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Thirty-five stable single sunspots of sufficiently regular round shapes were studied to determine the vertical magnetic field strength at the sunspot umbra–penumbra (UP) boundary and the degree of inclination of the total field vector at this boundary. A new data tool (SDO/hmi) called Space-weather HMI Active Region Patches (SHARPs) was used. Four different methods have been used to determine the UP boundary, including Otsu's mathematical method (Otsu, 1979). It is shown that there is no single value of the vertical component of the field at the UP boundary that is universal for spots of all sizes and field strengths. The value of 1867 G found earlier by Jurčák, (2011) was not confirmed either by our data or by the data of other authors (Schmassmann, et al., 2018; Loptien et al., 2020). We obtained the UP border, 〈Bver〉, of ~1.6 kg with a fairly large dispersion. It is important to note that the inclination of the total field vector γ remains almost constant at this boundary with very small dispersion (SD ~ 1.5–2.5 deg). This gives grounds to believe that this quantity determines the transition of the spot plasma to the magnetoconvection regime. [ABSTRACT FROM AUTHOR]

The influence of microbarite additive on the rheological properties of semidilute aqueous-saline solutions of two samples of carboxymethyl cellulose with high degree of substitution (polyanionic cellulose) and strongly different molecular mass (76 × 103 and 665 × 103) has been investigated by means of rotational viscometry and rotational rheometry. It has been shown that the introduction of microbarite in the solutions of high-molecular polyanionic cellulose leads to flocculation followed by precipitation, which is accompanied by the decrease in the systems viscosity. In the case of solutions of low-molecular polyanionic cellulose, the introduction of the additive has favored the formation of visually uniform systems stable during prolonged keeping and the increase in viscosity. In both cases, the introduction of microbarite in the solution altered its viscoelastic properties. The obtained results have evidenced the formation of polyelectrolyte–colloid complexes of different structure upon the interaction of microbarite particles and the chains of polyanionic cellulose of different length, which results in the change in the rheological properties of the solutions. [ABSTRACT FROM AUTHOR]

Lithium cobaltate with stoichiometric composition (LiCoO2) is synthesized by the sol–gel method. The physical parameters (particle size, specific surface area, and specific static conductivity) of studied samples are found and their dependence on the calcination temperature is revealed. The following three conduction mechanisms are shown to contribute to the conductivity value: frequency-independent σ0, ionic transport in the sample bulk σsv, and ionic transport at the electrode/ionic conductor interface σdl. The optimal modes of thermal treatment that allow the highly developed specific surface of LiCoO2 to be retained are determined. [ABSTRACT FROM AUTHOR]

Changes in the umbra brightness and in the magnetic field over time should occur on long-period sunspot oscillations in accordance with Birman's idea of inhibition of circulation (overturning) convection by a strong vertical magnetic field in antiphase mode.When the sunspot as a whole shifts upward, its power flux tube expands with a fixed magnetic flux, the magnetic field decreases, and the umbra brightness should increase. Vice versa, when the magnetic flux tube of the sunspot is lowered, it is compressed, the field grows, and the umbra brightness should decrease. Until now, this oscillatory process, which is described by the theoretical model of a shallow sunspot, has remained unexplored. This paper attempts to prove the Birman effect (Biermann, 1941) on the example of long-period oscillations of the sunspot 2010/12/07-13 (NOAA 11 133), for which there are available data from both the Solar and Heliospheric Observatory (SOHO) and Solar Dynamics Observatory (SDO). [ABSTRACT FROM AUTHOR]

Ferroelectric ceramic LixNa1 –xTayNb1 –yO3 (x = 0.17, y = 0–0.5) solid solutions with perovskite structure are synthesized for the first time by the thermobaric synthesis method (6 GPa, 1400–1800 K). The features of their structure and elastic properties are studied. It is shown that ceramic samples consist of grains of isomorphic shape and that faceting is inherent in the perovskite structure, allowing the coexistence of the rhombic phase of different symmetries of the P21ma and Pbcm unit cell. An increase in the synthesis temperature leads to a decrease in the Young's modulus. The dispersion of the permittivity and its temperature dependence are studied. Specific static values of electrical conductivity and their temperature dependence, as well as the most probable relaxation time, are determined. Carrier activation enthalpies Ha and transport enthalpy Hm are calculated. It is established that the studied ceramic samples undergo a ferroelectric phase transition, while an increase in tantalum concentration lowers the Curie temperature. Li0.17Na0.83Та0.1Nb0.9O3 in the paraelectric phase is found to be a superionic conductor. [ABSTRACT FROM AUTHOR]

