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51.
Single-phase sintered ceramic materials (ZrO2)1?x {(Y2O3) y (RE2O3)1-y x }x (RE=Nd, Ce, Dy, Er), were synthesized and electrical conductivity and transport number measurements were made as a function of temperature between 500 and 1200° C. The activation energies of conduction were determined, and it was found that the charge carriers in these solid solutions are oxygen ions. The fabricated electrolyte discs were used in cells of the type \(P_{O_2 }\) , Pt/zirconia solid solution/ \(P_{\mathop O\limits^{'} _2 }\) , platinum where \(P_{O_2 }\) =air (0.21 atm) and \(P_{\mathop O\limits^{'} _2 }\) =1 atm or argon-O2 mixtures. Below 700° C, the e.m.f. deviated from the theoretical values for completely ionic conduction; good agreement was observed above this temperature. 相似文献
52.
Heredia J.R. Perez Hidalgo F. Duran Paz J.L. 《Industrial Electronics, IEEE Transactions on》2001,48(5):1038-1040
In this letter, we propose a voltage-source inverter control working in the open loop of an induction motor measuring the stator current and using an artificial neural network. This technique has the mission to estimate the speed and torque of the rotor without using sensors. With this, a simple and cheap method of control is obtained, with as much precision and robustness as other more complex ones 相似文献
53.
Budge T. Craven S. Duran S. Pearson J.T. Welch R. Wossum M. 《Semiconductor Manufacturing, IEEE Transactions on》1990,3(1):28-32
The authors describe PARSEC, a system developed to automate processing, perform endpoint signal analysis, and monitor wafer movement within the plasma area. The system provides automatic downloading of process recipes, detection of defined process problems by the automated analysis of endpoint signals, automatic archiving of these signals, and automated data logging for increased lot-tracking efficiency. The system hardware, software, support tools, implementation, performance and results are described 相似文献
54.
55.
Quantifying Software Validity by Sampling 总被引:1,自引:0,他引:1
The point of all validation techniques is to raise assurance about the program under study, but no current methods can be realistically thought to give 100% assurance that a validated program will perform correctly. There are currently no useful ways for quantifying how 'well-validated' a program is. One measure of program correctness is the proportion of elements in the program's input domain for which it fails to execute correctly, since the proportion is zero i.f.f. the program is correct. This proportion can be estimated statistically from the results of program tests and from prior subjective assessments of the program's correctness. Three examples are presented of methods for determining s-confidence bounds on the failure proportion. It is shown that there are reasonable conditions (for programs with a finite number of paths) for which ensuring the testing of all paths does not give better assurance of program correctness. 相似文献
56.
Results that illustrate the determination of the parameters of a beta prior distribution when either the mean and one percentile or two percentiles are given are presented. Further results show how sensitive the parameters of the beta prior are to errors in the given values. The sensitivity of the probability distribution of the reliability of a system to errors in either the given mean and percentile or the given percentiles of the component beta priors is studied. Included in the study are several systems, ranging from simple ones that occur as subsystems of real systems up to a real type of system consisting of 74 components 相似文献
57.
Herschbach Peter; Duran Gabriele; Waadt Sabine; Zettler Angela; Amm Christoph; Marten-Mittag Birgit; Strian Friedrich 《Canadian Metallurgical Quarterly》1997,16(2):171
This study reports the psychometric properties of a 45-item diabetes-specific questionnaire, the Questionnaire on Stress in Patients with Diabetes—Revised (QSD-R), a modified and shortened version of the QSD (G. Duran et al; see record 1996-18805-001). The QSD-R was filled out by 1,930 individuals with insulin-dependent diabetes mellitus and noninsulin-dependent diabetes mellitus. Eight consistent scales were identified (values of Cronbach's α: .69–.81). The test-retest reliability for the total score after a 5-week interval was rtt?=?.63. The results provide evidence for the reliability and validity of this instrument. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
58.
Wind energy is assessed thermodynamically, from resource and technology perspectives. The thermodynamic characteristics of wind are considered. Wind speed is affected by air temperature and pressure and has an effect on wind turbine performance, based on wind chill effect and Bernoulli's equation. The wind chill effect leads to temperature differences that suggest enthalpy and entropy components must be considered in a thermodynamic analysis. The wind pressure effect based on Bernoulli's equation affects the entropy of wind. These components have not previously been considered in evaluations of wind turbine efficiency for electricity generation. A new efficiency formula for wind energy systems is described, which provides important information about the system. It is seen that average differences between energy and exergy efficiencies are approximately 40% at low wind speeds and up to approximately 55% at high wind speeds. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
59.
Juan M. Martínez Moreno C. Gómez Herrera E. Márquez Delgado C. Janer Del Valle L. Duran Hidalgo 《Journal of the American Oil Chemists' Society》1960,37(11):582-587
Expressed olive juice contains emulsified globules of olive oil. Electron photomicrographs of these globules show a rough
membrane protecting them against coalescence. Some features of the membranes, such as the existence of “poles” and deposited
microcrystals, are disclosed by the photographs and by electron diffraction patterns. Heavy metals appear to concentrate in
the membranes and not in the aqueous medium.
Presented at the 50th annual spring meeting, American Oil Chemists' Society, New Orleans, La., April 20–22, 1959. 相似文献
60.