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The assessment of the stock status and prospects for the fishery of the Barents Sea cod is characterized by significant uncertainty caused by the peculiarities of the age structure, which often led to significant differences in the results obtained using different models. As a result, this caused intense discussions both within the framework of the International Council for the Exploration of the Sea (ICES) and at the meetings of the Joint Norwegian-Russian Fisheries Commission. In 2021, at a specialized ICES workshop («benchmark» group), the input data and configuration of the main assessment model - SAM, were refined, related to the inclusion of additional information on older age groups. As a result, two models currently used by the ICES working group to estimate cod stock (SAM and TISVPA), which are very different in their approaches, showed that the number of generations born in 2004–2005 significantly decreased, which led to a decrease in cod biomass. An assessment of the prospects for the state of the stock, performed both on the basis of calculations using the SAM model and on the basis of an alternative approach using the AMO (Atlantic Multidecadal Oscillation Index), showed a high probability of further decline and stabilization of the spawning stock biomass (and catches) in the next 2–3 years, after which restoration of spawning stock biomass is likely due to sufficiently abumdante generations born in 2011 and 2014.

We performed multi-frequency studies on the gigahertz-peaked spectrum high-redshift quasar 0858-279. Initially, the source presented itself in the early VLBI images as a very peculiar resolved blob. We observed the quasar with the VLBA at 1.4-24 GHz in a dual-polarization mode. The high spatial resolution and the spectral index maps enabled us to resolve the core-jet structure and locate a weak and compact core by its inverted spectrum. The dominant jet component 20 parsecs away from the core was optically thin above 10 GHz and opaque below it. We also estimated an uncommonly strong magnetic field in the bright jet feature, which turned out to be around 1 G. The Faraday rotation measure maps revealed high RM values over 6000 rad/m^2. Additionally, these maps allowed us to follow the magnetic field direction in the bright jet feature being perpendicular to the propagation direction of the jet. All the results strongly indicated the formation of a shock wave in the dominant component arising from an interaction with the surrounding matter. Using the proposed hypothesis and the core shift approach, we discovered that the magnetic field in the core region is of the order of 0.1 G., Comment: 15 pages, 12 figures, accepted for publication in MNRAS

Evidence for bright radio blazars being high-energy neutrino sources was found in recent years. However, specifics of how and where these particles get produced still need to be determined. In this paper, we add 14 new IceCube events from 2020-2022 to update our analysis of the neutrino-blazars connection. We test and refine earlier findings by utilising the total of 71 track-like high-energy IceCube events from 2009-2022. We correlate them with the complete sample of 3412 extragalactic radio sources selected by their compact radio emission. We demonstrate that neutrinos are statistically associated with radio-bright blazars with a post-trial p-value of 3*10^-4. In addition to this statistical study, we confirm previous individual neutrino-blazar associations, find and discuss several new ones. Notably, PKS 1741-038 was selected earlier and had a second neutrino detected from its direction in 2022; PKS 0735+168 has experienced a major flare across the whole electromagnetic spectrum coincidently with a neutrino arrival from that direction in 2021., 10 pages, 5 figures, 2 machine-readable tables; V2: minor changes and updates, accepted by MNRAS

Neutron diffraction studies on the small-angle neutron spectrometer YuMO (Joint Institute for Nuclear Research, Dubna), based on the IBR-2 pulsed reactor, have been reviewed. The main parameters of small-angle spectrometers, based on the time-of-flight technique, are considered. It is shown that the flux on sample is the key parameter of the spectrometers based on pulsed sources, which makes it possible (along with application of a multidetector system) to expand the dynamic range of scattering vector magnitudes. The history of the setting up of the first small-angle instrument based on pulsed sources is overviewed. The directions of development of small-angle spectrometers are shown. The results of YuMO studies in the fields of polymers, biology, materials science, and physical chemistry are briefly reviewed. The main strategies of development of small-angle neutron scattering on pulsed sources are considered. The possibilities of the small-angle instruments based on a synchrotron source and on a neutron pulsed source are compared.

