全文获取类型
收费全文 | 498篇 |
免费 | 4篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 23篇 |
综合类 | 1篇 |
化学工业 | 138篇 |
金属工艺 | 14篇 |
机械仪表 | 16篇 |
建筑科学 | 10篇 |
能源动力 | 26篇 |
轻工业 | 49篇 |
石油天然气 | 1篇 |
无线电 | 24篇 |
一般工业技术 | 130篇 |
冶金工业 | 18篇 |
原子能技术 | 13篇 |
自动化技术 | 44篇 |
出版年
2024年 | 2篇 |
2022年 | 4篇 |
2021年 | 4篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 15篇 |
2013年 | 22篇 |
2012年 | 23篇 |
2011年 | 36篇 |
2010年 | 30篇 |
2009年 | 28篇 |
2008年 | 28篇 |
2007年 | 30篇 |
2006年 | 24篇 |
2005年 | 19篇 |
2004年 | 13篇 |
2003年 | 16篇 |
2002年 | 11篇 |
2001年 | 12篇 |
2000年 | 9篇 |
1999年 | 20篇 |
1998年 | 15篇 |
1997年 | 11篇 |
1996年 | 12篇 |
1995年 | 7篇 |
1994年 | 9篇 |
1993年 | 7篇 |
1992年 | 3篇 |
1991年 | 3篇 |
1990年 | 7篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 6篇 |
1986年 | 5篇 |
1985年 | 8篇 |
1983年 | 2篇 |
1982年 | 10篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 5篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 2篇 |
1971年 | 1篇 |
排序方式: 共有507条查询结果,搜索用时 15 毫秒
241.
Haruo Ihori Yuki Inagawa Naohiro Ito Masaharu Fujii Hideki Ninomiya 《Electrical Engineering in Japan》2012,179(1):8-14
Though it is said that the paperless age arrived with the spread of personal computers, the amount of office paper used shows no tendency to decrease. In general, used paper is recovered and recycled in order to preserve the environment. But labor and expense are required for the recovery of used paper and the recycled paper is lower in quality. If we could reuse used paper repeatedly without these disadvantages, for example, by using copying machines that could print again by removing the toner on used paper, it would be very convenient and ecological. We therefore studied the removal of toner from used paper by the laser ablation technique. As an optical source, an SHG‐YAG laser was chosen. The energy density of irradiation with an SHG‐YAG laser for the removal of toner from used paper was examined. At an energy density of approximately 12 mJ/mm2, which was the average value, the toner was removed sufficiently to allow reuse of the paper. The conditions of the laser irradiation, specifically the laser scanning speed and the number of irradiations, were studied. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(1): 8–14, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21214 相似文献
242.
Tomotaka Miyazawa Toshiyuki Fujii Susumu Onaka Masaharu Kato 《Journal of Materials Science》2011,46(12):4228-4235
Using a single crystal of a Cu–6 mass% Ag alloy aged at 723 K for various times, nano-sized Ag precipitates in a Cu matrix
were observed by conventional and ultra high-voltage transmission electron microscopes. The nano-sized Ag precipitates with
a radius of about 5 nm had a nearly spherical shape. The shape change from the nearly spherical shape to the {111} octahedral
shape occurred with increasing the size of the Ag precipitates to 11 nm. Elastic states of the Ag precipitates were evaluated
by observing moiré fringes formed between the Ag precipitates and the Cu matrix. The origin of the shape change of the nano-sized
Ag precipitates was discussed by considering the sum of elastic strain energy and interfacial energy. 相似文献
243.
Riki Toita Daisuke Asai Kentaro Otani Takahito Kawano Masaharu Murata Jeong-Hun Kang 《Lipids》2019,54(8):465-470
Lysophosphatidylcholine (lysoPtdCho) is produced mainly by the phospholipase A2-dependent hydrolysis of phosphatidylcholine (PtdCho) and can induce inflammatory activation and osteogenic gene expression in vascular smooth muscle cells. However, the mechanisms mediating these processes have not been fully elucidated. In this study, we investigated whether inhibition of protein kinase A (PKA) signaling suppressed lysoPtdCho-induced calcification of human aortic smooth muscle cells (HASMC). Calcium levels and alkaline phosphatase activity were significantly increased in HASMC treated with lysoPtdCho, but not PtdCho, compared with those in phosphate-buffered saline-treated HASMC. However, the addition of a PKA inhibitor (H-89) or PKA siRNA blocked lysoPtdCho-induced HASMC calcification. These results showed that lysoPtdCho could activate PKA-mediated HASMC calcification and that PKA may be a therapeutic target for lysoPtdCho-mediated vascular smooth muscle cell calcification. 相似文献
244.
245.
Takashi Kurosu Shiyoshi Yokoyama Masaharu Fujita Kazuo Chiba 《International journal of remote sensing》2013,34(4):595-613
This paper describes a method of improving classification accuracy when using Synthetic Aperture Radar (SAR) images. The classifier used is a maximum likelihood classifier. Texture and textural feature images were made and used for classification. The accuracy of various classification methods was compared. As a result, it was found that the best classification was produced by the aggregation of the classified image when using texture images as additional inputs to the classifier. It is also shown that textural analysis and the aggregation technique are useful in the classification of SAR images. 相似文献
246.
