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   201篇
  免费   3篇
  国内免费   4篇
安全科学   10篇
废物处理   4篇
环保管理   32篇
综合类   56篇
基础理论   49篇
污染及防治   31篇
评价与监测   9篇
社会与环境   10篇
灾害及防治   7篇
  2024年   1篇
  2023年   4篇
  2022年   2篇
  2021年   8篇
  2020年   5篇
  2019年   5篇
  2018年   10篇
  2017年   12篇
  2016年   12篇
  2015年   9篇
  2014年   5篇
  2013年   12篇
  2012年   8篇
  2011年   12篇
  2010年   5篇
  2009年   11篇
  2008年   19篇
  2007年   6篇
  2006年   11篇
  2005年   7篇
  2004年   3篇
  2003年   6篇
  2002年   13篇
  2001年   3篇
  2000年   3篇
  1998年   1篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1991年   1篇
  1990年   3篇
  1989年   1篇
  1987年   3篇
  1986年   2篇
  1982年   1篇
  1981年   1篇
排序方式: 共有208条查询结果,搜索用时 15 毫秒
41.
42.
43.
44.
45.
46.
Monthly stream water calcium and Gran alkalinity concentration data from 11 sub-catchments of the Nether Beck in the English Lake District have been used to appraise the transferability of the Scottish, River Dee-based G-BASH model. Readily available riparian zone geochemistry and flow paths were used initially to predict minimum and mean stream water concentrations at the Nether Beck, based on calibration equations from the River Dee catchment data. Predicted values significantly exceeded observed values. Differences in runoff between the two areas, leading to a dilution effect in the Nether Beck, explained most of the difference between observed and predicted values. Greater acid deposition in the Lake District also reduced stream water Gran alkalinity concentrations in that area. If regional differences in precipitation, evapotranspiration and pollutant deposition are incorporated into the model, it may then be used reliably to predict catchment susceptibility to acidification over a wide regional (national) scale.  相似文献   
47.
48.
49.
With a high sensitivity and specificity, non-invasive prenatal testing (NIPT) is an incomparable screening test for fetal aneuploidy. However, the method is rather newly introduced, and experiences with discordant results are few. We did a systematic review of literature reporting details of false positive and false negative NIPT results. Discordant sex chromosome results were not included. We identified 22 studies reporting case details. In total, 206 discordant cases were included, of which 88% were false positive and 12% false negative. Details on maternal age, gestational age, platform/company, Z-score, fetal fraction, results and explanation were specified. The main reasons for discordant results were confined placental mosaicism, maternal copy number variation, vanished twin, maternal cancer and true fetal mosaicism. A very high percentage of cases (67%) were reported with no obvious biological or technical explanation for the discordant result. The included cases represent only a minor part of the true number of false positive or false negative NIPT cases identified in fetal medicine clinics around the world. To ensure knowledge exchange and transparency of NIPT between laboratories, we suggest a systematic recording of discordant NIPT results, as well as a quality assurance by external quality control and accreditation. © 2017 John Wiley & Sons, Ltd.  相似文献   
50.
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