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排序方式: 共有889条查询结果,搜索用时 376 毫秒
91.
Lin C.-H. Yuan F. Shie C.-R. Chen K.-F. Hsu B.-C. Lee M.H. Pai W.W. Liu C.W. 《Electron Device Letters, IEEE》2002,23(7):431-433
Both electrical and optical reliabilities of PMOS and NMOS tunneling diodes are enhanced by oxide roughness, prepared by very high vacuum prebake technology. For rough PMOS devices, as compared to flat PMOS devices, the Weibull plot of TBD shows a 2.5-fold enhancement at 63% failure rate, while both the D2 and H2-treated flat PMOS devices show similar inferior reliability. For rough NMOS devices, as compared to flat NMOS devices, the Weibull plot of TBD shows a 4.9-fold enhancement at 63% failure rate. The time evolutions of the light emission from rough PMOS and NMOS diodes degrade much less than those of flat PMOS and NMOS diodes. The momentum reduction perpendicular to the Si/SiO2 interface by roughness scattering could possibly make it difficult to form defects in the bulk oxide and at the Si/SiO2 interface by the impact of the energetic electrons and holes 相似文献
92.
Guo J.-I. Yen J.-C. Pai H.-F. 《Vision, Image and Signal Processing, IEE Proceedings -》2002,149(4):237-243
The authors propose a voice over Internet protocol (VoIP) technique with a new hierarchical data security protection (HDSP) scheme. The proposed HDSP scheme can maintain the voice quality degraded from packet loss and preserve high data security. It performs both the data inter-leaving on the inter-frame of voice for achieving better error recovery of voices suffering from continuous packet loss, and the data encryption on the intra-frame of voice for achieving high data security, which are controlled by a random bit-string sequence generated from a chaotic system. To demonstrate the performance of the proposed HDSP scheme, we have successfully verified and analysed the proposed approach through software simulation and statistical measures on several test voices 相似文献
93.
94.
95.
Role of magnesium in cast aluminium alloy matrix composites 总被引:1,自引:0,他引:1
B. C. Pai Geetha Ramani R. M. Pillai K. G. Satyanarayana 《Journal of Materials Science》1995,30(8):1903-1911
Wetting between the dispersoid and the matrix alloy is the foremost requirement during the preparation of metal matrix composites (MMC) especially with the casting/liquid metal processing technique. The basic principles involved in improving wetting fall under three categories: (i) increasing the surface energies of the solids, (ii) decreasing the surface tension of the liquid matrix alloy, and (iii) decreasing the solid/liquid interfacial energy at the dispersoid matrix interface. The presence of magnesium, a powerful surfactant as well as a reactive element, in the aluminium alloy matrix seems to fulfil all the above three requirements. The role played by magnesium during the synthesis of aluminium alloy matrix composites with dispersoids such as zircon (ZrSiO4), zirconia (ZrO2), titania (TiO2), silica (SiO2), graphite, aluminium oxide (Al2O3) and silicon carbide (SiC), has been analysed. The important role played by the magnesium during the composite synthesis is the scavenging of the oxygen from the dispersoid surface, thus thinning the gas layer and improving wetting and reaction-aided wetting with the surface of the dispersoid. The combinations of magnesium and aluminium seem to have some synergistic effect on wetting. 相似文献
96.
M
S Ghatnekar J
S Pai M Ganesh 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2002,77(4):444-448
Bacterial polyesters have shown potential as biodegradable plastics. Microorganisms capable of producing these polyesters from cheaper carbon sources and methods for their efficient recovery are widely studied worldwide. Methylobacterium sp V49, an environmental isolate, was cultivated on a mineral salts medium containing different carbon sources. Maximum accumulation of poly‐3‐hydroxybutyrate (PHB) within the bacterial cell was observed with glucose as the carbon source. Methanol and sugars such as sucrose and lactose also induced PHB accumulation. The effect of C:N ratio on polymer accumulation was studied. Different strategies for the extraction and recovery of the polymer from the cells were compared. A non‐solvent‐based method using a high‐pressure homogenizer in the presence of SDS was found to be the most satisfactory. Maximum recovery of 98% was achieved by homogenizing the cells at 400 kgcm?2 in 5% SDS solution. © 2002 Society of Chemical Industry 相似文献
97.
T. P. D. Rajan R. M. Pillai B. C. Pai 《Metallurgical and Materials Transactions A》2002,33(8):2755-2761
Aluminosilicate short fibers are one of the less expensive reinforcements used for the fabrication of metal matrix composites
(MMCs). The present investigation evaluates the interfacial characteristics of Al-7Si-0.4Mg (356) alloy reinforced with 10
wt pct aluminosilicate short fibers using optical microscopy, electron microscopy, and X-ray analysis. The fibers used are
standard- and zirconiagrade aluminosilicate short fibers. The interfacial analysis has shown the formation of MgAl2O4 and Si in both grades of fibers. In addition, ZrAl3 formation is observed in the zirconia-grade fiber because of the interaction between the matrix and the dispersoid. The zirconia-grade
fiber is more susceptible to interfacial reaction than the standard-grade fiber because of the presence of the highly reactive
ZrO2 phase and a lower amount of the Al2O3 phase, which provides resistance to the reaction. 相似文献
98.
The online version of the original article can be found at 相似文献
99.
100.
Sauer P.W. Behera A.K. Pai M.A. Winkelman J.R. Chow J.H. 《Power Systems, IEEE Transactions on》1989,4(2):499-506
The authors address the effects of fast dynamics on direct energy methods that use a sustained fault trajectory to approximate critically cleared trajectories and the corresponding critical energies. Integral manifold concepts are used to explain why fast dynamics can destroy such an approximation. Methods to remedy this problem are given and illustrated with a ten-machine example 相似文献