The possible association with the high-energy neutrino event IceCube-170922A has sparked interest in the blazar TXS 0506+056. We present 72 instantaneous 1–22 GHz spectra measured over the past 20 years with the RATAN-600 telescope and compare them with the results of observations of 700 variable Active Galactic Nuclei (AGN) studied within the same program. The recent radio flare of TXS 0506+056 started from a minimum in 2013 and reached its first peak in December 2017 and a second peak in May-June 2018. This was the third strong radio flare in this source since 1997. The spectrum remains nearly flat during the flares. The spectral shape and variability pattern observed in TXS 0506+056 are typical for variable AGN. RadioAstron Space VLBI observations in 2013–2015 did not detect TXS 0506+056 on space-ground baselines of more than 9 Earth diameters. However, an observation on 23 September 2015 resulted in the detection of interferometric signal on 6 Earth diameter baselines at 18 cm close to the detection limit. We consider the possibility that TXS 0506+056 and other AGN may accelerate relativistic protons more efficiently than electrons. Relativistic protons are necessary to produce both the high-energy neutrinos observed in the IceCube Observatory and the high AGN brightness temperatures implied by the RadioAstron detection. They may also provide the main contribution to the observed synchrotron radiation of parsec-scale AGN jets. This supports the suggestion that relativistic protons may play a much more important part in extragalactic astrophysics than earlier anticipated.

An approach to constructing semiempirical equations of state of molecular crystals of nitro compounds is suggested allowing one to describe isothermal compression of the crystal of triaminotrinitrobenzene (1,3,5-triamino-2,4,6- trinitrobenzene) by the familiar modulus of three-dimensional compression and sublimation heat of the crystal obtained from experiments not related to isothermal compression. A comparative analysis of experimental data on isothermal compression of the molecular crystal of triaminotrinitrobenzene and calculations by the proposed equation of state have shown that the experimental and calculated values of pressure are within the limits of experimental uncertainty.

The Silicon Photomultiplier (SiPM) is a novel semiconducting photodetector which can detect single photons. It consists of many microcells (pixels) operating in the so-called Geiger mode. At present, there are two principal designs among such devices: surface pixel and deeply buried pixel (microwell) structures. The cellular structure decreases the device’s effective photosensitive area, expressed in terms of the geometrical fill factor. It is very important to take it into account when developing new constructions with high pixel densities that are necessary for increasing the dynamic range. It is believed that the fill factor of deep microwell SiPMs is close to unity. In this work, the technique and results of studying the zonal response of different SiPMs by scanning (moving) with micron laser spot are presented. It is shown that the geometrical fill factor of the deep microwell SiPM is less than 100% when detecting the red light (λ = 632 nm).

A method of “self-calibration” of two sectors of the RATAN-600 radio telescope based on synchronous measurements of strong extragalactic sources, including variable ones, is proposed. The method gives refined corrections to the standard calibration of each of the telescope’s sector. It is based on the fact that ideal synchronous independent measurements of the same object should give the same results. Differences from the unity of the result of approximating the flux ratio synchronously measured at two sectors for a subsample of strong sources are considered as systematic calibration errors and used to calculate corrections that exclude these errors, and are applied to measurements of all sample objects in this observation cycle. The method was tested with RATAN-600 two sectors in meridian multifrequency measurements and can be used for independent pairs of any closely spaced antennas. In this case, the analog of RATAN-600 sector is a separate telescope. For far-spaced antennas, an additional error will be introduced due to different effects of the atmosphere and altitude of objects during synchronous observations.

An analytical model of the equation of state is developed based on theoretical ideas about the structure of TATB. ^The model is validated against experimental data obtained in static and dynamic experiments. The theoretically sound equation of state was used to match different experimental data in order to maximize the use of empirical information. It is expected that the use of the equation of state will increase the accuracy of the description of thermodynamic parameters of unreacted TATB in numerical simulations of shock-wave and detonation processes.

