全文获取类型
收费全文 | 2011篇 |
免费 | 36篇 |
国内免费 | 9篇 |
专业分类
电工技术 | 55篇 |
综合类 | 5篇 |
化学工业 | 391篇 |
金属工艺 | 102篇 |
机械仪表 | 66篇 |
建筑科学 | 25篇 |
矿业工程 | 1篇 |
能源动力 | 46篇 |
轻工业 | 110篇 |
水利工程 | 3篇 |
石油天然气 | 1篇 |
无线电 | 225篇 |
一般工业技术 | 262篇 |
冶金工业 | 624篇 |
原子能技术 | 36篇 |
自动化技术 | 104篇 |
出版年
2023年 | 7篇 |
2022年 | 20篇 |
2021年 | 31篇 |
2020年 | 8篇 |
2019年 | 13篇 |
2018年 | 23篇 |
2017年 | 7篇 |
2016年 | 22篇 |
2015年 | 21篇 |
2014年 | 27篇 |
2013年 | 69篇 |
2012年 | 39篇 |
2011年 | 70篇 |
2010年 | 53篇 |
2009年 | 71篇 |
2008年 | 74篇 |
2007年 | 61篇 |
2006年 | 43篇 |
2005年 | 56篇 |
2004年 | 52篇 |
2003年 | 52篇 |
2002年 | 52篇 |
2001年 | 56篇 |
2000年 | 46篇 |
1999年 | 58篇 |
1998年 | 214篇 |
1997年 | 159篇 |
1996年 | 114篇 |
1995年 | 65篇 |
1994年 | 56篇 |
1993年 | 59篇 |
1992年 | 32篇 |
1991年 | 24篇 |
1990年 | 22篇 |
1989年 | 18篇 |
1988年 | 18篇 |
1987年 | 20篇 |
1986年 | 9篇 |
1985年 | 15篇 |
1984年 | 14篇 |
1983年 | 8篇 |
1982年 | 23篇 |
1981年 | 17篇 |
1980年 | 21篇 |
1979年 | 24篇 |
1978年 | 7篇 |
1977年 | 18篇 |
1976年 | 36篇 |
1975年 | 11篇 |
1966年 | 4篇 |
排序方式: 共有2056条查询结果,搜索用时 46 毫秒
51.
Amorphous ternary palladium-based alloys containing platinum group metals as an additional element were prepared by rapid quenching from the molten state and their anodic characteristics were investigated in a 4 mol dm?3 NaCl solution of pH 4 and 80° C. The amorphous alloys containing sufficient quantities of rhodium, platinum or iridium were passivated by anodic polarization and their corrosion rates at high current densities in the chlorine evolution region were extremely low. This fact was attributed to the formation of a highly protective passive film due to both the transformation to the amorphous structure and the addition of rhodium, platinum or indium. The electrocatalytic activities for chlorine evolution of amorphous alloys were higher than those of pure platinum group metals except palladium. In particular, the amorphous Pd41Ir40P19 alloy had the desired stable, high electrocatalytic activity for chlorine evolution and the high overvoltage for oxygen evolution. 相似文献
52.
Yamauchi Toshihiro Akao Yohei Yoshitani Ryota Nakamura Yuichi Hashimoto Masaki 《International Journal of Information Security》2021,20(4):461-473
International Journal of Information Security - Cyberattacks, especially attacks that exploit operating system vulnerabilities, have been increasing in recent years. In particular, if administrator... 相似文献
53.
Kazunori Nagasaka Takeshi Yoshida Yoshihiro Kita Fumio Hashimoto 《International Journal of Machine Tools and Manufacture》1987,27(2)
For optimization of abrasive cut-off operation, wheel wear equation must be identified before the operation is optimized. The equation is obtained by using GMDH algorithm with successive determination of trends containing interactive terms. In the model equation factors of grinding fluid are taken into consideration in addition to the factors of wheel, work material, feed (table speed) and wheel speed. For the identification of the model wheel wear tests are performed under the experimental design treating the above-mentioned factors as independent variables. The grinding ratio (output in the model) can be predicted for combinations of various factors using the model. With the wheel wear equation and machining cost model, the optimum combination of wheel, fluid, feed and wheel speed can be selected for a given work material. The relationships between these variables and the costs are investigated. 相似文献
54.
55.
K. Hashimoto M. YamasakiS. Meguro T. SasakiH. Katagiri K. IzumiyaN. Kumagai H. HabazakiE. Akiyama K. Asami 《Corrosion Science》2002,44(2):371-386
CO2 emissions, which induce global warming, increase with the development of economic activity. It is impossible to decrease the CO2 emissions by suppression of the economic activity. Global CO2 recycling can solve this problem. The global CO2 recycling consists of three district: The electricity is generated by solar cells on deserts. At desert coasts, the electricity is used for H2 production by seawater electrolysis and H2 is used for CH4 production by the reaction with CO2. CH4 which is the main component of liquefied natural gas is liquefied and transported to energy consuming districts where CO2 is recovered, liquefied and transported to the desert coasts. A CO2 recycling plant for substantiation of our idea has been built on the roof of the Institute for Materials Research in 1996. Key materials necessary for the global CO2 recycling are the anode and cathode for seawater electrolysis and the catalyst for CO2 conversion. All of them have been tailored by us. They have very high activity and selectivity for necessary reactions in addition to excellent durability. A pilot plant consisting of minimum units in an industrial scale is going to be built in three years. 相似文献
56.
