全文获取类型
收费全文 | 975篇 |
免费 | 22篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 67篇 |
化学工业 | 322篇 |
金属工艺 | 33篇 |
机械仪表 | 31篇 |
建筑科学 | 23篇 |
能源动力 | 50篇 |
轻工业 | 122篇 |
水利工程 | 1篇 |
石油天然气 | 2篇 |
无线电 | 54篇 |
一般工业技术 | 136篇 |
冶金工业 | 8篇 |
原子能技术 | 77篇 |
自动化技术 | 75篇 |
出版年
2024年 | 2篇 |
2023年 | 9篇 |
2021年 | 12篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 20篇 |
2015年 | 12篇 |
2014年 | 19篇 |
2013年 | 58篇 |
2012年 | 35篇 |
2011年 | 65篇 |
2010年 | 41篇 |
2009年 | 33篇 |
2008年 | 46篇 |
2007年 | 39篇 |
2006年 | 33篇 |
2005年 | 46篇 |
2004年 | 36篇 |
2003年 | 39篇 |
2002年 | 42篇 |
2001年 | 18篇 |
2000年 | 21篇 |
1999年 | 23篇 |
1998年 | 28篇 |
1997年 | 25篇 |
1996年 | 18篇 |
1995年 | 19篇 |
1994年 | 21篇 |
1993年 | 19篇 |
1992年 | 11篇 |
1991年 | 13篇 |
1990年 | 12篇 |
1989年 | 7篇 |
1988年 | 11篇 |
1987年 | 11篇 |
1986年 | 11篇 |
1985年 | 12篇 |
1984年 | 9篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 9篇 |
1978年 | 4篇 |
1977年 | 8篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 3篇 |
排序方式: 共有1001条查询结果,搜索用时 15 毫秒
91.
Masatoshi Nakamura Takenao Sugi Akio Ikeda Hiroshi Shibasaki 《International Journal of Adaptive Control and Signal Processing》2002,16(1):25-37
In view of the fact that the visual EEG interpretation could be a subjective task and may vary among the electroencephalographers, the main objective of this study was to develop an automatic EEG interpretation system which is adaptable to each electroencephalographer. The system adapted to each electroencephalographer would bring a close automatic EEG interpretation to that done by the electroencephalographer's visual interpretation. The adaptable automatic EEG interpretation was accomplished by using the constructive neural network with forgetting factor. The artificial neural network was constructed so as to give the integrative interpretation of the EEG based on the intermediate judgment of 13 items that characterized the visual interpretation. The developed method was evaluated based on the visually inspected EEG data of 37 patients by electroencephalographer‐A and the data of 20 patients by electroencephalographer‐B. The adapted ANN showed good agreement with each electroencephalographer's visual inspection. The proposed automatic EEG interpretation by use of the ANN can be a powerful assistant tool for individual electroencephalographers for their EEG interpretation. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
92.
IPN-related materials were synthesized from solution of two acrylate polymers having epoxide. From the dynamic mechanical spectroscopy, it was difficult to distinguish IPN or semi-IPN from mechanical blend in the case of PEMA/P2EHMA system. But some possibility of IPN phenomenon was observed. In the case of PEMA/PEA system, IPN synthesized from benzene-chloroform mixed solvent showed phase separation with the matrix of PEMA. IPN synthesized from xylene, however, showed phase separation with the matrix of PEA and the transition due to PEA shifted higher by 5°C than that of homo PEA. From the results, we concluded that PEMA/PEA system synthesized by xylene showed JPN phenomenon. 相似文献
93.
Numerical analyses of a two-dimensional single bubble in a stagnant liquid and in a linear shear flow were conducted in the present study using the volume of fluid method, which is based on the local-instantaneous field equations. It was clarified that this method gives qualitatively appropriate predictions for the effects of the Morton number and the Eotvos number on fluctuating bubble motion in a stagnant liquid. Calculated velocity and pressure distributions indicated that the Karman vortex causes a sinuous movement of the bubble. As for the bubble motion in a linear shear flow, calculated bubbles migrated in a lateral direction. The direction of the lateral migration agreed to available experimental data. It was also confirmed that (i) the direction or the magnitude of the lateral migration is affected by the Eotvos and the Morton numbers, and (ii) the interaction among the internal flow of the bubble, the wake of the bubble and the external shear flow plays an essential role for the lateral migration. 相似文献
94.
Akio Katsuki Hiromichi Onikura Takao Sajima Satoshi Machida Kazuhiro Oda 《Precision Engineering》1994,16(4):296-301
A laser-guided BTA tool has been developed to prevent axial hole deviations. Four kinds of experiments were conducted to examine the performance of this tool in detail and to determine its practical application using a duralumin (A2017-T4) workpiece with a prebored 108-mm diameter hole. The first experiment was performed to examine the conditions of the hole deviation in the case of normal deep-hole boring. The second was to examine whether the tool corrects for the stated hole deviation. The third was to examine whether the tool can go straight through to the target without shifting toward a thin wall (t = 0.7 mm) on one side of the workpiece. The fourth was to examine whether the tool can be guided toward the target without affecting a prebored hole, which was inclined to radial direction at 100 μm for a hole length of 100 mm. The experiments were performed with a rotating tool-stationary workpiece system. Rotational speed was 270 rpm and feed ws 0.125 mm/rev. Tool diameter was 110 mm. The results show that the tool can be guided to go straight through toward the target despite the disturbances. 相似文献
95.