Long-term variations of the magnetic field of solitary solar pores with periods in the range of 4–12 h are detected with the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory (SDO). These long-term oscillations of the pores obviously reflect the movements of these structures as whole magnetic formations around their equilibrium position. In this article, long-period oscillations of the solar pore are studied based on the SDO data for the first time. The results are interpreted with the solution obtained earlier for eigen oscillations of the system with time-varying stiffness. [ABSTRACT FROM AUTHOR]

The paper considers a special class of artifacts that appears in the useful signal when the source moves along a discrete matrix of the receiver. A parasitic component forms in the signal due to the displacement of the extreme value of the distributed field of the physical quantity from pixel to pixel (p2p effect). It is shown that a stepwise discretization of Δt < T (p2p) is a necessary but not sufficient condition for the formation of the p2p-artifact. For small field gradients (in particular, with good spatial resolution), the parasitic signal in the time series of the studied variable is either weakened or does not form at all. This assumption has been qualitatively verified by comparative analysis of sunspot data obtained with SOHO/MDI and SDO/HMI. In addition, the Y-p2p effect, which is associated with sunspot displacement along the meridian and influences the process of long-period sunspot oscillations, is considered in detail based on SDO/HMI data. It was found that there is an inverse relationship between changes in the umbral area of a spot and variations of its magnetic field strength. This property of long-period sunspot oscillations as a single magnetic structure indicates the magnetic flux in the sunspot umbra is preserved, and it plays an extremely important role for our understanding of the physical nature of these oscillations. [ABSTRACT FROM AUTHOR]

Solutions of poly(acrylic acid) mixtures with poly(sodium styrenesulfonate) in water and in decimolar hydrochloric acid are studied by potentiometry, viscometry, and rotational rheometry. It is shown that, in a wide range of mixture compositions, thermosensitive polyelectrolyte complexes are formed via ion–dipole interactions of functional groups of polymers. The formation of complexes in the semidilute solution regime is accompanied by a significant increase in viscosity as compared with solutions of the initial polymers, which makes it possible to obtain systems with high viscosity without using large concentrations of polyelectrolytes. The dependence of viscosity on the composition of the mixture passes through a maximum corresponding to the most complete binding of the components of the complex, and the position of the maximum does not depend on the molecular weight of poly(sodium styrenesulfonate) and is determined by the ratio of the concentrations of the functional groups of the polymers. The frequency dependences of the storage modulus and the loss modulus demonstrate that the system experiences strong structuring in the process of complex formation. [ABSTRACT FROM AUTHOR]

An important problem in the numerical simulation of turbulent heat exchange in fluids is accurate prediction of hydrodynamic characteristics of the flow in the boundary layer, which requires a fine grid near rigid surfaces. In applications, it is not always possible to have a fine grid and the use of a coarser grid results in significant loss of accuracy. A well-known approach to improving the accuracy of the numerical simulation of the boundary layer is the use of universal wall functions for computing the friction and thermal flux. In this paper, we consider the known wall functions for computing the thermal flux. The accuracy of these functions in problems of turbulent nonisothermal flow of fluid is studied. These are the flow in a plane channel, Couette flow, and flow along a heated plate. Each of these problems is solved on grids with various near wall resolutions. The results of solving these problems provide a basis for estimating the accuracy of the wall functions used for solving them. It is shown that the wall functions considered in this study yield nonmonotonic convergence of the results as the grid is refined. [ABSTRACT FROM AUTHOR]

The electrical properties and phase states of Li0.17Na0.83NbуТа1 –уO3 (y = 0.1–0.5) ferroelectric perovskite solid solutions prepared by high-pressure, high-temperature synthesis have been studied using impedance spectroscopy. The ε'(T) and σsv(T) curves of the solid solutions have been shown to have anomalies due to phase transitions of the materials. Their Curie temperature has been found to decrease with increasing Ta concentration. The static electrical conductivity of the solid solutions has been measured as a function of temperature and the enthalpies of activation of charge carriers in them have been evaluated. The Li0.17Na0.83Nb0.1Та0.9O3 solid solution has been shown to be a high-temperature superionic conductor. Possible mechanisms of the observed phenomena are discussed. [ABSTRACT FROM AUTHOR]

The structure of the yolk syncytial layer (YSL) of late embryos and larvae of the three-spined stickleback Gasterosteus aculeatus L. has been studied by histological methods. The YSL structure in this species has specific features that are related to the process of yolk utilization and features that are common for YSL of bony fishes, which are the structural regionalization, large polymorphic nuclei, and enclosing of the lipid droplets in YSL. We summarize original and published data on the diversity of YSL in bony fishes. The comparison is made for YSL and other structures that metabolize yolk in embryos in various animal taxa. [ABSTRACT FROM AUTHOR]

