全文获取类型
收费全文 | 5160篇 |
免费 | 84篇 |
国内免费 | 16篇 |
专业分类
电工技术 | 79篇 |
综合类 | 2篇 |
化学工业 | 1113篇 |
金属工艺 | 289篇 |
机械仪表 | 239篇 |
建筑科学 | 30篇 |
矿业工程 | 78篇 |
能源动力 | 47篇 |
轻工业 | 60篇 |
水利工程 | 81篇 |
石油天然气 | 213篇 |
无线电 | 469篇 |
一般工业技术 | 1260篇 |
冶金工业 | 577篇 |
原子能技术 | 404篇 |
自动化技术 | 319篇 |
出版年
2022年 | 150篇 |
2021年 | 151篇 |
2020年 | 91篇 |
2019年 | 91篇 |
2018年 | 170篇 |
2017年 | 175篇 |
2016年 | 216篇 |
2015年 | 92篇 |
2014年 | 155篇 |
2013年 | 223篇 |
2012年 | 209篇 |
2011年 | 232篇 |
2010年 | 176篇 |
2009年 | 204篇 |
2008年 | 187篇 |
2007年 | 174篇 |
2006年 | 130篇 |
2005年 | 126篇 |
2004年 | 103篇 |
2003年 | 91篇 |
2002年 | 100篇 |
2001年 | 75篇 |
2000年 | 74篇 |
1999年 | 74篇 |
1998年 | 98篇 |
1997年 | 80篇 |
1996年 | 69篇 |
1995年 | 76篇 |
1994年 | 49篇 |
1993年 | 59篇 |
1992年 | 45篇 |
1991年 | 51篇 |
1990年 | 51篇 |
1989年 | 47篇 |
1986年 | 45篇 |
1984年 | 44篇 |
1983年 | 52篇 |
1982年 | 48篇 |
1981年 | 55篇 |
1980年 | 44篇 |
1979年 | 47篇 |
1978年 | 74篇 |
1977年 | 65篇 |
1976年 | 81篇 |
1975年 | 52篇 |
1974年 | 52篇 |
1973年 | 48篇 |
1972年 | 44篇 |
1971年 | 40篇 |
1968年 | 37篇 |
排序方式: 共有5260条查询结果,搜索用时 15 毫秒
1.
V. E. Gromov A. M. Glezer K. V. Morozov Yu. F. Ivanov K. V. Volkov 《Russian Metallurgy (Metally)》2015,2015(13):1094-1097
A layer-by-layer analysis of the structures, the phase compositions, and the defect substructures of differentially hardened rails has been carried by optical and transmission electron microscopy. It is found that the material volume of the rail head fillet is cooled faster than the volume located along the central axis. 相似文献
2.
3.
Bochkareva N. I. Ivanov A. M. Klochkov A. V. Kogotkov V. S. Rebane Yu. T. Virko M. V. Shreter Y. G. 《Semiconductors》2015,49(6):827-835
Semiconductors - It is shown that the emission efficiency and the 1/f noise level in light-emitting diodes with InGaN/GaN quantum wells correlate with how the differential resistance of a diode... 相似文献
4.
The article describes the experience of implementing patient-focused care from a physician's perspective. Pitfalls that guarantee failure are presented, many of which are avoidable with early participation by all parties involved: administrators, nursing staff, physicians, and patients. Contamination of the process with downsizing needs, lack of support for staff in dealing with necessary change, loss of administrative commitment, and withholding of appropriated funds are among the key errors to be avoided. 相似文献
5.
6.
A. Ivanov 《Journal of Electronic Testing》2002,18(4-5):361-362
7.
8.
9.
P. V. Zrelov V. V. Ivanov 《Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment》1991,310(3):623-630
The statistical method of identification of relativistic charged particles by measurements of ionization losses or time-of-flights simultaneously in some detectors of an experimental plant on the basis of the new goodness-of-fit ωn3-criterion is considered. The method proposed has been used for the secondary particles identification from the high energy -particles fragmentation on target nuclei. The efficiency of the method is excellently illustrated by reliable separation of events (rare events as well), connected with the appearence of 1- and 2-charged particles. The comparison of the ωn3-method with the traditional methods and with the method based on the ωn2-criterion shows that the new method outperforms the ωn2-method and most of the traditional ones in efficiency, but compares unfavourably with the likelihood method in power, however, the former has a number of advantages as compared with the latter. 相似文献
10.