23 research outputs found
NMR Study of Disordered Inclusions in the Quenched Solid Helium
Phase structure of rapidly quenched solid helium samples is studied by the
NMR technique. The pulse NMR method is used for measurements of spin-lattice
and spin-spin relaxation times and spin diffusion coefficient
for all coexisting phases. It was found that quenched samples are two-phase
systems consisting of the hcp matrix and some inclusions which are
characterized by and values close to those in liquid phase. Such
liquid-like inclusions undergo a spontaneous transition to a new state with
anomalously short times. It is found that inclusions observed in both the
states disappear on careful annealing near the melting curve. It is assumed
that the liquid-like inclusions transform into a new state - a glass or a
crystal with a large number of dislocations. These disordered inclusions may be
responsible for the anomalous phenomena observed in supersolid region.Comment: 10 pages, 3 figure
ЭКСПЕДИЦИОННЫЕ РАДИОЭКОЛОГИЧЕСКИЕ ИССЛЕДОВАНИЯ В ЯПОНСКОМ МОРЕ И СЕВЕРО-ЗАПАДНОЙ ЧАСТИ ТИХОГО ОКЕАНА ПОСЛЕ АВАРИИ НА ЯПОНСКОЙ АЭС «ФУКУСИМА-1»: ПРЕДВАРИТЕЛЬНЫЕ РЕЗУЛЬТАТЫ
In the period from April 22 until May 20, 2011, an expedition aboard the research vessel “Pavel Gordienko” (Russian Federation) was carried out to the Sea of Japan and the Kuril-Kamchatka region of the Pacific Ocean. The main aim of the expedition was to study radioactive contamination of the atmospheric air and sea water after the accident at the NPP “Fukushima-1” in Japan. This paper provides preliminary results on the activity concentration of 137Cs and 134Cs in twenty four samples of sea water. The activity concentrations of 131I, 137Cs, 134Cs, and 7Be for twenty nine samples of atmospheric aerosols, which were sampled during the expedition, are also given. Despite the preliminary character of the results of this study, a generic conclusion on a negligible radiological impact of the anthropogenic gamma-ray-emitting radionuclides for the Far-Eastern sea areas of Russia can be reached. The investigations have been supported by a grant from the Russian Geographical Society.В период с 22 апреля по 20 мая 2011 г. на научно-исследовательском судне «Павел Гордиенко» (Российская Федерация) было проведено экспедиционное обследование Японского моря и Курило-Камчатского района Тихого океана. Основной целью экспедиции являлось исследование радиоактивного загрязнения воздушной и водной среды после аварии на АЭС «Фукусима-1» в Японии. В данной статье представлены предварительные результаты оценки содержания 137Cs и 134Cs в двадцати четырех пробах морской воды. Кроме этого, даны результаты определения содержания 131I, 137Cs, 134Cs, и 7Be в двадцати девяти пробах атмосферных аэрозолей, отобранных в рейсе. Несмотря на предварительный характер полученных результатов, проведенные исследования позволяют прийти к общему заключению о пренебрежимо малом влиянии изученных техногенных гамма-излучающих радионуклидов на радиационную обстановку в районах российского побережья Дальнего Востока. Грант на проведение исследований был выделен Попечительским советом Русского географического общества
RADIOECOLOGICAL INVESTIGATIONS IN THE SEA OF JAPAN AND THE NORTH-WEST PART OF THE PACIFIC OCEAN AFTER THE ACCIDENT AT THE NPP “FUKUSHIMA-1” IN JAPAN: PRELIMINARY RESULTS
In the period from April 22 until May 20, 2011, an expedition aboard the research vessel “Pavel Gordienko” (Russian Federation) was carried out to the Sea of Japan and the Kuril-Kamchatka region of the Pacific Ocean. The main aim of the expedition was to study radioactive contamination of the atmospheric air and sea water after the accident at the NPP “Fukushima-1” in Japan. This paper provides preliminary results on the activity concentration of 137Cs and 134Cs in twenty four samples of sea water. The activity concentrations of 131I, 137Cs, 134Cs, and 7Be for twenty nine samples of atmospheric aerosols, which were sampled during the expedition, are also given. Despite the preliminary character of the results of this study, a generic conclusion on a negligible radiological impact of the anthropogenic gamma-ray-emitting radionuclides for the Far-Eastern sea areas of Russia can be reached. The investigations have been supported by a grant from the Russian Geographical Society