This paper presents the form of the equations of state of molecular crystals of nitro compounds constructed on the basis of dividing Helmholtz free energy into an intramolecular and an intermolecular components. This division enabled us to determine the form of the Gruneisen equation for molecular crystals, the volume dependence of the Gruneisen coefficient, and the temperature dependence on the volumetric expansion coefficient. Comparative analysis of the calculated and experimental values of volumes of elementary cells of triaminotrinitrobenzene crystals depending on the temperature has shown their fair agreement.

We present Space-VLBI RadioAstron observations at 1.6 GHz and 4.8 GHz of the flat spectrum radio quasar 3C 273, with detections on baselines up to 4.5 and 3.3 Earth Diameters, respectively. Achieving the best angular resolution at 1.6 GHz to date, we have imaged limb-brightening in the jet, not previously detected in this source. In contrast, at 4.8 GHz, we detected emission from a central stream of plasma, with a spatial distribution complementary to the limb-brightened emission, indicating an origin in the spine of the jet. While a stratification across the jet width in the flow density, internal energy, magnetic field, or bulk flow velocity are usually invoked to explain the limb-brightening, the different jet structure detected at the two frequencies probably requires a stratification in the emitting electron energy distribution. Future dedicated numerical simulations will allow the determination of which combination of physical parameters are needed to reproduce the spine-sheath structure observed by Space-VLBI with RadioAstron in 3C 273. © ESO 2021., JLG and AF acknowledge financial support from the Spanish Ministerio de Economia y Competitividad (grants AYA2016-80889-P, PID2019-108995GB-C21), the Consejeria de Economia, Conocimiento, Empresas y Universidad of the Junta de Andalucia (grant P18-FR-1769), the Consejo Superior de Investigaciones Cientificas (grant 2019AEP112), and the State Agency for Research of the Spanish MCIU through the Center of Excellence Severo Ochoa award for the Instituto de Astrofisica de Andalucia (SEV-2017-0709). APL, YYK, and ABP were supported by the Russian Science Foundation (project 20-62-46021). TS was partly supported by the Academy of Finland projects 274477 and 315721. MP acknowledges the support by the Spanish Ministerio de Ciencia e Innovacion (MICINN) under grant PID2019-105510GB-C31. MP and JMM acknowledge financial support from the Spanish Ministry of Science through Grants PID2019-107427GB-C33 and AYA2016-77237-C3-3-P, and from the Generalitat Valenciana through grant PROMETEU/2019/071. JMA was supported by the German Research Foundation grant HE5937/2-2. LIG acknowledges support by the CSIRO Distinguished Visitor Programme. The RadioAstron project is led by the Astro Space Center of the Lebedev Physical Institute of the Russian Academy of Sciences and the Lavochkin Scientific and Production Association under a contract with the Roscosmos State Corporation, in collaboration with partner organizations in Russia and other countries. This publication has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 730562 [RadioNet].

The largest Key Science Program of the RadioAstron space VLBI mission is a survey of active galactic nuclei (AGN). The main goal of the survey is to measure and study the brightness of AGN cores in order to better understand the physics of their emission while taking interstellar scattering into consideration. In this paper we present detection statistics for observations on ground-space baselines of a complete sample of radio-strong AGN at the wavelengths of 18, 6, and 1.3 cm. Two-thirds of them are indeed detected by RadioAstron and are found to contain extremely compact, tens to hundreds of $\mu$as structures within their cores., Comment: Accepted to the Advances in Space Research special issue "High-resolution Space-Borne Radio Astronomy"

Recently we have shown that high-energy neutrinos above 200 TeV detected by IceCube are produced within several parsecs in the central regions of radio-bright blazars, that is active galactic nuclei with jets pointing towards us. To independently test this result and extend the analysis to a wider energy range, we use public data for all neutrino energies from seven years of IceCube observations. The IceCube point-source likelihood map is analyzed against the positions of blazars from a statistically complete sample selected by their compact radio flux density. The latter analysis delivers a 3.0 sigma significance with the combined post-trial significance of both studies being 4.1 sigma. The correlation is driven by a large number of blazars. Together with fainter but physically similar sources not included in the sample, they may explain the entire IceCube astrophysical neutrino flux as derived from muon-track analyses. The neutrinos can be produced in interactions of relativistic protons with X-ray self-Compton photons in parsec-scale blazar jets., Comment: 14 pages, 5 figures; accepted to ApJ; v2: extended and clarified discussion, added a diagram; v3: improved numerical estimates

