Radio Emission Variability of Supernova Remnants and a Possible Explanation of the Phenomenon

Astronomy Reports - The flux densities and current spectra of plerions and combined supernova remnants (SNRs): 3C58, 3C144, G11.2–0.3, G21.5–0.9, and 3C396 are determined on an...     

生态地质系统类型及其在生态系统结构中的地位和调查任务

介绍了生态地质学内容及其与地质生态学的关系;描述了岩石圈生态功能分类,即生态地质理论基础。生态地质学的研究对象是生态地质系统中直接作用于某些岩石圈或作用于其表面的生物群,包括人类和社会。生态地质系统分为4种类型：自然实体、自然理念、自然技术实体和自然技术理念。文中也描述了生态地质系统在生态系统结构中的地位,同时论证了生态地质系统的形成因素,科学的调查方法及所有相关的标准和指标,以及此项研究的复杂性。     

Modern Horizontal Movements in the Zones of Strong and Moderate Earthquakes of the Early 21st Century in the Central Sector of the Greater Caucasus: Characteristics Inferred from GPS Observations and Connection with Neotectonics and Deep Structure of the Earth’s Crust

Izvestiya, Atmospheric and Oceanic Physics - Analysis of GPS-measurements made for the first time along the geodesic profile crossing all the main geological structures in the Ossetian region of...     

Hazards and Risks of Recreation Water Use: Vectors of International Studies. The Quality of Recreation Environments

Water Resources - English-language scientific publications regarding the assessment of hazards and risks in recreational water use have been generalized. International publication activity has been...     

Study of Variations of Some Characteristics of the Giant Coronal Hole of 2015–2017

Geomagnetism and Aeronomy - Analysis of images of the full solar disk obtained by ground-based (BST-2, CrAO RAS) and space-based (SDO/AIA, SDO/HMI) instruments and the potential approximation...     

The Russian Arctic coastal zone management problems: past lessons and new realities

The growing attention to the development of coastal zone resources is notable not only for moderate and southern latitudes but also in the Arctic regions. In Russia this process has a history related to exploration of non-renewable resources and the long-term policy of moving labour forces to the Far North and East. The role of the Russian Arctic coastal zone in the national economy had been stimulated by active usage of the Northern Sea Route for 60 years as a mainstream Arctic transport line. Diversified human usage of all kinds of natural resources is getting more controversial. A deep revaluation of existing methods and management approaches is needed in accordance with the complexities of Russian social/economic and ecological factors in the Arctic. The modern challenge of transition towards sustainable development also needs to be reevaluated. The last decade has shown a real effort of all Arctic countries to expand cooperation in joint scientific multidisciplinary studies. The studies are aimed at elaboration of common views on Arctic development and protection of environment. Moreover, the Arctic shelf and coastal zone are getting a new arena of international investments for industrial projects and implementation due to recovery of huge deposits of oil and gas resources of sophisticated technologies. All this makes international scientific cooperation more of a reality.     

Tholeiitic and Alkaline Basaltic Lavas of Wang-Tian’e and Changbaishan Volcanoes (Northeastern China): Timing and Genetic Relationship

Doklady Earth Sciences - Changbaishan and Wang-Tian’e volcanoes of Changbaishan area (Northeast China) were formed with a slight time gap in the last four million years. Wang-Tian’e...     

Comendite Melts of the Early Mesozoic Bimodal Sant Association (Central Mongolia) and Mechanisms of Their Formation

Based on the investigation of melt inclusions using electron and ion microprobe analysis, we estimated the composition, evolution, and formation conditions of magmas producing the the comendites of the Sant bimodal volcanic association (Central Mongolia). The mechanisms of the formation of melts were determined. The primary melt and coexisting crystalline inclusions in quartz from three samples of comendites collected from different parts of the volcanic section were studied. Among the crystalline inclusions, sanidine, zircon, and the REE diortosilicate–chevkinite were identified. The phenocrysts of the comendites were determined to crystallize at temperatures of 880–960°C. The homogeneous glasses of melt inclusions have both trachydacite and rhyolite compositions. They are characterized by high concentrations of Zr, Nb, Rb, Y, Th and REE. Significant differences were determined in concentrations of Li and volatile component (H₂O and F) in the glasses: some of the melts are enriched in these components, whereas other are depleted in them.Analysis of the composition of the glasses of the homogenized melt inclusions in quartz of comendites from the Sant bimodal association allowed us to recognize magmatic processes responsible for formation of the comendite melts. The dominant role among them belongs to crystallization differentiation of the magma, accompanied by a process of liquid immiscibility with participation of fluoride melts.     

Spectrum and Variability of the Supernova Remnant G21.5-0.9

Measurements of the flux densities of the supernova remnant G21.5-0.9 at 4840 and 8450 MHz were performed in 2013–2018 on the 32-m telescope of the Svetloe Observatory of the Institute of Applied Astronomy, Russian Academy of Sciences. Multiple measurements revealed source variability. The flux densities of G21.5-0.9 for 1967–2010 from previously published data are used to compare the intensity of G21.5-0.9 and standard sources. An artificial-Moon flux scale is used to bring all the data into a single system and determine a refined spectrum. Analysis of the resulting data indicates that, first, the observed break in the source spectrum is not associated with energy losses of relativistic electrons due to synchrotron emission and, second, the source variability is manifest as flux-density changes described by one of two power-law dependencies for the flux versus frequency. The spectral indices of each of these dependencies have one of two constant values. Possible origins of the detected changes in the spectrum of G21.5-0.9 are discussed.