The non-parabolicity contribution of the conduction band and the hot electron effect t o the non-linear susceptibility of n-type InSb at T = 77 "R arc compared using the displaced Maxwell distribution function. Electron scattering on the optical phonons and impurities are taken int,o account. It is shown that a t high frequencics the non-linear susceptibility is due to the non-parabolicity of the conduc1,ion band. The papers [l to 61 consider the frequency conversion of electromagnetic radiation of optical rangc in AII1 B V semiconductors with a high concentration of donor impurities. The non-linear effects associated with an electron heating are investigat.ed in these papers on thc assumption that the impurities play the main role in the electron scattering. It is known that in intrinsic polar semiconductors a t temperatures of the order of 80 O K the optical phonons give the essential contribution to the scattering; in this case, the collisions with phonons are non-elastic. A strict solution of the kinetic equation presents a rather complicated problem for such non-elastic scattering. At the same t.ime, some features of the integral characteristics such as average momentum p , current j , and average energy E can be found from the conservation laws, in which the precise distribution function is substituted by an approximate one depending on the same integral characterist,ics. I n the case of the parabolic dispersion law1) the first intcgrals of the kinetic equation, t,he conservation law of momentum and energy, are of t.he forin S p ' d 3 p * . Es werden dcr

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The initial (background) seismicity of the territory of Gelendzhik with the high responsibility buildings projected for construction of (35-storey towers 123 meters high) is equal to 9 points according to the Map of General Seismicity of Russia (OSR-2015(B)) with the period of recurrence of tremors 1 time per 1000 years. The purpose of the study was to obtain the parameters of predictive seismic impacts for the site of the proposed construction taking into account regional seismotectonic and local seismic soil conditions. The influence of ground conditions on the on the seismicity of the research site was estimated when the bedrock in the Black Sea coast of the Caucasus, as a rule, lies not deep (several meters) from the surface and overlapping Quaternary sediments are flooded. Based on the result of vertical seismic profiling (VSP), a generalized geoseismic condition for the whole site was given. To determine the seismic intensity increment ΔI by the method of seismic rigidities comparison, the weighted average values of the S-waves velocities and the thickness of the soils up to the boundary of the reference soil were used in the calculations. Based on the obtained geoseismic model (results of engineering-geological and seismic studies), the NERA program calculated the parameters of seismic impacts from the most hazardous zones of origin of seismic foci (ASF) taking into account the initial seismic impacts in the territory of Gelendzhik and the results of seismic microzoning. It was found that the highest values of maximum accelerations at the studied site are caused by foci from the Mikhailovskaya and Gelendhizkskaya ASF zones; and the lower values are expected from outbreaks from the Tyapsinskaya and Akhtyrskaya ASF zones. To calculate the seismic load on the projected structures, it is proposed to use one set of synthesized accelerograms (X, Y, Z) simulating the impact from different PSF zones, which contain the entire set of vibration periods and cover the whole range of maximal velocities dangerous for the studied areas. The analysis obtained data shows good convergence of the seismic microzoning data obtained by the calculation method and seismic rigidity method.

In recent years the world has been actively developing oil and gas fields on the shelf, including in seismically active areas. On the seabed it is very difficult to carry out qualitative geological and geophysical studies and seismological observations in full, which are a part of seismic microzoning works. Programs for computational methods during seismic microzoning allow taking into account nonlinear soil properties. In the article the experience of studies on seismic microzoning (2012–2015) for the installation area of offshore structures on the shelf of the Middle Caspian Sea is considered. In conditions of absence of observations by bottom seismic stations the possibility of seismic hazard assessment by computational methods taking into account local soil conditions is shown. Thus the obtained values of seismic intensity are lower in comparison with the results of estimations by method of engineering and geological analogies and method of seismic rigidity. Maximal impacts from zones of possible earthquake sources most dangerous for Middle Caspian Sea have been taken into account by peculiarities of spectral composition of vibrations of ground bases in the form of reaction spectra.

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