We propose a criterion of transversality and disjointness for the Friedrichs and Krein extensions of a nonnegative symmetric operator in terms of the vectors {φj, j ϵ 𝕁} that form a Riesz basis of the defect subspace. The criterion is applied to the Friedrichs and Krein extensions of the minimal Schrodinger operator Ad with point potentials. We also present a new proof of the fact that the Friedrichs extension of the operator Ad is a free Hamiltonian.

We perform a numerical analysis of various modifications of the large-particle method applied to problems of wave dynamics (gas dynamics). We use modifications of the large-particle method to solve the problems on calculation of the decay of an arbitrary discontinuity, propagation of shock waves and propagation of rarefaction waves. Calculations of the propagation of stationary shock waves show that all considered modifications of the large-particle method allow to calculate correctly a pressure behind the shock wave, despite the fact that a width of the shock transition zone and a profile of the shock wave pressure in the zone depend on the modification of the large-particle method. During solving the problem on the decay of an arbitrary discontinuity, we show that the solution obtained by modified large-particle method with recalculation of pressure at the Euler stage best coincides with the analytical solution to the problem, both in the region of the shock wave and in the rarefaction wave region. A significant advantage of this modification is the fact that the considered problems can be solved without introducing the "artificial" viscosity into the laws of conservation.

The results of updating the parameters of motion of the Spektr-R spacecraft at the end of 2016 have shown that, in January 2018, with a probability close to unity, the condition that a spacecraft stay in the Earth’s shadow is violated; however, in May of the same year, the ballistic life of the spacecraft will be terminated. Thus, in 2017, the question arose of how to design the correction of flight of this spacecraft using its onboard propulsion system. The correction was designed with allowance for the fact that, for the first time since it was launched, the spacecraft in the course of several years, beginning with 2017, repeatedly approaches the Moon, deeply immersing into its sphere of influence. This paper presents the technologically and organizationally convenient, allowable versions of upcoming correction of the Spektr-R spacecraft trajectory and justifies the particular scheme of its implementation.

We observed with the VLBA at 2.3 and 8.6 GHz a complete flux-density limited sample of 482 radio sources with declination >+75 degrees brighter than 200 mJy at 1.4 GHz drawn from the NVSS catalog. 34% of the sources show parsec-scale emission above the flux density detection limit of 30 mJy; their accurate positions and parsec-scale structure parameters are determined. Among all the sources detected at least at the shortest VLBA baselines, the majority, or 72%, has a steep single-dish spectrum. The fraction of the sources with a detectable parsec-scale structure is above 95% among the flat-spectrum and close to 25% among the steep-spectrum objects. We identified 82 compact steep-spectrum source candidates, which make up 17% of the sample; most of them are reported for the first time. The compactness and the brightness temperature of the sources in our sample show a positive correlation with single-dish and VLBA spectral indices. All the sources with a significant 8 GHz variability were detected by the VLBA snapshot observations, which independently confirmed their compactness. We demonstrated that 54% of the sources detected by the VLBA at 2.3 GHz in our sample have a steep VLBA spectrum. The compact radio emission of these sources is likely dominated by optically thin jets or mini-lobes, not by an opaque jet core. These results show that future VLBI surveys aimed to search for new sources with parsec-scale structure should include not only flat-spectrum sources, but also steep-spectrum ones in order to reach an acceptable level of completeness., 27 pages, 16 figures (of them, 4 are figure sets), 7 tables (of them, 5 are machine readable); accepted to The Astronomical Journal. The machine readable tables and complete figure sets can be downloaded as ancillary files

