The review is compiled on the basis of the results of operation of the total ozone (TO) monitoring in Russia and adjoining territories functioning in the operational mode at the Central Aerological ...Observatory (CAO). The monitoring system uses data from the national network equipped with M-124 filter ozonometers under the methodological supervision of the Main Geophysical Observatory. The quality of the functioning of the entire system is operationally controlled in CAO based on the OMI satellite equipment observations (NASA, USA). Basic TO observation data are generalized for each month of the third quarter of 2020 and for the third quarter. Data of routine observations of surface ozone values in the Moscow region are also considered.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Virtually unlimited volumes of serpentine resources stimulate search for new procedures for its processing, including those involving thermal activation. Along with the calcination parameters ...(temperature, time), the crystal-chemical features of the initial serpentines are an important factor. They predetermine the sequence of the formation of new phases in the course of thermolysis and the content of these phases in the heat treatment product. The influence of the calcination temperature on the thermal decomposition of a serpentine mineral, antigorite, was studied by differential scanning calorimetry, X-ray diffraction analysis, and Mössbauer spectroscopy. Amorphous antigorite is not formed in the course of thermolysis, and the intermediate amorphous magnesia–silicate phase is a mixture of two dehydroxylates differing in the ability to react with acid solutions. The activity of the calcination products was determined by two different methods. The optimum calcination temperature is 750°C; it ensures the maximal content of the amorphous active magnesia–silicate phase.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The concentration of black carbon (BC), measured in near-surface air on the territory of the Pechora-Ilych State Natural Biosphere Reserve (PISNBR) on the western side of the Northern Ural Mountains, ...far from sources, is presented for two years (December 2017–November 2019). The temporal variations in BC concentration throughout a year and the location of its main sources are analyzed. The average values for two cold and two warm half-years were 128 and 62 ng/m
3
, respectively. The BC concentration in near-surface atmosphere was compared with MERRA-2 reanalysis data. On a monthly scale, the anomalous increase in BC concentration during short-term smoke aerosol transport across the observation area is more clearly revealed from the reanalysis data, rather than by values measured at a single point. Daily monitoring allows us to detect the specific dates of such situations.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Platinoan vysotskite metacrystals with inverse zoning are described. Their size is up to 0.5 mm. Association of these metacrystals are characterized by a “paracrystalline microboudinage” ...texture—specifically, corroded vysotskite fragments of the first (Pd
0.51
Pt
0.27
Ni
0.20
Fe
0.02
)S and second (Pd
0.49
Pt
0.30
Ni
0.18
Fe
0.03
)S generations, square vysotskite microcrystals of the third generation (Pd
0.47
Pt
0.32
Ni
0.19
Fe
0.02
)S overgrown with fourth-generation vysotskite (Pd
0.45
Pt
0.33
Ni
0.19–0.21
Fe
0.01
)S; these generations are overgrown with fifth-generation vysotskite (Pd
0.45
Pt
0.35
Ni
0.18
Fe
0.02
)S with rims of sixth-generation vysotskite (Pd
0.43
Pt
0.37–0.38
Ni
0.16–0.17
Fe
0.02
)S and the highest-Pt vysotskite of the seventh generation (Pd
0.44
Pt
0.43
Ni
0.09
Fe
0.02
Ru
0.01
)S. Platinoan vysotskite metacrystals are surrounded by halo of small skeletal microcrystals cooperite (Pt
0.96–0.97
Ni
0–0.03
Ru
0.01
)S. Platinoan vysotskite and cooperite develop in low-grade metamorphosed Co–Ni–Cu sulfide ores of the Oktyabrskoe deposit within the Noril
’
sk ore field, where these minerals replaced ferrous chlorite and corrensite, hydrogrossular, chalcopyrite, pentlandite, cubanite, and fassaite.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A novel methodology for characterization and quantification the acidic sites of different accessibility has been developed for dealuminated zeolite catalysts. The method is based on probing the ...accessibility of acid sites by IR spectroscopy of adsorbed alkylpyridines, followed by the characterization of the non-accessible sites by IR spectroscopy of subsequently adsorbed CO. The gradual increase of the size of alkylpyridine probe molecules in a series of experiments allows a step-by-step characterization of the nature and strength of sites with different accessibility. The approach proposed was tested on the series of small-port mordenites dealuminated up to Si/Al ratios of 11, 12, 14 and 18 and characterized by various techniques including XRD, TPD-NH
