141 research outputs found
The basic level of taxonomy of the concept "Visual Perception" : the case study of English and French verbs
The article deals with verb representation of visual perception in the English and French languages on the basis of construction of a complex cognitive model called the verb taxonomy of the concept VISUAL PERCEPTION. The model allows us to present a part of the lexical system of the English and French languages with account of the conceptual level, namely the concepts represented by verbs of visual perceptio
Реконструкция зимней температуры воздуха в голоцене по стабильным изотопам из ледяных жил в районе города Анадырь
The object of research is syncryogenic Holocene strata on the coast of the Onemen Bay, 2 km from the town of Anadyr. In July 2017, the outcrop of the first marine terrace uncovered by strong storms was examined. The stratigraphy of the outcrop was represented mainly by sandy loam (5–7 m thick) covered by peat (1–1.5 m) and underlain by sand. Numerous ice wedges were opened in the upper part of this outcrop. Along with that another outcropping of transect of a lakemarsh basin represented by a peat bog of 2–2.5 m thick underlain by sandy loam was also investigated. Ice wedges occur below the polygonal trenches. The present-day narrow ice wedges were found in the upper part of the peat bog. Two representative fragments of both the above outcrops were thoroughly examined. Radiocarbon dating had shown that accumulation of peat on surface of the first marine terrace started in early Holocene (about 8 ka BP). Accumulation of peatland within the lake-marsh basin was also dated to the beginning of the Holocene (about 9 ka BP). In the middle of the Holocene, it was most likely interrupted as a result of thermokarst processes and bogging of the surface. Formation of peatlands in Chukotka during the Holocene is known to be accompanied by active growth of the ice wedges inside them, so the age of the wedges studied by us was estimated as the beginning of the Holocene. The analysis of stable oxygen and hydrogen isotopes in the Holocene and the modern ice wedges had allowed establishing mainly the atmospheric type of moisture feeding of the wedges (due to melted snow) and lack of noticeable isotope fractionation during the ice formation. It has been found that δ18О and δ2Н values in the Holocene ice wedges were lower than in the modern wedges and snow by an average 2–3 and 7–12 ‰, respectively. Paleotemperature reconstructions performed on the basis of isotopeoxygen data showed that the air temperature of the coldest winter month in the first half of the Holocene in the Onemen Bay area was lower than the present-day ones by an average 2–3 °C, which is in a good agreement with the trend of rising winter temperatures throughout the Chukotka Peninsula, as well as in other areas of Eastern Siberia and Alaska. Объект исследований – синкриогенные голоценовые толщи на побережье залива Онемен, в 2 км от г. Анадырь. Изучены повторно-жильные льды, вскрытые в двух фрагментах обнажения первой морской террасы. При радиоуглеродном датировании вмещающего торфа установлено, что жилы начали активно формироваться в раннем голоцене (около 9–8 тыс. лет назад). Согласно палеотемпературным реконструкциям на основе изотопно-кислородных данных, температура воздуха самого холодного зимнего месяца в первой половине голоцена в районе залива Онемен была ниже современной на 2–3 оС
Реконструкция среднеянварской температуры воздуха в голоцене в низовьях реки Колымы
The object of study is ice wedges at 10 sites in the lower Kolyma River. The Holocene age of ice wedges is determined on the basis of radiocarbon dating of the enclosing sediments and location of ice wedges in alases, floodplains and lacustrine-paludal basins. The analysis of radiocarbon dates has shown that formation of alases with ice wedges began in early Greenlandian stage of Holocene (the oldest dates are 11 and 10.8 cal ka BP). The most active alas development and syngenetic ice wedge growth occurred since the second half of the Greenlandian stage till the middle-late Northgrippian stage of the Holocene, most of the available 14C dates fall in the range from 9.5 to 4.2 cal ka BP. Accumulation of the floodplain deposits of the Kolyma River occurred mainly during the Meghalayan stage, according to obtained 14C dates from 2.5 to 1.9 cal ka BP. Oxygen isotope data of studied ice wedges show that for the Holocene ice wedges the range of δ18O is about 4 ‰ (from –28 to –23.7 ‰) and for the modern ice veinlets– about 5 ‰ (from –28.1 to –23 ‰). Water of meteoric origin was the main source for ice wedge formation, however, for ice wedges on the floodplains some participation of surface (river) water is not excluded. Based on the refined equation of the ratio between ice wedge isotope composition and mean January air temperature, paleotemperatures for three key periods of the Holocene were calculated. It was established that mean January air temperature during the Holocene varied in the approximately same range: from –40.7 to –33.8 °С during the Greenlandian stage, from –38.6 to –33.3 °С during the Northgrippian stage and from –41.5 to –33 °С during the Meghalayan stage. This most likely indicates the stability of winter climatic conditions in the north of Yakutia during the Holocene, determined by the influence of Siberian anticyclone.Реконструкция среднеянварской температуры в низовьях р. Колыма для трёх ключевых периодов голоцена, выполненная на основе данных изотопного состава повторно-жильных льдов, показала, что среднеянварская температура воздуха в течение голоцена варьировала незначительно, средние значения для более тёплых и более суровых зим составляли −33 и −41 °C соответственно. Показана стабильность зимних климатических условий на севере Якутии в голоцене, определяемая влиянием сибирского антициклона
