全文获取类型
收费全文 | 1240篇 |
免费 | 36篇 |
专业分类
电工技术 | 17篇 |
综合类 | 7篇 |
化学工业 | 203篇 |
金属工艺 | 15篇 |
机械仪表 | 60篇 |
建筑科学 | 46篇 |
能源动力 | 47篇 |
轻工业 | 93篇 |
水利工程 | 10篇 |
无线电 | 154篇 |
一般工业技术 | 235篇 |
冶金工业 | 183篇 |
原子能技术 | 5篇 |
自动化技术 | 201篇 |
出版年
2023年 | 5篇 |
2022年 | 20篇 |
2021年 | 32篇 |
2020年 | 26篇 |
2019年 | 20篇 |
2018年 | 21篇 |
2017年 | 32篇 |
2016年 | 32篇 |
2015年 | 18篇 |
2014年 | 25篇 |
2013年 | 78篇 |
2012年 | 45篇 |
2011年 | 74篇 |
2010年 | 52篇 |
2009年 | 43篇 |
2008年 | 54篇 |
2007年 | 55篇 |
2006年 | 58篇 |
2005年 | 48篇 |
2004年 | 43篇 |
2003年 | 44篇 |
2002年 | 34篇 |
2001年 | 19篇 |
2000年 | 18篇 |
1999年 | 36篇 |
1998年 | 49篇 |
1997年 | 43篇 |
1996年 | 32篇 |
1995年 | 30篇 |
1994年 | 20篇 |
1993年 | 13篇 |
1992年 | 9篇 |
1991年 | 15篇 |
1990年 | 6篇 |
1989年 | 15篇 |
1988年 | 13篇 |
1987年 | 21篇 |
1986年 | 12篇 |
1985年 | 17篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1953年 | 1篇 |
1942年 | 2篇 |
排序方式: 共有1276条查询结果,搜索用时 10 毫秒
1.
Liang Y.C. Wenjiang Zeng Pick Hong Ong Zhaoxia Gao Jun Cai Balasubramanian N. 《Electron Device Letters, IEEE》2002,23(12):700-703
In this letter, a concise process technology is proposed for the first time to enable the fabrication of good quality three-dimensional (3-D) suspended radio frequency (RF) micro-inductors on bulk silicon, without utilizing the lithography process on sidewall and trench-bottom patterning. Samples were fabricated to demonstrate the applicability of the proposed process technology. 相似文献
2.
Alia-Klein Nelly; Goldstein Rita Z.; Tomasi Dardo; Zhang Lei; Fagin-Jones Stephanie; Telang Frank; Wang Gene-Jack; Fowler Joanna S.; Volkow Nora D. 《Canadian Metallurgical Quarterly》2007,7(4):735
Reports an error in "What is in a word? No versus Yes differentially engage the lateral orbitofrontal cortex" by Nelly Alia-Klein, Rita Z. Goldstein, Dardo Tomasi, Lei Zhang, Stephanie Fagin-Jones, Frank Telang, Gene-Jack Wang, Joanna S. Fowler and Nora D. Volkow (Emotion, 2007[Aug], Vol 7[3], 649-659). The supplemental materials link should appear as follows: http://dx.doi.org/10.1037/1528-3542.7.3.649.supp. (The following abstract of the original article appeared in record 2007-11660-018.) The words "No" and "Yes" are involved in conditioning to prohibit or encourage behavior, respectively. The authors, therefore, hypothesized that these words would be attributed to endogenous valence, activating neuronal circuits involved with valence and emotional control. Functional MRI (fMRI) at 4 Tesla was used to record regional brain activity while participants were exposed to emphatic vocalizations of the words. Results showed that No and Yes were associated with opposite brain-behavior responses; while No was negatively valenced, produced slower response times, and evoked a negative signal in the right lateral orbitofrontal cortex (OFC), Yes was positively valenced, produced faster response times, and evoked a positive signal in a contiguous region of the OFC. Attribution of negative valence to No and trait anger control were associated with increased responsivity of the OFC to No. Inasmuch as sensitivity to the prohibitive command No develops during childhood through interaction with primary caregivers as the first social objects, our findings may implicate the lateral OFC in the neurobiology of emotion regulation and subsequent social development. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
3.
W. L. Siew F. C. H. Oh A. S. H. Ong 《Journal of the American Oil Chemists' Society》1985,62(6):1036-1039
Some of the factors affecting cloud point determination of palm oleins are described. These are the type of container used, method of stirring, rate of stirring and bath temperature. The repeatability and reproducibility standard deviations of the method are determined from collaborative trials. Recommendations for the test are made to reduce the large variations among laboratories. 相似文献
4.
The authors examine effects on the torque that simple variations of the standard rotor pole face profile could have, basically from an elementary viewpoint of how the modified profiles affect the distribution and magnitude of the radial and tangential components of the flux density. It is observed that the average torque is mostly affected by changes that alter the dominant radial component, such as changes in the effective air gap length. The other observation that an increase in the average torque can also be obtained by a favorable shift in the torque versus angle characteristics by relatively simple changes of the rotor pole profile is not so well known. Such a shift that reduces the slope of the torque angle characteristic, skewing the curve towards the unaligned position, has two advantages: one is that the phase inductance is at its maximum positive slop and, hence, the maximum torque, when the phase is energized; second, the flatter inductance profile near the aligned position when the phase current is to be commutated would allow a faster drop off of the commutated current and, thus, a smaller negative torque 相似文献
5.
6.
W. Tang H.Z. Shi G. Xu B.S. Ong Z.D. Popovic J.C. Deng J. Zhao G.H. Rao 《Advanced materials (Deerfield Beach, Fla.)》2005,17(19):2307-2311
7.
In this study, four similar bench-scale submerged Anoxic/Oxic Membrane Bioreactors (MBR) were used simultaneously to investigate the effects of solids retention time (SRT) on organic and nitrogen removal in MBR for treating domestic wastewater. COD removal efficiencies in all reactors were consistently above 94% under steady state conditions. Complete conversion of NH(4+)-N to NO(3-)-N was readily achieved over a feed NH(4+)-N concentration range of 30 to 50 mg/L. It was also observed that SRT did not significantly affect the nitrification in the MBR systems investigated. The average denitrification efficiencies for the 3, 5, 10 and 20 days SRT operations were 43.9, 32.6, 47.5 and 66.5%, respectively. In general, the average effluent nitrogen concentrations, which were mainly nitrate, were about 22.2, 27.6, 21.7 and 13.9 mg/L for the 3, 5, 10 and 20 days SRT systems, respectively. The rate of membrane fouling at 3 days SRT operation was more rapid than that observed at 5 days SRT. No fouling was noted in the 10 days and 20 days SRT systems during the entire period of study. 相似文献
8.
9.
Jin B. Ong Osama K. Eyada PhD PE Abu S. Masud PhD PE 《Computers & Industrial Engineering》1989,17(1-4):85-89
This paper presents a Knowledge-based system (KBS) developed to allow users, who may not be knowledgeable about sensors, to select sensors suitable for their specific needs. The KBS runs on a micro-computer. The selection criteria are user specified and are based on the desired measurement parameters. The system output includes all of the operational and dimensional parameters of the recommended sensor, price, and vendor information. 相似文献
10.