全文获取类型
收费全文 | 1184篇 |
免费 | 23篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 84篇 |
化学工业 | 268篇 |
金属工艺 | 44篇 |
机械仪表 | 15篇 |
建筑科学 | 23篇 |
能源动力 | 58篇 |
轻工业 | 116篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
无线电 | 83篇 |
一般工业技术 | 224篇 |
冶金工业 | 169篇 |
原子能技术 | 55篇 |
自动化技术 | 67篇 |
出版年
2022年 | 17篇 |
2021年 | 18篇 |
2020年 | 11篇 |
2019年 | 22篇 |
2018年 | 30篇 |
2017年 | 19篇 |
2016年 | 14篇 |
2015年 | 9篇 |
2014年 | 32篇 |
2013年 | 60篇 |
2012年 | 48篇 |
2011年 | 51篇 |
2010年 | 39篇 |
2009年 | 51篇 |
2008年 | 61篇 |
2007年 | 57篇 |
2006年 | 38篇 |
2005年 | 45篇 |
2004年 | 43篇 |
2003年 | 43篇 |
2002年 | 31篇 |
2001年 | 17篇 |
2000年 | 11篇 |
1999年 | 34篇 |
1998年 | 66篇 |
1997年 | 51篇 |
1996年 | 37篇 |
1995年 | 31篇 |
1994年 | 33篇 |
1993年 | 27篇 |
1992年 | 17篇 |
1991年 | 12篇 |
1990年 | 14篇 |
1989年 | 14篇 |
1988年 | 12篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 4篇 |
1984年 | 12篇 |
1983年 | 4篇 |
1982年 | 9篇 |
1981年 | 6篇 |
1980年 | 3篇 |
1979年 | 8篇 |
1978年 | 7篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1973年 | 2篇 |
1972年 | 3篇 |
排序方式: 共有1211条查询结果,搜索用时 328 毫秒
991.
992.
Minoru Yamasaki 《Journal of Architectural Education》2013,67(2):48-49
Abstract While typically accorded form-driven interpretations, Kahn's work may contribute significantly to the emergent discourse on architecture and landscape. Meditations on landscape in Kahn's work and ideas, although present in an unsystematic and sporadic manner, provide a provocative way of thinking about a building's relationship with the landscape. Applying the phenomenological notion of “lived body,” a built work is seen not only inscrutably emplaced or intertwined with the landscape but also embodying it, thus making architecture inherently a landscape “event.” An analysis of Kahn's work and writings from the vantage point of landscape presents, first, an affirmation of Kahn's particular ideas about land and landscape and, second, a substantiation of the claim that architecture is a landscape phenomenon. 相似文献
993.
Toshihiko Noguchi Satoshi Yajima Hiroyoshi Komatsu 《Electrical Engineering in Japan》2011,176(4):52-60
This paper describes a gate drive circuit which is capable of driving an ultrahigh‐speed switching device and of suppressing high‐frequency noise caused by its high dV/dt ratio of 104 V/μs order. SiC (silicon carbide)‐based power semiconductor devices are very promising as next‐generation ultrahigh‐speed switching devices. However, one of their application problems is how to drive them with less high‐frequency noise without sacrificing their ultrahigh‐speed operation capability. The paper proposes a new gate drive circuit specialized for such devices, which charges and discharges the input capacitance of the device by using an impulse voltage generated by inductors. This ultrahigh‐speed switching operation causes a high‐frequency common‐mode noise current in the gate drive circuit, which penetrates an isolated power‐supply transformer due to the parasitic capacitance between the primary and the secondary windings. In order to overcome this secondary problem, a toroidal multicore transformer is also proposed in the paper in order to reduce the parasitic capacitance drastically. By applying the former technique, the turn‐on time and turn‐off time of the power device were shortened by 50% and by 20%, compared with a conventional push‐pull gate drive circuit, respectively. In addition, the latter technique allows reduction of the peak common‐mode noise current to 25%, compared with the use of a conventional standard utility power‐supply transformer. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 176(4): 52–60, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21124 相似文献
994.