Phylogeny and phylogeography of the roaches, genus Rutilus (Cyprinidae), at the Eastern part of its range as inferred from mtDNA analysis
The genus Rutilus is a widely distributed lineage of cyprinids and ranges from West Europe to East Siberia. Although matrilineal phylogeny and phylogeography of western species were already studied, roaches from remaining part of the range were not examined. Phylogenetic analysis based on cytochrome b sequences detected the following three major phylogenetic clades: (i) R. frisii, (ii) R. rutilus s. str., and (iii) group of six Ponto–Caspian taxa: R. caspicus, R. heckelii, R. rutilus aralensis, R. rutilus lacustris, R. schelkovnikovi, and R. stoumboudae. Our results suggest that these “species” within Ponto–Caspian clade could be a single species (R. lacustris by priority of description). The Ponto–Caspian clade is most widely distributed among others and covers the freshwaters from the Aegean Sea basin to Laptev Sea tributaries. Both R. rutilus s. str. and Ponto–Caspian clades sympatrically occur in Black Sea and Caspian Sea basins, Azov Sea itself, and even in drainage of White Sea. The vastest zone of contact (approximately 1700 km) was detected in the Volga basin. The spatial pattern of haplotype diversity and the shape of haplotype network argued for multiple refugia in Ponto–Caspian region as well as a rapid post-glacial colonization of Volga River and Siberia
Phylogeny and phylogeography of the roaches, genus Rutilus (Cyprinidae), at the Eastern part of its range as inferred from mtDNA analysis
The genus Rutilus is a widely distributed lineage of cyprinids and ranges from West Europe to East Siberia. Although matrilineal phylogeny and phylogeography of western species were already studied, roaches from remaining part of the range were not examined. Phylogenetic analysis based on cytochrome b sequences detected the following three major phylogenetic clades: (i) R. frisii, (ii) R. rutilus s. str., and (iii) group of six Ponto–Caspian taxa: R. caspicus, R. heckelii, R. rutilus aralensis, R. rutilus lacustris, R. schelkovnikovi, and R. stoumboudae. Our results suggest that these “species” within Ponto–Caspian clade could be a single species (R. lacustris by priority of description). The Ponto–Caspian clade is most widely distributed among others and covers the freshwaters from the Aegean Sea basin to Laptev Sea tributaries. Both R. rutilus s. str. and Ponto–Caspian clades sympatrically occur in Black Sea and Caspian Sea basins, Azov Sea itself, and even in drainage of White Sea. The vastest zone of contact (approximately 1700 km) was detected in the Volga basin. The spatial pattern of haplotype diversity and the shape of haplotype network argued for multiple refugia in Ponto–Caspian region as well as a rapid post-glacial colonization of Volga River and Siberia
Invasion ecology: an international perspective centered in the Holarctic
The Fourth International Symposium on Alien Species in the Holarctic was convened September 22-28, 2013, by the Russian Academy of Sciences at the I.D. Papanin Institute for the Biology of Inland Waters (IBIW) on the Volga River in Borok (approximate to 355 km north of Moscow). The Organizing Committee spanned five countries (France, People's Republic of China, Poland, Russian Federation, and the United States), with participants (n=150) across the breadth and depth of the Russian Federation, from countries in proximity to it (i.e., Armenia, Lithuania, Kazakhstan, Kyrgyzstan, Ukraine, Siberia, and The Republic of China), and more globally from the United States to Tasmania and Norway to South Africa. This report provides a synopsis of invasive species issues that were discussed at the symposium and, as such, provides an international window for the evaluation of fisheries-related topics in this part of the globe