Yu.M. Loskutov, V.V. Skobelev

It is shown that the region of applicability of the double logarithmic asymptote of the mass operator has an upper bound. In the rainbow-diagram approximation, the true asymptote beyond the limits of this region is found.

I.I. Minakova, G.P. Minina, B.A. Sil'nov

The frequency characteristics of a Thomson generator coupled inductively to a resonance loop of frequency close to a harmonic frequency are investigated theoretically and experimentally. It is shown that the character of the frequency dependence is different for tying at the harmonic frequency and at the fundamental tone; the difference corresponds to an additional phase shift of $\pi/2$. Some mechanisms leading to asymmetry of the frequency curve are considered.

I.P. Bazarov, P.N. Nikolaev

V.B. Gostev, A.R. Frenkin

Using a general solution of the inverse problem for tbe reconstruction of a confining potential $(\tilde{V}(r) \to \infty, r \to \infty$) from a reference potential $V(r)$, energy levels and normalizing constants, we analyze the corrections to the potential $\Delta V(r)$ and to the regular solutions of the radial Schrodinger equation when a finite number of the spectral characteristics are changed. For $r \to 0$ and any arbitrary changes of the spectrum $\Delta V(r) \sim r^{2l+1}$ ($l$ is the orbital angular momentum). For $r \to \infty$, the asymptotics of $\Delta V(r)$ are classified according to three different types of change of the spectral characteristics. It is shown that when additional energy levels are included or some energy levels are omitted, there is a one-to-one relationship between the asymptotic behavior of $\Delta V(r)$ and the period of radial oscillations of the classical motion in the field $V(r)$. All results can be carried through to the case of long-range attractive potentials ($\lim_{r\to\infty} = 0$, $\lim_{r\to\infty} r^2V(r = \infty)$, when the spectral density of the continuous spectrum is conserved.

L.V. Lazareva, O.S. Galkina

We study the transverse magnetoresistance, the Hall effect, and magnetization of monocrystalline gadolinium with $m=\rho_{300K}/\rho_{4.2K}=41$ at temperature 4.2 K and fields $H_{e_{max}}$ = 63 kOe. In the true fields $H_i = H_e - 4\pi IN \gg H_{is}$, where $I$ is the magnetization, $N$ is the demagnetiization factor of the samples, and $H_{is}$ is the true saturation field, we observe an increase of magnetoresistance and a linear dependence of the Hall emf on the field, which are associated with the fulfillment of the strong-field criterion $h \omega_H \gg kT$, where $\omega_H$ is the cyclotron frequency. Using the measured Hall emf in the fields $H_i \gg H_{is}$, we estimate the normal Hall coefficients $R_0$ and the difference of the carrier concentration $\Delta N$ per atom of gadolinium.

S.D. Varlamov, Yu.S. Konstantinov, A.M. Smirnov

The spin generation at two lines of NMR sample makes it possible to measure accurately the spectral interval between these lines. If the measured spectral interval is temperature dependent, the heating of the sample can be determined from the change of the spectral interval. When the sample is illwninated by light, the rate of heating of the sample is related to the light intensity. It is suggested that the double-frequency spin generation can be used to measure the light intensity absorved by a sample in the sensor of NMR spectrometer.

S.I. Babichenko, V.N. Rudenko, A.G. Yagola

Using numerical modeling, we estimate the parameters of an external force of a given form which perturbs a test oscillator with a registering relaxation circuit. The method and results are presented for two typical pulse signals with allowance for readout errors and the fluctuation of parameters of the registering circuit.

Yu.P. Pyt'ev

We consider the reduction problems for a measuring computational complex "device+ computer", which make it possible to improve considerably the characteristics of experimental instruments. It is shown how the investigator can use the complex as a device with given parameters.

A.A. Orlov, N.A. Solovaya

It is suggested, using results of a numerical investigation, that various variants of the intermediate orbits may be useful for the construct ion of an analytical theory for the motion of the outer satellites of Jupiter.

E.V. Galuzo, V.I. Kanavets

We model numerically the processes in a one-dimensional model of an active nonlinear resonant medium. Allowance is made for a close coupling between the wave and oscillatory phenomena, variable structure of the fields, and a variable spectrum. The model represents a discrete transmission line with resonance circuits which contain nonlinear components. We solve the nonstationary equations of the system, and the voltage distribution is found by the driving method. We study a number of nonlinear processes, including the radiation of the active layer and a mutual synchronization of the autogenerators with a narrowing of the spectrum.