全文获取类型
收费全文 | 541篇 |
免费 | 14篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 27篇 |
综合类 | 1篇 |
化学工业 | 130篇 |
金属工艺 | 48篇 |
机械仪表 | 13篇 |
建筑科学 | 3篇 |
能源动力 | 20篇 |
轻工业 | 25篇 |
无线电 | 62篇 |
一般工业技术 | 102篇 |
冶金工业 | 55篇 |
原子能技术 | 16篇 |
自动化技术 | 64篇 |
出版年
2023年 | 2篇 |
2022年 | 5篇 |
2021年 | 19篇 |
2020年 | 5篇 |
2019年 | 5篇 |
2018年 | 12篇 |
2017年 | 14篇 |
2016年 | 15篇 |
2015年 | 5篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 19篇 |
2011年 | 38篇 |
2010年 | 20篇 |
2009年 | 23篇 |
2008年 | 29篇 |
2007年 | 37篇 |
2006年 | 21篇 |
2005年 | 25篇 |
2004年 | 25篇 |
2003年 | 22篇 |
2002年 | 17篇 |
2001年 | 15篇 |
2000年 | 12篇 |
1999年 | 5篇 |
1998年 | 17篇 |
1997年 | 19篇 |
1996年 | 11篇 |
1995年 | 12篇 |
1994年 | 10篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 8篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 2篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有566条查询结果,搜索用时 15 毫秒
41.
Takahiro Yokoyama Akito Masuhara Tsunenobu Onodera Hitoshi Kasai Hidetoshi Oikawa 《Synthetic Metals》2009,159(9-10):897-899
Core/shell hybridized nanocrystals composed of Ag nanoparticle core and polydiacetylene shell were fabricated successfully by means of “co-reprecipitation/microwave irradiation method”. The hybridized nanocrystals were characterized using transmission electron microscopy (TEM) observation and UV–vis absorption spectroscopy. UV–vis spectral measurements revealed that polydiacetylene shell was the red phase while π-conjugated backbone is distorted. Detailed mechanism of formation of the red phase was discussed. 相似文献
42.
Isolation and characterization of poly(butylene succinate-co-butylene adipate)-degrading microorganism 总被引:1,自引:0,他引:1
Hayase N Yano H Kudoh E Tsutsumi C Ushio K Miyahara Y Tanaka S Nakagawa K 《Journal of Bioscience and Bioengineering》2004,97(2):131-133
Poly(butylene succinate-co-butylene adipate) (PBSA)-degrading bacterium, strain 1-A, was isolated from soil. Strain 1-A was identified as Bacillus pumilus on the basis of its physiological properties and partial 16S rRNA gene sequence. Strain 1-A also degraded poly(butylene succinate) (PBS) and poly(epsilon-caprolactone). On the other hand, poly(butylene adipate terephthalate) and poly(lactic acid) were minimally degraded by strain 1-A. The NMR spectra of degradation products from PBSA indicated that the adipate units were more rapidly degraded than 1,4-butanediol and succinate units. This seems to be one of the reasons why strain 1-A degraded PBSA faster than PBS. 相似文献
43.
44.
Xiaolin Zhang Hidetoshi Wakamatsu 《International Journal of Adaptive Control and Signal Processing》2001,15(7):697-713
In order to understand mechanisms of oculomotor control systems, an oculomotor model based on eye's anatomical structure and physiological mechanism is developed. In this model, various types of eye movements are considered, and two learning systems, one based on adaptive characteristics of flocculus and the other on vestibular nuclei's are developed. The role of neural paths from ocular muscle stretch receptors into flocculus, which were thought to not contribute in eye movement, is discussed in detail from the viewpoint of system control engineering. The experimental results through simulation show good control performance of the proposed model. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
45.
Masaki Matsui Akira Ito Masaya Kotani Yasuhiro Kubota Kazumasa Funabiki Jiye Jin Tsukasa Yoshida Hideki Minoura Hidetoshi Miura 《Dyes and Pigments》2009,80(2):233-238
The effects of the position and the type of carboxyl anchor group in double rhodanine-type indoline dyes on the performance of a zinc oxide dye-sensitized solar cell were examined. The optimum position for the carboxymethyl group was on the inner rhodanine moiety; a carboxymethyl group gave optimum results among carboxymethyl, -ethyl, and -propyl derivatives. 相似文献
46.
