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1.
Nature ; 599(7886): 616-621, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34759322

RESUMEN

The origin and early dispersal of speakers of Transeurasian languages-that is, Japanese, Korean, Tungusic, Mongolic and Turkic-is among the most disputed issues of Eurasian population history1-3. A key problem is the relationship between linguistic dispersals, agricultural expansions and population movements4,5. Here we address this question by 'triangulating' genetics, archaeology and linguistics in a unified perspective. We report wide-ranging datasets from these disciplines, including a comprehensive Transeurasian agropastoral and basic vocabulary; an archaeological database of 255 Neolithic-Bronze Age sites from Northeast Asia; and a collection of ancient genomes from Korea, the Ryukyu islands and early cereal farmers in Japan, complementing previously published genomes from East Asia. Challenging the traditional 'pastoralist hypothesis'6-8, we show that the common ancestry and primary dispersals of Transeurasian languages can be traced back to the first farmers moving across Northeast Asia from the Early Neolithic onwards, but that this shared heritage has been masked by extensive cultural interaction since the Bronze Age. As well as marking considerable progress in the three individual disciplines, by combining their converging evidence we show that the early spread of Transeurasian speakers was driven by agriculture.


Asunto(s)
Agricultura/historia , Arqueología , Genética de Población , Migración Humana/historia , Lenguaje/historia , Lingüística , China , Conjuntos de Datos como Asunto , Mapeo Geográfico , Historia Antigua , Humanos , Japón , Corea (Geográfico) , Mongolia
2.
Rev Sci Instrum ; 93(7): 073302, 2022 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-35922323

RESUMEN

In order to explore the applicability of superconducting magnets in a magnetic field range of 3 T or less, where superconducting magnets have not been much used so far, a prototype magnet development project has been launched in collaboration with Hanmi Techwin Corporation and Seoul National University. As a result of the project, here we report the design, construction, and operation results of a 2 T 240 mm defect-irrelevant winding (DIW) (RE) Ba2Cu3O7-x (REBCO) magnet. First, design goals were set considering its potential usage in industrial fields, and a 2 T 240 mm-bore multi-width no-insulation high-temperature superconductor magnet was designed accordingly. Based on the design, a total of 15 double pancake (DP) coils were wound, regardless of defects in REBCO tapes, and assembled together. After being installed in a conduction cooling system, the magnet was tested at a temperature of <20 K, and a magnetic field of 2 T at the magnet center was successfully generated with a total of four DP coils containing multiple defects. Based on the experimental results, the additional considerations required for the DIW approach at the magnet level are discussed.

3.
J Hazard Mater ; 324(Pt B): 373-381, 2017 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-27843021

RESUMEN

The feasibility of using microfluidic tests to investigate water-rock (mineral) interactions in fractures regarding sorption onto thin rock sections (i.e., shale and granite) of lead (Pb) and uranium (U) was evaluated using a synthetic PbCl2 solution and uranium-containing natural groundwater as fluids. Effluent composition and element distribution on the thin rock sections before and after microfluidic testing were analyzed. Most Pb removal (9.8mg/cm2) occurred within 3.5h (140 PVF), which was 74% of the total Pb removal (13.2mg/cm2) at the end of testing (14.5h, 560 PVF). Element composition on the thin shale sections determined by µ-XRF analysis indicated that Pb removal was related primarily to Fe-containing minerals (e.g., pyrite). Two thin granite sections (biotite rich, Bt-R and biotite poor, Bt-P) exhibited no marked difference in uranium removal capacity, but a slightly higher amount of uranium was removed onto the thin Bt-R section (266µg/cm2) than the thin Bt-P section (240µg/cm2) within 120h (4800 PVF). However, uranium could not be detected by micro X-ray fluorescence (µ-XRF) analysis, likely due to the detection limit. These results suggest that microfluidic testing on thin rock sections enables quantitative evaluation of rock (mineral)-water interactions at the micro-fracture or pore scale.

4.
J Environ Radioact ; 158-159: 30-7, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27060782

RESUMEN

In this study, the adsorption behavior of U(VI) on (oxy)hydroxides synthesized at different temperatures (25 and 75 °C) was investigated. Four (oxy)hydroxides were synthesized by drying slurries of Fe(III) and Fe(III)Cr(III) (oxy)hydroxide in a vacuum desiccator (25 °C) or in an oven (75 °C). Batch adsorption tests were conducted using the (oxy)hydroxides thus synthesized and groundwater containing uranium ions. In general, the U(VI) removal fraction significantly increased with increasing pH from 3 to 5, remained constant with increasing pH from 5 to 9, and decreased at pH greater than 9, regardless of the type of (oxy)hydroxides and solid-to-liquid ratio. The effect of pH on the U(VI) removal fraction was more significant at a low solid-to-liquid ratio. The oven-dried Fe(III) (oxy)hydroxide exhibited a U(VI) removal fraction lower than that of the vacuum-dried one, whereas the oven-dried Fe(III)Cr(III) (oxy)hydroxide exhibited a U(VI) removal fraction higher than that exhibited by the vacuum-dried one. X-ray photoelectron spectroscopy (XPS) analysis results indicated that the difference in the U(VI) removal fraction is attributed to the dissolution and precipitation of the Fe(III) (oxy)hydroxide during oven drying and dehydration of the Fe(III)Cr(III) (oxy)hydroxide during oven drying.


Asunto(s)
Compuestos de Cromo/química , Compuestos Férricos/química , Hidróxidos/química , Uranio/química , Adsorción , Concentración de Iones de Hidrógeno , Temperatura
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