全文获取类型
收费全文 | 1005篇 |
免费 | 38篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 77篇 |
综合类 | 2篇 |
化学工业 | 270篇 |
金属工艺 | 34篇 |
机械仪表 | 32篇 |
建筑科学 | 14篇 |
能源动力 | 56篇 |
轻工业 | 48篇 |
水利工程 | 2篇 |
石油天然气 | 3篇 |
无线电 | 63篇 |
一般工业技术 | 211篇 |
冶金工业 | 89篇 |
原子能技术 | 37篇 |
自动化技术 | 108篇 |
出版年
2023年 | 11篇 |
2022年 | 12篇 |
2021年 | 28篇 |
2020年 | 9篇 |
2019年 | 17篇 |
2018年 | 13篇 |
2017年 | 27篇 |
2016年 | 27篇 |
2015年 | 18篇 |
2014年 | 40篇 |
2013年 | 66篇 |
2012年 | 42篇 |
2011年 | 78篇 |
2010年 | 59篇 |
2009年 | 53篇 |
2008年 | 57篇 |
2007年 | 53篇 |
2006年 | 32篇 |
2005年 | 34篇 |
2004年 | 30篇 |
2003年 | 42篇 |
2002年 | 25篇 |
2001年 | 14篇 |
2000年 | 16篇 |
1999年 | 17篇 |
1998年 | 44篇 |
1997年 | 23篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 13篇 |
1993年 | 6篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 14篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 4篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1973年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有1046条查询结果,搜索用时 0 毫秒
61.
Yuichi Miura Kazuo Mori Takayoshi Mamiya Tetsumasa Nakayasu 《Journal of Low Temperature Physics》1998,113(5-6):757-762
We have measured the dissipation of dislocation motion in bcc solid
3
He using the high-Q torsional oscillator technique at 1079 Hz. We observed a broad maximum in the temperature dependence of the dissipation. The maximum of the dissipation can be explained by the theory of Granato and Lucke in which the dislocation mobility depends upon the interactions of dislocations with point defects.
4
He impurities tend to bind to the dislocation lines at low temperatures and pin this dislocation motion. The maximum of the dissipation corresponds to the depinning of the dislocation motion. From the amplitude dependence of the depinning temperature we first obtained the activation energy of 1.03 K of the impurity
4
He atom trapped on the dislocations in bcc solid
3
He at a molar volume of 24.30 cm
3
/mol. The activation energy of the impurity atom in bcc
3
He was found to be larger than the value of 0.7 Kin hcp
4
He. 相似文献
62.
Structural Distortion and Compositional Gradients Adjacent to Epitaxial LiMn2O4 Thin Film Interfaces
Xiang Gao Yumi H. Ikuhara Craig A. J. Fisher Hiroki Moriwake Akihide Kuwabara Hideki Oki Keiichi Kohama Ryuji Yoshida Rong Huang Yuichi Ikuhara 《Advanced Materials Interfaces》2014,1(8)
Thin film electrode materials are key components in the development of high rate, high capacity solid‐state Li‐ion batteries. Detailed knowledge of the epitaxial film/substrate(current‐collector) interface structures, which provides insights into epitaxial growth mechanisms and the effects of microstructure on electrochemical properties, is essential for efficient materials and device design. Here we report the epitaxial growth mechanism of a typical cathodic LiMn2O4 thin film by exploring the detailed structural and compositional variations in the vicinity of a film/substrate interface using state‐of‐the‐art scanning transmission electron microscopy. Direct observation of atom columns shows the epitaxial film forms an atomically flat and coherent heterointerface with the substrate, but that the crystal lattice is tetragonally distorted with a measurable compositional gradient from the interface to the crystal bulk. The growth mechanism is interpreted in terms of a combination of chemical and physicomechanical effects, namely a complex interplay between the internal Jahn‐Teller distortions induced by oxygen non‐stoichiometry and the lattice misfit strain. 相似文献
63.
Jiraporn Chingunpitak Satit Puttipipatkhachorn Yuichi Tozuka Kunikazu Moribe Keiji Yamamoto 《Drug development and industrial pharmacy》2013,39(6):609-617
The purpose of this study was to prepare fine particles of antimalarial drug dihydroartemisinin (DHA) by rapid expansion of supercritical solutions (RESS) using carbon dioxide as supercritical fluid. The mechanical grinding by jet mill and additional vibration rod mill also was performed as a comparative method. In the RESS process, drug particles were prepared by varying processing conditions, including extraction condition, pre-expansion condition, nozzle diameter, nozzle temperature, and collecting distance. Particle size and morphology and physicochemical characteristics of the drug particles were investigated. The RESS process could produce the smaller drug particles (about 1–2 μm) when compared to mechanical grinding method (about 7 μm). All RESS processing parameters had an effect on size and morphology of drug particles. The particle size of drug was related to the solubility of drug in supercritical CO2 at each processing condition. The fine particles of DHA (about 1 μm) with narrow size distribution could be obtained at extraction pressure of 18 MPa and extraction temperature of 32°C, which was closed to the critical temperature of supercritical CO2 whereas broad size distribution was obtained at extraction temperature of 60°C. Powder X-ray diffraction study indicated that the RESS-processed particles were in crystalline form. The results revealed that RESS process is applicable for micronization of DHA. 相似文献
64.
