Structure of natural impact glasses on AFM data

This work was supported by the RSF (project No. 17-17-01080)

Complexing processes in M(II)-dithiomalonamide-diacetyl triple systems (M = Ni, Cu) in ethanol solution and in a metal(II)hexacyanoferrate(II) gelatin-immobilized matrix materials

The complexing processes in the MII-dithiomalonamide-diacetyl triple system (M = Ni, Cu) occuring in the nickel(II)- and copper(II) hexacyanoferrate(II) gelatin-immobilized matrix in contact with aqueous alkaline solutions (pH∼12) containing dithiomalonamide and diacetyl at room temperature, and between MCl2, dithiomalonamide and diacetyl in EtOH solutions upon heating to ∼80°C, have been studied. In the Ni II-dithiomalonamide-diacetyl system, template synthesis occurs in EtOH solution but does not occur in the gelatin-immobilized matrix, whereas in the CuII-dithiomalonamide-diacetyl system, template synthesis occurs in the gelatin-immobilized matrix but not in EtOH solution. Dithiomalonamide and diacetyl are the ligand synthons in the processes indicated

NEW DATA ON AGE AND NATURE OF CARBONIZATION WITHIN SOUTHERN FLANK OF THE BAIKAL LEDGE OF THE SIBERIAN CRATON BASEMENT

The Baikal ledge rock formations in the Siberian craton structure are included in the Akitkan mobile belt which is considered as the Late Paleoproterozoic independent island arc system moved up to the ancient basement during the terrains amalgamation 1.91–2.00 Ga ago (Fig. 1) [Rosen, 2003; Gladkochub et al., 2009; Didenko et al., 2013].The Baikal ledge rock formations in the Siberian craton structure are included in the Akitkan mobile belt which is considered as the Late Paleoproterozoic independent island arc system moved up to the ancient basement during the terrains amalgamation 1.91–2.00 Ga ago (Fig. 1) [Rosen, 2003; Gladkochub et al., 2009; Didenko et al., 2013]

Microscopic investigation of nanoscale coesite crystals in ultra-high pressure silica glass from impactites

The study was supported by the Russian Science Foundation (project #17-17-01080)

Complex formation in Cu(II)-thioamide-carbonyl compound systems in ethanol solutions

The structures of metal complexes formed in systems Cu(II)-thioamide- carbonyl compounds in water-ethanol solutions were studied by spectroscopic and quantum-chemical methods. It was found that in systems containing thiocarbohydrazide, the processes of template synthesis in water-ethanol solution and in gelatin-immobilized matrices differ substantially. In the case of dithiooxamide and dithiomalonamide, no products of template synthesis were detected; these amides give with the Cu2+ ion the chelate complexes with a ratio Cu2+: ligand = 1: 2 and with the N2S 2 coordination core for dithiooxamide and S4 coordination core for dithiomalonamide. The quantum-chemical calculations in terms of the density functional theory were shown to adequately describe the structures of metal complexes and relative thermodynamic characteristics of the template synthesis processes in the systems under study. © Pleiades Publishing, Inc., 2006

Template synthesis in the nickel(II)-thiocarbohydrazide-propanone triple system

The complexing process proceeding in the Ni II -thiocarbohydrazide (H2N-H-NC(=S)-NH-NH2)-propanone triple system in EtOH solution and nickel(II)hexacyanoferrate(II) gelatin-immobilized matrix has been studied. It has been found that in the first case, template synthesis leading, as a minimum, to formation of three coordination compounds of Ni II with (N,N,S,S)-donor tetradentate ligands having NiL 1 , NiL 2 and NiL 3 compositions where L 1 is 4,6,6-trimethyl-2,3,7,8-tetraazanonen-3-di(thiohydrazide)-1,9, L 2 is 4,6,6,12-tetrametyl-1,9-dithio-2,3,7,8,10,11- hexaazatridekadien-3,11-hydrazide-1 and L 3 is 2,8,10,10,16- pentamethyl-5,13-dithio-3,4,6,7,11,12,14,15-octaazaheptadekatrien-2,7,15 is observed, whereas in the gelatin-immobilized matrix, a complexing process in the system considered does not occur. © Springer 2005