The skew-symmetric problem of bending vibration of a thick-walled finite-length shell with sliding fixation of its ends is studied within the framework of the theory of elasticity. The boundary-value problem is reduced to an infinite system of singular integral equations of the second kind. The expressions for the amplitude value of relative circumferential stress are obtained as functions of the dimensionless wave number. On the basis of the developed analytic algorithm, we performed a numerical experiment and obtained a great amount of graphic data containing both the quantitative and qualitative characteristics of bending vibration of a thick-walled shell depending on its geometric parameters and Poisson’s ratio of the material of the shell.

In 2010 commercial fishing of Greenland halibut in the Barents Sea was reopened. But due to poor fitting of the previous model to input data, management of fishery is currently being performed using the survey trends. In this paper, the calculations of the Barents Sea halibut stock based on the Schaefer production model have been presented and some conclusions about the applicability of this model have been made. Ключевые слова: черный палтус, оценка запаса, продукционная модель, Шефер, биомасса.

In this paper we present a solution of the model problem on the interaction of spherical shock waves with a heterogeneous layer located near a plane surface. The heterogeneous layer is a two-phase medium consisting of solid particles and a reactive gas phase. The gas phase composition is close to the composition of gaseous products of pyrolysis of forest combustible materials. It has been shown that oxidation reaction of carbon oxide leads to an accelerated rise in temperature and pressure in the gas phase and contributes to an increase in the velocity of propagation of the shock wave in a heterogeneous medium.

We consider a symmetric problem of the theory of elasticity for the stressed state of a thick-walled shell whose end faces are covered with a diaphragm. The boundary-value problem is reduced to an infinite system of singular integral equations of the second kind. The expressions for stresses characterizing the stressed state of this shell are deduced. Based on the developed analytic algorithm, we performed numerical experiments whose results are represented in the graphical form and contain new quantitative and qualitative data about the stressed state of a thick-walled shell depending on its geometric parameters and Poisson’s ratios of its materials.

To interpret radio interferometric observations sensitive to linear polarization it is necessary to take into account the effect of instrumental or “parasitic” polarization. In the case of ground-space very-long-baseline interferometry, this procedure involves a session of polarization-sensitive mapping with the sufficient number of ground stations and sufficiently small projections of ground-space baselines. In the paper, the problem of estimating the value of the instrumental polarization of the Spectr-R space radio telescope of the RadioAstron project using the results of the early scientific program for observing active galactic nuclei is addressed. We use a statistical approach to estimate the value of the instrumental polarization associated with the analysis of already obtained to present time intermediate results of the review of brightness temperatures. Estimates obtained for the frequency bands C and L (95% probability intervals [0.0646, 0.1267] and [0.0945, 0.1736] for 6 and 18 cm, respectively) suggest that the instrumental polarization of the radio telescope does not exceed the values typical for the ground VLBI stations.

An analysis has been made of the invariance of a widely used mathematical model of a "frozen" gas suspension with respect to the Galilean transformation. It has been shown that the equations of this model are not invariant with respect to the Galilean transformation, which results in a fictitious source term in the energy equation. Additional entropy increase leads to a violation of the second law of thermodynamics. In this work, the authors have proposed a modification of the "frozen"-gas-suspension model that leads to its invariance with respect to the Galilean transformation. Calculations have been performed and comparisons with an invariant model have been made.

A lifelong path of glory: on the 70th anniversary of the Chair of Dermatovenerology, South Ural State Medical University