Ni-P alloy/multiwalled carbon nanotube (MWCNT) composite films were fabricated on acrylonitrile butadiene styrene (ABS) resin by electroless plating and their microstructures, adhesion strengths, and friction properties were investigated. Various types of MWCNTs were used. In addition, various electroless plating baths were prepared to form Ni-P alloy matrices with various phosphorus contents. To enhance the adhesion strength, the ABS resin substrate was subjected to roughening treatment. The microstructures of the composite films were examined by scanning electron microscopy and X-ray diffraction. Their adhesion strengths were measured by tensile tests. The friction properties of the composite films were investigated using the ball-on-plate method. Ni-P alloy/MWCNT composite films containing various types of MWCNTs and with Ni-P alloy matrices having various phosphorus contents were fabricated on the ABS resin substrates by electroless deposition. The adhesion strength between the Ni-P alloy/MWCNT composite films and the ABS resin substrate was more than 1300 N cm− 2. The Ni-P alloy/MWCNT composite films had considerably lower friction coefficients than the Ni-P alloy films. The friction coefficients of the composite films were significantly affected by the type of MWCNTs used. 相似文献
995.
D. Takeuchi T. MakinoH. Kato M. OguraN. Tokuda K. Oyama T. Matsumoto H. OkushiS. Yamasaki 《Diamond and Related Materials》2011,20(7):917-921
We successfully observed electron emission from hydrogenated diamond p-i-n junction diodes with negative electron affinity during room temperature operation. The emissions started when the applied bias voltage produced flat-band conditions, where the capacitance-voltage characteristics showed carrier injection in the i-layer. In this low current injection region, the electron emission efficiency (η) of the p-i-n junction diodes (p is top layer) was about 5 × 10− 5, while that of the n-i-p diodes (n is top layer) was about 10− 8. With increasing diode current, both diodes showed an increase in η and a nonlinear increase in emission current. In the high current injection region with high diode current of 5-50 mA, both diodes had an emission current of almost 10 μA, where η of a p-i-n junction diode was 0.18%, while that of a n-i-p junction diode was 0.02%.Note that η, which corresponds to the electron emission mechanism, depended on the diode current level. 相似文献
996.
Ming Zhu Xiao Liu Baijun Liu Zhenhuan Jiang Toshihiko Matsumoto 《Polymer Bulletin》2011,67(9):1761-1771
A new diamine monomer, 1,5-bis[4-(4-aminophenoxy)]benzoyl-2,6-dimethoxynaphthalene, was synthesized via a Friedel–Crafts acylation
reaction followed by an aromatic nucleophilic substitution reaction. Six ether–ketone linked polymers, named as poly(ether
ketone azomethane)s and poly(ether ketone imide)s, were successfully prepared through the polycondensations of the diamine
monomer with dialdehydes and dianhydrides, respectively. These naphthylated polymers exhibited high T
g values (142–288 °C), due to their bulky and rigid chemical structure. Meanwhile, they showed good thermal stability and improved
solubility. Typically, some of them were casted into thin flexible film and showed high moduli. 相似文献
997.
Yi‐Li Pan Toshihiko Noda Kiyotaka Sasagawa Takashi Tokuda Jun Ohta 《IEEJ Transactions on Electrical and Electronic Engineering》2013,8(3):310-312
We have optimized the sputtering conditions for sputtered IrOx and TiN electrodes for retinal prosthesis. The basic electrochemical characteristics were evaluated by cyclic voltammetry, and the surface morphology was inspected by atomic force microscopy. To measure the charge delivery capacity (CDC), a 300‐µm diameter electrode was formed, a balanced biphasic current pulse was applied, and the voltage response was measured. From the experimental results, the CDCs of IrOx and TiN in the best sputtering conditions were improved by more than 8 and 4 times compared to that of Pt, respectively. © 2013 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
998.
Hiroshi Okuda Toshiki Horiuchi Toshiki Maruyama Michiaki Yamasaki Yoshihito Kawamura Koji Hagihara Shinji Kohara 《Metallurgical and Materials Transactions A》2014,45(1):147-151
Development of LPSO structure and in-plane ordering during annealing the Mg85Y9Zn ternary alloy sample at 673 K (400 °C) was examined by synchrotron radiation small-angle scattering/diffraction measurements. By examining the first diffraction peaks for 18R, 10H, and in-plane order spot, the growth kinetics of in-plane order domain and the transition from 10H into 18R were discussed. The domain growth of in-plane order was characterized by small domain with little correlation between neighboring segregation layers. 相似文献
999.
The rotational frequency noise (also known as the pulsation noise) due to the mistuning of impeller blade rows introduced at the manufacturing stage of the impellers is observed in the small-sized centrifugal compressor for automobile turbochargers. The present paper addresses the elucidation of the generating mechanism and parame- ter dependency such as the kind and degree of mistuning. In order to analyze numerically the rotational frequency noise due to mistuning, the unsteady computational fluid dynamics (CFD) of the whole compressor including vo- lute is executed, and the resultant time history of the pressure is fed into the spectral analysis. 相似文献
1000.