全文获取类型
收费全文 | 110篇 |
免费 | 3篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 45篇 |
金属工艺 | 1篇 |
机械仪表 | 1篇 |
建筑科学 | 1篇 |
轻工业 | 6篇 |
水利工程 | 1篇 |
无线电 | 11篇 |
一般工业技术 | 27篇 |
冶金工业 | 1篇 |
原子能技术 | 3篇 |
自动化技术 | 10篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 8篇 |
2019年 | 2篇 |
2018年 | 3篇 |
2017年 | 3篇 |
2016年 | 1篇 |
2015年 | 2篇 |
2014年 | 4篇 |
2013年 | 5篇 |
2012年 | 2篇 |
2011年 | 5篇 |
2010年 | 5篇 |
2009年 | 3篇 |
2008年 | 5篇 |
2007年 | 7篇 |
2006年 | 1篇 |
2005年 | 6篇 |
2004年 | 3篇 |
2003年 | 2篇 |
2002年 | 3篇 |
2000年 | 2篇 |
1999年 | 5篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 5篇 |
1978年 | 1篇 |
1976年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有113条查询结果,搜索用时 15 毫秒
11.
Electric-field distributions and carrier-density distributions in a GaAs m.e.s.f.e.t. at large drain voltages are investigated with a new analytical model, which takes account of the electron-drift-velocity saturation with negative differential mobility and the extension of a depletion layer towards the drain electrode. 相似文献
12.
13.
Kaya Demir Vijay Sukumaran Yoichiro Sato Abderrahim El Amrani Koushik Ramachandran Raghuram Pucha P. Markondeya Raj Venkatesh Sundaram Rao Tummala 《Journal of Materials Science: Materials in Electronics》2018,29(15):12669-12680
Glass is an ideal substrate material to enable 2.5D and 3D packaging of ICs at low cost and high performance. However, it is a brittle material and is prone to failures during fabrication and operation. Large coefficient of thermal expansion (CTE) mismatch between copper and glass leads to thermomechanical stresses that can lead to glass cracking and delamination from glass interfaces. This paper focuses on modeling and reliability characterization of copper-plated through-package-vias (TPV) in glass packages. Thermomechanical simulations were carried out to obtain design guidelines for reliable TPVs in glass. Test-vehicles with different glass thicknesses and copper TPV fabrication conditions were fabricated for thermal cycling tests, resistance monitoring and failure analysis. The reliability characterization results showed good thermomechanical reliability of TPVs in ultra-thin glass panels. 相似文献
14.
Kouki Ishii Yoshihiro Mizutani Yoshiro Suzuki Yoichiro Koga Ryosuke Matsuzaki 《Advanced Composite Materials》2019,28(4):383-395
Three-dimensional (3D) printing is an attractive technology to produce complex structures without the need for expensive tools and molds. Additives are usually incorporated with the plastic materials used in 3D printing to increase their strength and rigidity. In particular, carbon fiber-reinforced plastic (CFRP) shows promise as a material for use in 3D printing. However, the strength of CFRP after printing is still unclear, although it is known that its strength is affected by the plastic melting during printing. In this study, we analyzed the fracture behavior of CFRP specimens before and after bending to different curvature radii. From the experimental results, a fracture criterion that described the behavior of the materials by considering tensile and compressive loads was developed. The fracture mechanism was the same for CFRP specimens with different curvature radii. These results increase our understanding of the mechanical properties of CFRP materials used in 3D printing. 相似文献
15.
Shaoting Lin Yueying Yang Jiahua Ni Yoichiro Tsurimaki Xinyue Liu Baoyang Lu Yaodong Tu Jiawei Zhou Xuanhe Zhao Gang Chen 《Advanced functional materials》2021,31(36):2103551
Surface wetting prevents surface fogging on transparent materials by facilitating filmwise condensation with specific chemistry, but suffers from material and geometry selectivity. Extreme environments associated with high humidity and mechanical loading further limit their anti-fogging persistence. Here, a stretchable anti-fogging tape (SAT) that can be applied to diverse transparent materials with varied curvatures for persistent fogging prevention is reported. The SAT consists of three synergistically combined transparent layers: i) a stretchable and tough layer with large elastic recovery, ii) an endurant anti-fogging layer insensitive to ambient humidity, and iii) a robustly and reversibly adhesive layer. The SAT maintains high total transmittance (>90%) and low diffuse transmittance (<5%) in high-humidity environments, under various modes of mechanical deformations, and over a prolonged lifetime (193 days tested so far). Two applications are demonstrated, including the SAT-adhered eyeglasses and goggles for clear fog-free vision, and the SAT-adhered condensation cover for efficient solar-powered freshwater production. 相似文献
16.