The results of a large number of the antenna radiometric measurements at bands of 92, 18, 6.2, 1.35, and 1.7-1.2 cm are presented by the data of the standard telemetry system of the Spektr-R spacecraft. Both special sessions of calibration object observations in the mode of a single space radio telescope (SRT) operation and numerous observations of researched sources in the mode of the ground-space interferometer were used. The obtained results agree with the first results of Kardashev et al. (2013), i.e., within 10–15% at bands of 92, 18, and 6.2 cm and 20–25% at the band of 1.35 cm. In the main, the measurements for the eight subbands at wavelengths of 1.7-1.2 cm indicate a monotonic increase in the spectral system equivalent flux density (SEFD) of noise radiation with a frequency consistent with the calculated estimates for the discussed model. The sensitivity of the ground-space interferometer for the five subbands at wavelengths from 1.35 to 1.7 cm can be higher by a factor of 1.5, and for the three subbands from 1.35 to 1.2 cm lower by a factor of 1.5 than at the band of 1.35 cm. The SRT contribution to the interferometer sensitivity proportional to the square root of SEFD is close to the design one at the bands of 92 and 18 cm and decreases the design sensitivity approximately by a factor of 1.5 and 2 at the bands of 6.2 and 1.35 cm, respectively. These differences of implemented values from the design ones were not significantly affected the scientific program implementation.

Both traditional coolant purification methods (by means of traps and sorbents for removing cesium), the use of which supported successful operation of nuclear power installations equipped with fast-neutron reactors with a sodium coolant, and the possibility of removing oxygen from sodium through the use of hot traps are analyzed in substantiating the purification system for a nuclear power station equipped with a BN-1200 reactor. It is shown that a cold trap built into the reactor vessel must be a mandatory component of the reactor plant primary coolant circuit’s purification system. The use of hot traps allows oxygen to be removed from the sodium coolant down to permissible concentrations when the nuclear power station operates in its rated mode. The main lines of works aimed at improving the performance characteristics of cold traps are suggested based on the results of performed investigations.

The Russian Academy of Sciences and the Russian Federal Space Agency are planning to launch Radioastron in 2011, which is a unique space observatory with a 10-meter reflector antenna. In conjunction with the largest ground-based radio telescopes and tracking stations, it forms the first system that will be able to carry out studies with a resolution millions of times greater than that of eyesight.

The space interferometer Radioastron is working jointly with the largest radio telescopes of the world. Ground tracking stations provide for retrieving the information and determining the orbital parameters for data processing centers. The project is aimed at systematic studies of images of radio emitting regions, their coordinates, and time-dependent variations near super-massive black holes in galactic nuclei, stellarmass black holes, neutron and quark stars, regions of star and planet formation in our and other galaxies, the structure of interplanetary and interstellar plasma, and the Earth’s gravitational field.

Astronomy and astrophysics 603, A31 (2017). doi:10.1051/0004-6361/201629540, We present an extensive study of the BL Lac object Mrk 501 based on a data set collected during the multi-instrument campaign spanning from 2009 March 15 to 2009 August 1, which includes, among other instruments, MAGIC, VERITAS, Whipple 10 m, and Fermi-LAT to cover the γ-ray range from 0.1 GeV to 20 TeV; RXTE and Swift to cover wavelengths from UV tohard X-rays; and GASP-WEBT, which provides coverage of radio and optical wavelengths. Optical polarization measurements were provided for a fraction of the campaign by the Steward and St. Petersburg observatories. We evaluate the variability of the source and interband correlations, the γ-ray flaring activity occurring in May 2009, and interpret the results within two synchrotron self-Compton (SSC) scenarios. Aims. The multiband variability observed during the full campaign is addressed in terms of the fractional variability, and the possible correlations are studied by calculating the discrete correlation function for each pair of energy bands where the significance was evaluated with dedicated Monte Carlo simulations. The space of SSC model parameters is probed following a dedicated grid-scan strategy, allowing for a wide range of models to be tested and offering a study of the degeneracy of model-to-data agreement in the individual model parameters, hence providing a less biased interpretation than the “single-curve SSC model adjustment” typically reported in the literature. Methods. We find an increase in the fractional variability with energy, while no significant interband correlations of flux changes are found on the basis of the acquired data set. The SSC model grid-scan shows that the flaring activity around May 22 cannot be modeled adequately with a one-zone SSC scenario (using an electron energy distribution with two breaks), while it can be suitably described within a two (independent) zone SSC scenario. Here, one zone is responsible for the quiescent emission from the averaged 4.5-month observing period, while the other one, which is spatially separated from the first, dominates the flaring emission occurring at X-rays and very-high-energy (>100 GeV, VHE) γ rays. The flaring activity from May 1, which coincides with a rotation of the electric vector polarization angle (EVPA), cannot be satisfactorily reproduced by either a one-zone or a two-independent-zone SSC model, yet this is partially affected by the lack of strictly simultaneous observations and the presence of large flux changes on sub-hour timescales (detected at VHE γ rays). Results. The higher variability in the VHE emission and lack of correlation with the X-ray emission indicate that, at least during the 4.5-month observing campaign in 2009, the highest energy (and most variable) electrons that are responsible for the VHE γ rays do not make a dominant contribution to the ~1 keV emission. Alternatively, there could be a very variable component contributing to the VHE γ-ray emission in addition to that coming from the SSC scenario. The studies with our dedicated SSC grid-scan show that there is some degeneracy in both the one-zone and the two-zone SSC scenarios probed, with several combinations of model parameters yielding a similar model-to-data agreement, and some parameters better constrained than others. The observed γ-ray flaring activity, with the EVPA rotation coincident with the first γ-ray flare, resembles those reported previously for low frequency peaked blazars, hence suggesting that there are many similarities in the flaring mechanisms of blazars with different jet properties., Published by EDP Sciences, Les Ulis

Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of $10^{11.5}$ K. Relativistic boosting can increase its observed value, but apparent brightness temperatures much in excess of $10^{13}$ K are inaccessible using ground-based very long baseline interferometry (VLBI) at any wavelength. We present observations of the quasar 3C273, made with the space VLBI mission RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as small as 26 $\mu$as (2.7 light months) and brightness temperature in excess of $10^{13}$ K. These measurements challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive black holes and require a much higher Doppler factor than what is determined from jet apparent kinematics., Comment: 6 pages, 2 figures, 1 table; accepted by the Astrophysical Journal Letters

The characteristic and distinctive features of the visibility amplitude of interferometric observations for compact objects like stars in the immediate vicinity of the central black hole in our Galaxy are considered. These features are associated with the specifics of strong gravitational scattering of point sources by black holes, wormholes, or black_white holes. The revealed features will help to determine the most important topological characteristics of the central object in our Galaxy: whether this object possesses the properties of only a black hole or also has characteristics unique to wormholes or black_white holes. These studies can be used to interpret the results of optical, infrared, and radio interferometric observations., Comment: 17 pages, 8 figures

Microluminescence and laser confocal scanning microscopy techniques have been used to study spatial distribution of F-type color centers in LiF and mechanical stress profiles in Al 2 O 3 :Cr single crystals irradiated with 1.2 MeV/amu Ar, Kr, Xe and 3 MeV/amu Kr and Bi ions. It was found that F 2 and F 3 + -center profiles at low ion fluences correlate with ionizing energy loss profiles. With increasing ion fluence, after ion track halo overlapping, the luminescence yield is defined by radiation defects formed in elastic collisions in the end-of-range area. Stress profiles and stress tensor components in ruby crystals across swift heavy ion irradiated layers have been deduced from depth-resolved photo-stimulated spectra using piezospectroscopic effect. Experimental data show that that stresses are compressive in basal plane and tensile in perpendicular direction in all samples irradiated with high energy ions.

The sources of impurities entering the sodium in fast reactors were investigated. The analysis showed that oxygen and hydrogen can be removed from the sodium by using cold traps in all operating regimes of a nuclear power plant as well as hot traps. An operating regime preventing hydrogen accumulation in the first-loop cold trap is proposed for a system purifying the first two loops. A computer code for calculating the impurity mass transfer is perfected. Test calculations showed that the procedure developed and the code are both serviceable. The deviation of the computational results from the experimental data is about 30% on average. For a built-in purification system, it is essential to develop a cold trap with a large impurity capacity. It is shown on the basis of experiments that such cold traps can in principle be developed. Thermohydraulic and mass-transfer codes must be developed in order to realize this possibility.

