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   516篇
  免费   48篇
  国内免费   15篇
安全科学   158篇
废物处理   2篇
环保管理   128篇
综合类   83篇
基础理论   84篇
污染及防治   28篇
评价与监测   15篇
社会与环境   37篇
灾害及防治   44篇
  2024年   2篇
  2023年   9篇
  2022年   24篇
  2021年   31篇
  2020年   20篇
  2019年   29篇
  2018年   15篇
  2017年   25篇
  2016年   32篇
  2015年   25篇
  2014年   17篇
  2013年   48篇
  2012年   27篇
  2011年   21篇
  2010年   25篇
  2009年   29篇
  2008年   21篇
  2007年   27篇
  2006年   23篇
  2005年   19篇
  2004年   13篇
  2003年   14篇
  2002年   15篇
  2001年   6篇
  2000年   9篇
  1999年   8篇
  1998年   7篇
  1997年   6篇
  1996年   5篇
  1995年   3篇
  1994年   7篇
  1993年   3篇
  1992年   4篇
  1991年   2篇
  1990年   1篇
  1988年   1篇
  1986年   1篇
  1985年   1篇
  1984年   1篇
  1980年   1篇
  1979年   2篇
排序方式: 共有579条查询结果,搜索用时 0 毫秒
451.
火电厂烟气脱硝容量的合理性探讨   总被引:1,自引:0,他引:1  
根据美国20世纪90年代初的电力生产及火电NOx的排放情况,并结合我国的实际情况及控制火电NOx排放的趋势,提出2010年和2020年我国火电NOx排放总量控制目标,预测满足火电NOx控制目标的合理的火电厂烟气脱硝容量.  相似文献   
452.
The Ecosystem Management Decision Support (EMDS) system is an application framework for knowledge-based decision support of ecological assessments. EMDS integrates geographic information system and knowledge base system technologies to provide an analytical tool for environmental assessment and monitoring. The basic objective of EMDS is to improve the quality and completeness of environmental assessments and the efficiency with which they are performed. The USDA Forest Service and the U.S. Environmental Protection Agency have cooperatively developed an EMDS knowledge base for watershed condition assessment. Specifically, this knowledge base evaluates watershed processes, patterns, general effects of human activity, and fisheries habitat suitability. Such assessments are based on spatially explicit input data concerning current conditions and reference conditions which are subsequently interpreted by user-defined "fuzzy" membership functions. In this paper we describe basic components of our knowledge base for assessing watershed condition and illustrate its application within northern Idaho and northwestern Montana.  相似文献   
453.
Although protected areas represent a pivotal response to escalating anthropogenic threats, they face many pressures, inside and outside their boundaries. Amid these challenges, effective conservation is guided by evidence-based decision making supported by dynamic processes of learning and knowledge exchange. Although different models promote knowledge exchange, embedding research scientists within conservation agencies is best suited to supporting evidence-based conservation. Based on available literature and our experiences on several continents, we considered the benefits, challenges, and opportunities associated with embedding research scientists within conservation agencies and the research required to better understand the effectiveness of the embedding model for evidence-based conservation. Embedded researchers provide long-term commitment to building social capital among academic and nonacademic stakeholders; act as skilled gatekeepers who increase 2-way flow of knowledge between scientists and managers; attract, coordinate, and support management-relevant external research projects; drive the design and maintenance of long-term monitoring; and align their research with information needs. Notwithstanding the many benefits, research capacity of conservation agencies is declining worldwide. A significant challenge is that the values, structures, functions, and effectiveness of the embedding model of knowledge exchange remain poorly evaluated and documented. Also, embedded researchers have to balance their desire for creativity and flexibility with the standardization and quality control required by their public sector agencies; may be perceived as not credible because they are not truly independent of their agency; and have to couple scientific productivity with skills for transdisciplinary research, social facilitation, and stakeholder engagement. Systematic research on embedding and other models of knowledge exchange, across different world contexts, is required to better understand the benefits, costs, and institutional arrangements associated with different models.  相似文献   
454.
太湖流域严峻的水生态环境形势备受关注,而水生态环境功能分区管理体系实施现状和效果无法被准确把握。以太湖流域水生态环境功能分区为研究对象,基于四象限法则和二维向量结构指标体系等方法论,综合障碍因子分析与目标可达性分析,对太湖流域水生态环境功能分区管理绩效评估目标达成效率进行评估和预警,为水生态环境功能分区管控提供技术指导。结果表明,江苏省太湖流域目标达成效率情况较好,"高效"、"一般"、"低效"的比例依次下降,高预警级别的区域较少;环境效率指标中单位面积污染物减排管控效率较高,环境质量指标整体表现良好,须谨防向"低效"转变。  相似文献   
455.