Kenji Sunahara Yuji Ishida Shinji Yamashita Masaharu Yamamoto Hiroshi Nishikawa Kenji Matsuda 《摩擦学汇刊》2013,56(5):730-735
The dielectric breakdown characteristics of three types of grease used in motors are compared by direct observations of flashes caused by the electric discharge between surfaces composed of a steel ball and a glass disc coated with chromium and indium tin oxide films. The flashes produce pitting on the steel ball and coated glass disc surfaces. It has been found that the frequency of the flash signal depends on the film thickness. It has also been found that the dielectric breakdown of greases is mainly influenced by the base oil rather than the thickener. Furthermore, it has been proved through the calculation of electrical energy brought by the flash or dielectric breakdown that the pitting is caused by melting of the steel surface due to a concentration of the electric current. 相似文献
247.
The effects of freeze-thawing on the sizes and size distribution of egg yolk phosphatidylcholine (EggPC) liposomes in the presence of 0-40 mol% distearoylphosphatidylethanolamine-polyethyleneglycol 2000 (DSPE-PEG2000) prepared by detergent removal method were studied by quasielastic light scattering (QELS), gel exclusion chromatography, and freeze-fracture electron microscope. Especially, gel exclusion chromatography successfully provided the size distribution of polydisperse vesicle suspension. The mean diameters of the liposomes, which had originally large size, decreased with increase in the number of freeze-thawing cycles. On the contrary, the mean diameters of the liposomes, which had originally small size, increased with increase in the numbers of freeze-thawing cycles. After freeze-thawing over 10 times, the liposomal mean diameters fell into a range from 80 to 150 nm in spite of their original size. Gel exclusion chromatography showed that in the process of freeze-thawing of the liposomes containing DSPE-PEG 2000, two opponent events, one is fission and the other is fusion, occurred at the same time. 相似文献
248.
Daisuke Ishii Takehisa Fujita Masaharu Nakazawa 《Science and Technology of Advanced Materials》2013,14(5-6):715-718
Chemotaxis, the process by which cells move toward attractant molecules, operates in a range of biological processes including immunity, neuronal patterning, and morphogenesis. Dictyostelium discoideum cells display a strong chemotactic response to cyclic adenosine 3',5'-monophosphate (cAMP), which binds to a cell surface receptor. Each Dictyostelium has ca. 80000 cAMP receptors, and can transduce shallow spatial chemoattractant gradients into strongly localized intracellular responses in spite of large statistical fluctuation of receptor occupancy even in the case of very low cAMP concentration. In this study, we develop a stochastic model for gradient sensing by chemotactic cells. We simulate the binding of cAMP molecules to receptors by a Monte-Carlo method in order to account for statistical fluctuation of receptor occupancy and treat intracellular signal processing by a diffusion–translocation model, which includes the production of second-messenger molecules and positive feedback mechanisms mediated by effector molecules. Our simulation results show that the fluctuation of second-messenger concentration is much smaller than that of receptor occupancy, and that a shallow chemoattractant gradient are transduced into a large second-messenger concentration gradient through nonlinear signal amplification. 相似文献
249.
Baoshan Hu Hiroki Ago Yoshito Ito Kenji Kawahara Masaharu Tsuji Eisuke Magome Kazushi Sumitani Noriaki Mizuta Ken-ichi Ikeda Seigi Mizuno 《Carbon》2012,50(1):57-65
We report the atmospheric pressure chemical vapor deposition (CVD) growth of single-layer graphene over a crystalline Cu(1 1 1) film heteroepitaxially deposited on c-plane sapphire. Orientation-controlled, epitaxial single-layer graphene is achieved over the Cu(1 1 1) film on sapphire, while a polycrystalline Cu film deposited on a Si wafer gives non-uniform graphene with multi-layer flakes. Moreover, the CVD temperature is found to affect the quality and orientation of graphene grown on the Cu/sapphire substrates. The CVD growth at 1000 °C gives high-quality epitaxial single-layer graphene whose orientation of hexagonal lattice matches with the Cu(1 1 1) lattice which is determined by the sapphire’s crystallographic direction. At lower CVD temperature of 900 °C, low-quality graphene with enhanced Raman D band is obtained, and it showed two different orientations of the hexagonal lattice; one matches with the Cu lattice and another rotated by 30°. Carbon isotope-labeling experiment indicates rapid exchange of the surface-adsorbed and gas-supplied carbon atoms at the higher temperature, resulting in the highly crystallized graphene with energetically most stable orientation consistent with the underlying Cu(1 1 1) lattice. 相似文献
250.
Osamu Sato Sonko Osawa Yohan Kondo Masaharu Komori Toshiyuki Takatsuji 《Precision Engineering》2010,34(1):156
Gears are key elements of power transmission systems, and the inspection of their pitch deviation is one of the most important tests on gears. The specifications of gears are assessed using gear measuring instruments (GMIs) or coordinate measuring machines (CMMs), and the results of the measurements must be validated under an appropriate traceability system. In the traceability system, calibrated gauges whose measuring uncertainties are estimated are necessary. In the case of pitch deviation measurement, special artefacts or gears manufactured with high dimensional accuracy are used as reference gauges. In this paper, authors propose calibration and uncertainty evaluation methods for the single pitch deviation of gears measured using CMMs. First, the evaluation of single pitch deviation using a multiple-measurement technique and the estimation of its uncertainty based on the analysis of variance are formulated. Second, a technique for reducing the measurement trials based on the symmetry of the measurement is discussed. Finally, the proposed calibration method is validated through experiments. 相似文献