R e v i e w s

Theoretical and mathematical physics

Moscow University Physics Bulletin 2017. **72**. N 4. P. 329

In this work we are discussed the decay channels of the Higgs boson. In the framework of the Standard Model we are calculated the partial decay widths and displayed the decay widths as functions of the Higgs mass.

Show AbstractR e g u l a r p a p e r s

Theoretical and mathematical physics

Moscow University Physics Bulletin 2017. **72**. N 4. P. 340

The structure of partial radiation conditions operator is considered. Non local boundary conditions are determined by integrodifferential operator as some functional series. The principal part of this operator is given in explicit form. The remaining rapidly converging part of functional series determines the integral operator with continuous kernel.

Show AbstractRadiophysics, electronics, acoustics

Moscow University Physics Bulletin 2017. **72**. N 4. P. 345

Brillouin scattering in an infinite medium is anisotropic, with the threshold of absolute instability is due to the attenuation of the scattered waves. If the collision absorption mechanism prevails, the minimum threshold is observed in backward scattering. For the scattering region, limited in the longitudinal direction (parallel to pump wave propagation direction), the threshold will become greater than in infinite medium due to the appearance of convective losses associated with energy removal by scattered waves. In this paper we consider the scattering of a wide wave beam in the plasma, which size in a transverse direction substantially exceed longitudinal one. It is shown that in this case, the threshold for angularly scattered wave may be lower than the threshold for backward scattering due to the increased time of radiation output for interaction region. This effect has not attracted attention previously. In turn, the decrease of the threshold leads to increasing of loss due to radiation, which is important in plasma heating problems. The results can also be used for plasma diagnostics.

Show AbstractCondensed matter physics

Moscow University Physics Bulletin 2017. **72**. N 4. P. 364

The process of spherical particles Co$_3$O$_4$ reduction up to metallic Co in continuous H2 flow at the temperature intervals (200 – 300 ̊C) was studied by means of XRD method. The phase analysis of reduced particles showed their non-single state (coexistence of α-Co and β-Co). β-Co concentration increases with reduction temperature grow.

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 369

In the framework of molecular-statistical theory the causes of spontaneous polarization in synclinic and anticlinic smectic liquid crystals are discussed. The effect of the interaction of molecules, of external electric field and of the bent of molecules on the magnitude of the polarization are studied.

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 351

Two main factors which limit the power conversion efficiency of solar cells are light absorption and recombination processes. In photovoltaic (PV) devices, low energy photons cannot be absorbed and excite electrons from valance band to conduction band, hence do not contribute to the current. On the other hand, high energy photons cannot be efficiently used due to a poor match to the energy gap. Existence of charge recombination in PV devices causes the low conversion performance, which is indicated by the low open-circuit voltage (VOC). Using a blocking layer in system could effectively reduce the recombination of charge carriers. In this study, we simulated a solar cell with ITO/ZnO/P3HT&PCBM/Ag structure. To prevent the charge recombination, a ZnS QD layer was used which acts as a light absorbing and a recombination blocking layer in the ITO/ZnO film/ZnS QD/P3HT&PCBM/Ag structure. The simulated J-V characteristics of solar cells showed a close match with the experimental results. Simulate data showed an increase of conversion efficiency in ZnS QDSSC from 1.71 % to 3.10 %, which is relatively 81.28% increase.

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 358

We have preformed the first-principles calculations for the mechanical properties, Born effective charge tensors and high frequency dielectric constants of the eight phases of BaTiO$_3$. The independent elastic constants, bulk modulus, shear modulus, Young’s modulus and Poisson’s ratio were obtained, which were consistent with the available theoretical and experimental values. The mechanical stability and brittle/ductile behaviors of the eight phases of BaTiO$_3$ have been discussed. The calculated results indicated that the eight phases were all mechanically stable and behaved in a brittle manner. The calculated Born effective charge tensors shown the covalent Ti-O bond and ionic Ba-O bond. Moreover, the high frequency dielectric constants have been given.

Show AbstractBiophysics and medical physics

Moscow University Physics Bulletin 2017. **72**. N 4. P. 376

The binding of biotinylated aptamers to Lon protease, whose structures contain G-quadruplex fragments, with magnetic nanoparticles (MNP) functionalized by streptavidin is investigated. The conditions of the binding of target aptamers to MNP are fulfilled. The resulting complexes are assumed to be used for detection of Lon protease in different biological sources and for constructing of novel biomagnetic nanosensor system of the enzyme immunoassay.

