全文获取类型
收费全文 | 2843篇 |
免费 | 87篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 194篇 |
综合类 | 7篇 |
化学工业 | 852篇 |
金属工艺 | 82篇 |
机械仪表 | 77篇 |
建筑科学 | 44篇 |
能源动力 | 137篇 |
轻工业 | 305篇 |
水利工程 | 9篇 |
石油天然气 | 1篇 |
无线电 | 195篇 |
一般工业技术 | 519篇 |
冶金工业 | 125篇 |
原子能技术 | 143篇 |
自动化技术 | 248篇 |
出版年
2023年 | 12篇 |
2022年 | 37篇 |
2021年 | 59篇 |
2020年 | 31篇 |
2019年 | 45篇 |
2018年 | 55篇 |
2017年 | 45篇 |
2016年 | 55篇 |
2015年 | 42篇 |
2014年 | 103篇 |
2013年 | 164篇 |
2012年 | 133篇 |
2011年 | 197篇 |
2010年 | 143篇 |
2009年 | 148篇 |
2008年 | 152篇 |
2007年 | 149篇 |
2006年 | 131篇 |
2005年 | 127篇 |
2004年 | 93篇 |
2003年 | 108篇 |
2002年 | 100篇 |
2001年 | 55篇 |
2000年 | 49篇 |
1999年 | 50篇 |
1998年 | 79篇 |
1997年 | 53篇 |
1996年 | 51篇 |
1995年 | 42篇 |
1994年 | 54篇 |
1993年 | 36篇 |
1992年 | 21篇 |
1991年 | 25篇 |
1990年 | 23篇 |
1989年 | 26篇 |
1988年 | 13篇 |
1987年 | 22篇 |
1986年 | 18篇 |
1985年 | 25篇 |
1984年 | 17篇 |
1983年 | 23篇 |
1982年 | 20篇 |
1981年 | 19篇 |
1980年 | 26篇 |
1979年 | 15篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 12篇 |
1975年 | 6篇 |
1973年 | 5篇 |
排序方式: 共有2938条查询结果,搜索用时 15 毫秒
81.
Kenji Takizawa Tayfun E. Tezduyar Austin Buscher Shohei Asada 《Computational Mechanics》2014,54(4):955-971
To address the computational challenges associated with contact between moving interfaces, such as those in cardiovascular fluid–structure interaction (FSI), parachute FSI, and flapping-wing aerodynamics, we introduce a space–time (ST) interface-tracking method that can deal with topology change (TC). In cardiovascular FSI, our primary target is heart valves. The method is a new version of the deforming-spatial-domain/stabilized space–time (DSD/SST) method, and we call it ST-TC. It includes a master–slave system that maintains the connectivity of the “parent” mesh when there is contact between the moving interfaces. It is an efficient, practical alternative to using unstructured ST meshes, but without giving up on the accurate representation of the interface or consistent representation of the interface motion. We explain the method with conceptual examples and present 2D test computations with models representative of the classes of problems we are targeting. 相似文献
82.
This paper presents the silicon based on-chip antenna using a LC resonator. The proposed antenna consists of a stacked capacitor and a spiral inductor on silicon substrate. The spiral inductor structure without underpass was proposed for improvement the performance of the silicon based-antenna. The resonant frequency of the fabricated antenna was measured as 465 MHz. Its return loss was 23.4 dB at resonant frequency. The antenna has a gain of ?35.75 dBi due to small size and silicon substrate. However, the fabricated antenna has good performance in the near-field. 相似文献
83.
Yusei Maruyama Tsugiko Takase Masateru Yoshida Kensuke Kogure Kenji Suzuki Kazuyuki Tohji 《Fullerenes, Nanotubes and Carbon Nanostructures》2013,21(2):211-221
Abstract Single-walled carbon nanotubes (SWCNT) prepared by a DC-Arc-Discharge and purified by a hydrothermal treatment followed by several steps of procedures including heating, burning, extracting and acid-washing are investigated by a conventional STM technique morphologically and spectroscopically. The electical resistivities of compacted pellets (mats) of SWCNT are measured as a function of temperature in the range from the room-temperature to 1.5K. The behaviors seems to be essentially originated in the metallic nature of individual SWCNT. 相似文献
84.
