全文获取类型
收费全文 | 695篇 |
免费 | 25篇 |
国内免费 | 7篇 |
专业分类
电工技术 | 49篇 |
综合类 | 2篇 |
化学工业 | 183篇 |
金属工艺 | 25篇 |
机械仪表 | 27篇 |
建筑科学 | 17篇 |
能源动力 | 25篇 |
轻工业 | 37篇 |
水利工程 | 2篇 |
石油天然气 | 4篇 |
无线电 | 38篇 |
一般工业技术 | 179篇 |
冶金工业 | 76篇 |
原子能技术 | 18篇 |
自动化技术 | 45篇 |
出版年
2023年 | 3篇 |
2022年 | 14篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 10篇 |
2017年 | 9篇 |
2016年 | 19篇 |
2015年 | 9篇 |
2014年 | 24篇 |
2013年 | 40篇 |
2012年 | 17篇 |
2011年 | 29篇 |
2010年 | 23篇 |
2009年 | 40篇 |
2008年 | 39篇 |
2007年 | 27篇 |
2006年 | 30篇 |
2005年 | 31篇 |
2004年 | 33篇 |
2003年 | 21篇 |
2002年 | 26篇 |
2001年 | 7篇 |
2000年 | 21篇 |
1999年 | 16篇 |
1998年 | 29篇 |
1997年 | 26篇 |
1996年 | 19篇 |
1995年 | 20篇 |
1994年 | 19篇 |
1993年 | 14篇 |
1992年 | 8篇 |
1991年 | 6篇 |
1990年 | 3篇 |
1989年 | 9篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有727条查询结果,搜索用时 15 毫秒
51.
Yoshikazu Miyazawa 《International journal of control》2013,86(6):1937-1946
A reduced–order model for a multi–input single–output or a single–input multi–output continuous system is proposed. The model is especially suitable for the case where accuracy in the high-frequency region is important. It also satisfies basic conditions for reduced-order models, such as uniqueness, stability, and a simple calculation requirement. Chained aggregation with the minimization of truncation errors introduces an internal system representation characterized by a system matrix of Hessenberg form and a diagonalized covariance matrix. 相似文献
52.
Kyoji Kariya Yoshikazu Kanazawa Tadatsugu Hirose 《Journal of the Society for Information Display》2002,10(1):11-16
This paper describes the Alternate Lighting of Surfaces (ALIS) method as a promising drive technology which can lead to high‐resolution plasma‐display panels (PDPs). This technology provides a resolution of more than 1000 scanning lines without lowering luminance, thus enabling the essential requirements of HDTV. Moreover, it allows the number of scanning electrodes to be halved in comparison with the conventional method, as well as the circuit scale to be minimized due to the use of the single scanning drive. The ALIS method is expected to be a key technology that will help PDPs penetrate the TV market. 相似文献
53.
日本是一个地震多发的国家,而特殊的地形又决定了水坝在其经济社会发展中具有重要的地位,因此水坝的安全管理和地震安全评价就成为一个至关重要的方面. 相似文献
54.
55.
Yoshikazu Horino Miki Sugata Hitoshi Abe 《Advanced Synthesis \u0026amp; Catalysis》2016,358(7):1023-1028
A three‐component reaction of 3‐(tri‐n‐butylstannyl)allyl acetates, aldehydes, and triorganoboranes in the presence of a palladium‐Xantphos catalyst system predominately gave (E)‐anti‐homoallylic alcohols with high diastereoselectivity and good to high levels of alkene stereocontrol. An efficient chirality transfer was observed when an enantioenriched substrate was employed. The reaction was initiated by the formation of an allylic gem‐palladium/stannyl intermediate, which subsequently underwent allylation of the aldehyde by an allyltributyltin followed by a coupling reaction of the in‐situ‐generated (E)‐vinylpalladium acetate with the triorganoborane.
56.
A thermally activated model for evaluating the tensile yield strain of pristine single-walled carbon nanotubes (SWCNTs) is established. Using a parabolic function to accurately describe the dependence of stress on strain, we derive a yield function relating the yield strain to temperature, strain rate and tube length. The activation energy and activation area are then determined from the MD results of the tensile yield strain as a function of temperature. We find that the activation energies for armchair SWCNTs range from 7.18 to 11.94 eV, depending on the radius of SWCNTs. Analyses of activation area and MD results reveal that the nucleation of a critical defect, which leads to the failure of SWCNTs, grows from a single bond size at 300 K to almost twice the size at 2100 K. On the basis of activation parameters, our model can be used to predict the yield strain of SWCNTs under experimental conditions. 相似文献
57.
