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
1.
Konstantin V. Dergilev Evgeny K. Shevchenko Zoya I. Tsokolaeva Irina B. Beloglazova Ekaterina S. Zubkova Maria A. Boldyreva Mikhail Yu. Menshikov Elizaveta I. Ratner Dmitry Penkov Yelena V. Parfyonova 《International journal of molecular sciences》2020,21(24)
Cell therapy of the post-infarcted myocardium is still far from clinical use. Poor survival of transplanted cells, insufficient regeneration, and replacement of the damaged tissue limit the potential of currently available cell-based techniques. In this study, we generated a multilayered construct from adipose-derived mesenchymal stromal cells (MSCs) modified to secrete stem cell factor, SCF. In a rat model of myocardium infarction, we show that transplantation of SCF producing cell sheet induced activation of the epicardium and promoted the accumulation of c-kit positive cells in ischemic muscle. Morphometry showed the reduction of infarct size (16%) and a left ventricle expansion index (0.12) in the treatment group compared to controls (24–28%; 0.17–0.32). The ratio of viable myocardium was more than 1.5-fold higher, reaching 49% compared to the control (28%) or unmodified cell sheet group (30%). Finally, by day 30 after myocardium infarction, SCF-producing cell sheet transplantation increased left ventricle ejection fraction from 37% in the control sham-operated group to 53%. Our results suggest that, combining the genetic modification of MSCs and their assembly into a multilayered construct, we can provide prolonged pleiotropic effects to the damaged heart, induce endogenous regenerative processes, and improve cardiac function. 相似文献
2.
B. V. Dvoskin D. V. Gulyga A. F. Shevchenko N. T. Tkach N. S. Kharchenko V. P. Shkurenko 《Metallurgist》1989,33(4):68-69
Institute of Ferrous Metallurgy. Translated from Metallurg, No. 4, p. 24, April, 1989. 相似文献
3.
Androstenedione labeled with tritium at positions 1 and 2 was prepared. The molar radioactivity of the sample prepared using homogeneous catalysts was as high as 1.4-1.5 PBq mol-
1. [1,2-3H]Androst-4-ene-3,17-dione can be converted into the [1-3H]steroid with the molar radioactivity of 0.9 PBq mol-
1. 相似文献
4.
M. I. Surin V. E. Keilin S. M. Miklyaev S. A. Shevchenko 《Instruments and Experimental Techniques》2008,51(4):634-637
Within the framework of the “International Thermonuclear Experimental Reactor” (ITER) program, a prototype of a superconducting magnet for a 170-GHz gyrotron has been developed, manufactured, and tested. The operating induction value (7.1 T at the center of a 219-mm-diameter cold hole and 8.1 T on the winding) is reached at a current of 185.2 A. In the final version of the magnet, the required induction value was reached without aging. Special requirements are imposed on the distribution of the magnetic field along the axis, including an abrupt field decrease on both sides of the magnet. Axial forces are additionally taken by a special device. The magnet’s sections are wound with multifiber conductors based on niobium-tin and niobium-titanium alloys. Seventeen resistive shunts are provided for protecting sections during their transition to the normal state. The magnet is equipped with a device for removing a part of energy from the sections. Mechanical stresses in the magnet’s sections and the structure’s power elements have been measured during tests. 相似文献
5.
V. F. Shevchenko A. A. Petrov V. G. Petrov 《Journal of Infrared, Millimeter and Terahertz Waves》1993,14(9):1755-1768
A basic principle of pulse radar reflectometry is considered in this paper. A numerical analysis is performed in order to study errors appearing due to the expansion of a microwave pulse reflected from the plasma. A block diagram of the basic pulse radar scheme and its overall performance is presented. The first experimental results obtained on T11-M tokamak are discussed. An improved pulse radar scheme with cross-detection is considered. The results of bench test experiments and future applications of this scheme are discussed. 相似文献
6.
V. V. Bobrovskii V. R. Shevchenko 《Journal of Engineering Physics and Thermophysics》1994,66(1):26-29
The reaction between chlorine and an alkaline solution of hydrogen peroxide is suggested for the investigation of chemothermocapillary convection [1].Vitebsk Branch of the Institute of Solid State and Semiconductors Physics, Academy of Sciences of Belarus, Vitebsk, Belarus. Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 66, No. 1, pp. 30–33, January, 1994. 相似文献
7.
A. I. Gorelov A. I. Efanov V. G. Nazaryan V. V. Postnikov A. N. Sviridenkov V. V. Shevchenko 《Atomic Energy》1989,66(2):90-96
Translated from Atomnaya Énergiya, Vol. 66, No. 2, pp. 81–85, February, 1989. 相似文献
8.
9.
Translated from Kibernetika i Sistemnyi Analiz, No. 3, pp. 71–86, May–June, 1995. 相似文献
10.