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   46篇
  免费   0篇
化学   21篇
力学   1篇
数学   2篇
物理学   22篇
  2019年   2篇
  2018年   1篇
  2016年   1篇
  2013年   1篇
  2012年   1篇
  2011年   2篇
  2009年   3篇
  2008年   1篇
  2000年   11篇
  1999年   1篇
  1995年   2篇
  1994年   1篇
  1993年   1篇
  1992年   4篇
  1991年   2篇
  1988年   1篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1983年   1篇
  1982年   1篇
  1980年   2篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
排序方式: 共有46条查询结果,搜索用时 0 毫秒
11.
12.
The scattered-light method has been studied with the aim of developing a flow-optic relation which can be used for the analysis of three-dimensional flow problems of Newtonian fluids utilizing flow birefringence. A set of flow-optic relations which potentially can be adapted to three-dimensional scattered-light birefringent analysis has been developed on a phenomenological basis for the aqueous suspensions of Milling Yellow. Good agreement with theoretical solutions was obtained when these relations were applied to flows through channels of three different geometries.  相似文献   
13.
This personal account describes the pursuit of non‐fullerene acceptors designed from simple and accessible organic pi‐conjugated building blocks and assembled through efficient direct (hetero)arylation cross‐coupling protocols. Initial materials development focused on isoindigo and diketopyrrolopyrrole organic dyes flanked by imide‐based terminal acceptors. Efficiencies in solution‐processed organic solar cells were modest but highlighted the potential of the material design. Materials performance was improved through structural engineering to pair perylene diimide with these organic dyes. Optimization of active layer processing and solar cell device fabrication identified the perylene diimide flanked diketopyrrolopyrrole structure as the best framework, with fullerene‐free organic solar cells achieving power conversion efficiencies above 6 %. This material has met our criteria for a simple wide band gap fullerene alternative for pairing with a range of donor polymers.  相似文献   
14.
15.
The zeros in the complex z plane of the Whittaker function Wc/z,µ(z),closely related to spherical waves in the quantum-mechanicalCoulomb problem, are investigated for varying real values ofthe parameters c and µ  相似文献   
16.
17.
18.
The i.r. absorptivity of the R-branch maximum (9.48 μm) of gaseous ozone was determined at 25°C as a function of spectral resolution and absorbance a/a total pressure of 735 torr of dry air. Ozone samples produced by a high voltage discharge in oxygen, and measured accurately by either a pressure or volume change, were spectroscopically measured in a 57741. environmental chamber at paths up to 69.17 m. A linear relation between spectral slit (Δv) and the ratio of the absorbances (Rv/p) of the observed absorption minimum between the R and Q branches to the absorption maximum of the R-branch was found for cm-1 < Δv < 10cm-1 and for absorption up to 48%. The i.r. absorptivity varied approx. 20% (from 3.9 to 4.8 cm-1 STP) over the range of values for Rv/p studied. Absorptivity was weakly dependent on ozone abundance (w) for w?0.03 cm STP.  相似文献   
19.
20.

Background  

The hippocampus is essential for declarative memory synthesis and is a core pathological substrate for Alzheimer's disease (AD), the most common aging-related dementing disease. Acute increases in plasma cortisol are associated with transient hippocampal inhibition and retrograde amnesia, while chronic cortisol elevation is associated with hippocampal atrophy. Thus, cortisol levels could be monitored and managed in older people, to decrease their risk of AD type hippocampal dysfunction. We generated an in silicomodel of the chronic effects of elevated plasma cortisol on hippocampal activity and atrophy, using the systems biology mark-up language (SBML). We further challenged the model with biologically based interventions to ascertain if cortisol associated hippocampal dysfunction could be abrogated.  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