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Viktoria K. Kis Tatyana Shumilova Victor Masaitis 《Physics and Chemistry of Minerals》2016,43(9):661-670
High-resolution transmission electron microscopy was applied for the detailed nanostructural investigation of Popigai impact diamonds with the aim of revealing the nature of the amorphous carbon of the matrix. The successful application of two complementary specimen preparation methods, focused ion beam (FIB) milling and mechanical cleavage, allowed direct imaging of nanotwinned nanodiamond crystals embedded in a native amorphous carbon matrix for the first time. Based on its stability under the electron beam, native amorphous carbon can be easily distinguished from the amorphous carbon layer produced by FIB milling during specimen preparation. Electron energy loss spectroscopy of the native amorphous carbon revealed the dominance of sp 2-bonded carbon and the presence of a small amount of oxygen. The heterogeneous size distribution and twin density of the nanodiamond crystals and the structural properties of the native amorphous carbon are presumably related to non-graphitic (organic) carbon precursor material. 相似文献
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Mineralogy and Petrology - Complementary nano- and atomic-scale data from SEM, FIB, HRTEM, and EELS observations of after-coal impact diamonds from the giant Kara astrobleme are described,... 相似文献
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Pavlova L. M. Radomskaya V. I. Shumilova L. P. Sorokin A. P. Radomskii S. M. 《Doklady Earth Sciences》2020,492(2):438-441
Doklady Earth Sciences - Based on model experiments on the sorption of chemical elements from multicomponent solutions with fungi biomass, lignite, and humic acids, it was assumed that qualitative... 相似文献
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L. P. Plyusnina T. G. Shumilova S. I. Isaenko G. G. Likhoidov A. V. Ruslan 《Russian Journal of Pacific Geology》2013,7(4):288-298
The regional carbonization of the Riphean metamorphic complexes is discussed using as an example the Tamginskoe and Turgenevskoe graphite deposits located in the northern part of the Khanka terrane. It is shown that the noble metal mineralization associates closely with the graphitization. Isotopic, X-ray, and thermal analyses and Raman spectroscopy were first used for investigating the structural state of the graphite with defining its two varieties. The first of them is represented by nanocrystalline fluidogenic graphite that was formed during gas condensate crystallization from deep-seated reduced ore-bearing fluid. The second variety (large-flake graphite) represents a product of metamorphic recrystallization of carbonaceous terrigenous protoliths. The recrystallization was accompanied by the granitization of the sedimentary protolith, mobilization, and the transfer of the carbonaceous and ore matter of the host rocks. It is inferred that the graphitization associated with noble metal mineralization is a polygenic process. The graphite of the first generation associates closely with amorphous diamond-like carbon. This unexpected find may bear genetic information useful for geological and geochemical reconstructions. 相似文献
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Radomskaya V. I. Shumilova L. P. Noskova L. P. Sorokin A. P. Pavlova L. M. Ivanov V. V. 《Doklady Earth Sciences》2022,507(2):1033-1039
Doklady Earth Sciences - The occurrence forms and location features of rare-earth elements in Miocene brown coals have been studied at the Sergeevskoe deposit (Amur region). Humic acids have been... 相似文献
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V. I. Radomskaya S. M. Radomskii E. N. Kulik L. I. Rogulina L. P. Shumilova L. M. Pavlova 《Water Resources》2017,44(2):284-296
The distribution and fractionation of rare-earth elements (REE) are studied in the surface and subsurface waters and rocks of the Albynskoe Gold-Bearing Placer. The obtained data show the rocks of the placer to be enriched with rare-earth elements and to feature the predominance of light lanthanides over heavy ones. Groundwater show an equality between the groups of light and heavy lanthanides, while in the surface waters the concentration of light REE is much higher than that of heavy ones, thus reflecting the composition of the drained ore rocks. The leaching of rare-earth elements from rocks by atmospheric water is intensified by agents produced by microorganisms in their vital activity. 相似文献
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Doklady Earth Sciences - The results of geochemical studies of the diamondiferous suevites of the Kara astrobleme (Pay-Khoy) using a new approach based on “area” microprobe analysis of... 相似文献
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L. M. Pavlova V. I. Radomskaya L. P. Shumilova A. M. Ionov P. Sorokin 《Doklady Earth Sciences》2017,473(2):457-460
The mechanism of platinum biomineralization by microscopic fungi is displayed based on data of electron microscopy, infrared and X-ray photoelectronic spectroscopy. It was suggested the platinum sorption process by microscopic fungi has some stages. The initial interaction is carried out by the mechanisms of physical and chemical sorption. Hereafter the reduction process of adsorbed platinum ions up to zero state is performed, probably, for account of organic compounds, which are produced by fungi biomass as metabolism result, and the process terminates by nulvalent particles aggregating up to nanosize forms. Obtained data on the platinum biomineralization extends the concept concerning the character of forming platinum nanoparticles in carbonous paleobasin. 相似文献