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   2510篇
  免费   269篇
  国内免费   1篇
  2023年   17篇
  2022年   26篇
  2021年   69篇
  2020年   53篇
  2019年   44篇
  2018年   54篇
  2017年   49篇
  2016年   72篇
  2015年   157篇
  2014年   147篇
  2013年   175篇
  2012年   219篇
  2011年   213篇
  2010年   100篇
  2009年   103篇
  2008年   148篇
  2007年   153篇
  2006年   140篇
  2005年   127篇
  2004年   97篇
  2003年   89篇
  2002年   79篇
  2001年   26篇
  2000年   24篇
  1999年   37篇
  1998年   21篇
  1997年   15篇
  1996年   13篇
  1994年   11篇
  1992年   9篇
  1991年   17篇
  1990年   13篇
  1989年   11篇
  1988年   18篇
  1987年   10篇
  1985年   8篇
  1984年   11篇
  1983年   17篇
  1982年   8篇
  1981年   11篇
  1978年   10篇
  1977年   14篇
  1975年   7篇
  1974年   12篇
  1973年   12篇
  1972年   8篇
  1971年   10篇
  1970年   9篇
  1969年   8篇
  1968年   8篇
排序方式: 共有2780条查询结果,搜索用时 15 毫秒
201.
FVB/NJ mice frequently are used as transgenic hosts, but the suitability of this genetic background for transgenic and congenic models of systemic autoimmunity have not been reported. In this study, FVB/NJ mice were evaluated for the presence of serum autoantibodies and autoimmune kidney pathology. Previously unreported albuminuria was observed in aged female FVB/NJ mice; however, serum autoantibody testing, light microscopic evaluation of differentially stained renal sections, and evaluation of renal sections for immunoglobulin deposits revealed that the albuminuria was not of autoimmune etiology. Anecdotally, multiple characteristics of the FVB/NJ strain, including albuminuria, cholesterolemia, mild podocyte foot process effacement in aged female FVB/NJ kidneys and predisposition to enhanced Th2 immune responses, is reminiscent of human minimal change nephrotic syndrome (MCNS). We propose that mapping of genetic polymorphisms that are responsible for these traits in FVB/NJ mice may lead to increased understanding of mild nephrotic syndromes including MCNS and other proteinurias.  相似文献   
202.
Biogeochemistry - Agriculture alters the biogeochemical cycling of nutrients such as nitrogen (N), phosphorus (P), and silicon (Si) which contributes to the stoichiometric imbalance among these...  相似文献   
203.
204.
205.
206.
A new cyst nematode species, Globodera ellingtonae, was recently described from populations in Oregon and Idaho. This nematode has been shown to reproduce on potato. Because of this nematode’s close relationship to the potato cyst nematodes, G. rostochiensis and G. pallida, an understanding of the risk of its potential spread, including prediction of potential geographical distribution, is required. To determine the development of G. ellingtonae under different temperatures, we conducted growth chamber experiments over a range of temperatures (10.0°C to 26.5°C) and tracked length of time to various developmental stages, including adult females bearing the next generation of eggs. Both the time to peak population densities of G. ellingtonae life stages and their duration in roots generally increased with decreasing temperature. Regression of growth rate to second-stage (J2) and third-stage (J3) juveniles on temperature yielded different base temperatures: 6.3°C and 4.4°C for J2 and J3, respectively. Setting a base temperature of 6°C allowed calculation of the degree-days (DD6) over which different life stages occurred. The largest population densities of J2 were found in roots between 50 and 200 DD6. Population densities of J3 peaked between 200 and 300 DD6. Adult males were detected in soil starting at 300 to 400 DD6 and remained detectable for approximately 500 DD6. By 784 to 884 DD6, half of the eggs in adult females contained vermiform juveniles. Given the similarity in temperature ranges for successful development between G. ellingtonae and G. rostochiensis, G. ellingtonae populations likely could survive in the same geographic range in which G. rostochiensis now occurs.  相似文献   
207.
208.
209.
Integrating occupational safety and health (OSH) into life cycle assessment (LCA) may provide decision makers with insights and opportunities to prevent burden shifting of human health impacts between the nonwork environment and the work environment. We propose an integration approach that uses industry‐level work environment characterization factors (WE‐CFs) to convert industry activity into damage to human health attributable to the work environment, assessed as disability‐adjusted life years (DALYs). WE‐CFs are ratios of work‐related fatal and nonfatal injuries and illnesses occurring in the U.S. worker population to the amount of physical output from U.S. industries; they represent workplace hazards and exposures and are compatible with the life cycle inventory (LCI) structure common to process‐based LCA. A proof of concept demonstrates application of the WE‐CFs in an LCA of municipal solid waste landfill and incineration systems. Results from the proof of concept indicate that estimates of DALYs attributable to the work environment are comparable in magnitude to DALYs attributable to environmental emissions. Construction and infrastructure‐related work processes contributed the most to the work environment DALYs. A sensitivity analysis revealed that uncertainty in the physical output from industries had the most effect on the WE‐CFs. The results encourage implementation of WE‐CFs in future LCA studies, additional refinement of LCI processes to accurately capture industry outputs, and inclusion of infrastructure‐related processes in LCAs that evaluate OSH impacts.  相似文献   
210.
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