Abstract: Long-period oscillations in the brightness of the Sun as a star have been analyzed on the basis of measurements of the solar light reflected by planets when they come into the field of view of the Large Angle and Spectrometric Coronagraph (LASCO C3) onboard the Solar and Heliospheric Observatory (SOHO). We took sequences of FITS intensitygrams from the archive of the SOHO/LASCO C3 space observatory for the observational data; they were 1024 × 1024 pixels in size, and they were acquired with the 12-min interval. In 5-day continuous time series of the brightness of Mars and Jupiter, coinciding modes of 8-10 and 36-38 h were found. This coincidence apparently indicates their solar origin. In addition, for Mars, we obtained 25-day series of time variations of the reflected solar radiation, in which a mode with even a lower frequency of 8-10 days was detected. [ABSTRACT FROM AUTHOR]

The properties of the 12-h artifact in the data of the SDO/HMI instrument (Helioseismic and Magnetic Imager) caused by the nonzero radial velocity of the station relative to the Sun are investigated. The study has been carried out with respect to long-period oscillations of the magnetic field of sunspots for different station positions in the Earth’s orbit by the alternative spectral method of singular decomposition of the signal CaterPillarSSA. Features of artifact filtering, both in special positions of the station (at the points of aphelion and perihelion) and at arbitrarily selected orbital points, are considered. It is shown that the 12-h artifact mode can be completely filtered from the time series of the observed variable, not only at these two orbital points (because of the symmetry of the station’s radial velocity with respect to the zero mean here) but also at any others. It is shown that only a 12-h mode is physically justified, while the 24-h harmonic appears only as an artifact in the Fourier decomposition of the amplitude-modulated signal. It is emphasized that the values of the magnetic field measured with SDO/HMI are sensitive only to the station’s radial velocity absolute values with respect to the Sun and do not depend on its direction. It has been noted that the periods of sunspot oscillation as a whole obtained from SDO/HMI data after orbital artifact filtration fit well into the dependence diagram of the period of sunspot oscillations on the value of its magnetic field strength constructed earlier by SOHO/MDIdata. [ABSTRACT FROM AUTHOR]

Innovative nuclear energy system (INSS) designed to ensure effective use of uranium 238 and thorium 232 to produce energy. Maintain the neutron balance of this process requires the development and use of new types of nuclear fuel and structural materials. This requires the development of models to predict changes in their properties under the action of fields of different radiation, temperature, stress and exposure to various chemical substances. It is important achievement is not the limiting parameters, and the optimal combination of the properties of materials and their working conditions. In this paper parameters such as the fluence of fast neutrons, the reaction rate in the fuel rod cladding and the change of nuclide composition, in particular, developments of hydrogen and helium, influencing the change of the strength properties of steels, are calculated. [ABSTRACT FROM AUTHOR]

A numerical algorithm that correctly takes into account the force of gravity in the presence of density discontinuities is constructed using unstructured collocated grids and splitting algorithms based on SIMPLE-type methods. A correct hydrostatic pressure field is obtained by explicitly extracting the gravity force contribution to the pressure equation and computing it using the solution of the gravity equilibrium problem for a two-phase medium. To ensure that the force of gravity is balanced by the pressure gradient in the case of a medium at rest, an algorithm is proposed according to which the pressure gradient in the equations of motion is replaced by a modification allowing for the force of gravity. Well-known free-surface problems are used to show that, in contrast to previously known algorithms, the proposed ones on unstructured meshes correctly predict hydrostatic pressure fields and do not yield velocity oscillations or free-surface distortions. [ABSTRACT FROM AUTHOR]

The yolk syncytial layer (YSL) is a symplastic provisory system that forms at the early stages of embryogenesis of teleosts. The YSL serves morphogenetic, trophic, and immune functions. Despite its important role in development, data on the structure of YSL is scarce. In the present study, comparative histological research on the features of YSL structure in the development of larvae of four economically important species of Coregonidae (Salmoniformes)- Coregonus peled, Coregonus muksun, Coregonus nasus, and Stenodus leucichthys nelma-is presented. The YSL of the larvae of Coregonidae has a complex, differentiated structure. Functional regionalization of YSL cytoplasm, possibly determined by the specific features of nutrient assimilation, is typical for all aforementioned species. Cytoplasm that encircles a large oil globule appears striated. A division into an inner area, filled with yolk inclusions, and an outer, smoother homogeneous area, can be noted in the cytoplasm surrounding the yolk mass. The oil globule is retained after complete utilization of the yolk mass. The inequality of thickness of YSL along anteroposterior and dorsoventral axes also indicates the functional regionalization. The dorsomedial area of YSL, located under the intestine, is the least thick. Dorsolateral areas are strongly incrassated and envelop the intestine from two sides. Gigantic nuclei of exceptionally complex form are typical for YSL. Specific features apply to the form of YSL and its nuclei. Based on the obtained results, a fundamental similarity in organization of the YSL of larvae of the studied whitefishes can be concluded; however, its specific variations distinguishable on a histological level can be discussed. [ABSTRACT FROM AUTHOR]