Nosaka H. Sano E. Ishii K. Ida M. Kurishima K. Yamahata S. Shibata T. Fukuyama H. Yoneyama M. Enoki T. Muraguchi M. 《Solid-State Circuits, IEEE Journal of》2004,39(8):1361-1365
We describe a 40-Gbit/s-class clock and data recovery (CDR) circuit with an extremely wide pull-in range. A Darlington-type voltage-controlled oscillator (VCO) is newly designed to cover the STM-256/OC-768 full-rate-clock frequencies with a wide frequency margin. We also describe a new lock detector using an exclusive-NOR gate. The CDR IC was fabricated using InP/InGaAs HBTs. Error-free operation and wide eye opening were confirmed for 40-, 43-, and 45-Gbit/s PRBS with a word length of 2/sup 31/ - 1. We attached a frequency search and phase control (FSPC) circuit to the chip as a new frequency acquisition aid, and this allows the CDR circuit to pull in throughout a 39-45-Gbit/s range. The peak-to-peak and rms jitter of the recovered clock were 3.6 and 0.48 ps, respectively. 相似文献
58.
Hidetaka Yoshikawa Katsuya Fukuyama Yoichiro Nakahara Takehisa Konishi Nobuyuki Ichikuni Yasuko Yoshikawa Noboru Akuzawa Yoichi Takahashi Keiko Nishikawa 《Carbon》2003,41(15):2931-2938
The structure of bromine residue compounds was investigated by X-ray absorption fine structure (XAFS) in order to interpret where and how bromine is present in carbons with different degrees of graphitization. The residue compounds can be classified into three groups, as obtained from X-ray absorption near edge structure (XANES) spectra and the values of the intramolecular distance rBr–Br determined by extended X-ray absorption fine structure (EXAFS). In Group I, prepared from the host carbons heat treated at temperatures higher than 1900 °C, bromine exists in the interlayer space of graphite in the form of Br2 molecules with interaction of the π electrons of graphite. In Group III, from carbon heat treated at 1000 °C, most of the bromine probably reacts with carbon atoms having a dangling bond or functional groups. For Group II, where the host carbons are heat treated at intermediate temperatures, it is likely that bromine exists in undeveloped defects with a unique electronic state. 相似文献
59.
Toshihiro Isobe Yoshikazu Kameshima Akira Nakajima Kiyoshi Okada Yuji Hotta 《Journal of Porous Materials》2006,13(3):269-273
The effect of additives on paste rheology was investigated for preparation of porous ceramics with unidirectionally aligned
cylindrical pores. Ammonium poly-carboxylic acid (APA) used as a dispersant and it was adsorbed on alumina powder surface.
The adsorption isotherm of APA was fitted by Langmuir equation. The saturated monolayer adsorption was 5.9 mg/g. The apparent
viscosity became a minimum at 0.8 mass % of APA corresponding to 71.2 mPa⋅s. This APA amount of 5.6 mg/g, is in good agreement
with the observed APA amount. Since the nylon 66 fibers (0–35 vol. %) mixed with the alumina powder have a strong interaction
with each other, they became twisted and agglomerated. This agglomeration increased with increasing fiber content but decreased
by adding oleic acid. The pastes with added oleic acid were capable of being extruded at higher pressure. The obtained porous
alumina ceramics showed highly oriented cylindrical pores parallel to the extrusion direction. The pore orientation was higher
in the oleic acid added pastes than those without oleic acid. The added nylon 66 fibers are mostly converted to pores while
maintaining the original shape after sintering. The pore size distribution of the obtained porous ceramics measured by mercury
porosimetry method showed a peak at about 4 μm which is apparently smaller than that observed in the SEM photographs and the
obtained result is considered to be corresponding to the necks formed by fiber contacts. 相似文献
60.
Hiroi Masato Hojo Masayuki Hashimoto Yukio Abe Yoshikazu Dote Yasuhiko 《Industrial Electronics, IEEE Transactions on》1986,(2):110-113
A methodology of discontinuous feedback and continuous feedforward control is developed to achieve accurate decoupled tracking in a class of nonlinear, time varying systems in the presence of disturbances, parameter variations and nonlinear dynamic interactions. The method is based on an improved variable structure control with a sliding mode. 相似文献