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991.
992.
E. D. Éidel’man 《Technical Physics》1998,43(11):1275-1279
A theory is developed for a new type of transition — a change in the ratio of the longitudinal and transverse dimensions of
a convection cell as the thickness of a liquid layer is varied. A sudden change in the ratio of the cell dimensions takes
place because of a change in the predominant mechanism for excitation of convection. The governing influence of buoyancy forces
gives way to one of thermocapillary forces, and they in turn give way to the influence of thermoelectric forces for yet thinner
layers. As the layer thickness is reduced gradually at a fixed external heating, the ratio of the dimensions will take on
the values 0.7, 0.65, and 1, respectively.
Zh. Tekh. Fiz. 68, 7–11 (November 1998) 相似文献
993.
An analytic expression is derived for calculating the intensities of individual spin-rovibronic lines in the fully resolved
gas phase electronic spectrum of a polyatomic molecule, in which one of the zero-order electronic states is a triplet state.
The expression is employed to calculate the effect of fine structure splitting on the singlet-triplet absorption spectrum
of pyrazine using the parameters available from experiment. A transition from Hund’s coupling Case (a) to Case (b) on going
from low J to high J rotational levels is predicted to occur at a moderate resolution of a few hundred MHz. The effect is more pronounced in pyrazine-d
4 and the pyrazine-argon van der Waals complex owing to their larger mass.
Zh. éksp. Teor. Fiz. 114, 63–90 (July 1998)
Published in English in the original Russian journal. Reproduced here with stylistic changes by the Translation Editor. 相似文献
994.
The problem of calculating the noise factor of a traveling-wave gyrotron is solved for a model of a thin annular multistart-helical
electron flux taking into account the effect of the quasistatic space-charge field. Plots of the gain and the noise factor
of the traveling-wave gyrotron versus the electrical parameters of the amplifier are obtained.
Zh. Tekh. Fiz. 68, 130–132 (February 1998) 相似文献
995.
H.-J. Scheibe D. Drescher A. Kolitsch A. Mensch 《Fresenius' Journal of Analytical Chemistry》1995,353(5-8):690-694
Morphology and structure of amorphous carbon films deposited with a pulsed arc source (LASER-ARC) have been studied using microscopical methods (SEM, TEM and AFM), electron diffraction and spectroscopical investigation (EELS). The parameters of the arc source and the deposition conditions (substrate temperature) influence morphology and structure of deposited amorphous carbon films. Especially the incorporation and growth of particles, embedded in the film have been investigated. By particle analysis using an optical microscope a majority of particles that is smaller than 500 nm has been determined. The morphology has been also demonstrated similar by AFM and TEM images. Their number and size of particles is strongly influenced by the deposition temperature. The structure of amorphous film is characterized by the EELS-spectra, but the particle structure was not detectable. 相似文献
996.
Summary A new method of evaluating the Tolman cone angle from X-ray structural data available from the Cambridge Crystallographic Data Base has been developed and a statistical analysis of the cone angles of the phosphines PPh3, PMe2Ph, PMePh2, PMe3, PEt3 and PCy3 (Cy = cyclohexyl) in transition metal complexes has been completed. 相似文献
997.
998.
A near-field scanning optical microscope (NSOM), which we built, is used to investigate 1–5-μm wide stripes with a 10-nm thick
layer—a quantum well — on a GaAs surface. A map of the photoluminescence intensity is obtained synchronously with the topographic
profile of the structures. The measured spatial distribution of the photoluminescence intensity is described satisfactorily
in a model that takes into account carrier diffusion in the layer and the existence of a region with a short carrier lifetime
near the side boundaries of the layer.
Pis’ma Zh. éksp. Teor. Fiz. 63, No. 7, 523–527 (10 April 1996) 相似文献
999.
The motion of a relaxing system can be revealed by its optical properties. the computed emission spectrum of an excited solid-state impurity in a crystal, which relaxes towards the equilibrium position, exhibits a series of peaks revealing the stops at the classical turning points. Detection limits are discussed. 相似文献
1000.