Реконструкция средних температур января в раннем голоцене на северо-востоке Большеземельской тундры
The aim of the study was to establish the period of accumulation of peatland with ice wedges near Vorkuta town based on series of calibrated radiocarbon dates, to anchor in time the isotope-oxygen curve of syngenetic ice wedge from peatland and to reconstruct the mean January air temperature for the appropriate Holocene period. Analysis of a series of 14C dates showed that peatland near Vorkuta was actively formed between 10.5 and 6 cal. ka BP. Winter conditions in the Vorkuta area were quite severe, that favored to frost cracking of the peatland and syngenetic growth of ice wedges within the drier sites and peat-soil wedges within the watered sites. Ice wedge growth was the most active within the Greenlandian Stage of Holocene, between 10,5 and 9,7 cal. ka BP, the reconstructed mean January air temperature for this period varied between −23 and −25 oC; currently, such temperatures are recorded only during the coldest winters.Вблизи г. Воркута процессы заболачивания и образования торфа начались в первой половине гренландского периода голоцена – около 11–10 тыс. калиб. лет назад. Завершилось формирование торфяника 3–2 тыс. калиб. лет назад. Время активного формирования в торфянике сингенетических повторно-жильных льдов приходится на период между 10,5 и 9,7 тыс. калиб. лет назад, когда среднеянварская температура воздуха варьировала между −23 и −25 oC
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Investigation on the co-precipitation of transuranium elements from alkaline solutions by the method of appearing reagents
Highly alkaline radioactive waste solutions originating from production of plutonium for military purposes are stored in underground tanks at the U.S. Department of Energy Hanford Site. The purification of alkaline solutions from neptunium and plutonium is important in the treatment and disposal of these wastes. This report describes scoping tests with sodium hydroxide solutions, where precipitation techniques were investigated to perform the separation. Hydroxides of iron (III), manganese (II), cobalt (II, III), and chromium (III); manganese (IV) oxide, and sodium uranate were investigated as carriers. The report describes the optimum conditions that were identified to precipitate these carriers homogeneously throughout the solution by reductive, hydrolytic, or catalytic decomposition of alkali-soluble precursor compounds by a technique called the Method of Appearing Reagents. The coprecipitation of pentavalent and hexavalent neptunium and plutonium was investigated for the candidate agents under optimum conditions and is described in this report along with the following results. Plutonium coprecipitated well with all tested materials except manganese (IV) oxide. Neptunium only coprecipitated well with uranate. The report presents a hypothesis to explain these behaviors. Further tests with more complex solution matrices must be performed
Изотопно-кислородный состав льда ледника № 30 в горах Сунтар-Хаята
The object of research is the mountain-valley glacier № 30, located in the central part of the Suntar-Khayatа Ridge – one of the largest centers of modern glaciation of the North-East of Russia. This glacier had been chosen due to lamination of ice on its surface, providing successive sampling of increasingly young ice upward the glacier slope. At the end of August 2013, surface ice of the glacier was sampled within the altitude range 2060–2510, an age of this ice here was estimated to be about 500 years old. Variations of δ18О values in the glacier ice amounted about 5.5‰: from −20.2 to −25.9‰ that is numerically consistent with isotopic values for the neighboring glaciers № 29 and 31. No essential relation between the ice isotopic composition and altitude, age or the change of the ice granularity was found. Absence of high-altitude isotope effect is explained by the fact that preciptation on the glacier № 30 falls at the same level of condensation as well as by intensive infiltration-congelation ice formation and fixation in the firn and snow cover of a part of the meltwater coming from higher and steeper areas on gently sloping sites of the glacier. The δ18О values of ice from glacier № 30 are rather «heavy» for glaciers being formed in severe climate conditions with average January temperature of −28 °C. According to Dansgaard's dependence δ18Оprecipitation – t °Cair the winter snow on the glacier № 30 should be hypothetically characterized by the δ18О values from −30 to −40‰ which are typical ones for the winter snow in Siberia. Oxygen isotope values of the ice show insignificant contribution of winter snow into formation of the glacier and prevalence of spring-autumn snowfalls. No definite trend of changes in the glacier alimentation and the ice-formation process was found for the last 500 years.Рассмотрен изотопно-кислородный состав поверхностного льда ледника № 30 в горах Сунтар- Хаята, отобранного в 2013 г. Вариации δ18О во льду ледника № 30 составили около 5,5‰. При этом не отмечено существенного изменения изотопного состава льда с высотой или с его возрастом. Сопоставлен изотопный состав льда ледника № 30 и зимнего снега, выпадающего в разных районах Сибири. На основании полученных изотопных данных показано, что питание ледника происходит преимущественно за счёт весенне-осенних осадков при незначительном участии зимнего снега