As a concept, agroecology emphasises the interweaving of scientific and traditional ecological knowledge and is evolving in conjunction with farmer-led social movements from around the world addressing the health, equity and ecological sustainability of food systems. In Canada, many new agroecological farmers come from non-farming backgrounds and are finding limited training opportunities and support structures. While there is a growing literature on the evolution of agroecology, there is limited research on the existence and impact of training programmes on the subject-formation of new farmers. In this paper, we consider the subject-formation of new agroecological farmers through a case study of the Everdale Community Learning Centre, one of Canada’s only agroecological farm schools. In particular, we explore how the knowledge, practice, and relational identities of participating graduates are informed by and build on the science, practice, and movement of agroecology. Drawing on a survey and interviews with past participants, we found that Everdale’s education programme contributes to an agroecological subject-formation by promoting the co-creation of place-based agricultural knowledge; teaching the complexities of agroecology practice through both experiential and theoretical training; and, building a supportive community of peers. We conclude with reflections on ways to encourage a greater diversity of new farmer entrants and opportunities to support training programme graduates in establishing successful farms. These findings provide insight into developing new agroecological farmers and supporting the growing agroecological movement in Canada.  相似文献   
456.
Integrating science into resource management activities is a goal of the CALFED Bay-Delta Program, a multi-agency effort to address water supply reliability, ecological condition, drinking water quality, and levees in the Sacramento–San Joaquin Delta of northern California. Under CALFED, many different strategies were used to integrate science, including interaction between the research and management communities, public dialogues about scientific work, and peer review. This paper explores ways science was (and was not) integrated into CALFED's management actions and decision systems through three narratives describing different patterns of scientific integration and application in CALFED. Though a collaborative process and certain organizational conditions may be necessary for developing new understandings of the system of interest, we find that those factors are not sufficient for translating that knowledge into management actions and decision systems. We suggest that the application of knowledge may be facilitated or hindered by (1) differences in the objectives, approaches, and cultures of scientists operating in the research community and those operating in the management community and (2) other factors external to the collaborative process and organization.  相似文献   
457.
环境规划队伍是环保铁军的重要一员,随着生态文明建设和生态环境保护工作不断深入,我国环境规划院(所)建设逐步从无到有,人才队伍逐步发展壮大,支撑生态环境保护综合决策能力日益提高。本研究面向各省(区、市)及部分副省级城市环境规划院(所)开展了问卷调查,分析我国环境规划研究队伍和机构建设现状,围绕管理制度、市场发展、人才培养、交流合作等方面对未来发展进行展望。  相似文献   
458.
针对当前装备一线维修人员在技术支持上的存在的现实问题,提出了基于知识服务和协同模式构建协同式装备维修技术支持平台,在分析平台体系结构和功能的基础上,研究探讨了平台运作模式和关键技术。该平台为一线服务人员提供了"一站式"的技术支持和"定制式"的知识服务,实现了装备维修相关部门协同保障的"双赢"协作模式。  相似文献   
459.
下辽河平原多熟种植农业生态模式知识库研建   总被引:1,自引:0,他引:1  
本文以下辽河平原为背景,应用专家系统开发工具建立了多熟种植农业生态模式知识库,提出了建立该专家系统知识库的步骤:包括知识获取、知识表达、编码及证实。该专家系统知识库的建立能将有关多熟种植领域的专门知识和领域专家的经验以可接受的方式传递给农业决策者,从而提高农业决策的自动化和科学化。  相似文献   
460.
区域危险废物环境管理与风险控制是涉及到危险废物特性、环境、经济和社会等多因素的复杂过程,对资源环境的可持续发展和人体健康都至关重要。空间数据挖掘技术在传统数据挖掘的基础上增加空间维尺度,能够实现从空间数据库和非空间数据库中提取危险废物产生、转移、处置和管理过程中隐含的空间模式与特征。文章在传统的危险废物环境管理和风险控制方法的基础上,构建了区域危险废物空间数据挖掘的指标体系,并设计了一种基于空间数据挖掘技术的区域危险废物决策支持系统框架。该框架由数据层、数据挖掘层和显示层组成,为区域危险废物管理和决策提供了直观的、科学的和高效的支持,提供了一种新颖可行的思路和方法提高危险废物的环境管理和风险控制水平,具有一定的理论和现实意义。  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