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 383

Абстракт. Different mechanisms of temperature compensation of the frequency (period) of biochemical self-oscillations are considered. It is shown that system approach to clarification of the molecular nature of temperature compensation the frequency of biochemical self-oscillations more reasonable. The phenomenon of temperature compensation it is inherent not only for circadian oscillations ("biochemical clocks"), this is property of all multidimensional chemical oscillators. It is found out that stages with negative control coefficients over frequency are included into structure of "the setting generators" of biochemical self-oscillations and the balancing role of these stages more significantly. By calculation of control coefficients it is shown that significance of elementary stages in the mechanism of temperature compensation not equal and they are defined not only of control coefficients, and also depend on corresponding energy of activation. Therefore, different mutations differently influence temperature compensation of the period of circadian oscillations in different mutants

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 390

In the present work, we theoretically studied the impact of diffusion limitations that determine the degree of lateral mobility of protons and the mobile electronic carriers (plastoquinone, plastocyanin), on the kinetics of photoinduced changes in pHi in the metabolic state 3 (conditions of intensive synthesis of ATP) and 4 (the state of photosynthetic control). Numerical experiments have been conducted using our previously developed mathematical model of photosynthetic electron and proton transport in chloroplasts, taking into account the non-uniform distribution of the electron-transport and ATP-synthase complexes in thylakoid membranes of granal and stromal thylakoids. The kinetics of interthylakoid pHi variations and lateral profiles of mobile electron carriers concentrations in granal and intergranal thylakoids were studied. The model predicts the establishment of non-uniform lateral profiles of pHi under the conditions of intensive ATP synthesis, when the acidification of the lumen in the centre of grana occurs considerably slower than inside the stromal thylakoids. The variation of the diffusion coefficients of protons inside the thylakoids and the mobile electron carriers may result in a significant impact on the lateral profiles of pHi and the redox state of the mobile electron carriers.

Show AbstractAstronomy, astrophysics, and cosmology

Moscow University Physics Bulletin 2017. **72**. N 4. P. 396

Solution of the inverse problem of the one-dimensional mean field dynamo Parker's model in the thin spherical shell is considered. The method allows to find the spatial distribution of the energy sources in the model: the $\alpha $- and $\Omega $-effects, provided some constraints on the magnetic field are proposed. As an example of such constraint the maximal ratio of the magnetic energies in the northern and southern hemispheres is discussed. The method is a modification of the Monte Carlo method, suitable for application on the parallel computers. The idea is the minimisation of the cost-function, which describes deviation of model solution from the desired one. Calculations demonstrate that the energies ratio can exceed the order of magnitude as for the poloidal, as well as for the toroidal magnetic energies. The ratio depends on the distance between the zones of the maximal generation of the magnetic energies in the hemisphres, and the number of harmonics in the spectrum. The greater the distance, and the greater the number of harmonics the stronger is the equatorial assymetry of the magnetic field.

Show AbstractPhysics of Earth, atmosphere, and hydrosphere

Moscow University Physics Bulletin 2017. **72**. N 4. P. 402

It is shown that due to the relativistic transformation law of reflection angles adjoint of a moving retroreflector laser pulse propagates is achieved not strictly back, and at a small angle to the direction to the laser station Therefore it is not the central enters the receiving telescope laser station This beam is pulse beam and located at its periphery. As a result, the flow of electromagnetic energy received by the laser station, zavedo- mo less energy flow in the vicinity of the central beam. On the basis of the numerical analysis evaluated energy flux attenuation coefficient. It is shown that if the receiving telescope is separated from the laser station, to make his mobile and move along the Earth's surface so that the center of each spots formed by the reflected light pulses, got into the telescope, is that they received a stream of electromagnetic energy in the laser Location satellites will increase by more than 100 times, compared to the flow of energy, received stationary telescope laser station. from the above Research shows that the maximum speed on the surface Earth's center spot of the reflected light pulses from retroreflektoraISZ Owls do not exceed 8 km / h.

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 410

Errors of dispersions of sea surface slopes measured by means of the spacecraft-mounted lidars are analyzed. Errors caused by deviations of the real wave field from the Gaussian isotropic surface are considered. It is shown that the unaccounted deviations of slope distributions from the Gaussian lead to a systematic decreasing of the calculated slope dispersions values about 11-14%. It is shown that the effect of slopes anisotropy on their dispersions calculation upon the data of spacecraft vertical laser sounding can be neglected.

Show AbstractMoscow University Physics Bulletin 2017. **72**. N 4. P. 415

A classic problem of propagation of linear wave packets in dispersive media is considered. Asymptotics of the Cauchy problem for two-dimensional gaussian wave packets are found in terms of Fourier integrals. These asymptotic solutions are regular at caustics and describe new physical effects of the packet propagation: rotation in space and formation of wave front which dispersion appears to be anomalously slow as compared to the well-known solutions for dispersive waves.

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