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   619篇
  免费   48篇
  国内免费   1篇
电工技术   1篇
化学工业   189篇
金属工艺   13篇
机械仪表   15篇
建筑科学   18篇
能源动力   11篇
轻工业   133篇
水利工程   4篇
石油天然气   1篇
无线电   31篇
一般工业技术   84篇
冶金工业   93篇
原子能技术   3篇
自动化技术   72篇
  2023年   6篇
  2022年   28篇
  2021年   44篇
  2020年   14篇
  2019年   12篇
  2018年   20篇
  2017年   22篇
  2016年   29篇
  2015年   21篇
  2014年   24篇
  2013年   34篇
  2012年   28篇
  2011年   32篇
  2010年   30篇
  2009年   29篇
  2008年   30篇
  2007年   32篇
  2006年   24篇
  2005年   19篇
  2004年   17篇
  2003年   16篇
  2002年   17篇
  2001年   3篇
  2000年   10篇
  1999年   11篇
  1998年   25篇
  1997年   14篇
  1996年   7篇
  1995年   8篇
  1994年   2篇
  1993年   9篇
  1992年   3篇
  1990年   2篇
  1987年   2篇
  1986年   2篇
  1984年   2篇
  1980年   2篇
  1977年   2篇
  1976年   7篇
  1975年   2篇
  1973年   5篇
  1969年   2篇
  1968年   2篇
  1967年   2篇
  1964年   2篇
  1963年   1篇
  1960年   2篇
  1959年   1篇
  1958年   1篇
  1955年   1篇
排序方式: 共有668条查询结果,搜索用时 15 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.
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   
3.
4.
5.
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   
6.
The operation of a torsional oscillator for detection, of flow-driven textural transitions in, 3He-A is described. The detection technique, tracking the shift of the resonant frequency of the torsional oscillator, allows us to observe textural changes and the presence of vortices in zero magnetic field. It relies on. the anisotropic superfluid density of 3He-A and its change due to reorientation of the Î-texture caused by counterflow.  相似文献   
7.
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   
8.
The redox behavior of titanium in CaO-SiO2-TiO x melts was investigated using a slag-gas equilibrium technique. Titanium partitioning between Ti3+ and Ti4+ valency states and the ratio of activity coefficients of TiO1.5 and TiO2 were determined as functions of oxygen partial pressure, temperature, and slag composition. The equilibrium experiments were carried out at temperatures between 1783 and 1903 K under CO-CO2-Ar gas atmosphere with oxygen partial pressure ranging from 10−12 to 10−7 atm (1.01×10−10 kPa to 1.01×10−5 kPa). The slags had CaO/SiO2 ratios between 0.55 and 1.35 and total titanium oxide concentrations from 7 to 50 mass pct. Experimental results showed that the Ti3+/Ti4+ ratio in CaO-SiO2-TiO x slags, containing up to 50 mass pct TiO x , increased with decreasing oxygen partial pressure and decreased with increasing CaO/SiO2 ratio and decreasing temperature. Measured variation of the redox ratio Ti3+/Ti4+ with oxygen partial pressure closely followed the ideal behavior. Increasing the CaO/SiO2 ratio increased the ratio of activity coefficients of TiO1.5 and TiO2. The effect of total titania content on this ratio was more complex and in accord with Raman spectroscopy data.  相似文献   
9.
Impedance spectroscopy and gravimetry were employed to characterize alkyd-acrylate and styrene-acrylate water-borne resin film properties during wetting-through (i.e. during water uptake).  相似文献   
10.
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