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排序方式: 共有809条查询结果,搜索用时 15 毫秒
51.
Hiroyuki Moriuchi Yoshihiro Tadokoro Masahide Sato Takeshi Furusawa Noboru Suzuki 《Journal of Electronic Materials》2007,36(3):220-225
Lead-free commercial products have been dramatically increasing in the world markets as the restriction of certain hazardous
substances (RoHS) directive in the European Union has been enacted. At the same time, the problem of “tin whiskers” has become
one of the most serious problems in the industry. Growth of tin whiskers is believed to be related to residual stress inside
the tin plating film and external compressive stress. Whiskers in fine-pitch connectors have affected the practical production
of advanced digital equipment. The Japan Electronics and Information Technology Industries Association (JEITA) has proposed
a new testing method to evaluate tin whiskers, especially for the fine-pitch connectors. This paper describes the microstructures
of external stress whiskers and the mechanical indentation test method. 相似文献
52.
Shuang Bai Tetsuya Matsumoto Yoshinori Takeuchi Hiroaki Kudo Noboru Ohnishi 《Machine Vision and Applications》2013,24(5):959-970
In image classification based on bag of visual words framework, image patches used for creating image representations affect the classification performance significantly. However, currently, patches are sampled mainly based on processing low-level image information or just extracted regularly or randomly. These methods are not effective, because patches extracted through these approaches are not necessarily discriminative for image categorization. In this paper, we propose to utilize both bottom-up information through processing low-level image information and top-down information through exploring statistical properties of training image grids to extract image patches. In the proposed work, an input image is divided into regular grids, each of which is evaluated based on its bottom-up information and/or top-down information. Subsequently, every grid is assigned a saliency value based on its evaluation result, so that a saliency map can be created for the image. Finally, patch sampling from the input image is performed on the basis of the obtained saliency map. Furthermore, we propose a method to fuse these two kinds of information. The proposed methods are evaluated on both object categories and scene categories. Experiment results demonstrate their effectiveness. 相似文献
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54.
This paper describes the cogging torque characteristics of a magnetic‐geared motor with permanent magnets only on the high‐speed rotor. The operational principle, which is different from that of the magnetic‐geared motor with permanent magnets on the high‐speed rotor and stator, is described. The torque characteristics, especially the order of the cogging torque, are mathematically formulated and verified by conducting 3D finite element analysis and carrying out measurements on a prototype. A novel cogging torque reduction method is proposed and verified as well. 相似文献
55.
A hydrogen internal combustion engine (HICE) wastes more heat, and producing nearly three times more water than a conventional engine. This paper describes the principle behind a novel waste heat recovery sub-system that exploits the water produced by an HICE as the working fluid for an open-cycle power generation system based on the Rankine cycle. Water from the HICE exhaust is superheated by the waste heat from the HICE and used to produce power in a steam expander. A fundamental thermodynamic model shows the contribution of the sub-system to the overall thermal efficiency of the HICE at various engine speeds, with and without a condenser. The results show that the condenser is not cost-effective and that the overall thermal efficiency with the proposed sub-system is 27.2% to 33.6%, representing improvements of 2.9% to 3.7%, at engine speeds of 1500 to 4500 rpm. 相似文献
56.
Thermal Diffusion of Si Atoms at the Interface of Mo/Si Bilayers Studied with a Soft X-ray Emission Microscope 总被引:1,自引:1,他引:0
1 Introduction Thepropertyofthedeviceswithalayerstruc turesuchassuperlattices,multilayercoatings,andsemiconductordevicesisdependentuponthequali tyoftheinterfacebetweenadjacentlayers.Fromtheviewpointoftheirpracticalusage,thermalsta bilityoftheinterfaceis… 相似文献
57.
Hori Tetsuya; Moriyama Hideaki; Kawaguchi Jitsutaro; Hayashi-Iwasaki Yoko; Oshima Tairo; Tanaka Nobuo 《Protein engineering, design & selection : PEDS》2000,13(8):527-533
A temperature-jump (T-jump) time-resolved X-ray crystallographictechnique using the Laue method was developed to detect small,localized structural changes of proteins in crystals exposedto a temperature increase induced by laser irradiation. In achimeric protein between thermophilic and mesophilic 3-isopropylmalatedehydrogenases (2T2M6T), the initial structural change uponT-jump to a denaturing temperature (~90°C) was found tobe localized at a region which includes a ß-turn and aloop located between the two domains of the enzyme. A mutant,2T2M6T-E110P/S111G/S113E, having amino acid replacements inthis ß-turn region with the corresponding residues ofthe thermophilic enzyme, showed greater stability than the originalchimera (increase of Tm by ~10°C) and no T-jump-inducedstructural change in this region was detected by our method.These results indicate that thermal unfolding of the originalchimeric enzyme, 2T2M6T, is triggered in this ß-turn region. 相似文献
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60.
Mizuno T. Sugiyama N. Tezuka T. Moriyama Y. Nakaharai S. Maeda T. Takagi S. 《Electron Devices, IEEE Transactions on》2005,52(12):2690-2696
We have developed the source-heterojunction-MOS-transistor (SHOT), a novel high-speed MOSFET with relaxed-SiGe/strained-Si heterojunction source structures for quasi-ballistic or full-ballistic transistors. Using the band-offset energy at the source SiGe/strained-Si heterojunction, high velocity electrons can be injected into the strained-Si channel from the SiGe source region. For the first time, we have experimentally demonstrated that the transconductance is enhanced in SHOT for high applied drain voltage, compared to that of strained- and conventional silicon-on-insulator MOSFETs. We have also shown that the transconductance enhancement in SHOT depends on both the gate drive and the drain bias. 相似文献