Yoji Imai Akio Watanabe Isao Shimono 《Journal of Materials Science: Materials in Electronics》2003,14(3):149-156
Electronic band calculations of doped and undoped ZnO and ZnS have been done using density functional theory under the local density approximation so as to clarify the reason of the difference in behaviors of doped ZnO and ZnS. The reason why the electrical conductivity of ZnS is difficult to be increased by doping was discussed. In the case of doped ZnS, an impurity level was generated at deep position below the bottom of the conduction band of the host ZnS lattice and Fermi level was located at this impurity level. On the contrary, the shape of the density of states curve and the band structures of doped and undoped ZnO are alike with each other and the donor band is hybridized with the conduction band of the ZnO host material. This seems to result in contribution of doped electrons to electrical current in the case of doped ZnO. 相似文献
96.
Yuichi Maekawa Akio Yamaguchi Makoto Hara Yasuo Sekii 《Electrical Engineering in Japan》1994,114(8):1-12
This paper describes the development of dc XLPE cable. Through a series of material investigations, an XLPE compound containing highly purified special filler was developed. To check the dc insulation performance of the cable insulated with this new material, a prototype cable with 9 mm insulation thickness was manufactured. It was confirmed that the performance of the prototype cable was excellent. Based on the study of the prototype cable, a 250-kV dc cable with 20 mm insulation thickness was designed and manufactured. Through a series of voltage tests, excellent dc insulation performance of the developed cable was verified. 相似文献
97.
98.
Akio Ukita Waldemar Karwowski Gavriel Salvendy Wookgee Lee Joseph Zurada 《Journal of Intelligent Manufacturing》1996,7(4):329-339
Manufacturing of electronic circuits for microwave communication boards often requires tuning of different circuit characteristics by manual adjustment of several trimmer components, including the trimmer's resistance and capacitance. This manual tuning process was automated by applying the artificial neural network modeling approach. In the considered tuning process, which required manual adjustment of a set of trimmers, multiple specification criteria had to be satisfied by several trimmer rotations. The tuning process was described in terms of three independent steps: the circuit output measurement, trimmer selection, and trimmer rotation. The trimmer selection was performed by a semi-supervised neural network, which learned the patterns of circuit characteristics and the deviations between the ideal and practical outputs. Another network was developed for determination of trimmer rotation rate. The results, based on computer simulation of the tuning process, showed that the developed system improved performance of the tuning process, allowing for automation of the microwave circuit board tuning task in a real manufacturing environment. 相似文献
99.
Low resistivity transparent conducting Al-doped ZnO films prepared by pulsed laser deposition 总被引:1,自引:0,他引:1
Hideaki Agura Akio SuzukiTatsuhiko Matsushita Takanori AokiMasahiro Okuda 《Thin solid films》2003,445(2):263-267
A series of AZO films were grown on glass substrates by a method of pulsed laser deposition using a split target divided into AZO (Al2O3: 1 wt.%) and AZO (Al2O3: 2 wt.%). The film deposition took place at a substrate temperature of 230 °C within a magnetic field applied perpendicularly to the plume. To suppress the droplet generation caused by the intense laser energy, the laser energy density was reduced to 0.75 J/cm2 (15 mJ). For an approximately 280-nm thick-AZO film grown at a target-to-substrate distance of 25 mm, we obtained the lowest resistivity of 8.54×10−5 Ω·cm and an average transmittance of more than 88% in the visible range. In the cross-sectional TEM observation and XRD spectra, the regularity in the crystal growth was generated immediately from the interface between the substrate and the film. 相似文献
100.
Takashi Hirano Yuiko Kazahaya Akio Nakamura Toshihiro Miyao Shuichi Naito 《Catalysis Letters》2007,117(1-2):73-78
The effect of addition of In and Pb on the reduction of N2O by CO was studied over SiO2 supported Pd catalysts, using a closed gas circulation system as well as in-situ infrared spectroscopy. Formation of intermetallic
compounds such as Pd0.48In0.52, Pd3Pb and Pd3Pb2 was observed which caused a drastic enhancement of the rate of N2 formation. The infrared spectroscopic analyses revealed a weakening of the adsorption strength of CO on Pd metal by the formation
of intermetallic compounds, which is likely the main reason for the enhancement of the reaction rate. From a kinetic investigation
as well as in situ FT-IR observation during the N2O-CO reaction, a redox mechanism was proposed involving the oxidation of the surface by N2O followed by its reduction by CO. Over Pd/SiO2, the former process seems to be the rate limiting step because of the inhibition of N2O activation by strongly adsorbed CO. By adding In or Pb, the rate limiting step shifted to the latter process, which resulted
in a large enhancement in the rate of N2 formation. 相似文献