This paper presents a numerical and experimental study of the shock-wave processes evolving inside a closed vessel filled with mineral oil. Obtained experimental Hugoniot data for oil are compared with the corresponding data for water. It is found that compression of mineral oil and water can be described by approximately the same Hugoniot over a wide pressure range. Such similarity allows the use of water instead of mineral oil in the transformer explosion experiments and to describe the compression processes in both liquids using similar equations of state. The Kuznetsov equation of state for water is adopted for a numerical study of mineral oil compression. The features of the evolution of shock waves within mineral oil are analyzed using two-dimensional numerical simulations. Numerical results show that different energy sources may cause different scenarios of loading on the shell. The principal point is the phase transition taking place at relatively high temperatures for the case of high-power energy sources. In this case, a vapor-gaseous bubble emerges that qualitatively changes the dynamics of compression waves and the pattern of loads induced on the shell. Taking into account the features of the process together with the concept of water-oil similarity, the present work presents a new approach for experimental modeling of transformer shell destruction using an explosion with given characteristics in a water-filled shell. [ABSTRACT FROM AUTHOR]

We have studied the electrical properties of ceramic NbTaO samples, examined the dispersion of the real part of their dielectric permittivity ε′ at room temperature, and assessed their lattice dielectric permittivity ε′ The temperature dependences ε′( T) have been obtained at different frequencies, and the dielectric loss tan δ has been evaluated as a function of measuring electric field frequency and temperature. The direct-current conductivity (σ) of the solid solutions has been determined at room temperature. Using impedance spectroscopy data, we have obtained temperature dependences of σ for the NbTaO ceramics and evaluated the activation enthalpy for charge transport in these materials in different temperature ranges. [ABSTRACT FROM AUTHOR]

For the first time, the ultra-low oscillation mode of the sunspot magnetic field strength has been detected with a high degree of confidence by ground-based observations of sunspots with the Global Oscillation Network Group (GONG) network of telescopes. Synchronous series of magnetograms derived from the GONG and Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) have been processed. They were obtained on September 27-30, 2010, for the active region NOAA 11109 with a total duration of 80 h. The periods of magnetic field oscillations found by space data coincide with the periods defined with GONG. This confirms the physical reality of the oscillatory process. The power spectrum contains harmonics with periods of 26 h, 8-10 h, and 3-4 h. [ABSTRACT FROM AUTHOR]

The data of ground-based telescopes of the Global Oscillation Network Group (GONG) obtained in the $\mathrm{H}\upalpha$ line provide an opportunity to study the long-period oscillations of chromospheric filaments (quiescent prominences). For the first time, on the basis of time series of 5 days duration that we combined from the observations of three observatories of the GONG network, a new ultra-low mode with a period of between 20 and 30 hours was reliably detected in oscillations of a long-lived dark filament on the solar disk. [ABSTRACT FROM AUTHOR]

The structure of the yolk syncytial layer (YSL) of the larvae of two cyprinids, Danio rerio and Cyprinus carpio koi, has been studied by transmission electron microscopy and by the histological methods. The structure of the YSL of these taxonomically related species of Teleostei is characterized by both similarity and dissimilarity in particular features, related to the overall shape of YSL, functional regionalization, and programmed death. Original and published data on the morphofunctional structure of the YSL have been discussed for representatives of Teleostei, Myxini, Chondrichthyes, Lepisosteiformes and Cephalopoda. [ABSTRACT FROM AUTHOR]

A method for measuring the mechanical recoil impulse of a target produced by the relativistic electron beam of the Calamary accelerator is described. A detector based on a piezoelectric sensor is used in measurements. Results of measurements are presented for the mechanical recoil impulse produced by the relativistic electron beam with an energy as high as 300 keV, a current of up to 30 kA, and a duration of ~100 ns that is incident on an epoxy target. The energy flux density on the target surface is varied in the range of 1-10 GW/cm. The maximum measured impulse value is 0.32 N · s at an energy flux density of 10 GW/cm (an energy fluence of 810 J/cm2). [ABSTRACT FROM AUTHOR]

The concept of detonation wave initiation in the local volume of a fuel-gas mixture containing suspended chemically neutral microparticles heated by radiant energy from an external source is proposed. Mechanisms of initiation of the combustion and detonation waves in a region of accumulation of the radiation- heated microparticles have been studied by numerical simulation methods. Criteria that determine geometric dimensions of a region of the two-phase medium, which are necessary for the initiation of detonation waves, are formulated. [ABSTRACT FROM AUTHOR]