ВАРИАЦИИ ИЗОТОПОВ КИСЛОРОДА И ВОДОРОДА В СОВРЕМЕННОЙ ПЛАСТОВОЙ ЛЕДЯНОЙ ЗАЛЕЖИ В УСТЬЕ Р. АККАНИ, ВОСТОЧНАЯ ЧУКОТКА
The object of this study is a recently (or in the Holocene) formed thick (up 2.7 m in height) buried massive ice body, exposed in 2 km South-East from the mouth of the river Akkani in the North-East of Chukotka in the vicinity of the settlement Lavrentiya. The structural-textural characteristics of ice and enclosing deposits are considered. It is shown that the overlying layers of sediments are loams with a slab structure and vertical-layer medium and thin-chill cryogenic structure and ice sockets. The ice of the body is very pure and transparent, visible to a depth of 0.5 m. There are some inclusions found in massive ice: sand and loams presented in forms of thin interlayers of particles or granules. The ice is full of bubbles. The main method of the research was the analysis of isotopes of oxygen and hydrogen within the stratified ice body, and also relationships between them as well as ratios between the deuterium excess and δ2Н. The thick and relatively contemporary massive ice layer buried under a layer of proluvial sediments had been found for the first time, and together with this, the isotope variations of the buried ice (δ2Н and δ18O) were determined. The mean values of δ18О and δ2H in the ice are rather stable and equal to −17.1 and −128.3‰, respectively. These isotope characteristics may be used for cryogenic reconstructions of massive ice formations widely distributed in the late Quaternary deposits in Eastern Chukotka.Изучен изотопный состав кислорода и водорода мощного современного (голоценового) ледяного пласта, погребённого под слоем пролювиальных отложений на побережье Чукотки вблизи посёлка Лаврентия. Значения δ18О и δ2H во льду довольно однородны и составляют −17,1 и −128,3 ‰ соответственно. Изученный пластовый лёд в устье р. Аккани представляет собой захороненный перелетовывающий снежник, сформировавшийся с участием поверхностных вод и атмосферной влаги весенне-летнего периода
Microbial and Geochemical Evidence of Permafrost Formation at Mamontova Gora and Syrdakh, Central Yakutia
Biotracers marking the geologic history and permafrost evolution in Central Yakutia, including Yedoma Ice Complex (IC) deposits, were identified in a multiproxy analysis of water chemistry, isotopic signatures, and microbial datasets. The key study sections were the Mamontova Gora and Syrdakh exposures, well covered in the literature. In the Mamontova Gora section, two distinct IC strata with massive ice wedges were described and sampled, the upper and lower IC strata, while previously published studies focused only on the lower IC horizon. Our results suggest that these two IC horizons differ in water origin of wedge ice and in their cryogenic evolution, evidenced by the differences in their chemistry, water isotopic signatures and the microbial community compositions. Microbial community similarity between ground ice and host deposits is shown to be a proxy for syngenetic deposition and freezing. High community similarity indicates syngenetic formation of ice wedges and host deposits of the lower IC horizon at the Mamontova Gora exposure. The upper IC horizon in this exposure has much lower similarity metrics between ice wedge and host sediments, and we suggest epigenetic ice wedge development in this stratum. We found a certain correspondence between the water origin and the degree of evaporative transformation in ice wedges and the microbial community composition, notably, the presence of Chloroflexia bacteria, represented by Gitt-GS-136 and KD4-96 classes. These bacteria are absent at the ice wedges of lower IC stratum at Mamontova Gora originating from snowmelt, but are abundant in the Syrdakh ice wedges, where the meltwater underwent evaporative isotopical fractionation. Minor evaporative transformation of water in the upper IC horizon of Mamontova Gora, whose ice wedges formed by meltwater that was additionally fractionated corresponds with moderate abundance of these classes in its bacterial community. © Copyright © 2021 Cherbunina, Karaevskaya, Vasil’chuk, Tananaev, Shmelev, Budantseva, Merkel, Rakitin, Mardanov, Brouchkov and Bulat.We thank Samsonova Vera, Karzhavin Vladimir, Pankov Alexander, Andreevskaya Maya and Alexander Osipov for their for their invaluable assistance in field work
Реконструкция среднеянварской температуры воздуха в раннем голоцене на восточном побережье Чукотки
