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981.
The effect of enhanced diffusion caused by the electrical deactivation of arsenic on the reverse short-channel effect (RSCE) in NMOS devices is investigated. A simple four-mask process was utilized to fabricate deep sub-micron NMOS devices. Source/drain (S/D) implant and anneal conditions were varied in order to determine their implications on the RSCE. Results indicate that when high concentrations of arsenic deactivate, enhanced diffusion occurs, leading to significantly more RSCE. This implies that the dose of the arsenic implant and the subsequent anneals should be carefully considered in source/drain engineering  相似文献   
982.
The effect of grain misorientation on the sensitization of grain boundaries in austenitic stainless steel was investigated by sensitizing samples consisting of a large number of 50–80 μm size grains that were sintered to flat, 10 mm2 single crystals. Seven different sensitization treatments were employed and samples were intergranulary corroded in the modified Strauss test. X-ray pole figures were obtained for each sample and were used to identify the grain misorientations that were resistant to sensitization. In general, macroscopic grain boundary geometry could not explain the sensitization behaviour of most grain boundaries. Nevertheless, the Σ = 9 boundary was found to be especially resistant to sensitization. Results suggest that grain misorientation primarily affects the growth of sensitization rather than its nucleation. Finally, the crystallographic plane of the grain boundary appears to have an effect on sensitization. This revised version was published online in November 2006 with corrections to the Cover Date.  相似文献   
983.
The pulsed and CW laser performance of a range of titanium sapphire laser crystals is reported. Titanium ion concentration in the crystals ranged from 0.07 at.% to 0.25 and 0.41 at.% for some recently developed heavily doped crystals. Values of the crystal figure of merit lay between 30 and 220. Threshold, slope efficiency, tunability, and temporal response are assessed. Comparisons are made with the predictions of a simple rate equation model  相似文献   
984.
985.
Using a novel second-order mobility theory that was recently developed by the authors, this article develops new lower bounds on the number of frictionless fingers required to immobilize generic planar objects. We show that any generic smooth or polygonal planar object can be immobilized with three convex fingers or fixtures that have sufficiently flat curvature. Further, if it is possible to specify the fingertip curvature, then any generic smooth or polygonal object can be immobilized with two, possibly concave, fingers. © 1995 John Wiley & Sons, Inc.  相似文献   
986.
The opportunity afforded by International Space Year (ISY) for a dynamic interaction among science, technology, and society that addresses the urgent ecological, economic, and social problems confronting humanity is explored. Issues of population, economics, and equity are examined. The role of the global scientific framework, technological advances, and programmatic innovations of the 1980s is discussed  相似文献   
987.
The authors present a real-time database system capable of collecting and delivering a large amount of information accurately at a high speed and by a simple method. This system has a microprocessor unit (MPU) for each private communication line around the main memory and coordinates the independent parallel operation for a number of these MPUs with the main memory access operation, using a fixed cyclic scan method and having all the MPUs perform multi-operation. Many advantages can be expected when this method is adopted, especially for the monitoring and control of power systems. Degradation of the system can be avoided during an information rush due to accidents, and it can be easily extended when adding to or expanding the power facilities in the future. Excellent daily maintainability can be assured, and a low overall cost can be expected  相似文献   
988.
There is a common belief that CASE software enhances developer productivity and the quality of applications software. However, though the few empirical studies of the impact of CASE have produced inconclusive findings, they do indicate an absence of appreciable productivity gains. There is a need to determine the extent to which CASE products are worth their cost, and this paper focuses on the key methodological issues involved in assessing the cost-effectiveness of CASE products. Existing studies of the impact of CASE software have considered developers' perceptions, but have not considered system users' perceptions nor used software metrics to assess applications software. It is also rare for the characteristics of the development environments and other factors that have an important bearing on the productivity and quality of software to be investigated. In this paper, perceptual and objective measurement, and the different ways of designing the research and of accessing the population of CASE users, are outlined and evaluated. While the aim is to establish the most appropriate research design and measurement approaches for determining the value of CASE tools, the conclusions are also relevant to the assessment of the impact of other new software technologies.  相似文献   
989.
Electrokinetic capillary techniques can exploit numerous separation principles, making them flexible and easily applicable to a variety of separation problems. In recent publications, this emerging technology has been shown to be well suited for monitoring drugs and metabolites in body fluids, including serum, saliva and urine. Most attention has been focused on micellar electrokinetic capillary chromatography (MECC) because it permits the separation and determination of drugs with discrimination being largely based on differences in hydrophobicity. An overview of literature data on the MECC of drugs in body fluids and recent data obtained with antiepileptics in serum and saliva, with model mixtures of illicit drugs, and with extracts from urine specimens that tested positively for opiates and cocaine metabolites are presented. Emphasis is focused on buffer selection and simple sample preparation procedures, including direct injection of body fluids, ultrafiltration and solid-phase extraction.  相似文献   
990.
Ni/α-quartz bilayers were irradiated at 77 K with 200 keV Na+ ions at a fluence of 5 × 1016 ions/cm2 and annealed in hydrogen up to 883 K. The Na-migration at the Ni/α-quartz interface and towards the Ni-surface, the hydrogen storage in the irradiated region, and the Ni/α-quartz interface broadening due to Na implantation and decoration were investigated via Rutherford Backscattering Spectrometry (RBS) and Resonant Nuclear Reaction Analysis (RNRA). We demonstrate that after a one hour-annealing at 833 K a large fraction of the implanted Na has been trapped at the Ni/α-quartz interface from where it is released at 883 K. The results are discussed and compared with our findings in Na-irradiated metals and silicon compounds.  相似文献   
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