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   3374篇
  免费   374篇
  国内免费   1337篇
安全科学   436篇
废物处理   44篇
环保管理   473篇
综合类   2419篇
基础理论   754篇
环境理论   4篇
污染及防治   176篇
评价与监测   99篇
社会与环境   420篇
灾害及防治   260篇
  2024年   32篇
  2023年   118篇
  2022年   238篇
  2021年   242篇
  2020年   218篇
  2019年   223篇
  2018年   201篇
  2017年   204篇
  2016年   214篇
  2015年   199篇
  2014年   187篇
  2013年   298篇
  2012年   285篇
  2011年   311篇
  2010年   223篇
  2009年   216篇
  2008年   171篇
  2007年   240篇
  2006年   189篇
  2005年   196篇
  2004年   142篇
  2003年   135篇
  2002年   98篇
  2001年   67篇
  2000年   89篇
  1999年   62篇
  1998年   46篇
  1997年   45篇
  1996年   39篇
  1995年   26篇
  1994年   36篇
  1993年   20篇
  1992年   13篇
  1991年   7篇
  1990年   13篇
  1989年   5篇
  1988年   6篇
  1986年   5篇
  1985年   3篇
  1984年   2篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1980年   4篇
  1979年   1篇
  1978年   3篇
  1977年   2篇
  1972年   1篇
  1971年   2篇
  1970年   1篇
排序方式: 共有5085条查询结果,搜索用时 203 毫秒
331.
利用红外技术探测地质构造是预防巷道作业重大安全事故的有效途径。笔者根据红外辐射原理 ,分析了地质构造引起的岩石密度变化和巷道围岩辐射功率之间的相关性 ,提出了红外探测巷道地质构造的理论、方法及适用条件。应用结果表明 :红外探测技术不仅可简便、直观地分析和预测采掘巷道围岩地质的变化趋势 ,而且可用于巷道围岩瓦斯涌出异常地段的原因探测 ,指导安全防范措施的有效实施  相似文献   
332.
基于小波包分析的爆破振动危害评价初探   总被引:2,自引:0,他引:2  
结合振动主频的质点振速判据是对单一质点振速判据的补充和完善.但该判据的振动主频是通过FFT变换的频谱分析的方法获得的,不能体现爆破振动波形的多主振频带特征,而且由于方法本身的局限性使得主振频率发生的时间段不能确定.小波包分析法则克服了FFT频谱分析的局限,有效地分解和重构原始信号中的细节信号,并将其作为评价不同频率细节信号的爆破振动危害效果的基础.本文针对爆破振动的小波包分析法进行了研究,对各小波包细节信号加载条件下的不同危害效果进行了讨论,得到了相应的质点振速判据,并将该方法所得到的判据与FFT变换的频谱分析方法所得到的判据进行了对比.结果表明,基于小波包分析法的质点振速判据更加符合爆破振动危害的真实情况.  相似文献   
333.
ABSTRACT: Many urban and suburban communities in the Midwest are seeking to establish sustainable, morphologically and hydraulically varied, yet dynamically stable fluvial systems that are capable of supporting healthy, biologically diverse aquatic ecosystems — a process known as stream naturalization. This paper describes an integrated research program that seeks to develop a scientific and technological framework to support two stream naturalization projects near Chicago, Illinois. The research program integrates theory and methods in fluvial geomorphology, aquatic ecology, hydraulic engineering and social theory. Both the conceptual and the practical challenges of that integration are discussed. Scientific and technical support emphasize the development of predictive tools to evaluate the performance of possible naturalization designs at scales most appropriate to community based projects. Social analysis focuses on place based evaluations of how communities formulate an environmental vision and then, through decision making, translate this vision into specific stream naturalization strategies. Integration of scientific and technical with social components occurs in the context of community based decision making as the predictive tools are employed by project scientists to help local communities translate their environmental visions into concrete environmental designs. Social analysis of this decision making process reveals how the interplay between the community's vision of what they want the watershed to become, and the scientific perspective on what the watershed can become to achieve the community's environmental goals, leads to the implementation of specific stream naturalization practices.  相似文献   
334.
