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1.
The defect structure of monoclinic ZrO2 was studied by measuring the transfer numbers and electrical conductivity as functions of O2 pressure and temperature. The data suggest a defect structure of doubly ionized oxygen vacancies at low pressures, i.e. <10−19 atm, and singly ionized oxygen interstitials at pressures >10−9 atm. Zirconia is primarily an ionic conductor below #700°C and an electronic conductor at 700° to 1000°C for 10−22 ≤Po2 ≤1 atm. 相似文献
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3.
Abstract A new type of codes that correct only a given number of adjacent errors in the binary case have been introduced in this paper. These codes are adjacent-error correcting perfect and form a doubly infinite class, i.e., for a given number of adjacent errors these exist for different lengths as also for different number of adjacent errors these can be developed for specific lengths. 相似文献
4.
G V PAVAN KUMAR 《Bulletin of Materials Science》2011,34(3):417-422
We report for the first time, on the utility of plant-based biomaterial as enhanced-Raman scattering probes. The bio-substrate used in this study are commonly found in plant extracts, and are cost-effective, mechanically robust, flexible and easily transportable. The probe was fabricated by coating the plant extract with gold nanoparticles and characterized. By employing a ‘single-touch contact’ method, we reveal the ability of these probes to detect routinely used Raman markers such as 2-napthalenethiol and rhodamine B, at nano-molar concentrations, in dry and liquid forms, respectively. Reproducibility of the signals with variation <5%, and the ability to detect biomolecules are demonstrated herein. We envision these bio-probes as potential candidates for enhanced Raman sensing in chemical, environmental, and archaeological applications. By further engineering the shape, morphology, and surface chemistry of these micro-probes, we foresee their utility as miniaturized, natural SERS substrates. 相似文献
5.
ARUP DASGUPTA AKASH SINGH PRADYUMNA KUMAR PARIDA R RAMASESHAN P KUPPUSAMI S SAROJA M VIJAYALAKSHMI 《Bulletin of Materials Science》2011,34(3):483-489
The growth characteristics of titanium films deposited on glass, silicon (100) and oxygen free high purity copper substrate using magnetron sputtering have been investigated using X-ray diffraction, electron microscopy and scratch indentation techniques. The study of interface between the titanium film and the substrate was carried out to determine coating thickness, as well as intermixing of the elements at the interface. Studies revealed that the interface is free from voids and intermixing of the film and the substrate. Microstructural and diffraction analysis showed that the Ti coating was polycrystalline and exhibited columnar growth. The Ti crystallite size varied between 24 and 58 nm depending on the substrate. The thickness of the films were typically about 4 μm. Scratch test indicated that the films are adherent and the first critical load to failure was observed to be 4·5 N ± 2 N. 相似文献
6.
In this paper, dynamically balanced gait generation problem of a 7-DOF two-legged robot moving up and down through the sloping surface is presented. The gait of the lower links during locomotion is obtained after assuming suitable trajectories for the swing leg and hip joint. The trunk motion is initially generated based on the concept of static balance, which is different from the well-known semi-inverse method and then checked for its dynamic balance calculated using the concept of Zero-Moment Point (ZMP). Lagrange–Euler formulation is attempted for the determination of joint torques. Average power consumption at each joint is then determined based on the computed torques. Moreover, the variations of dynamic balance margin and average power consumption are studied for both ascending and descending through the sloping surface. Both of them are found to be more for the ascending gait generation compared to those for the descending case. The effects of variations of the slope have also been studied on the average dynamic balance margin and power consumption for both the cases. 相似文献
7.
Switched-capacitor networks realizing second-order filter characteristics are presented. Realization is achieved with unity-gain amplifiers as buffers. The circuits have small sensitivities, good dynamic range and a reasonable spread of capacitor values. The filters can be used for high-Q realization and a relatively high frequency range. 相似文献
8.
A new configuration for operational amplifier based instrumentation amplifier is presented. The analytical expressions are obtained and the performance of the proposed circuit is examined in relation to the conventional circuit. Simulation and experimental results are presented which establish the superiority of the proposed instrumentation amplifier topology over the conventional circuit. The effect of second pole of op amps on the circuit stability has also been investigated. Numerical results are given in support of theoretical conclusions. 相似文献
9.
R. C. KUMAR 《International Journal of Electronics》2013,100(6):689-695
A theory of the space-charge capacitance of a metal-semiconductor contact has been developed by solving the Poisson equation for the space-charge region under zero current condition. The space charge is assumed to consist not only of ionized donors and acceptors but also of electrons and holes. An explicit expression for the space-charge capacitance under those general conditions is given. In an appendix a procedure is outlined whereby the theory could be developed for the case of Fermi statistics with partially ionized donors. 相似文献
10.
Extraction of lipids from whole peanut kernels can be accomplished much faster in an automatic solvent extractor with a lower solvent: seed ratio than by immersion or in a Soxhlet extractor. A possible explanation of the function of moisture in the extraction of lipids from the whole peanut kernels has been put forward. This mode of extraction is expected to produce economically fat-lean kernels, while oil is obtained as a co-product. 相似文献