland caribou (Rangifer tarandus caribou) populations. Restoration of human-altered habitat has therefore been identified as a critical management tool for achieving self-sustaining woodland caribou populations. However, only recently has testing of the response of caribou and other wildlife to restoration activities been conducted. Early work has centered around assessing changes in wildlife use of restored seismic lines. We evaluated whether restoration reduces the movement rates of predators and their associated prey, which is expected to decrease predator hunting efficiency and ultimately reduce caribou mortality. We developed a new method for using cameras to measure fine-scale movement by measuring speed as animals traveled between cameras in an array. We used our method to quantify speed of caribou, moose (Alces alces), bears (Ursus americanus), and wolves (Canis lupus) on treated (restored) and untreated seismic lines. Restoration treatments reduced travel speeds along seismic lines of wolves by 1.38 km/h, bears by 0.55 km/h, and caribou by 1.57 km/h, but did not reduce moose travel speeds. Reduced predator and caribou speeds on treated seismic lines are predicted to decrease encounter rates between predators and caribou and thus lower caribou kill rates. However, further work is needed to determine whether reduced movement rates result in reduced encounter rates with prey, and ultimately reduced caribou mortality.  相似文献   
278.
In this short essay it is argued that recent criticisms portraying the activist environmental movement as overly pessimistic are valid and that the communication of this pessimism to the public at large has been largely counterproductive to the objectives of environmentalists. It is argued that, in contrast to historic assumptions of a ‘progress paradigm’ that epitomized the widely held optimism of the past, the shock tactics and pessimistic media campaigns employed by the activist environmental movement, and the media that capitalizes upon those campaigns, have contributed to the creation of a figurative hopeless age. The key characterization of the hopeless age is the widely held assumption that the future will be worse than the present and that the lives of future generations will be diminished relative to our own. It is argued that the creation of this social-psychological phenomenon is counterproductive to the aims of the environmental movement and that the restoration of a collective vision and message of hope would be far more productive. Lastly, some reasons for a hopeful outlook are suggested.
Andrew McKinleyEmail: Email:
  相似文献   
279.
苗绿田 《环境科学》1990,11(6):58-61
本文对风引起海面油膜的漂移速度的关系,通过水面紊动剪切应力的平衡理论,推导出风系数的近似计算公式。结合有关现场观测资料和风洞模拟试验结果,确定油膜的风漂移速度与风速之比的经验系数为1.6—3.5%。  相似文献   
280.
针对金川矿区控制性工程所潜在的安全隐患,首先明确了影响矿区控制性工程稳定的主要因素是采动影响,提出了开展岩移规律与动态预测研究的必要性,论述了国内外岩移规律研究的现状及发展趋势,提出了该课题研究的主要内容以及关键技术,最后阐述了课题研究应采用的理论与技术方法.  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