Neutrino-pair creation by a nonrelativistic neutron in the field of a circularly polarized plane electromagnetic wave is considered. An expression is obtained for the total probability of the process as a function of the frequency of the incident wave and the anomalous magnetic moment of the neutron.
Show AbstractA systematic theory of a fluid with spin is developed on the basis of a first-order variational principle. The proposed theory is appropriate not only for Einstein-Cartan theory but also in a wider class of gage theories in which the gravitational Lagrangian includes terms that are quadratic in the torsion and curvature.
Show AbstractThe lepton contribution to the polarizational operator of a W boson in a constant homogeneous magnetic field is calculated in a single-loop approximation. Various limiting cases are investigated. The lepton contribution to the anomalous magnetic moment of the W boson is singled out from the expansion of the expression for the polarization operator in a weak field.
Show AbstractThe results of photofission of $^{24}Mg$, $^{26}Mg$, $^{28}Si$, and $^{32}S$ nuclei within the framework of the semimicroscopic vibration model are discussed. It is shown that configurational splitting of the dipole giant resonance (DGR) is observed for all these nuclei. Including states corresponding to transitions from partially filled levels in the particlehole basis allows the basic structural features of the experimental photoabsorption cross sections to be explained. The role of isospin DGR fission is studied for the $^{26}Mg$ nucleus.
Show AbstractA model of an adaptive optical system of aperture probing with systematic introduction of variation in the phase of the light wave is investigated. The system has three control loops and permits stabilization of the position of the coherent light beam in space (two control loops) and automatic focusing of this beam.
Show AbstractParametric generation in the field of a multimode pumping wave is investigated numerically and analytically, in the case when diffractional effects are significant. The dependence of the efficiency of energy transformation and the degree of coherence of the wave generated on the number of spatial inhomogeneities of the pumping beam is analyzed. It is shown that, in conditions of strong energy transfer, conditions of self-channeling of the individual inhomogeneities set in, and the efficiency of the process at the length of diffractional reduction of the phases is practically independent of the initial mode composition of the pumping wave.
Show AbstractThe acoustic field of a slow quasi-shear wave created by a plane converter with a Gaussian aperture function close to the crystallographic direction [110] is investigated for paratellurite and calomel crystals. The parabolic approximation of the wave-vector surface is used. The dependence of the parabolic-approximation coefficients on the wave-vector direction is given. The limits of parabolicity are given. The method of calculating the geometry of the acoustic beam excited along the axis [110] is considered.
Show AbstractExperimental results are given for the distribution of pressure pulsations as a function of the angle between the direction of the fluid flow and the position of pulsation detection by a small sensitive element. Angular and spectral characteristics of the pressure pulsations are obtained at small flow velocities (0.25 and 0.5 m/sec). It is shown that the maximum pulsations are obtained in the "dark" part of the sphere in the turbulized flow region.
Show AbstractVariation in the parameters of slow induction of fluorescence is studied as a function of the light intensity during growth. The relation between the inductional transitions of fluorescence and the functional activity of the photosynthetic apparatus is shown. The action of chemical agents (antimycin A and $NH_4Cl$) on the kinetics of slow induction of fluorescence is also studied.
Show AbstractThe action of laser radiation on the semiconductor-electrolyte system leads to acceleration of the reduction of nickel and/or ordering of the residue structure. The mechanism of increase in the deposition rate is associated with a set of thermal and electrical influences of laser radiation on the given system.
Show AbstractThe nuclear gamma-resonance method is used to study the local distribution of atoms in the 3d sublattice of intermetallides in the quasibinary system $Ho(Fe_{1-x}Mn_x)_2$ and a ternary superstructure of stoichiometry $Ho(Fe_{0,25}Mn_{0,75})_2$ is observed.
Show AbstractUtilizing the direct transformation of electromagnetic and acoustic waves in conducting media offers the possibility of a fundamentally new approach to the formulation of the ultrasound experiment. Contactless methods that have been based on this phenomenon for changing the velocity and damping of ultrasound in metals and semiconductors are described.
