全文获取类型
收费全文 | 677篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 16篇 |
综合类 | 1篇 |
化学工业 | 105篇 |
金属工艺 | 8篇 |
机械仪表 | 45篇 |
建筑科学 | 9篇 |
能源动力 | 10篇 |
轻工业 | 27篇 |
水利工程 | 1篇 |
无线电 | 72篇 |
一般工业技术 | 106篇 |
冶金工业 | 216篇 |
原子能技术 | 23篇 |
自动化技术 | 54篇 |
出版年
2023年 | 8篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 13篇 |
2017年 | 7篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 22篇 |
2012年 | 25篇 |
2011年 | 32篇 |
2010年 | 16篇 |
2009年 | 32篇 |
2008年 | 25篇 |
2007年 | 16篇 |
2006年 | 20篇 |
2005年 | 16篇 |
2004年 | 16篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 16篇 |
2000年 | 6篇 |
1999年 | 22篇 |
1998年 | 70篇 |
1997年 | 61篇 |
1996年 | 29篇 |
1995年 | 20篇 |
1994年 | 17篇 |
1993年 | 20篇 |
1992年 | 9篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 10篇 |
1985年 | 16篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 1篇 |
1973年 | 1篇 |
排序方式: 共有693条查询结果,搜索用时 687 毫秒
41.
42.
Masuda K Haramaki T Nakashima S Habert B Martinez I Kashiwabara S 《Applied spectroscopy》2003,57(3):274-281
The attenuated total reflectance infrared (ATR-IR) spectra of several aqueous solutions have been measured by using a newly developed heatable rod-type ATR cell. The OH stretching bands showed systematic change with increasing solute concentrations and these changes can be explained by four different OH components based on curve-fitting results. NaCl solutions show longer H-bond distance character, while carbonate solutions present shorter ones. The Na2CO3 1 M solution conserves this shorter H-bond nature up to 100 degrees C. On the other hand, the loose nature of NaCl solutions becomes less pronounced at higher temperatures because of the dissociation of pure water clusters. These in situ observations of water structures are generally in agreement with the expected nature of fluids within the earth. 相似文献
43.
Chunqing?HeEmail author Takenori?Suzuki Eisaku?Hamada Hitoshi?Kobayashi Kenjiro?Kondo Victor?P.?Shantarovich Yasuo?Ito 《Materials Research Innovations》2003,7(1):37-41
Polymer structures have been investigated using positron annihilation lifetime spectroscopy (PALS) with a slow positron beam
as well as a conventional radioactive source (22Na). The properties of the free volume holes near the polymer surface were studied as a function of the positron implantation
energy. The longest lifetime was associated with ortho-positronium (o-Ps) annihilation in the free volume holes. In polytetrafluoroethylene film, the lifetime of o-Ps was observed to decrease with increasing positron implantation depth, and a significant change in the o-Ps lifetime was found at a short distance (about 10 nm) from the surface, while its intensity increased. This result implies
that near the polymer surface the free volume holes become larger that in the bulk. The effect of temperature on the polymer
sub-surface layers was also studied. For high molecular weight polystyrene, the glass transition temperature for the sub-surface
was lower than that for the bulk and thermal expansion coefficient of the sub-surface layers was found to be larger than the
bulk value.
Electronic Publication 相似文献
44.
Takeshi Ando Eiichi Ohki Yasutaka Nakashima Yutaka Akita Hiroshi Iijima Osamu Tanaka 《Advanced Robotics》2013,27(15):1727-1746
The article describes the development of a gait phase time-based split-belt treadmill measurement system. Conventional methods of measuring gait phase, such as the foot switch and force plate, require significant preparation and are costly. In this article, we propose a simple, cheap, and accurate gait phase measurement system that utilizes only the treadmill motor current value. Comparison of this algorithm with conventional methods reveals that the proposed algorithm is as accurate as the foot switch. Moreover, the proposed algorithm can estimate stance phase within a 0.2?s error of the measured value of the force plate in most cases (four out of five healthy subjects). This accuracy is higher than that of the foot switch which is widely used in the clinical field. 相似文献
45.