The geometric parameters and relationships of the horizontal and vertical velocities in a giant convective cylindrical cell were analyzed based on a continuity equation with the given vertical distribution of unperturbed gas density in the convective zone of the Sun. It has been found that the lower edge of such a convective cell must be positioned at a depth of 20 Mm in the secondary helium ionization zone. In addition, under the assumption that the plasma conductivity in the convective zone is caused by small-scale turbulence, a new stationary solution was obtained for the problem of magnetic field diffusion in the pattern of slow conductive plasma flows in scales of a convective cell. [ABSTRACT FROM AUTHOR]

The sol-gel technique is used to study synthesis of lithium-lanthanum titanate LiLaTiO ( x = 0.167 and 0.11) using water-soluble salts of LiNO · 3HO, LaO and a citrate Ti(IV) complex. This process allows obtaining single-phase crystalline compounds of LiLaTiO and LiLaTiO with a perovskite structure after precursor sintering at 1000°C. The synthesized LiLaTiO powders are described using the methods of XRD, DTA/TG, and SEM microscopy. Conductivity of LiLaTiO by the Li ion is determined using the impedance spectrometry technique in the range of 1-2 × 10 Hz and is 8 × 10- S/cm at the room temperature. The temperature dependence is studied and the activation energy of ion conductivity of LiLaTiO is studied in the range of 25-200°C. [ABSTRACT FROM AUTHOR]

Three independent sets of data: (i) series of filtergrams obtained in line CaII K (393.416 nm) with the ground-based telescope Precision Solar Photometric Telescope (PSPT) of Mauna Loa Solar Observatory; (ii) series of filtergrams of Atmospheric Imaging Assembly (AIA) of the Solar Dynamics Observatory (SDO) in λ160 nm and (iii) series of magnetograms of Helioseismic and Magnetic Imager (HMI) of SDO have been processed to reveal reliably the existence of spatial cellular structures on the solar photosphere at scale about of 300 arcsec. This scale is intermediate between supergranules and giant cells (∼30,000 and ∼300,000 km across, respectively). To identify the different spatial structures the tens of two-dimensional power spectra ( 2DFFT) have been averaged. For one-dimensional photometric cross sections of frames, the Fourier power spectra ( FFT) and wavelet transforms (Morlet 5-th order) have been calculated. [ABSTRACT FROM AUTHOR]

The studyof detonation-like mode of laser induced damage propagation was considered. Velocity of this propagation is two orders of magnitude faster than known published data on burning fiber glass. The condition of optical fiber and enough long laser pulse let us obtain laser induced damage propagation passing near hundred own core diameters during pulse. The using as target the core of silica-based optical fiber has some diagnostic advantages. It allows spatially splits "start" and "stop" points and to supply the same form of energy deposition in every cross section of optical fiber. Tested regime demonstrates near constant velocities during 250 ns in the range of laser intensity 2-4.5 GW/cm2. [ABSTRACT FROM AUTHOR]

Long (up to 100 hours) time series of SOHO/ MDI Doppler data are analyzed. The power spectrum of radial velocity time series in the quiet photosphere is observed to have, along with the known 5-min mode, a stable strong mode with a period of about 32 h, which is close to the supergranulation cell lifetime. The spatial distribution of the amplitudes of these oscillations also coincides with the characteristic size scale of supergranulation (∼35 Mm). [ABSTRACT FROM AUTHOR]

We have studied the structural and electrical properties of the LiNaNbO solid solution prepared by a conventional ceramic processing technique and high-temperature, high-pressure synthesis. The synthesis of the LiNaNbO solid solution at high pressure and temperature ( p = 6 GPa, T = 1400-1800 K) allows one to achieve a higher degree of structural order and better microhomogeneity. This is accompanied by a considerable increase in dielectric permittivity and ionic conductivity, because ion transport is contributed by the grain boundaries of the ceramic, which have a considerably larger area than those in the LiNaNbO solid solution prepared by conventional ceramic processing. [ABSTRACT FROM AUTHOR]

Results of X-ray diffraction, dielectric, and Raman studies of the ferroelectric Li0.125Na0.875NbO3solid solution obtained under hot-pressing conditions (6 GPa, 1400 and 1800 K) are compared with those of the same compound synthesized by conventional ceramics technology. The thermo-barometric synthesis is found to improve the ordering of cations and to increase the value of dielectric permittivity and ion conductivity of the ceramics. [ABSTRACT FROM PUBLISHER]

Two types of pneumatic pressure difference sensor-transducers for an integration of universal automated liquid dosage systems (ADS) are considered. Recommendations for the choice of sensor type depending of physical and chemical properties of dosed compositions are given. It is shown that the use of manometer type sensor with blind-end measuring type allows to broaden functional possibilities of ADS to work with viscous liquids environments. The description of functional diagram of batching ADS with sensor transducer of manometer type. [ABSTRACT FROM AUTHOR]