Application of 57Fe Mössbauer spectroscopy as a tool for mining exploration of bornite (Cu5FeS4) copper ore

Nuclear resonance methods, including Mössbauer spectroscopy,are considered as unique techniques suitable for remote on-line mineralogical analysis. The employment of these methods provides potentially significant commercial benefits for mining industry. As applied to copper sulfide ores, Mössbauer spectroscopy method is suitable for the analysis noted. Bornite (formally Cu5FeS4) is a significant part of copper ore and identification of its properties is important for economic exploitation of commercial copper ore deposits. A series of natural bornite samples was studied by 57Fe Mössbauer spectroscopy. Two aspects were considered: reexamination of 57Fe Mössbauer properties of natural bornite samples and their stability irrespective of origin and potential use of miniaturized Mössbauer spectrometers MIMOS II for in-situ bornite identification. The results obtained show a number of potential benefits of introducing the available portative Mössbauer equipment into the mining industry for express mineralogical analysis. In addition, results of some preliminary 63,65Cu nuclear quadrupole resonance (NQR) studies of bornite are reported and their merits with Mössbauer techniques for bornite detection discussed. © 2013 Springer Science+Business Media Dordrecht

Application of 57Fe Mössbauer spectroscopy as a tool for mining exploration of bornite (Cu5FeS4) copper ore

Nuclear resonance methods, including Mössbauer spectroscopy, are considered as unique techniques suitable for remote on-line mineralogical analysis. The employment of these methods provides potentially significant commercial benefits for mining industry. As applied to copper sulfide ores, Mössbauer spectroscopy method is suitable for the analysis noted. Bornite (formally Cu5FeS4) is a significant part of copper ore and identification of its properties is important for economic exploitation of commercial copper ore deposits. A series of natural bornite samples was studied by 57Fe Mössbauer spectroscopy. Two aspects were considered: reexamination of 57Fe Mössbauer properties of natural bornite samples and their stability irrespective of origin and potential use of miniaturized Mössbauer spectrometers MIMOS II for in-situ bornite identification. The results obtained show a number of potential benefits of introducing the available portative Mössbauer equipment into the mining industry for express mineralogical analysis. In addition, results of some preliminary 63,65Cu nuclear quadrupole resonance (NQR) studies of bornite are reported and their merits with Mössbauer techniques for bornite detection discussed

Towards an improved understanding of biogeochemical processes across surface-groundwater interactions in intermittent rivers and ephemeral streams

Surface-groundwater interactions in intermittent rivers and ephemeral streams (IRES), waterways which do not flow year-round, are spatially and temporally dynamic because of alternations between flowing, non-flowing and dry hydrological states. Interactions between surface and groundwater often create mixing zones with distinct redox gradients, potentially driving high rates of carbon and nutrient cycling. Yet a complete understanding of how underlying biogeochemical processes across surface-groundwater flowpaths in IRES differ among various hydrological states remains elusive. Here, we present a conceptual framework relating spatial and temporal hydrological variability in surface water-groundwater interactions to biogeochemical processing hotspots in IRES. We combine a review of theIRES biogeochemistry literature with concepts of IRES hydrogeomorphology to: (i) outline common distinctions among hydrological states in IRES; (ii) use these distinctions, together with considerations of carbon, nitrogen, and phosphorus cycles within IRES, to predict the relative potential for biogeochemical processing across different reach-scale processing zones (flowing water, fragmented pools, hyporheic zones, groundwater, and emerged sediments); and (iii) explore the potential spatial and temporal variability of carbon and nutrient biogeochemical processing across entire IRES networks. Our approach estimates the greatest reach-scale potential for biogeochemical processing when IRES reaches are fragmented into isolated surface water pools, and highlights the potential of relatively understudied processing zones, such as emerged sediments. Furthermore, biogeochemical processing in fluvial networks dominated by IRES is likely more temporally than spatially variable. We conclude that biogeochemical research in IRES would benefit from focusing on interactions between different nutrient cycles, surface-groundwater interactions in non-flowing states, and consideration of fluvial network architecture. Our conceptual framework outlines opportunities to advance studies and expand understanding of biogeochemistry in IRES