Riho Kataishi Takayuki Ikeda Toshiki Sasaki Kouhei Toyotaka Daiki Nakamura Hiroyuki Miyake Yuji Iwaki Kazunori Watanabe Yuichi Yanagisawa Hisao Ikeda Harue Nakashima Nobuharu Ohsawa Shingo Eguchi Satoshi Seo Yoshiharu Hirakata Shunpei Yamazaki Daisuke Kurosaki Masakatsu Ohno Chris Bower Darryl Cotton Andrew Matthews Piers Andrew Catalin Gheorghiu Johan Bergquist 《Journal of the Society for Information Display》2014,22(8):381-392
In this study, white organic electroluminescent devices with microcavity structures were developed. A flexible high‐resolution active‐matrix organic light‐emitting diode display with low power consumption using red, green, blue, and white sub‐pixels formed by a color‐filter method was fabricated. In addition, a side‐roll touch display was developed in combination with a capacitive flexible touch screen. 相似文献
65.
Effect of Cation Doping on the Superplastic Flow in Yttria-Stabilized Tetragonal Zirconia Polycrystals 总被引:1,自引:0,他引:1
Junpei Mimurada Manabu Nakano Kazutaka Sasaki Yuichi Ikuhara Taketo Sakuma 《Journal of the American Ceramic Society》2001,84(8):1817-1821
The superplastic characteristics of various cation-doped yttria-stabilized tetragonal zirconia polycrystals (Y-TZP) were examined. For 1 mol% cation doping the true stress of Y-TZP is very dependent on the ionic radii of the doped cations; for instance, smaller cation radii give rise to lower true stress when compared with the other compositions for the same grain size, strain rate, and testing temperature. The altered true stress level must be due to the change in diffusivity of the accommodation process for grain boundary sliding caused by the addition of cations in ZrO2 . The strain to failure of the doped zirconia is affected by both ionic radius and valence of the dopant cations. 相似文献
66.
To understand the cause of read/write error due to lube accumulation, a model to simulate the slider’s response to the contact impact, which can occur between a lubricant droplet on the disk and a slider, was developed. The contact impact model is based on the water-hammer pressure model with an additional damping force, where the wave-shock pressure is assumed to function as the contact pressure, and the damping force defines the damping characteristics of the impact which are due to the lubricant’s high viscosity and squeeze between the droplet and slider contact area along the slider local velocity direction. The transient contact impact is dependent on lube droplet density, disk velocity, pitch angle of the slider, and contact area between the droplet and the slider. The measured read/write signal jump due to lube pickup can be explained by the simulation results. This modeling and simulation are helpful to us in understanding the read/write signal loss due to a lube droplet at head disk interface. 相似文献
67.
Saki Kondo Tsukasa Azeta Yoshiaki Ukita Yuichi Utsumi 《Microsystem Technologies》2010,16(8-9):1577-1580
The use of three-dimensional (3D) microstructures is becoming essential attempt to develop next generations’ microdevices, to integrate many modules and various functions, and enhance the performance of device. In this paper, we present a new concept for lab on a chip using 3D structure and centrifugal pumping for integrated functional fluid systems such as high-throughput screening, and point of care testing systems which has stacked multiple structures with 3D-interconnection. The use of 3D structure brings many benefits for above high throughput systems, such as possibility to integrate various modules enabling to perform total assay operation, from sample preparation for biochemical reaction and their detection on one platform. For this concept, the most important key technology is control of a vertical valving and transportation of liquid between different 2D micro channel networks with different height levels. We demonstrated such vertical liquid transportation in 3D micro channel networks through the high aspect ratio capillary bundle filter by controlling spinning speed of device and centrifugal force as a pumping force, and confirmed capillary bundle could be employed as vertical microvalve for 3D fluidic systems using centrifugal force as a pumping method. 相似文献
68.
Shigeaki Yamamoto Yoshiaki Ukita Kozo Mochiji Yuichi Utsumi 《Electrical Engineering in Japan》2012,178(4):49-54
Polytetrafluoroethylene (PTFE) is a very attractive material for various fields because of its chemical resistance, insulation properties, and hydrophobic properties. However, it is difficult to fabricate PTFE microstructures with conventional techniques such as semiconductor processes or micromachining. We have succeeded in the fabrication of high‐aspect‐ratio microfluidics parts from PTFE by direct in‐vacuum photo‐etching utilizing synchrotron radiation (SR) at energy levels from 2 to 12 keV. This paper presents an analysis of the mechanisms of the PTFE microfabrication process and describes newly discovered processing characteristics of PTFE. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(4): 49–54, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21152 相似文献
69.
Ryota Imazawa Makoto Nakagawa Shuji Kamio Ryuma Hihara Takuma Yamada Michiaki Inomoto Yuichi Takase Yasushi Ono 《Electrical Engineering in Japan》2012,179(2):20-26
The UTST (University of Tokyo Spherical Tokamak) device was constructed for the purpose of exploring the formation of ultrahigh‐beta ST (spherical tokamak) plasma using the double null plasma merging method. When two plasmas merge together to form a single plasma, magnetic field lines reconnect, and magnetic field energy is converted to plasma kinetic energy, increasing the plasma beta. Merging start‐up has been demonstrated in the TS‐3/4, START, and MAST devices using coils inside the vacuum vessel, and the TS‐3 plasma obtained a 50% beta. In order to demonstrate start‐up in a more reactor‐relevant situation, UTST has all poloidal field (PF) coils outside the vacuum vessel. The first plasma experiment on the UTST was begun in December 2007. In the results, the plasma obtained 10 kA by using only the outer PF coils and a single ST was generated in the lower area (z = –0.3 to –1.0 m) close to a washer gun. This result suggests that another washer gun on the top of the UTST can allow the generation of ST in the upper area and merging start‐up by using outer PF coils. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 179(2): 20–26, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21216 相似文献
70.