The theory of the nonstationary diffusiophoresis of a large spherical solid particle in a viscous gaseous medium is beginning to be constructed. Hydrodynamic and diffusion problems are divided into stationary and strictly nonstationary parts. The solution of the stationary parts of these problems has yielded the final formula for determining the stationary component of the diffusiophoretic velocity of the particle considered. A corresponding formula in the space of Laplace images has been obtained for determining the nonstationary component of the diffusiophoretic velocity of this particle. [ABSTRACT FROM AUTHOR]

Long-period oscillations of the magnetic field and the line-of-sight velocity have been detected in sunspots based on the synchronous 90-h time series of magnetograms and dopplergrams obtained with the MDI(SOHO) device. The sunspot eigenmode (12–30 h), the periods of which nonlinearly depend on the magnetic field strength, predominates in the magnetic field oscillation spectrum. The mode, which is probably induced by motions of supergranulation cells (33 h), predominates in the sunspot line-of-sight velocity oscillation spectrum. A strong mode (33 h), which indicates that long-period quasi-oscillations of supergranulation exist, was also detected in the velocity power spectrum for a quiet photosphere, together with the known 5-min mode. [ABSTRACT FROM AUTHOR]

An analysis of oscillatory processes with periods not shorter than several tens of minutes in three isolated sunspots, which were observed during identical periods in the optical and radio bands, is illustrated. SDO/HMI magnetograms at an interval of 45 s and radio maps at a wavelength of 1.76 cm, obtained using a Nobeyama radioheliograph (NoRH), have been used. The time profiles, which were constructed based on the NoRH and SDO/HMI data, indicate that the oscillations of the radioemission correlate with those of the sunspot magnetic field. The wavelet spectra and cross-wavelet transform reveal common oscillation periods of 30–40, 70–100, and 150–200 min. The identical oscillation periods, found using fundamentally different methods from ground-based and space observations, confirm the solar nature of these oscillations, which can be interpreted as oscillations of a sunspot as a whole. [ABSTRACT FROM AUTHOR]

Synthesis from aqueous peroxide solutions provides lithium-aluminum titanophosphate LiAlTi(PO) (LATP) with particles of submicron size and conductivity of (4-5) × 10 S/cm at the room temperature. LATP were characterized using the methods of XRD, DTA/TG, measurement of specific surface area, ionic and electronic conductivity. According to XRD, a single-phase crystalline product with the specific surface area of 8.2 m/g is formed as a result of precursor sintering at 700°C (the average particle size of electrolyte was 250 nm). Sizes of coherent-scattering region were calculated on the basis of the values of intrinsic broadening of diffraction maximums. Analysis of broadening of diffraction maximums indicates that the size of primary LATP crystallites after sintering at 700°C was 90 nm according to peak (113) (2θ = 24.5°) and 110 nm according to peak (104) (2θ = 20.9°). The synthesized submicron LATP powders are suitable for formation of solid electrolyte films using the method of aerosol deposition. [ABSTRACT FROM AUTHOR]

We compare the microstructure, electrical properties, and Raman spectra of ceramic samples of the LiNaTaNbO ferroelectric solid solution prepared by a conventional ceramic processing technique using ceramic powders with different particle sizes. The LiNaTaNbO solid solutions prepared from the powders of different particle sizes are shown to differ only slightly in average grain size, pore size, and porosity, but the particle size of the ceramic powder has a significant effect on their electrical properties. The difference in properties between the samples is due not so much to the difference in particle size between the parent ceramic powders as to the fact that the diffusion processes involved in solid-state synthesis may give rise to composition gradients, and grains that differ in size may differ in microstructure and composition. [ABSTRACT FROM AUTHOR]

It is shown that long-period (T = 10-20 h) oscillations of the magnetic field in sunspots, combined in bipolar groups, are excited synchronously in the main and tail spots of a group. At the same time, there is no correlation between long-period oscillations of the field of sunspots which are in different active regions, i.e., spaced sunspots oscillate independently. This fact eliminates the question about the apparatus nature of the oscillations of interest (if there is an artifact, oscillations of all sunspots on the visible solar hemisphere would be synchronous!). High-resolution (0.5 angular seconds per pixel) MDI(SOHO) data show a high correlation between long-period oscillations of the magnetic field at isolated points of the sunspot shadow. This points to the fact that the sunspot shadow participates in long-period oscillations as a quite integral physical formation. [ABSTRACT FROM AUTHOR]

