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排序方式: 共有10000条查询结果,搜索用时 46 毫秒
91.
OSEK/VDX——汽车电子系统的开放式平台 总被引:6,自引:0,他引:6
介绍了当前在国际汽车工业界日益占据主导地位的汽车电子系统开放式平台--OSEK/VDX体系.详细地论述了这种体系的由来、运行机制和最新的发展动向,以及它对汽车电子技术发展的深远影响. 相似文献
92.
Bo Jiang Jeffrey L. Brown Jane Sheraton Nathalie Fortin Howard Bussey 《Yeast (Chichester, England)》1994,10(3):341-353
We have identified three yeast genes, KES1, HES1 and OSH1, whose products show homology to the human oxysterol binding protein (OSBP). Mutations in these genes resulted in pleiotropic sterol-related phenotypes. These include tryptophan-transport defects and nystatin resistance, shown by double and triple mutants. In addition, mutant combinations showed small but apparently cumulative reductions in membrane ergosterol levels. The three yeast genes are also functionally related as overexpression of HES1 or KES1 alleviated the tryptophan-transport defect in kes1Δ or osh1Δ mutants, respectively. Our study implicates this new yeast gene family in ergosterol synthesis and provides comparative evidence of a role for human OSBP in cholesterol synthesis. 相似文献
93.
Measurement and modeling of self-heating in SOI nMOSFET's 总被引:4,自引:0,他引:4
Su L.T. Chung J.E. Antoniadis D.A. Goodson K.E. Flik M.I. 《Electron Devices, IEEE Transactions on》1994,41(1):69-75
Self-heating in SOI nMOSFET's is measured and modeled. Temperature rises in excess of 100 K are observed for SOI devices under static operating conditions. The measured temperature rise agrees well with the predictions of an analytical model and is a function of the silicon thickness, buried oxide thickness, and channel-metal contact separation. Under dynamic circuit conditions, the channel temperatures are much lower than predicted from the static power dissipation. This work provides the foundation for the extraction of device modeling parameters for dynamic operation (at constant temperature) from static device characterization data (where temperature varies widely). Self-heating does not greatly reduce the electromigration reliability of SOI circuits, but might influence SOI device design, e.g., requiring a thinner buried oxide layer for particular applications and scaled geometries 相似文献
94.
Ching-Chuan Su Jenn-Ming Guan 《Microwave Theory and Techniques》1994,42(10):1998-2006
A numerical procedure using the finite-difference technique, simultaneous iteration based on the power method, and the Chebyshev-polynomial preconditioning is proposed to analyze dielectric-loaded cavities. The merit of this method is that no matrix inversions are invoked and the convergence rate of the power method is greatly accelerated by the preconditioning. The TE, TM, and hybrid modes in axisymmetrical cavities loaded with a rod or ring dielectric resonator are analyzed. For the hybrid modes, an Hr-Hz formulation is proposed. Accurate numerical results are obtained efficiently and no spurious solutions are found by the present method 相似文献
95.
The current-voltage characteristics of the P-N double quantum well resonant interband tunneling (RIT) diodes in InAlAs-InGaAs system have been improved in this letter. The peak-to-valley current ratio (PVCR) is as high as 144 at room temperature. As we know, this is the highest room temperature PVCR ever reported in any tunneling devices. Moreover, the influence of the central barrier thickness varying from 10 Å to 30 Å on the device characteristics is also studied 相似文献
96.
Ti-23Al-14Nb-3V合金氩弧焊接头的显微组织及其力学性能 总被引:6,自引:1,他引:5
研究了预热对Ti-23Al-14Nb-3V合金焊接性,特别是对消除氩弧焊冷裂纹的作用以及对接头显微组织和力学性能的影响。结果表明,焊前预热可有效降低该合金的冷裂倾向。经预热处理后,焊缝区的结晶层状线消失,热影响区的硬度峰得到缓和,整个焊缝的显微硬度分布趋于均匀,但焊缝区的枝晶发生粗化,热影响区有所扩大。焊件接头的拉伸试验表明,预热可使焊缝区的接头强度系数增加,但无论预热与否,接头强度均低于母材强度,且不显示宏观塑性。 相似文献
97.
98.
The major steps of sewerage rehabilitation include inspection of sewerage, assessment of structural conditions, computation of structural condition grades, and determination of rehabilitation methods and materials. Conventionally, sewerage rehabilitation planning relies on experts with professional background that is tedious and time-consuming. This paper proposes an automation model of planning optimal sewerage rehabilitation strategies for the sewer system by integrating image process, clustering technology, optimization, and visualization display. Firstly, image processing techniques, such as wavelet transformation and co-occurrence features extraction, were employed to extract various characteristics of structural failures from CCTV inspection images. Secondly, a classification neural network was established to automatically interpret the structural conditions by comparing the extracted features with the typical failures in a databank. Then, to achieve optimal rehabilitation efficiency, a genetic algorithm was used to determine appropriate rehabilitation methods and substitution materials for the pipe sections with a risk of mal-function and even collapse. Finally, the result from the automation model can be visualized in a geographic information system in which essential information of the sewer system and sewerage rehabilitation plans are graphically displayed. For demonstration, the automation model of optimal sewerage rehabilitation planning was applied to a sewer system in east Taichung, Chinese Taiwan. 相似文献
99.
中国香港电信与盈科数码动力有限公司合并以后更名为电信盈科。它由一家以技术为主的电信公司转型为亚太地区、特别是两岸三地的商界及个人客户提供服务的综合通信服务供应商,主要提供电话服务、互联网、商企电贸服务、数据中心、客户联络中心、环球通信服务和基建业务。分析了2001-2002年上半年其电信、商企电贸、基建以及与Telstra结盟等业务市场的经营情况。 相似文献
100.
H.C. Su L.A. Wang 《Photonics Technology Letters, IEEE》2003,15(10):1357-1359
We demonstrate a novel polarized superfluorescent fiber source (SFS) that increases the output power in the desired polarization by a factor of 1.96 over that of an unpolarized SFS at the same pump. This is achieved by inserting a polarizer at the optimal point in the bidirectionally pumped erbium-doped fiber of an unpolarized SFS. Stable pump-power-dependent mean wavelength operation and less sensitivity to the insertion loss, important for fiber-optic gyroscope applications, are obtained in this configuration. 相似文献