实施可持续发展战略,就是要实现经济建设与环境保护协调发展。本文从佳木斯市实际出发,提出了环境保护职能部门如何参与经济结构调整以实现经济与环境协调发展的意见和建议。  相似文献   
335.
This paper examines the relationship between community preparedness and response to natural disaster and their level and pattern of community development. This is done by investigating preparation and response to the 1997 Red River Flood by three rural communities in Manitoba, Canada. The communities were selected because of their different ethnic mix and associated level and pattern of community development. The hypothesis was supported that the level and pattern of community development affect community capacity to respond to flooding. Communities characterised by higher levels of physical, human and social capital were better prepared and more effective responders to the flood. However, where the pattern of community development was characterised by high levels of social capital, decision-making processes were complicated.  相似文献   
336.
Identifying and mapping community vulnerability   总被引:30,自引:1,他引:29  
Morrow BH 《Disasters》1999,23(1):1-18
Disaster vulnerability is socially constructed, i.e., it arises out of the social and economic circumstances of everyday living. Most often discussed from the perspective of developing nations, this article extends the argument using American demographic trends. Examples from recent disasters, Hurricane Andrew in particular, illustrate how certain categories of people, such as the poor, the elderly, women-headed households and recent residents, are at greater risk throughout the disaster response process. Knowledge of where these groups are concentrated within communities and the general nature of their circumstances is an important step towards effective emergency management. Emergency planners, policy-makers and responding organisations are encouraged to identify and locate high-risk sectors on Community Vulnerability Maps, integrating this information into GIS systems where feasible. Effective disaster management calls for aggressively involving these neighbourhoods and groups at all levels of planning and response, as well as mitigation efforts that address the root causes of vulnerability.  相似文献   
337.
Pilgrim NK 《Disasters》1999,23(1):45-65
In November 1989 a major landslide destroyed the link road to the village of Sapni in Kinnaur District of Himachal Pradesh in the Indian Himalaya. Although aware of the risk of further landslide activity, the community has campaigned successfully for reconstruction of the road. Decisions of this kind take place at the local level, through village institutions and open debate, with good feedback between villages and district government authorities. In this way a balance is established between meeting more immediate needs (such as domestic water supply, irrigation, road access) and taking acceptable risks. Using the Sapni landslide as a case study, this paper explores the issue of 'acceptable risk', and looks at the existing strategy for risk and disaster reduction in the district.  相似文献   
338.
对1997年5月10日伊朗东部加恩-贝尔兼德地震中出现的几类结构的震害现象进行了初步的描述与分析,同时,就经抗震设防与未防抗震设防结构的震害现明作了对比。对震区重建及附近地区新建结构抗震问题的解决有一定的参考意义。  相似文献   
339.
民用建筑结构燃爆事故及防灾措施   总被引:6,自引:0,他引:6  
收集了一些典型民用燃气爆炸事故的实例, 在此基础上对结构的破坏形式进行了分类,并分析了引起各种结构破坏的主要原因, 通过分析提出了防止结构破坏的具体措施  相似文献   
340.
ABSTRACT

Public participation in the form of public meetings and written submissions has been criticised as a democratic ritual that fails to give citizens a real voice in government decisions. Participatory mapping and community surveys are alternative public participation (PP) methods that can augment legally required processes for land use planning. To date, there has been little evaluation research comparing the information content generated by required PP processes and alternative PP sources with respect to local land use decisions. Using multiple development projects from a case study community, we analysed and compared information generated from three different sources of public participation: (1) formal public comment (written submissions), (2) responses to community survey questions, and (3) land use preferences generated from participatory mapping. We found public comment strongly supported development while results from survey questions and participatory mapping methods revealed community ambivalence. The differences in public opinion are attributed to two key factors: the representativeness of participants in the PP process and the specific methods used for measuring public opinion. Community surveys and participatory mapping generated more accurate and representative community information compared to the formal PP process which was characterised by lower participation and vulnerability to special interest manipulation. For local government decision makers, the political risk of broadening PP information appears high relative to the risk of inaccurately assessing public opinion thus limiting adoption of alternative PP methods such as participatory mapping.  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