3, nitrogen adsorption–desorption,
1H MAS NMR and IR spectroscopy. It has been demonstrated that upon dealumination of the small-port MOR, two phenomena related to accessibility occur: (i) the acid sites in the side pockets become accessible for such probe molecules as pyridine due to the partial destruction of side pockets upon dealumination (ii) subsequently, the formation of secondary mesopore system due to further dealumination makes the zeolite crystals completely accessible to relatively bulky molecules such as lutidine, collidine, 2,6-di-
tert-butylpyridine.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Polymer compositions of folic acid based on an amphiphilic copolymer of
N
-vinylpyrrolidone with methacrylic acid, branched with triethylene glycol dimethacrylate, were developed and characterized by ...DLS,
1
H NMR, IR spectroscopy, DSC, and TGA in solutions and in the solid state. Electron absorption spectroscopy was used to determine the effective binding constant of folic acid and the copolymer in isopropanol and in aqueous media. The behavior of nanoscale systems in water depending on the medium temperature and pH was studied, and their hydrodynamic radii were determined. Quantum chemical modeling of the structure of the intermolecular complexes was carried out, and it was shown that the hydrogen bonds formed by oxygen atoms of carboxy groups of either folic acid or methacrylic acid units and hydrogen atoms are weak. The cytotoxicity of polymer compositions with different contents of folic acid (0.5–4 wt.%) was studied on normal (
FetMSC, Vero
) and tumor cell cultures, namely,
HeLa
(human cervical adenocarcinoma, clone
M-HeLa
) and
HepG2
(human liver carcinoma), and their high biocompatibility was demonstrated. Fluorescence microscopy was used to study the accumulation dynamics of polymer particles loaded with folic acid and a fluorescent dye, namely, zinc tetraphenylporphyrinate, in
Vero
and
HeLa
cells. Inferences were made about the prospects of the obtained compositions as targeted delivery systems.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
We report the results of petrological, geochemical, and geochronological investigations of the unusual K‐rich L chondrite melt rock Northwest Africa 6486 (NWA 6486). The rock has slightly ...fractionated siderophile elements and a mostly unfractionated L chondrite pattern of lithophile elements with the exceptions of enrichments in K and Rb and chondritic Sr abundance similar to the K‐rich inclusions found in the ordinary chondrites and indicating a fractionation of alkaline elements through the vapor. We suggest that NWA 6486 and related K‐rich chondritic inclusions were formed in situ on the OC parent bodies and that K and Rb enrichment of these rock most probably is a result of the selective impact evaporation of volatile alkali elements followed by the reaction of a vapor with shock melt. NWA 6486 recorded a breakup event of the L chondrite parent asteroid at 470 Ma during which it was formed. Unusual veins, depleted in K, Na, Ca, and Al relative to the host rock were found in NWA 6486. We suggest that NWA 6486 was affected by aqueous fluids that produced alteration zones depleted in a feldspar component on the walls of opened fractures. The melt veins could be formed during a subsequent impact event by in situ melting of the fracture walls or due to decomposition of an injected supercritical aqueous silicate fluid. The aqueous alteration and the second impact event had no detectable effect on Ar and oxygen isotopic systems. Cosmic ray exposure ages indicate that NWA 6486 was ejected from its parent asteroid ~3–4 Ma ago.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
The vibrational properties of yttrium iron garnet Y
3
Fe
5
O
12
at a high quasihydrostatic pressure are studied by the Raman spectroscopy method. Raman spectra are measured in a high-pressure diamond ...anvil cell in the pressure range of 0–72 GPa at room temperature. A fundamental change in the character of spectra with the disappearance of sharp peaks is detected near ~50 GPa. This confirms a phase transition from the crystalline to amorphous state, which was previously detected by other experimental methods. This transition is accompanied by spin crossover in Fe
3+
ions, which transit from the high-spin (HS,
S
= 5/2) to low-spin (LS,
S
= 1/2) state. The pressure dependences of phonon modes in Y
3
Fe
5
O
12
are measured from atmospheric pressure to the critical phase transition pressure.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A new method for the synthesis of benzofuro3,2-
d
pyrimidines was developed based on the oxidation of 2-(5-bromo-3,4-dihydropyrimidin-4-yl)phenols followed by the intramolecular nucleophilic aromatic ...substitution reaction.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