A Parashar AA Akhand R Rawar T Furuno M Nakanishi M Kato H Suzuki I Nakashima 《Canadian Metallurgical Quarterly》1999,26(1-2):227-231
The mechanism of the lymphocyte stimulatory action of sulfhydryl group-reactive mercuric ions was studied with respect to its potential ability to induce a protein tyrosine phosphorylation-linked signal for mobilization of free Ca2+ into cytoplasm and nucleus of the cell. Exposure of human leukamic T cell line (Jurkat) cells to high (1 mM) and low (0.01 mM) concentrations of HgCl2 induced tyrosine phosphorylation of multiple proteins in a concentration-dependent manner. Confocal microscopy directly visualized the time course localization of Ca2+ inside the cells after exposure to HgCl2. The onset and level of Ca2+ mobilization following HgCl2 exposure were in parallel to those of protein tyrosine phosphorylation. Interestingly, by either concentration of HgCl2, Ca2+ was mobilized in both cytoplasm and nucleus almost simultaneously, and the level of Ca2+ mobilization in the nucleus was more than that in the cytoplasm. All the HgCl2-mediated Ca2+ mobilization was prevented by addition of protein kinase inhibitor staurosporin prior to HgCl2. These results suggest that heavy metal stress triggers a protein tyrosine phosphorylation-linked signal that leads to a nuclear event-dominant Ca2+ mobilization. 相似文献
46.
47.
M Haraguchi S Arinaga T Sakata H Ueo H Nakashima K Shibuta M Mori T Akiyoshi 《Canadian Metallurgical Quarterly》1997,13(6):554-556
We designed a new bag-carrier device system for continuous intravenous hyperalimentation. The patient carries it on his shoulder and can both walk up and down stairs and go out. The use of this device is simple and easy, and was found to increase the patient's opportunity to engage in physical activity. 相似文献
48.
Tsuyoshi Kawai Akihiro Kubota Kensuke Kawamura Hiroyuki Tsumatori Takuya Nakashima 《Thin solid films》2008,516(9):2666-2669
Diffusion kinetics of three dyes in nematic liquid crystals are studied with single-molecule fluorescence autocorrelation spectroscopy. Markedly large anisotropy was observed in the diffusion coefficient and structure of diffusion molecules showed no marked effect on the anisotropy. 相似文献
49.
Ray Nakashima Shuanghui Hao Hideki Honda Ryuichi Oguro Hidekazu Miyakawa Teruo Tsuji 《Electrical Engineering in Japan》2004,147(4):68-76
In this paper, position control of a linear slider with twin linear drives is considered. Recently, for high‐speed response, several linear motors have been used for linear slider systems. In such a linear slider, if the linear drives are controlled individually, their position responses may undergo vibrational disturbance by interaction with the output of the motors. To control this vibration, this paper presents a dynamic model of a linear slider system which consists of two motion systems decoupled by coordinate transformation, and proposes a feedback controller which is designed for these two decoupled systems. The effectiveness of the proposed method is confirmed by experiments. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 147(4): 68–76, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10291 相似文献
50.
C. Gaire Y. Ou H. Arao M. Egami A. Nakashima R. C. Picu G.-C. Wang T.-M. Lu 《Journal of Porous Materials》2010,17(1):11-18
Mechanical properties of porous methyl silsesquioxane samples with dielectric constant 2.4 and 2.0 and a recently developed
nanoclustering silica film samples with dielectric constants 2.3 and 2.0 were evaluated using an atomic force microscope based
nanoindentation. It was found that the Young’s modulus and the hardness decrease while the fracture toughness increases with
a decrease in the dielectric constant in the same type of material. Moreover, the Young’s modulus and the hardness of the
nanoclustering silica films were observed to be at least twice and fracture toughness values ~1.3–1.5 higher than those for
methyl silsesquioxane films with similar dielectric constants. The high resolution topographic imaging capability of atomic
force microscope was shown to be particularly useful in the measurement of cracks generated by the ultra-low indentation loads,
and the evaluation of the fracture toughness of the nanoscale volumes of materials. 相似文献