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11.
Dmitry Yu. Murzin 《Chemical engineering science》2002,57(8):1299-1306
Several aspects of heterogeneous catalytic kinetics over induced nonuniform surfaces are considered. The reaction mechanism is thought to occur through a surface collision of species, adsorbed on two distinct surface sites, which display nonuniform behavior. The expressions for rates of elementary reactions have been deduced within the framework of the surface electronic gas model, which accounts for the case of inhomogeneous surface. Equations for catalyst activity in the range of medium coverage have been derived and compared with the power-law model. 相似文献
12.
13.
N. A. Makarov 《Glass and Ceramics》2007,64(3-4):120-123
A dispersion-hardened material with average flexural strength 580 ± 40 MPa, which is a promising building material, has been
fabricated by introducing a CaO-ZnO-Al2O3-SiO2 eutectic additive and tetragonal zirconium dioxide into aluminum oxide synthesized by calcining the hydroxide. The sintering
temperature of this ceramic is 1550°C. The properties of the eutectic of this system are analyzed, and the optimal liquid-phase
composition which gives intense sintering of the aluminum oxide is determined.
__________
Translated from Steklo i Keramika, No. 4, pp. 12–15, April, 2007. 相似文献
14.
R. Bunk U. Leske R. Krompass Z. Pretch K. Rudolf R. Herbig K. Pitch V. A. Tsykanov O. V. Skiba V. A. Makarov L. P. Bol'shakov P. T. Porodnov A. A. Maershin S. S. Keruchen'ko 《Atomic Energy》1989,67(5):802-806
Translated from Atomnaya Énergiya, Vol. 67, No. 5, pp. 320–323, November, 1989. 相似文献
15.
A physically simple but mathematically cumbersome problem of rotating heavy string with one fixed top point was studied. A nonlinear equation of its two-dimensional shapes of relative equilibrium was obtained and solved numerically. A linear case of small displacements was analyzed in terms of Bessel functions. The qualitative and quantitative behavior of the problem is discussed with the help of a bifurcation diagram. Dynamics of the two-dimensional model near the equilibrium positions were studied with the help of a simulation using the absolute nodal coordinate formulation (ANCF); the equilibriums were found to be instable. The reason for instability is explained using a variational principle. The outlines for further full three-dimensional analysis are briefly proposed in this paper, and the full derivation will be explained in the next paper. 相似文献
16.
A theoretical study is reported of the magnetic-field-controlled optical transmission through a stack of identical bilayers in which one layer is bigyrotropic and the other is nonmagnetic and isotropic. An analytical expression for the complex transmittance is derived. The transmittance–wavelength characteristic is examined for different magnetizations and for fixed materials parameters and total number of bilayers. The magnetization dependence of the position, height, and width of the center peak is investigated. The effect is calculated of magnetization on the ellipticity of transmitted light and the angle of optical rotation. 相似文献
17.
Translated from Steklo i Keramika, No. 1, pp. 11–12, January, 1992. 相似文献
18.
N. A. Cherkashin M. V. Maksimov A. G. Makarov V. A. Shchukin V. M. Ustinov N. V. Lukovskaya Yu. G. Musikhin G. E. Cirlin N. A. Bert Zh. I. Alferov N. N. Ledentsov D. Bimberg 《Semiconductors》2003,37(7):861-865
The effect of the growth temperature on the density, lateral size, and height of InAs-GaAs quantum dots (QD) has been studied by transmission electron microscopy. With the growth temperature increasing from 450 to 520°C, the density and height of QDs decrease, whereas their lateral size increases; i.e., the QDs are flattened. The blue shift of the photoluminescence line indicates decreasing QD volume. The observed behavior is in agreement with the thermodynamic model of QD formation. The effect of lowering the substrate temperature immediately after the formation of QDs on the QD parameters has been studied. On lowering the temperature, the lateral size of QDs decreases and their density increases; i.e., the parameters of QD arrays tend to acquire the equilibrium parameters corresponding at the temperature to which the cooling is done. The QD height rapidly increases with cooling and may exceed the equilibrium value for a finite time of cooling, which enables fabrication of QD arrays with a prescribed ratio between height and lateral size by choosing the time of cooling. 相似文献
19.
A method and algorithm of adaptive frequency measurements, and the flow diagram of a wide band adaptive computer data input module with frequency range from 7.6 mHz to 64.54 MHz are described.Translated from Izmeritel'naya Tekhnika, No. 3, pp. 18–20, March, 1995. 相似文献
20.
We describe the simplest mechanism of cluster structure formation in the timefront of an acoustic signal propagating in a
submerged channel under ray chaos conditions. It is shown that this cluster structure is related to the phase space structure.
This relation allows, in principle, the characteristics of an inhomogeneous medium to be determined from the timefront shape
parameters. As an example, the period of inhomogeneity is calculated for a periodic perturbation in the sound velocity caused
by an internal wave propagation. 相似文献