We describe a facility for testing the properties of different objects affected by a sequence of highpower pulses of the microwave electromagnetic field. The facility performance is implemented due to the power level and stability of the single-mode generation of a free electron maser with an output frequency of 30 GHz, which have been achieved at the Joint Institute for Nuclear Research and the Institute of Applied Physics of the Russian Academy of Sciences. This paper describes the experiments on studying of the thermal fatigue of the copper surface in a test cavity, which models the thermal regime of the accelerating structure of the CLIC project (CERN), as well as the experiments on irradiation of biological tissues, metal films, and nanoclusters.

An algorithm for step-by-step identification of blaCTX-M genes determining the resistance to cephalosporins III–IV in gram-negative bacteria is developed. The algorithm allows identification of 49 genes out of 96, which are already present in the GenBank database. The remaining 47 genes are identified in several small groups of 2 to 6 genes, excluding the blaCTX-M-14-like subgroup, which comprises 13 genes. The blaCTX-M genes’ identification is carried out with two-step restriction fragment length polymorphism analysis (PCR-RFLP) of a 544-bp-long PCR-product.

A procedure for solving three-dimensional mixed symmetric problems of electroelasticity theory for a piezoceramic layer with an inclusion, which is weakened with a through hole, is proposed. The boundary-value problem is reduced to a system of 12k (k = 1, 2, …) integrodifferential equations. Expressions for stresses characterizing the stress state of the inhomogeneous layer are found. Calculation results for characteristic stresses are presented. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/24146

Radio observations of the Crab pulsar were performed on the 100-m radio telescope of the Green Bank Observatory at a frequency of 2100 MHz in a 64-MHz band in two channels with right-and left-circular polarization. The Mark5A recording system was used. During 15 min of observing time, 609 giant pulses were recorded; the brightest had a peak flux density of 670 kJy. The energy distribution has been constructed, polarization properties have been analyzed, and the characteristic temporal and frequency scales in the radio emission of the detected giant pulses have been found. Comparison of these parameters indicates that the properties of giant pulses detected at the main-pulse and interpulse longitudes do not differ, as is clearly observed at frequencies above 4 GHz. Probable origins of the frequency evolution of the properties of giant pulses are discussed.

The existing high-resolution methods for obtaining structural parameters of biological membrane objects are associated, as a rule, with strong physical and chemical actions on the soft membrane structure. Therefore the results of such experiments have an ambiguity arising from the changes in the structure of objects in the process of measurements. Investigations of living membrane systems retaining their main biological functions are a considerable challenge. Our object of study was the structure of mitochondria by small-angle neutron scattering (SANS). Functioning mitochondria carries out the ATP synthesis (source of energy for cellular activities) that is realized by the oxidative phosphorylation system located in the inner mitochondrial membrane. In the 1970s, small-angle X-ray scattering was applied to investigate the structure of intact mitochondria [1–2], but there are no neutron investigations. As compared to X-rays, thermal neutrons have less damaging effect on biological objects and are sensitive...

We report on a multiwavelength campaign for the radio-loud narrow-line Seyfert 1 (NLS1) galaxy PMN J0948+0022 (z= 0.5846) performed in 2010 July–September and triggered by a high-energy γ-ray outburst observed by the Large Area Telescope onboard the Fermi Gamma-ray Space Telescope. The peak flux in the 0.1–100 GeV energy band exceeded, for the first time in this type of source, the value of ~10^(−6) photon cm^(−2) s^(−1), corresponding to an observed luminosity of ~10^(48) erg s^(−1). Although the source was too close to the Sun position to organize a densely sampled follow-up, it was possible to gather some multiwavelength data that confirmed the state of high activity across the sampled electromagnetic spectrum. The comparison of the spectral energy distribution of the NLS1 PMN J0948+0022 with that of a typical blazar – such as 3C 273 – shows that the power emitted at γ-rays is extreme.