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   30973篇
  免费   355篇
  国内免费   461篇
安全科学   1014篇
废物处理   1476篇
环保管理   3792篇
综合类   5120篇
基础理论   8130篇
环境理论   19篇
污染及防治   8134篇
评价与监测   2128篇
社会与环境   1793篇
灾害及防治   183篇
  2023年   138篇
  2022年   320篇
  2021年   318篇
  2020年   244篇
  2019年   291篇
  2018年   484篇
  2017年   484篇
  2016年   757篇
  2015年   581篇
  2014年   905篇
  2013年   2478篇
  2012年   1086篇
  2011年   1474篇
  2010年   1196篇
  2009年   1218篇
  2008年   1457篇
  2007年   1510篇
  2006年   1302篇
  2005年   1107篇
  2004年   1001篇
  2003年   1096篇
  2002年   978篇
  2001年   1249篇
  2000年   885篇
  1999年   527篇
  1998年   359篇
  1997年   367篇
  1996年   366篇
  1995年   434篇
  1994年   453篇
  1993年   359篇
  1992年   383篇
  1991年   354篇
  1990年   393篇
  1989年   346篇
  1988年   304篇
  1987年   282篇
  1986年   230篇
  1985年   253篇
  1984年   275篇
  1983年   260篇
  1982年   248篇
  1981年   229篇
  1980年   183篇
  1979年   199篇
  1978年   183篇
  1975年   142篇
  1974年   122篇
  1972年   130篇
  1971年   133篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
891.
892.
Abstract:  The Society for Conservation Biology (SCB) can enhance conservation of biodiversity in North America by increasing its engagement in public policy. Toward this end, the North America Section of SCB is establishing partnerships with other professional organizations in order to speak more powerfully to decision makers and taking other actions—such as increasing interaction with chapters—geared to engage members more substantively in science-policy issues. Additionally, the section is developing a North American Biodiversity Blueprint, which spans the continental United States and Canada and is informed by natural and social science. This blueprint is intended to clarify the policy challenges for protecting continental biodiversity, to foster bilateral collaboration to resolve common problems, and to suggest rational alternative policies and practices that are more likely than current practices to sustain North America's natural heritage. Conservation scientists and practitioners can play a key role by drawing policy makers' attention to ultimate, as well as proximate, causes of biodiversity decline and to the ecological and economic consequences of not addressing these threats.  相似文献   
893.
Abstract: As zebra mussels (Dreissena polymorpha) continue to spread among inland lakes of the United States and Canada, there is growing interest from professionals, citizens, and other stakeholders to know which lakes are likely to be colonized by zebra mussels. Thus, we developed a classification of lake suitability for zebra mussels on the basis of measured or estimated concentrations of dissolved calcium in lake water and applied the classification to >11,500 lakes in Wisconsin and the Upper Peninsula of Michigan. The majority of lakes (58%) were classified as unsuitable (<10 mg/L Ca) for survival and reproduction of zebra mussels, 27% were identified as suitable (≥21 mg/L Ca), and 15% were classified as borderline suitable (≥10 and <21 mg/L Ca). Of the 77 inland lakes with confirmed zebra mussel records for which data on dissolved calcium were available, our method classified 74 as suitable and 3 as borderline suitable. To communicate this lake‐specific suitability information and to help prioritize regional efforts to monitor and prevent the expansion of zebra mussels and other invasive species, we developed a web‐based interface (available from http://www.aissmartprevention.wisc.edu/ ). Although we are still uncertain of how access to suitability information ultimately affects decision making, we believe this is a useful case study of building communication channels among researchers, practitioners, and the public.  相似文献   
894.
Environmental Science and Pollution Research - The order Odonata has been regularly used as an indicator of the ecosystem’s condition. The objective of this review was to analyze the...  相似文献   
895.
Environmental Science and Pollution Research - The process TiO2/PAC/UV-vis has been under study and compared with the isolated treatments of adsorption and photocatalysis determining possible...  相似文献   
896.
Environmental Science and Pollution Research - Acrylamide (AA) is a hazardous chemical that is widely used in industrial practices. Spirulina platensis (SP) is a blue green alga that is rich in...  相似文献   
897.
Environmental Science and Pollution Research - Banana is one of the most important agricultural products of Ecuador. It relies on intensive monoculture cropping systems with a large volume of...  相似文献   
898.
Environmental Science and Pollution Research - This paper presents the synthesis of a hybrid material through the use of natural pozzolan and titanium(IV) isopropoxide using the sol-gel method and...  相似文献   
899.
Environmental Science and Pollution Research - Persistent organic pollutants (POPs) are still globally distributed and can exert different effects on ecosystems. Little is known about the...  相似文献   
900.
Environmental Science and Pollution Research - Environmental arsenic exposure in adults and children has been associated with a reduction in the expression of club cell secretory protein (CC16) and...  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