Measurement of two dimensional spectral energy density in homogeneous M.H.D. turbulence

1985 ◽  
Vol 32 (12) ◽  
pp. 999
Keyword(s):  
Energy Density ◽  
Spectral Energy ◽  
Two Dimensional ◽  
Spectral Energy Density

Phonon spectral energy density in metals with the cubic lattice structure

2020 ◽  
pp. 102-106
Author(s):  
A.V. Orlov ◽  
◽  
M.A. Gumirov ◽  
V.L. Orlov ◽  
V.I. Selenski ◽  
...  
Keyword(s):  
Energy Density ◽  
Lattice Structure ◽  
Spectral Energy ◽  
Spectral Energy Density ◽  
Cubic Lattice

scholarly journals Излучение дробного осциллятора

2021 ◽  
Vol 47 (22) ◽  
pp. 49
Author(s):  
С.Ш. Рехвиашвили ◽  
А.В. Псху ◽  
З.Ч. Маргушев
Keyword(s):  
Energy Density ◽  
Spectral Line ◽  
Radiation Spectrum ◽  
Emission Spectra ◽  
Dipole Approximation ◽  
Spectral Energy ◽  
Spectral Energy Density ◽  
Model Sets ◽  
Fractional Oscillator ◽  
Lorentzian Spectrum

The spectral energy density of the oscillator radiation is calculated in the dipole approximation. The oscillator motion is described by an equation with fractional integro-differentiation. The fractional oscillator model can describe various types of radiation, including those with a nonexponential relaxation law. Found the shape of the spectral line of radiation. The obtained result is compared with the classical Lorentzian spectrum and experimental emission spectra of monochromatic and phosphor LEDs. The order of fractional integro-differentiation in the model sets the magnitude of the broadening of the radiation spectrum.

PHONON SPECTRAL ENERGY DENSITY IN METALSWITH THE CUBIC LATTICE STRUCTURE

2020 ◽  
pp. 73-78
Author(s):  
A. V. Orlov ◽  
V. I. Zelenskiy
Keyword(s):  
Heat Capacity ◽  
Energy Density ◽  
Crystal Lattice ◽  
Lattice Structure ◽  
Spectral Composition ◽  
Debye Model ◽  
Spectral Energy ◽  
Spectral Energy Density ◽  
Objective Description ◽  
Physical Reasons

This study derives an expression of spectral energy density of acoustic phonons, as well as introducing the basic properties of anharmonic phonons and deriving an expression of their spectral energy density. The description of the vibrations of the atoms of the crystal lattice to this day cannot be considered completely finished, despite the existence of the theory of heat capacity at a constant volume (Debye theory). Debye's theory perfectly explains the law of cubic increase in heat capacity with temperature at low values of the latter. However, at high temperatures, the Debye model seems insufficiently substantiated. In particular, it is not clear for what physical reasons the value of the critical frequency was introduced - the phonon frequency, above which their appearance is impossible. In addition, the spectral energy density of anharmonism phonons is not considered, although this information is extremely important. It is the spectral composition of the anharmonic phonons that is necessary for an objective description of the phonon-phonon interaction in a crystal. In this paper, the principles are stated on the basis of which the spectral energy density of phonons can be calculated. The consideration is carried out for a simple cubic crystal lattice.

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