全文获取类型
收费全文 | 991篇 |
免费 | 9篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 9篇 |
化学工业 | 235篇 |
金属工艺 | 54篇 |
机械仪表 | 15篇 |
建筑科学 | 9篇 |
矿业工程 | 9篇 |
能源动力 | 3篇 |
轻工业 | 14篇 |
水利工程 | 12篇 |
石油天然气 | 40篇 |
无线电 | 57篇 |
一般工业技术 | 249篇 |
冶金工业 | 220篇 |
原子能技术 | 33篇 |
自动化技术 | 42篇 |
出版年
2022年 | 16篇 |
2021年 | 16篇 |
2020年 | 19篇 |
2019年 | 18篇 |
2018年 | 24篇 |
2017年 | 29篇 |
2016年 | 21篇 |
2015年 | 13篇 |
2014年 | 26篇 |
2013年 | 25篇 |
2012年 | 20篇 |
2011年 | 33篇 |
2010年 | 24篇 |
2009年 | 29篇 |
2008年 | 27篇 |
2007年 | 25篇 |
2006年 | 21篇 |
2005年 | 19篇 |
2004年 | 14篇 |
2003年 | 21篇 |
2002年 | 25篇 |
2001年 | 22篇 |
2000年 | 15篇 |
1998年 | 39篇 |
1997年 | 24篇 |
1996年 | 16篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 18篇 |
1992年 | 24篇 |
1991年 | 14篇 |
1990年 | 14篇 |
1989年 | 19篇 |
1987年 | 11篇 |
1986年 | 22篇 |
1985年 | 10篇 |
1984年 | 15篇 |
1981年 | 11篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1978年 | 13篇 |
1977年 | 22篇 |
1976年 | 16篇 |
1975年 | 16篇 |
1974年 | 13篇 |
1973年 | 11篇 |
1972年 | 14篇 |
1971年 | 11篇 |
1969年 | 10篇 |
1968年 | 12篇 |
排序方式: 共有1001条查询结果,搜索用时 15 毫秒
31.
32.
Segregation of calcium on the surface of aluminum-based powders and its effect on oxidation kinetics
V. G. Shevchenko M. V. Kuznetsov S. A. Bibanaeva A. V. Konyukova I. A. Chupova I. N. Latosh V. A. Kochedykov D. A. Eselevich 《Protection of Metals and Physical Chemistry of Surfaces》2012,48(6):631-635
Segregation in the surface layers of an aluminum alloy powder containing 1.3 wt % calcium is studied. With the use of X-ray photoelectron spectroscopy, it is found that the surface calcium content is increased to 34 wt % compared to the bulk. Oxidation of the powder in air studied with the use of thermogravimetry and differential scanning calorimetry showed that the high surface concentration and high chemical activity of calcium result in a doubling of the reaction yield at a temperature of 1750 K. 相似文献
33.
γ-Aminobutyric acid (GABA), 3-hydroxy-L-tyrosine (D0PA), and Pro-Gly-Pro-Leu were labeled with hydrogen isotopes. The mean deuterium content per molecule was 7.5 atoms in Pro-Gly-Pro-Leu and up to 4 atoms in GABA and DOPA. The incorporation of isotopes depending on the reaction conditions was monitored by mass spectrometry. The isotope exchange efficiency was found to strongly depend not only on the reaction temperature and catalyst: substrate ratio, but also on processes occurring on the support surface. 相似文献
34.
35.
36.
37.
38.
The productivity of filtration systems for dewatering of finely dispersed suspensions can be increased by pulsating overpressure. For suspensions of marine organic‐mineral sediments, press filtration processes were investigated under static and pulsating overpressure. The influence of the static pressure component, the pressure amplitude characteristic, the pressure vibration frequency, and the filtration time on the volume of filtrate were determined. Based on Darcy's law, a model of the filtration process under static overpressure was developed. For pulsating overpressure, the mathematical theory of experiment planning and the statistical data analysis method were used. 相似文献
39.
The combinatoric and topological analysis and modeling of the self-assembly of the Na26Cd141–hP168 crystal structure (space group Pbcm; a = 5.483 Å, b = 24.519 Å, and c = 14.573 Å; and V = 1895 Å3) are performed using computational methods (the ToposPro software package). Ninety-eight versions of the cluster representation of the 3D atomic network with the number of structural units ranging from four to seven are found. It is determined that polyhedral clusters–precursors C8 = 0@Na2Cd6 and C9 = 0@Na3Cd6 are templates, on the surface of which atomic shells consisting of 38 and 41 atoms are formed. The composition of the two-layer clusters is C46 = 0@(Na2Cd6)@(Na12Cd26) and C50 = 0@(Na3Cd6)@(Na6Cd35). The centers of clusters C46 and C50 are occupied by positions 1a with the symmetry 6/mmm and 2c with the symmetry −6m2. The symmetry and topology codes of the processes of self-assembly of 3D structures from nanoclusters–precursors C46 and C50 are reconstructed. 相似文献
40.