全文获取类型
收费全文 | 167130篇 |
免费 | 11861篇 |
国内免费 | 6123篇 |
专业分类
电工技术 | 8755篇 |
技术理论 | 9篇 |
综合类 | 8744篇 |
化学工业 | 27335篇 |
金属工艺 | 9996篇 |
机械仪表 | 10095篇 |
建筑科学 | 9803篇 |
矿业工程 | 3942篇 |
能源动力 | 3653篇 |
轻工业 | 9385篇 |
水利工程 | 3158篇 |
石油天然气 | 9554篇 |
武器工业 | 1053篇 |
无线电 | 17567篇 |
一般工业技术 | 26783篇 |
冶金工业 | 11085篇 |
原子能技术 | 4831篇 |
自动化技术 | 19366篇 |
出版年
2024年 | 716篇 |
2023年 | 2330篇 |
2022年 | 4629篇 |
2021年 | 6228篇 |
2020年 | 4681篇 |
2019年 | 4028篇 |
2018年 | 5139篇 |
2017年 | 5599篇 |
2016年 | 5142篇 |
2015年 | 5668篇 |
2014年 | 7323篇 |
2013年 | 8913篇 |
2012年 | 9565篇 |
2011年 | 10270篇 |
2010年 | 8741篇 |
2009年 | 8550篇 |
2008年 | 8422篇 |
2007年 | 7914篇 |
2006年 | 7336篇 |
2005年 | 6267篇 |
2004年 | 4786篇 |
2003年 | 4719篇 |
2002年 | 4751篇 |
2001年 | 4324篇 |
2000年 | 3746篇 |
1999年 | 3326篇 |
1998年 | 2625篇 |
1997年 | 2212篇 |
1996年 | 1981篇 |
1995年 | 1736篇 |
1994年 | 1466篇 |
1993年 | 1244篇 |
1992年 | 1216篇 |
1991年 | 1074篇 |
1990年 | 1091篇 |
1989年 | 1009篇 |
1988年 | 896篇 |
1987年 | 841篇 |
1986年 | 763篇 |
1985年 | 715篇 |
1984年 | 701篇 |
1981年 | 668篇 |
1979年 | 736篇 |
1978年 | 777篇 |
1977年 | 739篇 |
1976年 | 755篇 |
1975年 | 713篇 |
1974年 | 719篇 |
1973年 | 723篇 |
1972年 | 705篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
V. I. Timoshenko Yu. V. Knyshenko Yu. G. Lyashenko 《Journal of Engineering Physics and Thermophysics》1997,70(3):394-398
The effect of turbulizing asperities positioned on one of the walls of a plane channel on the intensity of exchange processes
near a smooth wall with injection of different working media is studied experimentally.
Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 70, No. 3, pp. 404–408, 1997. 相似文献
82.
83.
Scientific-Technical Center “Atomtekhénergo.” Leningrad Nuclear Power Plant. N. V. Sultanov Institute of Nuclear Reactors,
Russian Scientific Center “Kurchatovskii institut.” Translated from Atomnaya énergiya, Vol. 76, No. 6, pp. 470–473, June,
1994. 相似文献
84.
85.
86.
Analytical solution of a system of nonlinear measuring equations of a 12-pole microwave reflectometer was obtained. Criteria for selecting a true solution in the general case were developed and the analysis was conducted for a number of particular cases that may generate practical interest. 相似文献
87.
The formation specifics of the structure and phase composition of densely sintered ceramics based on a low-melting argillaceous
material from Belarus together with a combined flux and a grog additive are investigated. The correlation between the physicochemical
properties, structure, phase composition, and the time-temperature firing schedules of the developed materials are investigated.
Electron probe microanalysis makes it possible to monitor variations in the chemical composition at various local sites and
compare it with the estimated composition of the mixture. The optimum regimes for the heat treatment of articles are determined.
__________
Translated from Steklo i Keramika, No. 6, pp. 32 – 36, June, 2005. 相似文献
88.
We present an automatic algorithm to segment all the local and global asymmetric units of a three-dimensional density map of icosahedral viruses. This approach is readily applicable to the structural analysis of a broad range of virus structures that are reconstructed using cryo-electron microscopy (cryo-EM) technique. Our algorithm includes three major steps operating on the three dimensional density map: the detection of critical points of the volumetric density function, the detection of global and local symmetry axes, and, finally, the boundary segmentation of all the asymmetric units. We demonstrate the efficacy of our algorithm and report our results on several experimental volumetric datasets, consisting of both reconstructed cryo-EM molecular density maps taken from the European Bioinformatics Institute archive, as well our own synthetically generated (blurred) maps calculated from X-ray resolution molecular structural data taken from the Protein Data Bank. 相似文献
89.
90.