Sun-Chan Jeong Ichiro Katayama Hirokane Kawakami Yutaka Watanabe Hironobu Ishiyama Nobuaki Imai Yoshikazu Hirayama Hiroari Miyatake Masao Sataka Satoru Okayasu Hiroyuki Sugai Shin-Ichi Ichikawa Katsuhisa Nishio Shinichi Mitsuoka Takamitsu Nakanoya Masahito Yahagi Takanori Hashimoto Kazunori Takada Mamoru Watanabe Tomoko Ishikawa Akihiro Iwase 《Journal of Phase Equilibria and Diffusion》2005,26(5):472-476
For the effective use of short-lived radioactive beams, soon to be available at the Tokai Radioactive Ion Accelerator Complex, the authors have developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound βLiAl using an α-emitting radiotracer of 8Li (T1/2=0.84 s). It was found that the time-dependent yields of the α particles from the diffusing 8Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in βLiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects (i.e., the existence of the atomic vacancies of Li and the defects in Ga sites that are replaced by Li). 相似文献
57.
Wang P Behan G Kirkland AI Nellist PD Cosgriff EC D'Alfonso AJ Morgan AJ Allen LJ Hashimoto A Takeguchi M Mitsuishi K Shimojo M 《Ultramicroscopy》2011,111(7):877-886
Scanning confocal electron microscopy (SCEM) offers a mechanism for three-dimensional imaging of materials, which makes use of the reduced depth of field in an aberration-corrected transmission electron microscope. The simplest configuration of SCEM is the bright-field mode. In this paper we present experimental data and simulations showing the form of bright-field SCEM images. We show that the depth dependence of the three-dimensional image can be explained in terms of two-dimensional images formed in the detector plane. For a crystalline sample, this so-called probe image is shown to be similar to a conventional diffraction pattern. Experimental results and simulations show how the diffracted probes in this image are elongated in thicker crystals and the use of this elongation to estimate sample thickness is explored. 相似文献
58.
Hiroki Kikuchi Shigeki Hashimoto Shinichiro Tajiri Tsuneo Hayashi Yutaka Sugawara Michio Oka Yoshiyuki Akiyama Akira Nakamura Naoya Eguchi 《Journal of the Society for Information Display》2009,17(3):263-269
Abstract— A high‐pixel‐rate, high‐contrast (30,000:1) wide‐color‐gamut grating‐light‐valve laser projector is reported. A new optical engine enabling high‐frame‐rate (240 Hz) scan projection is employed. Panoramic wide‐angle‐scan projection with a 64:9 aspect ratio was also developed. Speckle noise is eliminated using a simple but highly efficient technique. The optical throughput efficiency of the grating‐light‐valve laser projector is reviewed. 相似文献
59.
Kuramochi K Suzuki K Yamazaki T Mitsuishi K Furuya K Hashimoto I Watanabe K 《Ultramicroscopy》2008,109(1):96-103
The structure and composition of the 1/4{110} twin boundary in alpha-Zn7Sb2O12 have been determined by using quantitative high-angle annular dark field scanning transmission electron microscopy (HAADF STEM) analysis. The noise in the experimental HAADF STEM images is reduced by using the maximum entropy method and average processing, and the parameters used in dynamical simulations are experimentally determined. From the analysis, it has been found that octahedral sites in the twin boundary slightly shift parallel to the [110] direction, and a reduction of the Sb concentration at the octahedral sites on the plane adjacent to the twin boundary was detected. The reduction was measured from three regions in the same twin boundary, and the Sb concentrations were 4 +/- 3, 8 +/- 3 and 19 +/-2 at% from 33 at%. 相似文献
60.
A novel method for three-dimensional observation of the vascular networks in the whole mouse brain 总被引:1,自引:0,他引:1
A novel method for acquiring serial images suitable for three-dimensional reconstruction of vascular networks in the whole brain of mouse was developed. The brain infused with a White India ink-gelatin solution was fixed and embedded in paraffin containing Sudan Black B through xylene also containing Sudan Black B. Each sliced surface of the paraffin block was coated with liquid paraffin and its image was serially acquired. Coating with liquid paraffin extremely improved the quality of the image. The series of serial images was free of distortion and a three-dimensional image was reconstructed without the problem of the alignment and registration of adjacent images. The volume-rendered image indicated three-dimensional distribution of blood vessels in a whole brain. No ghost or shadow was observed on a volume-rendered image of the White India ink-gelatin infused brain. The z-axial resolution examined on the orthogonal sections reconstituted from serial images obtained at an interval of 5 mum showed no cross talk, indicating that the z-axial resolution was no larger than 5 mum. A proper understanding of the vascular system in a whole brain is indispensable to reveal the development of the vascular system in the brain of normal and genetically manipulated mouse and vascular alterations in pathological situation, such as stroke and neurodegenerative disease. Although simple and inexpensive, this method will provide fundamental information on the vascular system in a whole brain. 相似文献