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   546篇
  免费   19篇
  国内免费   3篇
安全科学   32篇
废物处理   50篇
环保管理   89篇
综合类   87篇
基础理论   111篇
环境理论   1篇
污染及防治   135篇
评价与监测   27篇
社会与环境   24篇
灾害及防治   12篇
  2023年   3篇
  2022年   10篇
  2021年   9篇
  2020年   12篇
  2019年   12篇
  2018年   17篇
  2017年   18篇
  2016年   21篇
  2015年   19篇
  2014年   21篇
  2013年   48篇
  2012年   31篇
  2011年   42篇
  2010年   24篇
  2009年   22篇
  2008年   22篇
  2007年   28篇
  2006年   30篇
  2005年   22篇
  2004年   14篇
  2003年   16篇
  2002年   19篇
  2001年   13篇
  2000年   3篇
  1999年   5篇
  1998年   1篇
  1997年   8篇
  1996年   8篇
  1995年   10篇
  1994年   15篇
  1993年   9篇
  1992年   6篇
  1991年   9篇
  1990年   1篇
  1989年   2篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   1篇
  1983年   2篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1974年   1篇
  1970年   1篇
  1968年   1篇
  1965年   1篇
  1956年   1篇
排序方式: 共有568条查询结果,搜索用时 679 毫秒
351.
This paper examines how Australian land use plans incorporate provisions for sustainable urban form, design, biodiversity conservation, and climate change. Despite the long-standing sustainability objectives in state policy frameworks, a survey of 291 comprehensive plans finds implementation within local instruments is far from universal. Differences in patterns of policy adoption, as well as potential explanations for these differences, including geographical location, patterns of residential growth, the socio-economic composition of local communities, political forces, and policy evolution over time, are explored. Overall, areas experiencing more intensive growth tend to have newer plans, which in turn, contain more sustainability provisions, suggesting a responsive rather than repressive relationship between development pressures and regulatory development control.  相似文献   
352.
This study examines the perspectives of Sami community members and university researchers regarding the ethical considerations for engagement in Community-Based Participatory Research (CBPR) with Sami communities in northern Finland. Key informant interviews were conducted with Sami people from Finland who were exposed to or participated in research in their communities as well as with researchers who have conducted research with the Sami in Finland across diverse topics. Five themes were identified: establishing trust, research preparation, research comprehension, research ethics, and inclusion in research. The differences in participant perspectives were compared based on their community versus researcher roles. Our findings emphasize the need for (1) strategies to develop and maintain trust between Sami communities and researchers; (2) methods to bridge concepts of bias projected onto Sami communities and researchers by the others’ differing world views and beliefs about research; and (3) increased education in community-engaged methods for social and natural scientists working with Sami communities. This study supports the need for the development of formalized ethical protocols for conducting community-based engaged research with and for Sami people in Finland that ensure mutually beneficial research for all involved.  相似文献   
353.
Habitat suitability maps are commonly created by modeling a species’ environmental niche from occurrences and environmental characteristics. Here, we introduce the hyper-envelope modeling interface (HEMI), providing a new method for creating habitat suitability models using Bezier surfaces to model a species niche in environmental space. HEMI allows modeled surfaces to be visualized and edited in environmental space based on expert knowledge and does not require absence points for model development. The modeled surfaces require relatively few parameters compared to similar modeling approaches and may produce models that better match ecological niche theory. As a case study, we modeled the invasive species tamarisk (Tamarix spp.) in the western USA. We compare results from HEMI with those from existing similar modeling approaches (including BioClim, BioMapper, and Maxent). We used synthetic surfaces to create visualizations of the various models in environmental space and used modified area under the curve (AUC) statistic and akaike information criterion (AIC) as measures of model performance. We show that HEMI produced slightly better AUC values, except for Maxent and better AIC values overall. HEMI created a model with only ten parameters while Maxent produced a model with over 100 and BioClim used only eight. Additionally, HEMI allowed visualization and editing of the model in environmental space to develop alternative potential habitat scenarios. The use of Bezier surfaces can provide simple models that match our expectations of biological niche models and, at least in some cases, out-perform more complex approaches.  相似文献   
354.
The shape of features involved in key biological functions, such as teeth in nutrition, can provide insights into ecological processes even in ancient time, by linking the occupation of the morphological space (disparity) to the occupation of the ecological space. Investigating disparity in radiating groups may provide insights into the ecological diversification underlying evolution of morphological diversity. Actinopterygian fishes initiated their radiation in the Devonian, a period characterized by the diversification of marine ecosystem. Although a former morpho-functional analysis of jaw shape concluded to conservative and poorly diversified morphologies in this early part of their history, fish tooth disparity evidenced here an unsuspected diversity of possible functional significance in the pivotal period of the Late Devonian (Famennian). All teeth being caniniforms, some were stocky and robust, in agreement with expectations for active generalist predators. More surprisingly, elongated teeth also occurred at the beginning of Famennian. Their needle-like shape challenges morpho-functional interpretations by making them fragile in response to bending or torsion. The occurrence of both types of fish teeth during the beginning of the Famennian points to a discrete but real increase in disparity, thus testifying a first burst of feeding specialization despite overall conservative jaw morphology. The disappearance of these needle-like teeth in the Late Famennian might have been related to a relay in dental diversity with abundant co-occurring groups, namely conodonts and chondrichthyans (sharks).  相似文献   
355.
356.
357.
358.
359.
360.
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