Shinji Hirai Eiji Sumita Kazuyoshi Shimakage Yoichiro Uemura Toshiyuki Nishimura Mamoru Mitomo 《Journal of the American Ceramic Society》2004,87(1):23-28
Cerium monosulfide (CeS) powder was synthesized by the reduction of Ce2 S3 powder with metallic Ce, which was obtained from ceria (CeO2 ) powder using carbon disulfide (CS2 ) gas. To obtain the maximum amount of CeS from a mixture of Ce2 S3 and Ce, an excess amount of metallic Ce, a stoichiometric composition, was necessary in the synthesis at 1273 K for 10.8 ks. The preliminary sintering experiments also were performed using a synthetic CeS powder containing a small amount of Ce, Ce2 O2 S, and β-Ce2 S3 as impurities. It was found that the oxygen content in the sintered compact decreases gradually as the sintering temperature increases, because of the removal of the impurities due to the evaporation of the volatile CeO. Single-phase CeS was formed by sintering at 2173 K. To evaluate the activation energy for densification of single-phase CeS, a CeS powder was prepared by milling an initial sintered compact and was used as an ingredient for hot-press experiments. Densification data during hot-press sintering were analyzed using a kinetic equation, showing that boundary diffusion is a rate-limiting process. The results suggest that this boundary diffusion model can explain well the densification data, with an apparent activation energy of 479 kJ·mol-1 . 相似文献
17.
Transesterifications were investigated to determine a means for preparing polyunsaturated phospholipids simply from soy phospholipid,
sardine oil, and two kinds of microbial lipases originating fromCandida cylindracea andRhizopus delemar.
The optimum reaction conditions forCandida cylindracea lipase were: 4 g of sardine oil, 10 mL of water, 0.7 g of lipase, 10 mL of hexane, 48 hr of reaction time at 37°C for 3 g
of soy phospholipid, for which the transesterification ratio reached approximately 45%. Recovery of phospholipid was low,
because hydrolysis also occurred under these reaction conditions. However, hydrolysis could be suppressed by using glycerine
instead of water, and the recovery of phospholipid increased to 47%, although the transesterification ratio was reduced to
32%.
Rhizopus delemar lipase has 1,3-specificity for triglycerides, and the transesterification ratio was approximately 37% in the 1-position of
phospholipid. The resulting phospholipid was rich in polyunsaturated fatty acids and linoleic acid, while the total percentage
of polyunsaturated fatty acids incorporated was 18.4%. Therefore, polyunsaturated phospholipids can be prepared easily by
transesterification of soy phospholipid with fish oil by means of commercial lipases. 相似文献
18.
Takagi S Ogasawara T Matsumoto Y 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2008,366(1873):2117-2129
It is well known that a bubble in contaminated water rises much slower than one in purified water, and the rising velocity in a contaminated system can be less than half that in a purified system. This phenomenon is explained by the so-called Marangoni effect caused by surfactant adsorption on the bubble surface. In other words, while a bubble is rising, there exists a surface concentration distribution of surfactant along the bubble surface because the adsorbed surfactant is swept off from the front part and accumulates in the rear part by advection. Owing to this surfactant accumulation in the rear part, a variation of surface tension appears along the surface and this causes a tangential shear stress on the bubble surface. This shear stress results in the decrease in the rising velocity of the bubble in contaminated liquid. More interestingly, this Marangoni effect influences not only the bubble's rising velocity but also its lateral migration in the presence of mean shear. Together, these influences cause a drastic change of the whole bubbly flow structures. In this paper, we discuss some experimental results related to this drastic change in bubbly flow structure. We show that bubble clustering phenomena are observed in an upward bubbly channel flow under certain conditions of surfactant concentrations. This cluster disappears with an increase in the concentration. We explain this phenomenon by reference to the lift force acting on a bubble in aqueous surfactant solutions. It is shown that the shear-induced lift force acting on a contaminated bubble of 1mm size can be much smaller than that on a clean bubble. 相似文献
19.
Transparent zinc oxide (ZnO) thin films were deposited on various substrates using a pulsed laser deposition (PLD) technique. During the PLD, oxygen pressure and substrate temperature were varied in order to find an optimal preparation condition of ZnO for thin film transistor (TFT) application. Dependence of optical, electrical and crystalline properties on the deposition conditions was investigated. The ZnO thin films were then deposited on SiN/c-Si layer structures in order to fabricate a TFT device. The pulsed laser deposited ZnO films showed a remarkable TFT performance: field effect mobility (μFE) of 2.4-12.85 cm2/V s and ratio of on and off current (Ron/off) in 2-6 order range. Influence of ZnO preparation conditions on the resulting TFT performance was discussed. 相似文献
20.
Yoichiro Masuda Akira Baba Mamoru Ohmori Hiroshi Masumoto Takashi Gotoh Toshio Hirai 《Integrated ferroelectrics》2013,141(1-3):35-45
Abstract The crystalline structure, dielectric relaxation and ferroelectric properties of the solid solution, Nd x Bi4-x Ti3O12 (NBIT) compound were measured. The Curie temperature of the NBIT ceramics was determined to be 490°C from dielectric measurements. The dielectric constant of the NBIT ceramics shows a small anisotropic property. Polarization switching was observed using a Sawyer-Tower circuit at 50 Hz. Remnant polarizations and coercive fields could not be confirmed since the hysteresis loops were not saturated. The large dielectric relaxation is observed in the frequency range between 100 kHz and 1 MHz. 相似文献