The microstructure and electrical properties of two samples of the ferroelectric Li0.03Na0.97Ta0.05Nb0.95O3ceramic solid solution prepared from initial charge stocks of different dispersity by conventional ceramics technology are compared. The average size of grains and concentration of pores in the samples are found to be of little difference while the electrical properties of the ceramics are strongly affected by the grain size of the initial mixture. The difference in properties is due to conditions at the diffusion stage of the solid-phase synthesis caused by differences in composition of larger grains rather than the grain size itself. [ABSTRACT FROM AUTHOR]

A data acquisition system of the focusing double-arm spectrometer (FODS) setup is described. The information from each recording electronic module is read in response to each trigger by an ЛЭ-74 high-speed controller with a buffer memory and is transmitted by a PCI-7200 extension card to the computer memory at the end of the spill. All crates are read in parallel, ensuring a high speed of operation of the system (8000 events per spill for one spectrometer arm). The system is able to read data from different detectors (drift chambers, proportional chambers, calorimeters, Cherenkov radiation ring spectrometer, etc.), possesses a high flexibility, i.e., ensures readout of information for several types of triggers (inclusive, arm coincidence, two particles in one arm, etc.), and enables calibration of detectors in each spill. The software is based on the MIDAS project with an open initial code and allows one to control operation of all detectors during experiments. [ABSTRACT FROM AUTHOR]

The time ranges of the fracture of polymethylmethacrylate and polystyrene during the action of a shock wave generated by a high-current pulsed electron beam are experimentally determined using laser probing in combination with electron-optical chronography. It is shown that fractures occur during unloading of a material, i.e., after the passage of the shock wave. Although the characters of fracture of these polymers near the surface irradiated by electron beam are different, the fracture wave velocities in them are found to be close. [ABSTRACT FROM AUTHOR]

A monitoring system comprising ionization and scintillation monitors has been developed to measure the intensity and to control the quality of the beam at the FODS spectrometer. The system has been designed for operation with beam intensities of 10-10 particles/s. The characteristics of the system components are presented. [ABSTRACT FROM AUTHOR]

As a result of processing long (up to 144 h) series of sunspot magnetograms obtained on the SOHO (Solar and Heliospheric Observatory) spacecraft with the MDI (Michelson Doppler Imager) instrument it is shown that the mode with a period of 800-1300 min is a limiting low-frequency oscillation mode of the magnetic field of a sunspot as a whole. Its period is essentially and nonlinearly depends on the sunspot magnetic field strength. In addition to this mode, higher harmonics are also revealed in the sunspot oscillation spectra in the bands 40-45, 60-80, 135-170, 220-250, and 480-520 min. The oscillation power in these bands monotonically and rapidly decreases with increasing frequency, which is characteristic for overtones arising due to the nonlinear nature of oscillations. The limiting oscillation mode stably exists in sunspots for 1.5-2 days, which coincides with the average lifetime of a supergranular cell. The mode with the period of 35-48 h observed in the power spectrum is not an eigen mode of sunspots, because its period is independent of its magnetic field strength. Probably, it occurs as a quasiperiod of an external exciting force caused by disturbances from supergranular cells surrounding the sunspot. [ABSTRACT FROM AUTHOR]

Results of studies of dielectric properties and conductivity in 290–700 K range of temperature and frequencies from 25 to 106 Hz in ferroelectric perovskite solid solutions Li0.07Na0.93Ta0.1Nb0.9 O3 and Li0.07Na0.93Ta0.111Nb0.889 O3 are reported. A first-order ferroelectric phase transition proceeds in both studied compositions within the observed range of temperature. The co-precipitated Ta2yNb2(1-y)O5 pentoxides being used for synthesis of Li0.07Na0.93Ta0.111Nb0.889O3 the Curie point shifts by ∼75 K to a lower temperature while compared with Li0.07Na0.93Ta0.1Nb0.9O3 synthesised from mechanical mixture of the Ta2O5 and Nb2O5 oxides the high-frequency dielectric permittivity and ion conductivity of relatively low value of activation enthalpy increases. [ABSTRACT FROM PUBLISHER]

Results of the studies of electric and elastic parameters as functions of concentration in ferroelectric LiхNa1-хTa0.1Nb0.9O3 (x = 0-0.16) solid solutions and comparative studies of the elastic properties by acoustic and contact probe techniques are reported. The electric and elastic properties of LiхNa1-хTa0.1Nb0.9O3 solid solutions are shown to be rather sensitive to structural distortion at concentration-induced structural phase transitions. The values of elastic modules obtained from acoustic measurements are found to be in good agreement with those obtained by contact probe techniques. [ABSTRACT FROM AUTHOR]

