全文获取类型
收费全文 | 19768篇 |
免费 | 273篇 |
国内免费 | 84篇 |
专业分类
电工技术 | 707篇 |
综合类 | 89篇 |
化学工业 | 2914篇 |
金属工艺 | 1288篇 |
机械仪表 | 1607篇 |
建筑科学 | 335篇 |
矿业工程 | 307篇 |
能源动力 | 122篇 |
轻工业 | 433篇 |
水利工程 | 383篇 |
石油天然气 | 858篇 |
武器工业 | 11篇 |
无线电 | 2040篇 |
一般工业技术 | 5012篇 |
冶金工业 | 2018篇 |
原子能技术 | 421篇 |
自动化技术 | 1580篇 |
出版年
2023年 | 50篇 |
2022年 | 302篇 |
2021年 | 460篇 |
2020年 | 376篇 |
2019年 | 522篇 |
2018年 | 1083篇 |
2017年 | 1129篇 |
2016年 | 1323篇 |
2015年 | 757篇 |
2014年 | 1094篇 |
2013年 | 1428篇 |
2012年 | 1283篇 |
2011年 | 1184篇 |
2010年 | 1163篇 |
2009年 | 1341篇 |
2008年 | 1239篇 |
2007年 | 1175篇 |
2006年 | 938篇 |
2005年 | 545篇 |
2004年 | 312篇 |
2003年 | 137篇 |
2002年 | 143篇 |
2001年 | 135篇 |
2000年 | 458篇 |
1999年 | 342篇 |
1998年 | 336篇 |
1997年 | 344篇 |
1996年 | 46篇 |
1995年 | 14篇 |
1994年 | 17篇 |
1993年 | 13篇 |
1992年 | 17篇 |
1991年 | 11篇 |
1990年 | 22篇 |
1985年 | 20篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1978年 | 23篇 |
1977年 | 12篇 |
1976年 | 24篇 |
1974年 | 21篇 |
1973年 | 14篇 |
1970年 | 12篇 |
1969年 | 23篇 |
1968年 | 15篇 |
1967年 | 10篇 |
1960年 | 10篇 |
1959年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
S. A. Pul’nev A. I. Pryadko A. V. Chikiryaka V. I. Nikolaev 《Technical Physics Letters》2018,44(11):992-994
The behavior of a superelastic Cu?14.2% Al?4%Ni single crystal in the case of high reversible strains under a longitudinal bending force was investigated. The effect of strain confinement along the crystal length was revealed and studied. The highest reversible strains (up to 10%) were shown to be confined within the central part of the bent crystal. 相似文献
32.
33.
34.
D. A. Kudryashov A. S. Gudovskikh A. M. Mozharov A. D. Bol’shakov I. S. Mukhin Zh. I. Alferov 《Technical Physics Letters》2015,41(12):1120-1123
Design and operation modes of double-junction monolithic lattice-matched solar cells based on the ZnSiP2/Si system of materials have been calculated. The effect of the photoactive region thickness and minority carrier lifetime in ZnSiP2 layers on the efficiency of conversion of the incident solar light energy into electrical power was determined. It is shown that solar cells based on ZnSiP2/Si heterostructures can provide efficiencies of 28.8% at AM1.5D, 100 mW/cm2, and 33.3% at AM1.5D, 200 W/cm2. 相似文献
35.
The dynamic interaction between the mechanical and electrical drive parameters when damage suddenly appears in the mechanical part of a conveyer belt is investigated. The possibility of using the change in the motor’s electrical parameters as a diagnostic signal is assessed. A model for investigating the dynamic processes in the system consisting of the grid, the induction motor, and the conveyer belt is proposed. The grid and induction motor are described by a model of fourth-order state space, whose output is the torque at the motor shaft. The moments of inertia and pliability of the links between the elements in the mechanical part of the conveyer belt are determined. By gradually identifying the elements with the minimum moment of inertia and distributing their moments of inertia and pliabilities among the adjacent elements, we obtain a three-mass system simulating the mechanical part of the conveyer belt. This dynamic model is solved by means of Matlab Simulink software. The energy characteristics of the drive are determined in dynamic processes following a mechanical accident. 相似文献
36.
A. E. Kudryashov Zh. V. Eremeeva E. A. Levashov V. Yu. Lopatin A. V. Sevost’yanova E. I. Zamulaeva 《Surface Engineering and Applied Electrochemistry》2018,54(5):437-445
Electrospark treatment of OT4-1 titanium alloy was performed sequentially with a STIM-20N hard-alloy electrode (TiC–20% Ni) and carbon-containing material (graphite and carbon-based composite materials). Kinetics of the mass transfer of the hard-alloy electrode was studied. The cathode mass loss during the first minute of the treatment was established. The kinetics results were processed using the methods of mathematical statistics. The erosion resistance of the applied carbon-containing materials was determined. Phase composition and relief of the coatings formed were analyzed. It was found that the application of the carbon-containing material increases the content of refractory phases in the coatings. Increase in the time of the treatment using the carbon-containing materials decreases the roughness of the coatings. 相似文献
37.
该文利用色集事先分配法、构造染色法、反证法探讨了完全三部图K4,4,p (p≥1008)的点可区别IE-全染色问题,确定了K4,4,p (p≥1008)的点可区别IE-全染色数。 相似文献
38.
Burdin D. A. Savel’ev D. V. Ekonomov N. A. Chashin D. V. Fetisov Yu. K. 《Technical Physics Letters》2020,46(5):487-490
Technical Physics Letters - The magnetoelectric (ME) effect in a planar amorphous ferromagnet–piezoelectric lead zirconate titanate (PZT) composite structure can be effectively excited by... 相似文献
39.
40.
D. A. Mirzaev N. I. Vorob’ev O. K. Tokovi D. V. Shaburov E. A. Fominykh 《Russian Metallurgy (Metally)》2006,(1):38-41
The solutions to a differential equation for the problem of heating of a cylinder in a medium with a fixed temperature are used to obtain equations for estimating the change in the hydrogen concentration in forgings from data on the hydrogen concentration at the cylinder axis or on the average bulk hydrogen concentration. Similar equations are also obtained for forgings having square cross sections. The calculation demonstrates that, for the case of a twofold decrease in the hydrogen concentration in a forging, the calculated times of annealing of a cylindrical forging differ by three times. 相似文献