Reduction of Vibration in Concentrated Winding Permanent Magnet Synchronous Motor by Means of Skew Effects of Rotor 下载免费PDF全文
Ryoichi Takahata Shinichi Wakui Kenji Miyata Keiji Noma Masaharu Senoo 《Electrical Engineering in Japan》2014,187(2):33-43
Global warming and the problem of successfully incorporating environmental safeguards are promoting the need for a more power‐efficient motor. Therefore, as a driving source, permanent magnet synchronous motors (PMSMs) with concentrated winding are widely used in a variety of fields. However, a PMSM with a concentrated winding generates more vibration than one with a distributed winding because of the radial electromagnetic force. This paper describes the effect of a new skewed rotor on the characteristics of a concentrated winding PMSM. We investigated this effect by three‐dimensional finite element method (3D FEM) analysis and measurement. We also demonstrate that the proposed rotor is effective in reducing the radial electromagnetic force without decreasing motor efficiency. © 2014 Wiley Periodicals, Inc. Electr Eng Jpn, 187(2): 33–43, 2014; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.22400 相似文献
85.
Kenji Hirota Kazuhiko Kitamura Yoshihiko Ukai Keiichi Matsunaga 《Journal of Materials Processing Technology》2014,214(10):2095-2101
In this paper, a new assembling method of spline joints that enables tight fitting in a simple manner by allowing slight plastic deformation at the spline teeth was introduced. Experiments were carried out for the spline joints of medium carbon steel varying the overlap zone between the male and the female spline teeth. Axial joining strength was increased with increase in the overlap length due to the residual compressive stress by forming. The joint by the proposed method also showed higher torsional strength than the conventional joint. Improvement in the torsional strength was explained based on the deformation and hardness distribution around the spline teeth. With respect to the shape of overlap zone, better results were obtained when using the specimen having a uniform overlap length along the axial direction. 相似文献
86.
87.
88.
Carlo M. Orofeo Hiroki Hibino Kenji Kawahara Yui Ogawa Masaharu Tsuji Ken-ichi Ikeda Seigi Mizuno Hiroki Ago 《Carbon》2012,50(6):2189-2196
We demonstrate that domain structure of single-layer graphene grown by ambient pressure chemical vapor deposition is strongly dependent on the crystallinity of the Cu catalyst. Low energy electron microscopy analysis reveals that graphene grown using a Cu foil gives small and mis-oriented graphene domains with a number of domain boundaries. On the other hand, no apparent domain boundaries are observed in graphene grown over a heteroepitaxial Cu(111) film deposited on sapphire due to unified orientation of graphene hexagons. The difference in the domain structures is correlated with the difference in the crystal plane and grain structure of the Cu metal. The graphene film grown on the heteroepitaxial Cu film exhibits much higher carrier mobility than that grown on the Cu foil. 相似文献
89.
Texture,sensory and swallowing characteristics of high-pressure-heat-treated pork meat gel as a dysphagia diet 总被引:2,自引:0,他引:2
To develop a soft meat product for a dysphagia diet, high-pressure technology was applied. Pressure-heat-treated ground pork meat (PH) was prepared from ground pork mixed with water (ground meat: water, 1:0.5 or 1:1) and salt (1.5%). PH-gels were made from these meat homogenates by treatment at 400 MPa for 20 min, followed by heat treatment. Heat-treated pork meat homogenates (H) were also prepared. The hardness and adhesiveness of the 1:1PH-gel was lower than those of the 1:1H-gel. The PH-gel scored higher in sensory evaluations of elasticity, smoothness and ease of swallowing. Scanning electron micrographs indicated that the superior textural property of the 1:1PH-gel was caused by a network of myosin filaments. Videofluoroscopic examination of swallowing revealed that the 1:1PH-gel was easy to swallow and left little residue in the oropharynx. These results proved the utility of pressurization in creating a dysphagia meat diet. 相似文献
90.
Mechanically Robust and Self‐Healable Superlattice Nanocomposites by Self‐Assembly of Single‐Component “Sticky” Polymer‐Grafted Nanoparticles 下载免费PDF全文