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101.
The letter presents a novel means of mesh adaption when the finite-element method is applied to the semiconductor equations. Using triangular elements it has the ability to avoid obtuse angles while still allowing flexibility in mesh design. The usefulness of the method is demonstrated by a simulation of an MOS device operating at a high drain voltage where generation due to impact ionisation becomes significant. 相似文献
102.
Effects of Zirconia on Microstructure and Dielectric Properties of Barium Titanate Ceramics 总被引:1,自引:0,他引:1
Timothy R. Armstrong Laurie E. Morgens Alena K. Maurice Relva C. Buchanan 《Journal of the American Ceramic Society》1989,72(4):605-611
Dielectric properties and structural characteristics of BaTiO3 ceramics are significantly influenced by small addition (2 wt%) of ZrO2 . SEM and TEM observations revealed enhanced microstructural uniformity and retarded grain growth depending on sintering temperature. Above 1320°C, Zr diffusion into the BaTiO3 lattice resulted in a chemical modification of the tetragonal structure and the development of core–shell grains. Below 1320°C, TEM analysis showed ZrO2 at the grain boundaries as discrete particles (∼0.03μm). X-ray diffraction analysis revealed a decrease in the axial (c/a) ratio with decreasing grain size. A corresponding decrease in the spontaneous polarization, and twinned domain structures, were also observed in the fine-grained ceramics. These samples also showed a flattened permittivity response with temperature and significantly lower losses. 相似文献
103.
The influence of polycrystal grain size on several mechanical properties of materials 总被引:1,自引:0,他引:1
R. W. Armstrong 《Metallurgical and Materials Transactions B》1970,1(5):1169-1176
The ductile-brittle transition, hardness, fatigue, and creep behavior of polycrystalline materials are known to be influenced under certain conditions by the polycrystal grain size. These properties have been correlated, historically, with the material stress-strain behavior. The (Hall-Petch) stress-grain size relations are useful for describing the complete stress-strain behavior for polycrystals and, therefore, these relations provide a reference for understanding the manner in which these other properties should also depend on the grain size. In some cases, the grain size dependence of a particular property follows directly from this connection. 相似文献
104.
Pei-Ying Chiang May-chen Kuo Jessy Lee C.-C. Jay Kuo Todd Richmond Milton Rosenberg Jeff Lund Kip Haynes Lindsay Armstrong 《Journal of Visual Communication and Image Representation》2010,21(3):200-209
The Automated Metadata Indexing and Analysis (AMIA) project aims to provide an effective digital asset management (DAM) tool for large digital asset databases. We began with text-based indexing since it is still the most reliable approach as compared with other content-based media features. AMIA not only searches for the text of the file name, but also utilizes embedded information such as the metadata in Maya files. The AMIA system builds a linked map between all dependency files. We present an approach of preserving previously established metadata created by the old DAM tools, such as AlienBrain, and integrating them into the new system. Findings indicate that AMIA has significantly improved search performance comparing to previous DAM tools. Finally, the ongoing and future work in the AMIA project is described. 相似文献
105.
E. Bruce Nauman Mathew Armstrong Jakub Horak 《Chemical Engineering and Processing: Process Intensification》2010
Conventional static mixers typically require high length to diameter ratios to be effective. This paper considers static mixers design to increase first appearance times in short, fat reactors. Three types are considered: conical baffles and annular baffles for tubular reactors and axial baffles for reactors with a rectangular cross-section. Relatively simple designs allow production increases (or reactor volume decreases) on the order of 20–50%. 相似文献
106.
Joseph J. Armstrong Adilakshmi G. Robin C. R. Rene Vidhya S. Narukullapati Bharath Kumar Reddy M. Koti Kumar T. Ch. Anil 《SILICON》2023,15(1):127-131
Silicon - We designed a new model tunnel field-effect transistor (TFET) based on Triple Heterojunction Tunnel Field Effect Transistor (THJ-TFET) is investigated and designed in this paper. This... 相似文献
107.
108.
A Langer MW Krucoff P Klootwijk ML Simoons CB Granger A Barr RM Califf PW Armstrong 《Canadian Metallurgical Quarterly》1998,31(4):783-789
OBJECTIVES: We sought to study the relation between recurrent ST segment shift within 6 to 24 h of initial resolution of ST elevation after thrombolytic therapy and 30-day and 1-year mortality. BACKGROUND: Rapid and stable resolution of ST segment elevation in relation to thrombolytic therapy in patients with an acute myocardial infarction is an indicator of culprit artery patency. Whether recurrence of ST segment shift during continuous ST monitoring after initial resolution is related to poor prognosis has not been studied. METHODS: ST segment monitoring was performed within 30 min after thrombolytic therapy for acute myocardial infarction. The predictive value of a new ST segment shift (assessed as > or = 0.1-mV deviation from the baseline) 6 to 24 h after thrombolytic therapy was studied with respect to 30-day and 1-year mortality. RESULTS: Of 734 patients, 243 had a new ST segment shift (33%). The 30-day mortality rate in patients with an ST shift (7.8%) was significantly higher than that in patients without an ST shift (2.25%, p = 0.001), as was the 1-year mortality rate (10.3% vs. 5.7%, respectively, p = 0.025). Multivariable analysis revealed an independent predictive value of ST shift with respect to 30-day mortality (p = 0.008), even after consideration of multiple clinical risk factors in the overall Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO)-I mortality model (p = 0.0001). Moreover, the duration of the ST shift bore a direct relation with 1-year mortality (p = 0.008). CONCLUSIONS: Detection of ST segment shift early after thrombolytic therapy for acute myocardial infarction is a simple, noninvasive means of identifying patients at high risk and is superior to other commonly assessed clinical risk factors. Thus, patients with a new ST shift after the first 6 h, but within 24 h, represent a high risk group that may benefit from more aggressive intervention, whereas patients without evidence of an ST shift represent a low risk subgroup. 相似文献
109.
6.1.4控制屏蔽机箱的放电 屏蔽是一种抑制ESD的有效方式,可以对ESD进行适当的控制,使得ESD不会影响产品内部电路的正常工作。第4部分内容对屏蔽技术进行了讨论,我们所要做的就是让机箱在非常高的频率具有理想的屏蔽效能。 相似文献
110.
Talk Radio as Interpersonal Communication 总被引:2,自引:0,他引:2
Those who called in to talk radio programs tended to find face-to-face communication less rewarding, were less mobile, felt talk radio was more important to them, and listened for more hours a day than those who did not call but who did listen. 相似文献