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   656篇
  免费   31篇
  国内免费   19篇
安全科学   80篇
废物处理   13篇
环保管理   114篇
综合类   310篇
基础理论   67篇
环境理论   2篇
污染及防治   26篇
评价与监测   48篇
社会与环境   36篇
灾害及防治   10篇
  2023年   5篇
  2022年   7篇
  2021年   9篇
  2020年   9篇
  2019年   15篇
  2018年   3篇
  2017年   22篇
  2016年   20篇
  2015年   22篇
  2014年   14篇
  2013年   44篇
  2012年   37篇
  2011年   46篇
  2010年   44篇
  2009年   48篇
  2008年   36篇
  2007年   48篇
  2006年   37篇
  2005年   57篇
  2004年   31篇
  2003年   29篇
  2002年   29篇
  2001年   17篇
  2000年   22篇
  1999年   8篇
  1998年   5篇
  1997年   5篇
  1996年   8篇
  1995年   4篇
  1994年   1篇
  1993年   4篇
  1992年   6篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1987年   2篇
  1985年   1篇
  1980年   2篇
  1977年   1篇
  1973年   1篇
  1971年   1篇
排序方式: 共有706条查询结果,搜索用时 15 毫秒
181.
物流业为碳排放量较大的行业,也是国家重点鼓励和支持的产业,实现其低碳化有利于增强行业竞争力、缓解环境问题、推动社会经济生态低碳化发展.物流业面对低碳化发展的机遇与挑战,应正视行业低碳化发展在政策和体制上存在的问题,同时需要政府健全低碳物流激励约束机制、完善物流相关基础设施;企业要有效实现共同配送和联合运输,积极推进低碳物流技术的研发与推广,完善物流信息系统,优化物流节点;社会公众形成低碳意识,支持低碳产品.  相似文献   
182.
Abstract:  In an earlier paper ( Pergams & Nyberg 2001 ) we found that the proportion of the prairie deer mouse ( Peromyscus maniculatus bairdii ), among all local Peromyscus museum specimens collected in the Chicago region, had significantly declined over time. This proportion changed from about 50% before 1900 to <10% in the last 25 years. Based on this proportion a regression model predicted the local extinction of the prairie deer mouse in 2009. To evaluate that prediction, we estimated current deer mouse abundance by live trapping small mammals at 15 preserves in Cook and Lake counties, Illinois (USA) at which prairie deer mice had previously been caught or that still contained their preferred open habitat. In 1900 trap nights, 477 mammals were caught, including 251 white-footed mice ( P. leucopus ), but only one prairie deer mouse. The observed proportion of Peromyscus that were prairie deer mice, 0.4%, was even lower than the 4.5% predicted for 2000. Here we also introduce a simple, new community proportions model, which for any given geographic region compares the proportions of species recently caught with the proportions of species in museums. We compared proportions of seven species collected in Cook and Lake counties and examined by Hoffmeister (1989) with proportions of these species that we caught. Ten percent of the museum community was prairie deer mice, but only 0.2% of our catch was. The current local scarcity of the prairie deer mouse is consistent with the regression-based prediction of its eminent local extinction. More conservation attention should be paid to changes in relative abundance of once-common species.  相似文献   
183.
目前,环境问题日趋突出,成为全球关注的重点。这已不是一个国家、一个政府、一个研究所所能解决的事情,需要全世界的共同努力。环境教育亦是一个不可缺少的环节,这篇文章将从环境教育面对环境问题应该怎么做进行分析,把环境教育氛围普通环境教育和专业环境教育,具体分析这两种环境教育类型在面对环境问题时的不同做法。  相似文献   
184.
摘要:当代社会,生态问题已成为全球性的问题。但早在马克思生存的时代就已经初露端倪,马克思对此进行了详细的阐述并且提出了解决途径。  相似文献   
185.
介绍了德钦县概况,分析了德钦县存在的主要问题,提出了保护对策及建议。  相似文献   
186.
A successful emergency management for chemical industrial parks (CIPs) accidents includes the route and shelter selection. Both of them are based on the collection of chemicals, atmosphere, geographic and population databases of CIPs. This decision process can be considered as a kind of transportation-location problem (TLP). In this paper, a conceptual model of emergency decision system for TLP of CIPs has been reported and a new multi-objective TLP model of pedestrian evacuation has also been proposed. The model includes sub-criteria, and the affected areas are categorized into a priority hierarchy based on human vulnerability model (HVM). The model can be used to design shelter places and guide the evacuation of the affected people. Besides, it can maximize the total time satisfaction level of evacuees combined with the routes passable probabilities. Finally, a case study shows that this model is flexible and applicable to various scenarios and risk measures.  相似文献   
187.
常见离子对蛋壳粉吸附溶液中磷的影响   总被引:1,自引:0,他引:1  
研究了水体中常见离子对蛋壳粉吸附溶液中磷的影响.实验结果表明,SO2-4、Cl-和NO-3的存在,对天然蛋壳粉吸附磷过程产生协同作用,但协同作用不明显;HCO-3表现出吸附抑制作用;Ca2+和Mg2+表现出较为显著的吸附协同作用,其中Ca2+最为显著;NH+4离子存在时,几乎不产生影响.富集系数和吸附平衡下降率均可有效表述常见离子对蛋壳粉吸附磷过程的影响程度.  相似文献   
188.
ABSTRACT

Sustainable agriculture implies trade-offs with farm animal welfare. Proposals to increase agricultural productivity and ecological sustainability alike, are often linked to intensification, which may restrict animal welfare. Despite the growing importance of farm animal welfare for the alignment of agricultural and environmental policy, determinants of decision-making at the EU level remain unexplored. This article contributes to closing this research gap, broadening our understanding of why policymakers vote for the enactment of animal welfare policies. Applying the Social Identities in the Policy Process (SIPP) perspective we highlight the role of group membership for individual decision-making. By means of a quantitative analysis of voting behaviour in the European Parliament on two animal welfare policies, we show that different identities are salient. The strongest predictor is political group membership. In case of defections from the group line, the salience of national, sectoral and also demographic identities adds to the understanding of decision-making.  相似文献   
189.
本文把森林灭火看成是一个系统,称为灭火系统.文中用最优化方法讨论了这个系统.  相似文献   
190.
A three-tiered structure of land-use and environmental management is here proposed for Australia. The structure is based on the idea that environment means the environment of people, and that environmental problems arise when a change in the interaction between people and their environment leads to conflicts about the use of land and resources. The heterogeneity of society means that a range of human aspirations and value systems must be satisfied by environmental managers. Existing methods of environmental management fail to achieve these objectives, due to inadequate perception of environmental problems by decision-makers, and the inability of currently available impact assessment techniques to resolve human conflicts associated with the use of land and resources. The main work of planning and managing land use and the environment would be carried out by regional authorities, supported by federal and state policy. Examples are given of moves towards regional administration in England and Wales, Western Australia, Australia and New Zealand. Community participation in the decision-making process is essential and can be achieved by electoral representation to the authoritative bodies and through procedures that ensure informed public comment on planning proposals.  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