We applied special data-processing algorithms to the study of long-period oscillations of the magnetic-field strength and the line-of-sight velocity in sunspots. The oscillations were investigated with two independent groups of data. First, we used an eight-hour-long series of solar spectrograms, obtained with the solar telescope at the Pulkovo Observatory. We simultaneously measured Doppler shifts of six spectral lines, formed at different heights in the atmosphere. Second, we had a long time series of full-disk magnetograms (10 - 34 hour) from SOHO/MDI for the line-of-sight magnetic-field component. Both ground- and space-based observations revealed long-period modes of oscillations (40 - 45, 60 - 80, and 160 - 180 minutes) in the power spectrum of the sunspots and surrounding magnetic structures. With the SOHO/MDI data, one can study the longer periodicities. We obtained two new significant periods (> 3 σ) in the power spectra of sunspots: around 250 and 480 minutes. The power of the oscillations in the lower frequencies is always higher than in the higher ones. The amplitude of the long-period magnetic-field modes shows magnitudes of about 200 - 250 G. The amplitude of the line-of-sight velocity periodicities is about 60 - 110 m s. The absence of low-frequency oscillations in the telluric line proves their solar nature. Moreover, the absence of low-frequency oscillations of the line-of-sight velocity in the quiet photosphere (free of magnetic elements) proves their direct connection to magnetic structures. Long-period modes of oscillation observed in magnetic elements surrounding the sunspot are spread over the meso-granulation scales (10″ - 12″), while the sunspot itself oscillates as a whole. The amplitude of the long-period mode of the line-of-sight velocity in a sunspot decreases rapidly with height: these oscillations are clearly visible in the spectral lines originating at heights of approximately 200 km and fade away in lines originating at 500 km. We found a new interesting property: the low-frequency oscillations of a sunspot are strongly reduced when there is a steady temporal trend (strengthening or weakening) of the sunspot's magnetic field. Another important result is that the frequency of long-period oscillations evidently depends on the sunspot's magnetic-field strength. [ABSTRACT FROM AUTHOR]

We propose mathematical models for determining the parameters of mechanical action under volumetric absorption of intense energy fluxes acting on targets consisting of heterogeneous materials. We focus on spheroplastics-materials having in their composition multilayer hollow microspheres. [ABSTRACT FROM AUTHOR]

We have studied the electrical and elastic properties of Li xNa1 − xTa0.1Nb0.9O3 ( x = 0–0.16) ferroelectric ceramic solid solutions. The results demonstrate that these properties of the Li xNa1 − xTa0.1Nb0.9O3 solid solutions are rather sensitive to the lattice distortions resulting from compositional structural phase transitions. The elastic constants determined by acoustic and contact techniques agree well. [ABSTRACT FROM AUTHOR]

We present the results of processing three 256-min series of observations of quasi-periodic oscillations of the field of line-of-sight velocities in three sunspots. The Doppler shifts were determined simultaneously for six spectral lines formed at different heights in the solar atmosphere. In addition to the well-known high-frequency (periods of 3–5 min) oscillations, a band of low-frequency oscillations with periods of 60–80 min is revealed in the spectra of the sunspot umbra and magnetic elements located in immediate proximity of the sunspot. Unlike the short-period modes, the power of the long-period mode of line-of-sight velocity oscillations in the sunspot decreases sharply with height: these oscillations are distinctly seen in the line formed at a height of 200 km and almost are not seen in the line with the formation height of 500 km. This is indicative of different physical nature of the short-period and long-period oscillations of a sunspot. If the former are caused by slow magnetosonic waves within the field tube of the spot, the latter are representative of global vertical-radial oscillations of a magnetic element (spot, pore) as a whole near the position of a stable equilibrium. [ABSTRACT FROM AUTHOR]

Abstract: A novel target configuration for equation of state measurements using intense ion beams is proposed. It is based on a stack consisting of several thin foils which expand quasi-statically when heated with the ion beam. The merging of the single foils causes a sharp increase of the expansion velocity. Together with the known energy deposition of the ion beam this allows direct determination of equation of state data. The parameters of the stack target were optimized with hydrodynamic calculations. Finally, a simple analytical model to predict the expansion velocity was developed. [Copyright &y& Elsevier]

Allozyme variation of chum salmon Oncorhynchus keta was examined in the populations from nine rivers of the Russian Far East. A total of 12 loci were tested, and eight of these were shown to be polymorphic. The greatest contribution to the samples differentiation was made by the EST-D1* and sIDHP-2* loci. Most of the allele diversity was distributed among the individuals within the samples. The among-sample differences within races were statistically significant and accounted for slightly more than 7% of total variation. The differences between the races constituted 0.1% and were statistically nonsignificant. Genetic similarity of seasonal races within single locality allowed suggestion on their secondary formation after settling of founder population into a certain region. [ABSTRACT FROM AUTHOR]