Constraints on the Regimes of Electron Acceleration in Solar Flares

Astronomy Letters - Based on the observations of microwave impulsive bursts recorded at the Nobeyama Radio Observatory, we have obtained constraints on the regimes of electron acceleration in solar...     

Circumbinary Planetary Systems in the Solar Neighborhood: Stability and Habitability

Astronomy Letters - The radii of the inner and outer boundaries of the circumbinary habitable zone (CBHZ) and the radii of the circumbinary chaotic zone (CBCZ) have been calculated for close binary...     

Chaotic Asteroidal Dynamics and Maximum Lyapunov Exponents

This paper describes the results of studies of dynamical chaos in the problem of the orbital dynamics of asteroids near the 3 : 1 mean-motion resonance with Jupiter. Maximum Lyapunov characteristic exponents (MLCEs) are used as an indicator and a measure of the chaoticity of motion. MLCE values are determined for trajectories calculated by the numerical integration of equations of motion in the planar elliptical restricted three-body problem. The dependence of the MLCE on the problem parameters and on the initial data is analyzed. The inference is made that the domain of chaos in the phase space of the problem considered consists of two components of different nature. The values of the MLCEs observed for one of the components (namely, for the component corresponding to low-eccentricity asteroidal orbits) are compared to the theoretical estimates obtained within the framework of model of the resonance as a perturbed nonlinear pendulum.     

Platinum Mineralization in Multimetal Gold–Polymetallic,Au–Bi,Cu–Mo Porphyry,Cu–Ni,Titanomagnetite, and Copper–Sulfide Ore Deposits and Occurrences of the Upper Amur Region (Far East,Russia)

New data on platinum mineralization in ores, metasomatic rocks, concentrates, and tailings and wastes of some gold–polymetallic, Au–Bi, Cu–Mo porphyry, Cu–Ni, and titanomagnetite ore deposits and occurrences of the Upper Amur Region are presented. The contents of platinoids, Au and Ag in multimetal ores of gold-polymetallic, Au–Bi, Cu–Mo porphyry, Cu–Ni, and titanomagnetite ore deposits and ore occurrences are given. In addition, recommendations on the necessity of continuing scientific studies, revision, and resampling works in the search for platinoids in other complex ores of deposits and occurrences of the Upper Amur Region are given.     

The engineering-physical basis of temperature regime regulation of ground massifs in northern construction

Artificial ground freezing at low temperatures provides a solution to such complicated problems as strengthening foundations, improvement of their reliability and the provision of the watertightness of the ground.

Ground cooling and freezing directly changes the stress—deformation state of foundations and underground constructions.

Basic diagrams on ways and means of forming low temperature frozen zones of a definite shape in the ground are given in the paper. Peculiarities of the work of the seasonally functioning heat-exchange devices and systems are discussed.

The development and refinements of methods of calculation and long-term forecast of temperature fields in artificially cooled ground massifs is of great importance.

Experimental data on migration phenomena in freezing soils and the methods of the numerical modeling of cooled massifs are discussed.

The paper is illustrated by diagrams, test results and calculation data.     

Spectroscopic study of the optical counterpart to the fast X-ray transient IGR J17544-2619 based on observations at the 1.5-m RTT-150 telescope

We present the results of our long-term photometric and spectroscopic observations at the Russian–Turkish RTT-150 telescope for the optical counterpart to one of the best-known sources, representatives of the class of fast X-ray transients, IGR J17544-2619. Based on our optical data, we have determined for the first time the orbital and physical parameters of the binary system by the methods of Doppler spectroscopy.We have calculated theoretical spectra of the optical counterpart by applying non- LTE corrections for selected lines and obtained the parameters of the stellar atmosphere (T _eff = 33 000 K, log g = 3.85, R = 9.5 R _⊙, and M = 23 M _⊙). The latter suggest that the optical star is not a supergiant as has been thought previously.     

Rotational Dynamics and Evolution of Planetary Satellites in the Solar and Exoplanetary Systems

Solar System Research - In this review we consider the main rotation regimes that are inherent for planetary satellites of the Solar System, satellites of trans-Neptunian objects, and potential...     

Learning about parameter and structural uncertainty in carbon cycle models

Uncertainty in the response of the global carbon cycle to anthropogenic emissions plays a key role in assessments of potential future climate change and response strategies. We investigate how fast this uncertainty might change as additional data on the global carbon budget becomes available over the twenty-first century. Using a simple global carbon cycle model and focusing on both parameter and structural uncertainty in the terrestrial sink, we find that additional global data leads to substantial learning (i.e., changes in uncertainty) under some conditions but not others. If the model structure is assumed known and only parameter uncertainty is considered, learning is rather limited if observational errors in the data or the magnitude of unexplained natural variability are not reduced. Learning about parameter values can be substantial, however, when errors in data or unexplained variability are reduced. We also find that, on the one hand, uncertainty in the model structure has a much bigger impact on uncertainty in projections of future atmospheric composition than does parameter uncertainty. But on the other, it is also possible to learn more about the model structure than the parameter values, even from global budget data that does not improve over time in terms of its associated errors. As an example, we illustrate how one standard model structure, if incorrect, could become inconsistent with global budget data within 40 years. The rate of learning in this analysis is affected by the choice of a relatively simple carbon cycle model, the use of observations only of global emissions and atmospheric concentration, and the assumption of perfect autocorrelation in observational errors and variability. Future work could usefully improve the approach in each of these areas.     

Features of the Behavior of Microwave and Ultraviolet Emission of Solar Active Regions in Relation to Eruptive and Confined Flares

Geomagnetism and Aeronomy - In this study, a comparative analysis was carried out on the preflare and flare conditions for six flares accompanied by coronal mass ejections (CMEs) and five events...