全文获取类型
收费全文 | 5004篇 |
免费 | 154篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 89篇 |
综合类 | 8篇 |
化学工业 | 925篇 |
金属工艺 | 120篇 |
机械仪表 | 131篇 |
建筑科学 | 182篇 |
矿业工程 | 11篇 |
能源动力 | 139篇 |
轻工业 | 275篇 |
水利工程 | 32篇 |
石油天然气 | 14篇 |
无线电 | 664篇 |
一般工业技术 | 834篇 |
冶金工业 | 932篇 |
原子能技术 | 30篇 |
自动化技术 | 781篇 |
出版年
2023年 | 24篇 |
2021年 | 75篇 |
2020年 | 49篇 |
2019年 | 59篇 |
2018年 | 86篇 |
2017年 | 77篇 |
2016年 | 91篇 |
2015年 | 75篇 |
2014年 | 144篇 |
2013年 | 340篇 |
2012年 | 219篇 |
2011年 | 267篇 |
2010年 | 193篇 |
2009年 | 225篇 |
2008年 | 285篇 |
2007年 | 227篇 |
2006年 | 185篇 |
2005年 | 167篇 |
2004年 | 154篇 |
2003年 | 140篇 |
2002年 | 141篇 |
2001年 | 95篇 |
2000年 | 90篇 |
1999年 | 100篇 |
1998年 | 182篇 |
1997年 | 122篇 |
1996年 | 82篇 |
1995年 | 81篇 |
1994年 | 89篇 |
1993年 | 63篇 |
1992年 | 85篇 |
1991年 | 61篇 |
1990年 | 52篇 |
1989年 | 42篇 |
1988年 | 47篇 |
1987年 | 38篇 |
1986年 | 39篇 |
1985年 | 44篇 |
1984年 | 57篇 |
1983年 | 46篇 |
1982年 | 48篇 |
1981年 | 37篇 |
1980年 | 36篇 |
1979年 | 31篇 |
1978年 | 33篇 |
1977年 | 37篇 |
1976年 | 41篇 |
1975年 | 28篇 |
1974年 | 31篇 |
1973年 | 33篇 |
排序方式: 共有5167条查询结果,搜索用时 390 毫秒
1.
Journal of Signal Processing Systems - With the latest development of automation technology, object detection technology has received more and more research attention. Automated object detection... 相似文献
2.
3.
4.
Honour Index (HoI), a method to evaluate research performance within different research fields, was derived from the impact
factor (IF). It can be used to rate and compare different categories of journals. HoI was used in this study to determine
the scientific productivity of stem cell research in the Asian Four Dragons (Hong Kong, Singapore, South Korea and Taiwan)
from 1981 to 2001. The methodology applied in this study represents a synthesis of universal indicator studies and bibliometric
analyses of subfields at the micro-level. We discuss several comparisons, and conclude the developmental trend in stem cell
research for two decades.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Polyaryloxydiphenylsilanes were prepared from phosphorus‐containing diols and diphenydichlorolsilane through solution polymerization. With a stoichiometric imbalance in feed monomers, the resulting polymers exhibited moderate melting points and good processing properties. The polymers prepared showed initial decomposition temperatures above 340 °C, excellent thermal stability, high char yields at 850 °C and very high limited oxygen index values of 56–59. The polymers' char yields and their (P + Si) contents showed linear relationships. © 2003 Society of Chemical Industry 相似文献
6.
Heng Zhang Jack Gromek Gayath W. Fernando Harris L. Marcus Sam Boorse 《Journal of Phase Equilibria》2002,23(3):246-248
The thermal equilibrium decomposition properties of the PdO-Pd system under oxygen partial pressures ranging from 0.1 to 1.0 atm in a total combined pressure of oxygen and nitrogen of 1.0 atm were investigated by means of thermal-gravimetric analyses. The phase diagram of Pd-PdO over the range of oxygen/nitrogen gas concentration was established. The decomposition temperature of PdO to Pd was found to increase with the partial pressure of oxygen. 相似文献
7.
8.
Dynamic cardiomyoplasty (DCM) involves the electrical stimulation of a pedicled latissimus dorsi muscle flap wrapped around the falling ventricle as a means of cardiac assist. To further elucidate a potential neurohumoral mechanism for improvement of cardiac output after myoplasty, we evaluated the hemodynamic effects of in situ stimulation of the latissimus dorsi muscle (in the absence of cardiomyoplasty). In seven mongrel dogs, a nerve cuff electrode (Medtronic 6901) was placed around the left thoracodorsal nerve (TDN). This was attached to a pulse generator (Medtronic, Itrel 7420), delivering a 4.0 volt, 0.19 second on, 0.81 second off, 33 Hz, 210 microsecond pulse width, cyclic bursts similar to that used in DCM. Stroke volume index (SVI) and other hemodynamic parameters as well as plasma norepinephrine (NE) levels were measured at five stages: baseline, stimulator on at 0, 2, and 5 minutes, and stimulator off at 30 minutes after. The animals were then subjected to 4 weeks of rapid pacing at 240 beats/min (Medtronic 8329) to induce heart failure, and as the rapid pacing was discontinued, measurements were repeated as above. After rapid pacing, cardiac function was significantly depressed, and NE was elevated (133 +/- 69 versus 500 +/- 353 pg/mL, p < 0.05). In the normal hearts, TDN stimulation increased SVI, heart rate, systemic pressure, and NE levels. In heart failure, however, no significant changes in cardiac function and NE levels were noted. In conclusion, our data indicate that in the normal hearts, afferent impulses from TDN stimulation alone may augment cardiac function by means of a neurohumoral effect that is not seen in severe heart failure. The implications of these findings in DCM are discussed. 相似文献
9.
Jack J. Domet III T.M. Rajkumar Domet III David Yen 《Information Systems Management》1994,11(4):39-45
The realization of digital multimedia's full business potential requires networking. This article discusses the value-added benefits to the corporation of networked multimedia as well as the choice of architectures and technologies needed to deliver multimedia networking solutions. 相似文献
10.
Chih-Wea Wang Chi-Feng Wu Jin-Fu Li Cheng-Wen Wu Tony Teng Kevin Chiu Hsiao-Ping Lin 《Journal of Electronic Testing》2002,18(6):637-647
In this paper we propose a novel built-in self-test (BIST) design for embedded SRAM cores. Our contribution includes a compact and efficient BIST circuit with diagnosis support and an automatic diagnostic system. The diagnosis module of our BIST circuit can capture the error syndromes as well as fault locations for the purposes of repair and fault/failure analysis. In addition, our design provides programmability for custom March algorithms with lower hardware cost. The combination of the on-line programming mode and diagnostic system dramatically reduces the effort in design debugging and yield enhancement. We have designed and implemented test chips with our BIST design. Experimental results show that the area overhead of the proposed BIST design is only 2.4% for a 128 KB SRAM, and 0.65% for a 2 MB one. 相似文献