The investigation is concerned with the Early Holocene syngenetic massive wedge ice exposed in the outcrop of a polygonal peatland in the upper part of the third marine terrace near Lorino settlement on the eastern coast of Chukotka. Based on the obtained radiocarbon dates of peat, it was found that the formation of a peatland in the area began about 14–13 cal ka BP, at the end of the Younger Dryas, while the termination of the active stage of peat accumulation was dated to about 10–9 cal ka BP. The beginning of peat accumulation at the end of the Younger Dryas, earlier the officially accepted limit of the lower boundary of the Holocene (11.7 cal ka BP), and the termination of its formation by the middle of the Greenlandian Holocene period is not a rare phenomenon in Russian permafrost zone, although it is traditionally assumed that the most active formation of peatlands has been going on during the thermal maximum in the middle of the Holocene. The age inversions noted in the peat vertical profiles are the most likely indicative of the processes of re-deposition of ancient organic material due to erosion by water of the third marine terrace sediments and the separation of the allochthonous peat. During the period from 2015 to 2021, six fragments of peatland exposures with the ice wedges were studied. Analysis of the obtained data on the content of stable oxygen isotopes in the ice show that δ18О values vary within the range from –15.5 to –18‰. These values are in good agreement with the data for Early Holocene ice wedges earlier obtained in other areas of the eastern coast of Chukotka (Anadyr town, Uelen settlement), where authors report the δ18O values from –16 to –19.4‰. This suggests that the ice wedge growth as well as the peat accumulation were the most active in Early Holocene. The highest δ18О values (from –13.1 to –16.8‰) were obtained for the modern ice veinlets. The ratio δ2 H–δ18O in the ice wedges, in general, is indicative of a good preservation of isotope signature of winter precipitation. It has been found that approximate mean January air temperature in the Early Greenlandian period varied from –23 to –27°С, which is, on average, 3°С below than the present-day ones.Формирование полигонального торфяника на поверхности третьей морской террасы в районе села Лорино на восточном побережье Чукотки началось в конце позднего дриаса и завершилось в начале голоцена. Среднеянварская температура воздуха в первой половине гренландского периода голоцена, реконструированная на основе данных изотопного состава повторно-жильных льдов, возраст которых не моложе 10–9 тыс. кал. лет назад, в среднем на 3°С ниже современной и варьировала от –23 до –27°С
Реконструкция зимней температуры воздуха раннего и среднего голоцена по изотопному составу ледяных жил восточного побережья полуострова Дауркина, Чукотка
The object of research is the Holocene massive ice veins on the Eastern coast of the Daurkin Peninsula, the easternmost part of the Chukotka. Peat bogs with ice veins occur on the surface of marine terraces (near Uelen and Lorino settlements) and on flood plain of the Koolen’ Lake; the thickness of peat varies from 0.7 to 2.5 m. Radiocarbon dating of the peat enclosing the investigated ice veins near Uelen and Lorino indicated that the beginning of peat accumulation began at the end of Late Pleistocene – early Holocene, about 11 cal ka BP. On the flood plain of the Koolen’ Lake peat bogs began to accumulate in the middle Holocene, i.e. around 6 cal ka BP. At the initial stage of peat bogs formation the rate of peat accumulation was high and could reach 1 cm/10 years. Ice veins occur at a depth of 0.5–1 m, and their lower parts are located in the underlying peat sandy loams and loams. In the upper levels of the peat bogs, narrow present-day ice veins are found, which are sometimes embedded in the upper parts of Holocene veins. A clear sign of syngenetic growth of veins is the upward bending of the layers of the host peat at the lateral contacts with the veins. The main source of water for the formation of ice veins is snow, as evidenced by the ratio of stable isotopes of oxygen and hydrogen and the values of deuterium excesses in the ice. A slight admixture of saline water (probably from a seasonally thawed layer) was noted in the veins near the Lorino settlement. Reconstructions of winter air paleotemperatures, performed on the basis of data of isotope-oxygen composition of ice from the veins, did show that at the period between 11 and 6 cal Ka BP, the mean winter air temperature on the Daurkin Peninsula was by 2–5 oC lower than today, but the air temperature of the coldest month (January or February) was still lower (by 4-8 oC) than today. The noticeable trend of increase of stable isotope values in the ice veins from early Holocene to the present time is indicative of a steady positive trend of mean winter air temperatures in the Holocene.Реконструкции зимних палеотемператур воздуха на основе данных изотопно-кислородного состава льда жил показали, что между 11 и 6 тыс. кал. лет назад среднезимняя температура воздуха была на 2–5оС ниже современной, а температура воздуха самого холодного месяца (января или февраля) – на 4–8оС ниже современной. Установлен устойчивый положительный тренд зимних температур воздуха от раннего голоцена до настоящего времени
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