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   956篇
  免费   18篇
  国内免费   17篇
安全科学   103篇
废物处理   29篇
环保管理   213篇
综合类   191篇
基础理论   226篇
污染及防治   150篇
评价与监测   46篇
社会与环境   27篇
灾害及防治   6篇
  2023年   12篇
  2022年   4篇
  2021年   17篇
  2020年   23篇
  2019年   13篇
  2018年   25篇
  2017年   19篇
  2016年   39篇
  2015年   25篇
  2014年   34篇
  2013年   74篇
  2012年   37篇
  2011年   60篇
  2010年   36篇
  2009年   47篇
  2008年   51篇
  2007年   40篇
  2006年   47篇
  2005年   38篇
  2004年   27篇
  2003年   34篇
  2002年   33篇
  2001年   21篇
  2000年   24篇
  1999年   9篇
  1998年   7篇
  1997年   7篇
  1996年   15篇
  1995年   14篇
  1994年   15篇
  1993年   13篇
  1992年   11篇
  1991年   11篇
  1990年   8篇
  1989年   6篇
  1988年   11篇
  1987年   12篇
  1986年   5篇
  1985年   10篇
  1984年   6篇
  1983年   10篇
  1982年   8篇
  1981年   14篇
  1980年   6篇
  1979年   3篇
  1978年   2篇
  1977年   2篇
  1972年   1篇
  1962年   1篇
  1956年   1篇
排序方式: 共有991条查询结果,搜索用时 31 毫秒
61.
62.
A wide spectrum of genetic causes may lead to nonimmune hydrops fetalis (NIHF), and a thorough phenotypic and genetic evaluation are essential to determine the underlying etiology, optimally manage these pregnancies, and inform discussions about anticipated prognosis. In this review, we outline the known genetic etiologies of NIHF by fetal organ system affected, and provide a systematic approach to the evaluation of NIHF. Some of the underlying genetic disorders are associated with characteristic phenotypic features that may be seen on prenatal ultrasound, such as hepatomegaly with lysosomal storage disorders, hyperechoic kidneys with congenital nephrosis, or pulmonary valve stenosis with RASopathies. However, this is not always the case, and the approach to evaluation must include prenatal ultrasound findings as well as genetic testing and many other factors. Genetic testing that has been utilized for NIHF ranges from standard chromosomal microarray or karyotype to gene panels and broad approaches such as whole exome sequencing. Family and obstetric history, as well as pathology examination, can yield additional clues that are helpful in establishing a diagnosis. A systematic approach to evaluation can guide a more targeted approach to genetic evaluation, diagnosis, and management of NIHF.  相似文献   
63.
64.
Some neighbourhood environments have become dumping grounds for locally unwanted land uses (LULUs) that middle-class Americans do not want near their homes. LULUs may combine with other pariah land uses to collectively undermine the quality of the local environment, reduce investment, government services, the proportion of middle-income people and associated businesses. As important neighbourhood attributes are lost, illegal activities, derelict structures, trash-strewn lots and the concentration of poor and unhealthy people may increase. This paper describes the theory behind the impact of pariah land uses through examples of the downward spiral experienced by Camden, New Jersey and the south Bronx, New York. It then documents the experience of one community, Elizabethport, New Jersey, in reversing that downward spiral. Success in Elizabethport came from the synergistic activities of local, state and federal governments, community groups, and not-for-profit organizations as they struggled to regain control through local environmental management, rebuilding, and reducing crime. Social capital was also strengthened by using a local community health concern—that of childhood asthma. Efforts to reverse the downward spiral of urban decay from pariah land uses should be multi-faceted, spurred by local efforts that address local concerns.  相似文献   
65.
66.
67.
68.
69.
70.
Ten ways remote sensing can contribute to conservation   总被引:1,自引:0,他引:1       下载免费PDF全文
In an effort to increase conservation effectiveness through the use of Earth observation technologies, a group of remote sensing scientists affiliated with government and academic institutions and conservation organizations identified 10 questions in conservation for which the potential to be answered would be greatly increased by use of remotely sensed data and analyses of those data. Our goals were to increase conservation practitioners’ use of remote sensing to support their work, increase collaboration between the conservation science and remote sensing communities, identify and develop new and innovative uses of remote sensing for advancing conservation science, provide guidance to space agencies on how future satellite missions can support conservation science, and generate support from the public and private sector in the use of remote sensing data to address the 10 conservation questions. We identified a broad initial list of questions on the basis of an email chain‐referral survey. We then used a workshop‐based iterative and collaborative approach to whittle the list down to these final questions (which represent 10 major themes in conservation): How can global Earth observation data be used to model species distributions and abundances? How can remote sensing improve the understanding of animal movements? How can remotely sensed ecosystem variables be used to understand, monitor, and predict ecosystem response and resilience to multiple stressors? How can remote sensing be used to monitor the effects of climate on ecosystems? How can near real‐time ecosystem monitoring catalyze threat reduction, governance and regulation compliance, and resource management decisions? How can remote sensing inform configuration of protected area networks at spatial extents relevant to populations of target species and ecosystem services? How can remote sensing‐derived products be used to value and monitor changes in ecosystem services? How can remote sensing be used to monitor and evaluate the effectiveness of conservation efforts? How does the expansion and intensification of agriculture and aquaculture alter ecosystems and the services they provide? How can remote sensing be used to determine the degree to which ecosystems are being disturbed or degraded and the effects of these changes on species and ecosystem functions?  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