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   1527篇
  免费   113篇
  国内免费   2篇
电工技术   9篇
化学工业   420篇
金属工艺   40篇
机械仪表   42篇
建筑科学   47篇
矿业工程   4篇
能源动力   38篇
轻工业   350篇
水利工程   12篇
石油天然气   15篇
无线电   61篇
一般工业技术   261篇
冶金工业   157篇
原子能技术   12篇
自动化技术   174篇
  2024年   5篇
  2023年   22篇
  2022年   14篇
  2021年   96篇
  2020年   43篇
  2019年   48篇
  2018年   59篇
  2017年   50篇
  2016年   77篇
  2015年   50篇
  2014年   61篇
  2013年   118篇
  2012年   102篇
  2011年   104篇
  2010年   80篇
  2009年   79篇
  2008年   69篇
  2007年   78篇
  2006年   68篇
  2005年   35篇
  2004年   31篇
  2003年   42篇
  2002年   38篇
  2001年   17篇
  2000年   17篇
  1999年   16篇
  1998年   51篇
  1997年   42篇
  1996年   27篇
  1995年   23篇
  1994年   10篇
  1993年   14篇
  1992年   3篇
  1991年   9篇
  1988年   5篇
  1987年   3篇
  1986年   5篇
  1985年   3篇
  1984年   4篇
  1982年   4篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   3篇
  1976年   2篇
  1973年   1篇
  1972年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
排序方式: 共有1642条查询结果,搜索用时 14 毫秒
1.
Thyromimetics, whose physicochemical characteristics are analog to thyroid hormones (THs) and their derivatives, are promising candidates as novel therapeutics for neurodegenerative and metabolic pathologies. In particular, sobetirome (GC-1), one of the initial halogen-free thyromimetics, and newly synthesized IS25 and TG68, with optimized ADME-Tox profile, have recently attracted attention owing to their superior therapeutic benefits, selectivity, and enhanced permeability. Here, we further explored the functional capabilities of these thyromimetics to inhibit transthyretin (TTR) amyloidosis. TTR is a homotetrameric transporter protein for THs, yet it is also responsible for severe amyloid fibril formation, which is facilitated by tetramer dissociation into non-native monomers. By combining nuclear magnetic resonance (NMR) spectroscopy, computational simulation, and biochemical assays, we found that GC-1 and newly designed diphenyl-methane-based thyromimetics, namely IS25 and TG68, are TTR stabilizers and efficient suppressors of TTR aggregation. Based on these observations, we propose the novel potential of thyromimetics as a multi-functional therapeutic molecule for TTR-related pathologies, including neurodegenerative diseases.  相似文献   
2.
Theoretical Foundations of Chemical Engineering - The corona onset voltage is an important operating parameter in the electrostatic precipitation of nanoparticulate, however, its experimental...  相似文献   
3.
Metallurgical and Materials Transactions B - The quality requirements of aluminum products are steadily increasing, and the presence of non-metallic inclusions have a large impact on the quality of...  相似文献   
4.
5.
6.
Vegetable-based polyurethane (PU) was prepared in the thin film form by spin coating. This polymer is synthesised from castor oil, which can be extracted from the seeds of a native plant in Brazil called mamona. This polymer is biocompatible and is being used as material for artificial bone. The PU was characterised by dielectric spectroscopy in a wide range of frequency (10–5 Hz to 105 Hz) and by thermally stimulated discharge current (TSDC) measurements. The glass transition temperature (T g = 39°C) was determined and using the initial rise method the activation energy was found to be 1.58 eV.  相似文献   
7.
8.
We discuss the performance, of a normal metal hot electron bolometer (NHEB) that we have measured at 0.3 K. We found that the noise equivalent power was limited by the amplifier noise. To improve the NHEB power response and to make it more robust and reliable we propose to substitute the normal metal with heavily doped silicon. The heavily doped silicon behaves like a metal with lower carrier concentration and has a smaller electron–phonon thermal coupling. We have fabricated superconductor-doped silicon-superconductor contacts (S-Sm-S) and we have used them as thermometers and coolers.  相似文献   
9.
In this work a new class of numerical methods for the BGK model of kinetic equations is presented. In principle, schemes of any order of accuracy in both space and time can be constructed with this technique. The methods proposed are based on an explicit–implicit time discretization. In particular the convective terms are treated explicitly, while the source terms are implicit. In this fashion even problems with infinite stiffness can be integrated with relatively large time steps. The conservation properties of the schemes are investigated. Numerical results are shown for schemes of order 1, 2 and 5 in space, and up to third-order accurate in time.  相似文献   
10.
A chlorination process for recovering Zr from zircaloy scrap has been studied. Zircaloy chlorination was possible at temperatures as low as 220 °C. The scale microstructure and its effect on the zircaloy reactivity was analysed using Thermogravimetric analysis (TGA), X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDXS) and scanning electron microscopy (SEM) techniques. A solid-solid phase transformation took place into the oxide scale during the zircaloy chlorination. Zirconium, as ZrCl4(g), was separated from the oxide scale and chlorides of Cr and Fe. The effect of the reaction temperature was also analysed.  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