New remains of a Taymyr mammoth, including bones, bone collagen, hairs, skin, and soft (muscle and fat) tissues were studied comprehensively by mineralogical, spectroscopic, chromatographic, and isotope-geochemical methods. The results were used to infer the mammoth's biological age and diet, paleoclimatic conditions, and the mechanisms and degree of fossilization of the remains.
View Article and Find Full Text PDFThe pyrochlore-type solid-solution formation in a BiMgCuTaO system, synthesized for the first time, is observed at ≤ 0.56. High-temperature X-ray diffraction showed that the pyrochlore phase exists in air up to 1080 °C, where its thermal decomposition leads to the segregation of (Mg,Cu)TaO.
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September 2021
The samples of Ni-doped bismuth magnesium tantalate pyrochlores with the general formula Bi(Mg Ni )TaO ( = 0.3, 0.5, 0.
View Article and Find Full Text PDFThermal behavior of the orthorhombic (α) and triclinic (β) polymorphs of BiNbO was studied by the methods of high-temperature powder X-ray diffraction (HTPXRD) and differential scanning calorimetry (DCS) in the temperature range 25-1200 °C. The study revealed the sequence of thermal phase transformations and the new high-temperature modification, γ-BiNbO, which was formed above 1001 °C and existed up to the melting temperature of BiNbO. The incongruent melting of BiNbO was characterized by the formation of the cubic phase with the approximate composition BiNbO.
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