An analysis is given of the nonlinear oscillations of the components of manipulator devices, taking into account their viscoelastic prop erties. An averaging procedure is used to calculate the small oscillations of manipulator components that accompany the programmed motion of the mechanism.
Show AbstractА calculation is reported of the mean charge $\bar{i}$ and the charge fractions $F_i$. of an equilibrium beam of helium ions in high and low density media as functions of the charge $Z_t$ of the target nuclei in the range $1\le Z_t \le 24$ and ion velocities in the range $V_0\le V\le 3V_0$. It is shown that the functions $\bar{i}(Z_t)$ and $F_i(Z_t)$ may bе very different in low and high density targets.
Show AbstractThe method of hyperspherical harmonic s is used to obtain an approximate analytic solution of the quantum- mechanical problem of the helium atom. The calculated ground- state energy differs from the exact value bу only 3,8%. The express ion for the wave function is reproduced.
Show AbstractThe minimum noise in measuring circuits consisting of а test oscillator and а resonance electromechanical transducer is discussed. А formula is given for the amplitude of the threhold signal for large values of the electromechanical coupling coefficient.
Show AbstractIt is shown that а regular external disturbance outside synchronization regions leads to the smoothing of the spectral density of chaotic oscillations in auto-stochastic systems. Different scenarios of transition to chaos in а nonautonomous generator of chaotic oscillations that incorporates а tunnel diode are discussed.
Show AbstractAn analysis of the characteristic equation for the active waveguide of the injection laser with arbitrarily specified transverse geometry is used to derive and investigate the equation for the energy balance during transverse - mode generation.
Show AbstractScanning electron microscopy was used to investigate the structure of single-crystal $BaY_2F_8$. The experirnental results indicate that the structure factor contributes to the optical spectra of the single crystals.
Show AbstractА numerical simulation is reported of the production of а plasma mirror on the surface of silicon bу picosecond laser pulses. The dependence of the mirror lifetime on the parameters of the exciting pulse and the properties of the silicon surface is discussed.
Show AbstractThe evaluation of the matrix element sof the electric dipole transition between states in the continuous spectrum is discussed. Recurrence relations are obtained for the contribution to the matrix elements of the integral evaluated over the region outside the atom in terms of the values of the wave functions and their derivatives on the boundary.
Show AbstractThe Bragg diffraction problem is solved for а bounded sound beam, using а new method employing а four- dimensional spectral representation of the light and sound beams.
Show AbstractThe use of modern techniques in the investigation of Raman scattering in $\alpha$- quartz exposed to small reactor doses was used to separate the influence of neutron and $\gamma$ - components on the spectrum and to demonstrate the presence of а small frequency shift of the Raman lines.
Show AbstractThe synthesis of reflecting coatings with а 180° phase difference between the s and р cornponents of the reflected field at an angle of incidence of 45° in the wavelength range $\Delta \lambda /\lambda=\pm 5 \%$ is discussed. Exarnples of synthesized systerns are reproduced.
Show AbstractPeriodic temperature variations are accompanied bу а separation of the Earth's mantle into mineralogical fractions at temperatures below the solidus point of rock. А physical model is put forward for the formation of magmatic melts of different chemical compositions.
Show AbstractА dynarnic theory of Cornpton and therrnal diffusion scattering during the diffraction of X-rays Ьу perfect crystals with an epitaxial filrn on the surface is developed.
Show AbstractIt is shown that а nonlinear dynamic structure such as а soliton can appear in the domain wall of а massive magnetic sample.
Show AbstractThe effect of all-sided pressure on the rnagnetization of single-crystal terЫurn is investigated. Giant volurne magnetostriction, $\sim 650\cdot 10^{-6}$, is found. The dependence of the magnetic anisotropy constant $K_6$ on pressure is found to bе described bу а single-ion theory of magnetic anisotropy.
Show AbstractThe effect of excimer-laser pulses on the photoluminescent properties of GaAs and GaAsP was investigated. It was shown that, depending on the initial defects present in the samples, the laser pulses give rise to the generation of annihilation of radiationless recombination centers.
Show AbstractAn analysis is given of the reduction of experimental data for models with an а priori unknown correlation operator representing measurement uncertainties.
Show AbstractAn analytic study is reported of the deterioration in the temporal coherence of а powerful light pulse that is randomly modulated in space during time-dependent thermal self-interaction. Expressions are obtained for the beam width, radius, and coherent time.
Show AbstractА method has been developed for measuring а submicron capacitive gap and to determine its size without direct measurement. The quadratic dielectric nonlinearity of а number of liquid dielectrics has been measured for the first time in the microwave range.
Show AbstractAn application of the sensitive- point method to the staЫlization of the multifrequency output of а spin oscillator is discussed. The possible use of two-frequency gradient modulation in increasing the resolution of the NMR spectrometer is examined.
Show AbstractА classification is given for the singular points of streamlines of the active and reactive intensity. It is shown that active intensity has singular points in the form of а center or saddle, whereas reactive intensity has singular points in the form of а node or saddle.
Show AbstractThe geometric acoustic approximation used to analyze thermal selffocusing of saw-tooth waves. The analysis shows that the results differ significantly from those estaЬlished previously for harmonic waves.
Show AbstractThe reaction of ocean surface to а tropical cyclone (ТC) is discussed in terms of the "shallow water" model. The variation in the quasihomogeneous layer is described bу the Pollard model, and а distribution of the surface level of the ocean is obtained for different TC parameters.
Show AbstractIt is shown that p-n conversion under electron bombardment of $р-InSb\langle Ge\rangle$ samples, the electron concentration passes through а maximum, and а limiting state with n- type conductivity is reached. These re sults are explained in terms of the formation of complexes consisting of primary defects and impurity atoms.
Show AbstractА theoretical study is reported of the effect of absorption of molecules on the semiconductor- metal phase - transition temperature in $VO_2$ films. The theoretical predictions are compared with experimental data.
Show AbstractSamples of $n-Pb_{1-x}Ge_xTe_{1-y}Se_y$ with $y\approx 1$ and germanium concentration below the threshold for the onset of ferroelectric properties were found to exhibit low- temperature electron scattering. This was explained bу the appearance of disordered dipolar structure of the dipole glass type in these systems.
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