Hajime Araki Taichi Kaji Masahito Yamamoto Keiji Suzuki Azuma Ohuchi 《Electrical Engineering in Japan》2001,135(4):43-51
The optimal sequential problem is defined as the problem of finding the minimum cost partition of the nodes of a directed acyclic graph into subsets of a given size, subject to the constraint that the precedence relationships among the elements are satisfied. A heuristic algorithm based on tabu search has been proposed for this problem [2]. However, there is a tendency for the solutions obtained by tabu search to become trapped in bad local optima in parallel graphs with random edge costs. In this paper we present a genetic algorithm for the optimal sequential partitioning problem. We develop an effective two‐point partial order crossover satisfying sequential conditions, which preserve better blocks that have a larger sum of edge costs. In this crossover we introduce the roulette selection method to escape local optima. We also assess the effectiveness of the algorithm. The results show that this proposed algorithm outperforms any other algorithm using tabu search in terms of solution quality. © 2001 Scripta Technica, Electr Eng Jpn, 135(4): 43–51, 2001 相似文献
47.
We studied the relationship between the structure of aromatic compounds and the overcharge protection effect, using cyclohexylbenzene, isopropylbenzene, and toluene as the overcharge protection agents. Cyclohexylbenzene proved to be the most effective overcharge protection agent among these aromatic compounds. The effect is enhanced using a higher concentration of cyclohexylbenzene and elevated temperatures. The reaction product of cyclohexylbenzene was analyzed using field desorption mass spectrometry to elucidate its reaction mechanism. The results suggested that some of the overcharge reaction products of CHB were more reactive than that of IPB, which is consistent with the better suppressing effect on overcharging of the active material in the positive electrode. 相似文献
48.
Hidetoshi Somekawa Tadanobu Inoue Alok Singh Toshiji Mukai 《Metallurgical and Materials Transactions A》2011,42(8):2475-2480
The deformation mechanism in the crack-tip region of a fine-grained Mg-2.4 at. pct Zn binary alloy was investigated by focused
ion beam (FIB) and transmission electron microscopy (TEM) observation and finite element analysis (FEA) at the beginning of
the fracture toughness test. The deformed microstructure observations showed the formation of subgrains instead of deformation
twins in the fracture toughness tested sample, which was performed at a conventional crosshead speed of 1 mm/min. By preventing
the formation of deformation twins at the beginning of the test, the crack tip of the fine-grained magnesium alloys became
blunted, and thus, the alloys obtained high fracture toughness. Finite element results showed that the temperature increased
50 to 110 K, and the strain rate became two orders of magnitude higher; however, this temperature increment was not sufficient
to form high-angle grain boundaries, i.e., a complete occurrence of dynamic recrystallization. On the other hand, the deformed microstructure observations in the sample,
which was tested at a crosshead speed of 50 mm/min, showed the formation of nano-order {10-12} deformation twins and subgrains.
The formation of deformation twins was caused, in part, by the severe strain from the operation of a high strain rate in the
crack-tip region. 相似文献
49.
Hidetoshi Miyazaki Shin-ichi Kikitsu Hisao Suzuki Toshitaka Ota 《Advanced Powder Technology》2011,22(4):544-547
In an effort to improve energy-efficient windows, we experimented with a precursor slurry composite by using needle-like TiO2 particles as the filler in a urethane matrix. Applying dc bias to the slurry failed to array the needle-like particles in the composite and to deposit on the film surface because of electrophoretic movement. However, applying ac bias of ±5 V to the precursor slurry composite for 12 h resulted in the needle-like TiO2 particles being arrayed in the composite in a direction normal to the film surface. This resulted in an improvement in the energy efficiency of the material through an angular dependence of transmittance in the visible–near-infrared range. 相似文献
50.
Iwata Y. Momodomi M. Tanaka T. Oodaira H. Itoh Y. Nakayama R. Kirisawa R. Aritome S. Endoh T. Shirota R. Ohuchi K. Masuoka F. 《Solid-State Circuits, IEEE Journal of》1990,25(2):417-424
A high-density, 5-V-only, 4-Mb CMOS EEPROM with a NAND-structured cell using Fowler-Nordheim tunneling for programming is discussed. The block-page mode is utilized for high-speed programming and easy microprocessor interface. On-chip test circuits for shortening test time and for evaluating cell characteristics yield highly reliable EEPROMs. The NAND EEPROM has many applications for microcomputer systems that require small size and large nonvolatile storage systems with low power consumption 相似文献