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1.
A recently proposed measurement technique (P. Spirito and G. Cocorullo, IEEE Trans. Electron Devices, vol.ED-32, no.9, p.1708-13, 1985) to evaluate the recombination lifetime along epitaxial layers is used to characterize the quality of very thin Si epitaxial layers used for bipolar technology. The experimental results show the ability of the technique to give accurate and detailed information on the quality of epilayers that could be useful in monitoring and improving the growth process. The experimental results show that the lifetime values in thin epilayers are not correlated with doping profiles in the same layers; moreover, they are only slightly dependent on different processes used to make the test devices  相似文献   
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ABSTRACT: The heat resistance of 35 Salmonella strains was determined at 55 to 65°C. No correlation between the heat resistance and the origin of the Salmonella spp. could be established. D-values in chicken broth, using a linear regression, of an 8 Salmonella serotype cocktail were 4.87, 2.72, 1.30, and 0.41 min at 55, 58, 60 and 62°C, respectively. Using a linear model, the D-values ranged from 4.86 min at 55°C to 0.38 min at 62°C. When the 8 Salmonella serotype cocktail was heated in meat, D-values at the common test temperatures of 58 and 60°C calculated by both approaches were significantly higher (p < 0.05) than those observed in chicken broth.  相似文献   
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The authors have fabricated the first gate-self-aligned germanium MISFETs and have obtained record transconductance for germanium FETs. The devices fabricated are p-channel, inversion-mode germanium MISFETs. A germanium-oxynitride gate dielectric is used and aluminum gates, serve as the mask for self-aligned source and drain implants. A maximum room-temperature transconductance of 104 mS/mm was measured for a 0.6-μm gate length. A hole inversion channel mobility of 640 cm2 /V-s was calculated using transconductance and capacitance data from long-channel devices. This large hole channel mobility suggests that germanium may be an attractive candidate for CMOS technology  相似文献   
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The effects of phenytoin (DPH), carbamazepine (CBZ) and diazepam (DZP) on anoxia-induced injury in CNS white matter were studied using the in vitro rat optic nerve preparation. Optic nerves were subjected to 60 min of anoxia and functional recovery was assessed using the area under the compound action potential. Under normoxic conditions, application of DPH, CBZ and DZP reduced compound action potential area over concentration ranges known to block sodium channels. All three compounds, however, protected against anoxic injury at concentrations below those that inhibited the normoxic compound action potential. Thus, the application of 1 microM DPH, CBZ or DZP during anoxia resulted in compound action potential recovery to 60.0, 53.8 and 69.2% of control, respectively, compared to compound action potential recovery of 34.8% in the absence of drugs (P < .05 in all three cases). In the cases of CBZ and DPH, 60% improvement in recovery from anoxia was produced by concentrations well below those employed clinically to treat epilepsy, suggesting a potential role for these drugs in the protection of CNS white matter from anoxic injury.  相似文献   
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A growing market demand for high-performance voice, data, image and video networks, coupled with advances in high-speed technologies has heightened interest in broadband ISDN (BISDN) throughout the world. Network providers, equipment manufacturers and standards bodies are working jointly to accelerate the definition of BISDN interfaces in anticipation of emerging market opportunities. BISDN is being designed as the foundation upon which to implement very flexible, high-bandwidth, high-performance networks. A multiplexing concept called asynchronous transfer mode (ATM), which can offer bandwidth on demand at rates exceeding 150 Mb/s, high-speed packet switching, and an efficient protocol which adapts existing information streams into the ATM format are key attributes of the emerging BISDN network standards. This paper reviews the motivations behind BISDN, explains its key attributes and challenges and discusses possible strategies for evolving today's network toward BISDN.  相似文献   
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The hole lifetime within a heavily doped n+ region has been determined using a measurement technique which evaluates the effective recombination velocity of n-n+ interfaces. The recombination model of a high/low junction is reviewed. The experiment is described. The measurement results are presented and discussed. Measurements of n+ layers of different types, like substrates, implanted buried layers, and diffused layers, suggest that the minority-carrier lifetime of such regions can be strongly degraded by the device fabrication processes. Results are consistent with the Shockley-Reed-Hall (SRH) lifetime value, which is two orders of magnitude lower than previously published values for bulk material  相似文献   
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An explicit second-order finite-difference computer model was developed and optimized for solution of the Shallow Water Equations. The model was applied to the Feather River below the Oroville Dam and Thermalito Afterbay near Gridley, California. Two versions of the computer model were constructed to run on either Central Processing Units or Graphical Processing Units, utilizing Fortran, C, C++, and the NVIDIA Compute Unified Device Architecture (CUDA) parallel computing platform. The underlying algorithm utilizes a structured grid and is capable of handling the wetting and drying of cells. It was developed with view to maximizing stability while maintaining accuracy, and allowing for flexibility of the computational domain. Comparisons with analytical and observed results showed the proposed methodology to be robust, accurate, and efficient. The models were applied to a section of the Feather River where observations of flow depths and volumetric flow rates are available for multiple flood events. The domain surface was partially developed using high-resolution photogrammetric data obtained through use of unmanned aerial vehicles. Runtimes and results were compared to the United States Bureau of Reclamations’ implicit finite-volume numerical method and with field observation with generally good correspondence.  相似文献   
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Different types of "relapse crises" and associated coping responses were associated with the resumption of smoking using a prospective design. One hundred and two previously heavy smokers (M?=?23.9 cigarettes a day) who achieved initial abstinence through a smoking cessation program were interviewed by telephone at 1, 2, and 3 months posttreatment. At each assessment, subjects described relapse crises, situations in which they were tempted to smoke or actually smoked but resumed abstinence (lapsed). Prospective analyses indicated that any smoking lapse is strongly related to subsequent relapse. Situational characteristics of relapse crises and the number of cognitive and behavioral coping responses reported during crises were only modestly consistent over time and were unrelated to later relapse. Confidence ratings and situational attributions about the relapse crises were also not prospectively associated with eventual relapse. Subanalyses suggested that lapses associated with urges and emotional (guilt) responses and lapses occurring in frequent situations are more likely to result in relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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