全文获取类型
收费全文 | 491篇 |
免费 | 36篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 32篇 |
化学工业 | 131篇 |
金属工艺 | 9篇 |
机械仪表 | 14篇 |
建筑科学 | 14篇 |
能源动力 | 26篇 |
轻工业 | 41篇 |
石油天然气 | 11篇 |
无线电 | 35篇 |
一般工业技术 | 104篇 |
冶金工业 | 38篇 |
原子能技术 | 16篇 |
自动化技术 | 58篇 |
出版年
2023年 | 4篇 |
2022年 | 15篇 |
2021年 | 25篇 |
2020年 | 12篇 |
2019年 | 14篇 |
2018年 | 19篇 |
2017年 | 20篇 |
2016年 | 21篇 |
2015年 | 16篇 |
2014年 | 14篇 |
2013年 | 25篇 |
2012年 | 31篇 |
2011年 | 41篇 |
2010年 | 26篇 |
2009年 | 28篇 |
2008年 | 25篇 |
2007年 | 33篇 |
2006年 | 15篇 |
2005年 | 11篇 |
2004年 | 15篇 |
2003年 | 9篇 |
2002年 | 2篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 3篇 |
1998年 | 13篇 |
1997年 | 4篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1975年 | 3篇 |
1974年 | 1篇 |
排序方式: 共有529条查询结果,搜索用时 15 毫秒
61.
62.
Ondrej L. Krivanek Niklas Dellby Matthew F. Murfitt Matthew F. Chisholm Timothy J. Pennycook Kazutomo Suenaga Valeria Nicolosi 《Ultramicroscopy》2010
Aberration correction of the scanning transmission electron microscope (STEM) has made it possible to reach probe sizes close to 1 Å at 60 keV, an operating energy that avoids direct knock-on damage in materials consisting of light atoms such as B, C, N and O. Although greatly reduced, some radiation damage is still present at this energy, and this limits the maximum usable electron dose. Elemental analysis by electron energy loss spectroscopy (EELS) is then usefully supplemented by annular dark field (ADF) imaging, for which the signal is larger. Because of its strong Z dependence, ADF allows the chemical identification of individual atoms, both heavy and light, and it can also record the atomic motion of individual heavy atoms in considerable detail. We illustrate these points by ADF images and EELS of nanotubes containing nanopods filled with single atoms of Er, and by ADF images of graphene with impurity atoms. 相似文献
63.
H. Sawada T. Sasaki F. Hosokawa S. Yuasa M. Terao M. Kawazoe T. Nakamichi T. Kaneyama Y. Kondo K. Kimoto K. Suenaga 《Ultramicroscopy》2010
We developed a new electron optical system with three dodecapoles to compensate for spherical aberration and six-fold astigmatism, which generally remains in a two-hexapole type corrector. In this study, we applied the corrector for image-forming system in transmission electron microscope. Compensation for higher-order aberration was demonstrated through a diffractogram tableau using a triple three-fold astigmatism field system, which was then compared with a double hexapole field system. Using this electron optical system, six-fold astigmatism was measured to be less than 0.1 mm at an acceleration voltage of 60 kV, showing that the system successfully compensated for six-fold astigmatism. 相似文献
65.
Yasutaka Fujimoto Taichi Imai Atsuo Kawamura Yosuke Asano 《IEEJ Transactions on Electrical and Electronic Engineering》2009,4(2):218-230
This paper introduces biped robot adaptation to human living environment from viewpoints of battery operation time extension and environmental recognition. These issues are important when robots actually work at home. First, in order to extend battery operation time, we propose energy-saving bipedal locomotion gait. The problem is formulated as an optimal control problem, which is conventionally hard to solve when a target system is complicated. In this paper, partial derivatives appeared in optimal control problem are implicitly represented by using automatic differentiation technique. This approach enables complicated optimal control problem solvable. In combination with receding horizon control, its computation cost is also reduced. Second, we introduce the biped walk tracking based on the camera image mounted on the walking robot, and the visual servoing by the posture change for the purpose of the target image tracking in the camera frame. We propose a new control law to track the rotated target object using the characteristic of the walking, which considered the interference between translational motion and rotational motion. The decoupling is realized by simulations and experiments. As a result, the walking robot tracked the translated and rotated target object without a practical issue. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
66.
Determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of water-soluble tetrazolium salts 总被引:1,自引:0,他引:1
Tadayuki Tsukatani Hikaru Suenaga Munetaka Ishiyama Takatoshi Ezoe Kiyoshi Matsumoto 《Food chemistry》2011
A method for the determination of water-soluble vitamins using a colorimetric microbial viability assay based on the reduction of the tetrazolium salt {2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt (WST-8)} via 2-methyl-1,4-napthoquinone (NQ) was developed. Measurement conditions were optimized for the microbiological determination of water-soluble vitamins, such as vitamin B6, biotin, folic acid, niacin, and pantothenic acid, using microorganisms that have a water-soluble vitamin requirement. A linear relationship between absorbance and water-soluble vitamin concentration was obtained. The proposed method was applied to determine the concentration of vitamin B6 in various foodstuffs. There was good agreement between vitamin B6 concentrations determined after 24 h using the WST-8 colorimetric method and those obtained after 48 h using a conventional method. The results suggest that the WST-8 colorimetric assay is a useful method for the rapid determination of water-soluble vitamins in a 96-well microtiter plate. 相似文献
67.
Gaowa Bai Daisuke Furushima Toshiro Niki Takashi Matsuba Yosuke Maeda Atsushi Takahashi Toshio Hattori Yugo Ashino 《International journal of molecular sciences》2021,22(9)
Numbers of patients with coronavirus disease 2019 (COVID-19) have increased rapidly worldwide. Plasma levels of full-length galectin-9 (FL-Gal9) and osteopontin (FL-OPN) as well as their truncated forms (Tr-Gal9, Ud-OPN, respectively), are representative inflammatory biomarkers. Here, we measured FL-Gal9, FL-OPN, Tr-Gal9, and Ud-OPN in 94 plasma samples obtained from 23 COVID-19-infected patients with mild clinical symptoms (CV), 25 COVID-19 patients associated with pneumonia (CP), and 14 patients with bacterial infection (ID). The four proteins were significantly elevated in the CP group when compared with healthy individuals. ROC analysis between the CV and CP groups showed that C-reactive protein had the highest ability to differentiate, followed by Tr-Gal9 and ferritin. Spearman’s correlation analysis showed that Tr-Gal9 and Ud-OPN but not FL-Gal9 and FL-OPN, had a significant association with laboratory markers for lung function, inflammation, coagulopathy, and kidney function in CP patients. CP patients treated with tocilizumab had reduced levels of FL-Gal9, Tr-Gal9, and Ud-OPN. It was suggested that OPN is cleaved by interleukin-6-dependent proteases. These findings suggest that the cleaved forms of OPN and galectin-9 can be used to monitor the severity of pathological inflammation and the therapeutic effects of tocilizumab in CP patients. 相似文献
68.
A Restart Control Method for Position Sensorless PMSM Drive Systems Without Potential Transformer for Railway Vehicle Traction
下载免费PDF全文
![点击此处可从《Electrical Engineering in Japan》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Shun Taniguchi Kazuya Yasui Kazuaki Yuki Yosuke Nakazawa Shouji Onda 《Electrical Engineering in Japan》2015,193(3):44-53
This paper proposes a restart control method for position sensorless PMSM drive systems without a potential transformer for railway vehicle traction. This method can estimate the initial rotor speed and position under coasting conditions over the entire speed range. The method can also be used when the back‐EMF voltage is higher than the inverter DC link voltage. The proposed method is verified by experiments using a 200‐kW PMSM. 相似文献
69.
Yosuke Yamazaki Takayuki Otsuka Kazuo Okamura Yoji Shibutani 《Materials Science & Technology》2020,36(6):750-758
ABSTRACTHeat treatment, such as quenching and carburising, often involves volume change caused by phenomena such as thermal expansion, phase transformation, and carbide precipitation during tempering. During the tempering process, an external force induces additional plastic deformation. The authors termed this phenomenon ‘tempering plasticity’. In this study, we performed crystal plasticity analysis using fast Fourier transform considering the volume change in carbides to assess the mechanism of tempering plasticity. As a result, tempering plastic strain occurred as the volume fraction of carbide increased, and the tempering plastic phenomenon could be reproduced based on the transformation model proposed by Greenwood–Johnson. The result supports the idea that the volume change accompanied by carbide precipitation is an important mechanism that invokes tempering plasticity. 相似文献
70.