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   79篇
  免费   9篇
  国内免费   7篇
安全科学   20篇
废物处理   2篇
环保管理   24篇
综合类   24篇
基础理论   10篇
污染及防治   1篇
评价与监测   4篇
社会与环境   7篇
灾害及防治   3篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2019年   5篇
  2018年   2篇
  2017年   8篇
  2016年   2篇
  2015年   2篇
  2014年   5篇
  2013年   7篇
  2012年   6篇
  2011年   4篇
  2010年   3篇
  2009年   9篇
  2008年   6篇
  2007年   4篇
  2006年   5篇
  2005年   2篇
  2003年   3篇
  2002年   3篇
  2001年   5篇
  2000年   2篇
  1999年   1篇
  1997年   1篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1979年   1篇
排序方式: 共有95条查询结果,搜索用时 15 毫秒
81.
Non‐pharmaceutical interventions (NPIs) are an important public health tool for responding to infectious disease outbreaks, including pandemics. However, little is known about the individual characteristics associated with support for NPIs, or whether they are consistent across regions. This study draws on survey data from four regions—Hong Kong, Singapore, Taiwan, and the United States—collected following the Severe Acute Respiratory Syndrome (SARS) outbreak of 2002–03, and employs regression techniques to estimate predictors of NPI support. It finds that characteristics associated with NPI support vary widely by region, possibly because of cultural variation and prior experience, and that minority groups tend to be less supportive of NPIs when arrest is the consequence of noncompliance. Prior experience of face‐mask usage also results in increased support for future usage, as well as other NPIs. Policymakers should be attentive to local preferences and to the application of compulsory interventions. It is speculated here that some public health interventions may serve as ‘gateway’ exposures to future public health interventions.  相似文献   
82.
本文采用政策分析法,对比中英资源综合利用的政策及实施手段,着重剖析英国政策工具及经验,为我国相关政策的硕层设计提出建议。分析指出:英国资源综合利用的政策属于固体废弃物管理的框架,优点为管理部门职责清晰、政策实施的动力明确。本文建议我国资源综合利用政策的顶层设计可以从五个方面借鉴英国模式。第一,我国有必要明确资源综合利用概念中“资源”的内涵;第二,引入抑制型、强制型政策工具,以强化资源综合利用政策的实施;第三,明确企业应遵守的法律、法规、可享受的具体优惠政策;第四,结合我国资源综合利用的水平、现状,制定资源综合利用技术标准,让相关的政策更具有可操作性;第五,规范各行业的综合利用活动并加强执法监督。  相似文献   
83.
通过对色觉、科学仪器、测不准原理的分析,认为认识在感性阶段是客主体相互作用的结果.感官的生物学意义在于对客体的区别.这种区别是相对准确的,而不是与客体严格一一对应的.科学仪器是人感官的延伸.色觉与其它感官和科学仪器同是人类认识工具.测不准问题是与认识工具直接相关,与客主体相互影响密不可分的,它在宏观上和微观上同时存在,它不是非决定论的理论依据.  相似文献   
84.
ABSTRACT: The Stream Corridor Assessment survey has been developed by the Maryland Department of Natural Resources as a watershed management tool to identify environmental problems and to help prioritize restoration opportunities on a watershed basis. Potential environmental problems commonly identified during the survey include: stream channel alterations, excessive bank erosion, exposed pipes, inadequate stream buffers, fish migration blockages, trash dumping sites, near stream construction, pipe outfalls, and unusual conditions. In addition, the survey records information on the location of potential wetlands creation sites and collects data on the general condition of instream and riparian habitats. Over the past several years, in collaboration with the Maryland Conservation Corps, watershed associations, and local governments, more than 3,293 km (2,046 miles) of Maryland streams have been surveyed. Overall, the survey has proven to be a cost effective starting point for many watershed restoration efforts.  相似文献   
85.
模具在金属塑性成形过程中起着十分重要的作用。就一般而言,模具在金属成形过程中的变形被忽略,将之视为刚性体。然而在金属精密成形中,模具的变形对成形件的尺寸精度将产生较大的影响。利用SuperForm软件针对模具在工件挤压过程中的变形进行了有限元数值模拟,对这一问题作了初步分析与探讨,为工厂实际生产的工艺制定、模具设计提供理论参考与依据。  相似文献   
86.
在一定的碳当量的条件下 ,提高硅碳比 (Si/C) ,可以提高机床铸件的抗拉强度、硬度及硬度均匀性 ,降低残留应力 ,改善铸造性能和机加工性能 ,降低废品率。从而达到提高机床的刚度和精度稳定性的目的  相似文献   
87.
各种分子遗传技术为不同生物种类间进行直接比较和分子水平的遗传多样性的度量、研究提供了新的途径。本文讨论了此类分子水平研究所取得的一些新的进展,并指出了有关分子工具应用于生物多样性研究中存在的一些问题。  相似文献   
88.
本文主要介绍了美国公路安全改进计划(HSIP)的制定背景及其自评工具在领导、管理、规划、实施、评价方面的详细内容和实施方法。同时也描述了如何分析评价结果和制定行动计划,从而最大限度地保障人民群众的生命和财产安全。  相似文献   
89.
Researchers are increasingly turning to network theory to understand the social nature of animal populations. We present a computational framework that is the first step in a series of works that will allow us to develop a quantitative methodology of social network sampling to aid ecologists in their social network data collection. To develop our methodology, we need to be able to generate networks from which to sample. Ideally, we need to perform a systematic study of sampling protocols on different known network structures, as network structure might affect the robustness of any particular sampling methodology. Thus, we present a computational tool for generating network structures that have user-defined distributions for network properties and for key measures of interest to ecologists. The user defines the values of these measures and the tool will generate appropriate network randomizations with those properties. This tool will be used as a framework for developing a sampling methodology, although we do not present a full methodology here. We describe the method used by the tool, demonstrate its effectiveness, and discuss how the tool can now be utilized. We provide a proof-of-concept example (using the assortativity measure) of how such networks can be used, along with a simulated egocentric sampling regime, to test the level of equivalence of the sampled network to the actual network. This contribution is part of the special issue “Social Networks: new perspectives” (Guest Editors: J. Krause, D. Lusseau and R. James).  相似文献   
90.
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