Show AbstractThe temperature dependence of the volt-ampere characteristics of photoelectric converters (PEC) p-Si/polymer material/$SnO_2$ is investigated for samples with different levels of silicon doping. The relation is established between the mechanism of current-carrier transport and the no-load potential $V_{хх}$. It is shown that the reduction in $V_{хх}$ with increase in the level of silicon doping may be associated with increase in the PEC dark current on account of the multistage-tunneling mechanism.
Show AbstractA relaxational semiconductor with an injective contact is considered. It is shown that a term that is activationally dependent on the temperature may appear in the expression for the thermoemf of the sample, in the given conditions.
Show AbstractA quantitative scheme of the energy band structure is constructed by the pseudopotential method, with correction with respect to the experimental reflection spectrum of a chip of BeO single crystal in the fundamental region of the spectrum. The results are compared with known theoretical and experimental data.
Show AbstractA development of the well-known method of laser probing of the marine surface is proposed. The method developed for analyzing the map of flashing points allows the Phillips spectral parameters to be derived from six independent measurements.
Show AbstractThe problem of the relation between the pressure and wind-velocity fields in atmospheric eddies is solved. On the basis of comparison of the data of full-scale and laboratory experiments, it is proposed that a parameter relating the pressure minimum and the maximum of the surface-wind velocity be used to estimate the intensity of the eddies.
Show AbstractData on the mean parameters and the number of local magnetic structures (LMS) at the Sun, such as active regions, ephemeral regions, magnetic points, and magnetic elements, do not contradict the concept that the whole set of LMS is described, in a rough approximation, by a single power-law spectrum.
Show AbstractThe limiting sensitivity of a solid-state gravitational antenna with a recording element based on a radiofrequency squid is theoretically investigated, choosing a working point between adjacent plateaus. Formulas are obtained for estimating the minimum observable force determined by the thermal noise of the contact, the thermal noise of the contour, and the nonthermodynamic fluctuations of the preamplifier, with amplitude demodulation of the squid output signal. The optimal magnetomechanical coupling.coefficient is determined as a function of the parameter $g$.
Show AbstractThe theory of an autodyne spin generator (ASG), which is a spin generator on the side. band with modulation of the HF field, is given. In its construction, the ASG consists of a nonisochronous audyne sensor of NMR signals with a working sample in the coil of an oscillatory loop. It is shown that excitation of spin generation becomes possible as a result of mixed amplitude-frequency modulation of the autodyne oscillations, ensuring satisfaction of the condition of phase balance at near-Larmor frequencies.
Show AbstractAn analytical solution is given for the problem of the interaction of "thin" completely magnetized plasma and an electron beam in conditions of the collective Cherenkov effect. The saturation mechanism of the beam-plasma instability in the given conditions is elucidated.
Show AbstractThe results of investigating a continuous jet laser based on Rhodamine 6G with a nonsteady resonator are presented. The possibility, in principle, of realizing conditions of kinematic mode stabilization is demonstrated. The basic laws determining the features of supershortpulse generation in this laser in comparison with lasers of other types are established.
Show AbstractCompounds $RFeGe_2O_7$ containing two kinds of magnetic ions - $Fe^{3+}$ and $R^{3+}$ (R = La-Gd) - are synthesized for the first time. The M$\stackrel{..}{o}$ssbauer spectra of $^{57}Fe^{3+}$ are measured, together with its magnetic and elastic properties; antiferromagnetic ordering at temperatures 5-9 K is observed. The ordering temperatures, paramagnetic temperatures, and superfine fields at $^{57}Fe^{3+}$ nuclei are determined. It is concluded that the $R^{3+}—Fe^{3+}$ interaction in these compounds is comparable with the $Fe^{3+}—Fe^{3+}$ interaction, and makes a significant contribution to the magnetic and elastic properties.
Show AbstractThe thermal and dielectric properties of $\gamma$-irradiated diglycerine-nitrate crystals are investigated at radiation doses of 1-30 MR. The data obtained are discussed in the context of the most probable type of radiation defects.
Show AbstractIt is established by means of X-ray diffraction analysis and diffractional electron microscopy, that the amorphous alloy $Cu_{35}Zr_{65}$ undergoes natural aging. After holding at room temperature for three years, partial crystallization of $CuZr_2$ phase occurs. It is shown that both topological and compositional short-range microheterogeneity is observed in the amorphous phase remaining after partial crystallization.
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