The complexes AgL
2
PF
6
(
I
) and ZnLCl
2
(
II
) (L = 2-(3,5-dimethyl-1
H
-pyrazol-1-yl)-4,6-diphenylpyrimidine) were prepared by the reaction of zinc(II) chloride or silver(I) hexafluorophosphate ...with L (M : L molar ratio of 1 : 1 or 1 : 2) in organic solvents. The structure of the complexes was determined by X-ray diffraction (CIF file CCDC no. 2118498). In both complexes, L is coordinated in the bidentate chelating manner; the coordination unit is a distorted tetrahedron. The coordination unit of
II
is formed by one coordinated molecule L and two chloride ions (ZnN
2
Cl
2
); in the case of silver(I), there are two molecules L (AgN
4
). The photoluminescent properties of compounds
I
and
II
in the solid state were studied. The compound
II
shows fluorescence (1.3, 11 ns) in the blue spectral range (λ
max
= 378 nm; quantum yield of 7.8%). The maximum at 530 nm in the photoluminescence spectrum of
I
is red-shifted by ~140–160 nm relative to the emission maxima of L and
II
. The complex
I
shows white light emission (1.6, 11 ns, quantum yield of 5.5%), which is due to intraligand transitions perturbed by the coordination of L to the silver atom. The photostability of
I
was studied at 300 and 80 K.
The role of local vs regional drivers of long-term community dynamics is still poorly explored. Intertidal macrofauna was studied in two small bights of the White Sea, the Medvezhya (MB, steeply ...sloping sandy beach, 66° 21′ N, 33° 36′ E) and Seldyanaya (SB, sheltered silty flat, 66° 20′ N, 33° 37′ E). Macrofauna was collected annually in 1987–2017 four times a year (in winter, spring, summer, and autumn) at four stations arranged across the beaches. Both communities were similar in species composition, spatial distribution, and functional structure but substantially differed in their dynamics. Epifauna was more abundant in MB and infauna in SB. The total biomass in MB showed a long-term upward trend with 4- to 5-year quasi-periodic oscillations without clear seasonal variations. In SB, biomass showed no long-term trend but seasonal and interannual variations, dropping sharply after severe ice-scouring events and only partially recovering afterwards. Species richness was relatively constant in MB but decreased in SB, dropping noticeably after scouring impact. Species structure in MB showed two relatively stable states, with a transition period in 1993–1998, when the structure gradually changed. In SB, no clear long-term trends in structure were observed, but rapid and abrupt fluctuations occurred in years of severe ice scour, particularly in winter/spring. The community dynamics is suggested to be largely determined by local topography and disturbance regime, resulting in relative stability of the MB assemblage but a gradual degradation of that in SB, without any correlation with climatic variables (sea surface temperature and Arctic Oscillation Index).
Abstract
The Baikal-GVD is a neutrino telescope situated in the deepest freshwater lake in the world — Lake Baikal. The design of the Baikal-GVD trigger system allows also to study the ambient light ...of the lake. The analysis of the optical light activity of Baikal water, particularly, time and spatial variations of the luminescence activity for data collected in years 2018, 2019, and 2020 is presented. For the first time we observed highly luminescent layer moving upwards with maximal speed of 28 m/day in January 2021.
Hibbingite, siderite, and their manganoan varieties replacing magnetite and associated sulfides are widespread in tectonized and metamorphosed pentlandite–putoranite ores with magnetite at the deep ...level of the Oktyabrskoe deposit in the Norlisk ore field, Krasnoyarsk krai. Hibbingite aggregates are formed by intergrown lamellar crystals. Hibbingite,
(OH)
3
Cl, contains 2–38 mol % kempite endmember,
(OH)
3
Cl. Hibbingite with 7–13% kempite molecule is common. Hibbingite replacing magnetite and putoranite is enriched in Cu, up to 2.6 wt %, which corresponds to the 4 mol % atacamite endmember,
(OH)
3
Cl. Hibbingite replacing magnetite and pentlandite is enriched in Ni, up to 1.5 wt %. In zoned siderite crystals, the siderite core is depleted in minor elements, whereas the rim is enriched in Mn (up to 23 mol % rhodochrosite molecule) and Cu (up to 4.5 wt % CuO). Native silver and sphalerite enriched in Cd are associated with hibbingite and siderite. These are low-temperature metamorphic-hydrothermal assemblages formed under zeolite facies conditions. Replacement of magnetite by hibbingite and siderite is a reductive process that appears to have occurred in an acidic–CO
2
environment possibly involving hydrocarbons or hydrogen. The likely reaction is Fe
2+
O
4
+ HCl + СО
2
+ H
2
→
(OH)
3
Cl + Fe
2+
CO
3
.
Neutrino physics and JINR Bednyakov, V A; Naumov, D V; Smirnov, O Yu
Physics Uspekhi,
01/2016, Letnik:
59, Številka:
3
Journal Article
Recenzirano
The current status of neutrino physics is briefly reviewed, the basic properties of the neutrino are discussed, and the most challenging problems in this rapidly developing field are described. ...Written to mark the anniversary of the Joint Institute for Nuclear Research, this paper highlights JINR's contributions to the development of neutrino physics and places special emphasis on the prospects of the JINR neutrino program.
Abstract
The first stage of the construction of the Baikal-GVD deep underwater neutrino telescope is planned to be completed in 2024. For the second stage of the detector deployment, a data ...acquisition system based on fiber-optic technologies has been proposed, which will allow for increased data throughput and more flexible trigger conditions. A dedicated test facility has been built and deployed at the Baikal-GVD site to test the new technological solutions. We present the principles of operation and results of tests of the new data acquisition system.
The results of the development and the main characteristics of a new generation of semiconductor current switches (250 kA/25 kV/70 C) based on assemblies of series-connected reverse switched-on ...dynistors (RSDs) are presented. The methods for increasing the switched power and increasing the service life and reliability of RSD switches with maintenance of the previously accepted weight and size indicators were studied. The problem was solved by reducing the RSD power loss and increasing the resistance of the contact connections to the effects of high-power current pulses. The switch design was modernized and the silicon structure was optimized; a new technology for low-temperature connections in the silicon–metal system with the use of silver was developed, thus making it possible to double the active contact area and improve the load characteristics and service life of the new switches. The operating and maximum permissible values of the starting and switched currents were determined. The results of the operation of RSD switches in capacitive energy-storage devices of high-power laser devices are presented. Based on the results of life tests, the service life of new devices was assessed.
The development of a pulsed volume discharge with pre-ionization in a non-uniform supersonic air flow near the wedge in the shock tube channel and the gas-dynamic flow that occur after the discharge ...has been experimentally studied. Plasma configurations that occur near the bottom of the wedge were investigated for the discharge initiated at various stages of an unsteady flow. The self-localization conditions of a volume discharge in the vortex zone behind the wedge are analyzed at the incident shock wave Mach numbers of 2.6–3.5 (at the flow Mach numbers up to 1.50 and a density up to0.15 kg/m
3
).
Aim. To determine the dependence of adiponectin gene expression by subcutaneous, epicardial and perivascular adipocytes on the degree of coronary lesion in coronary heart disease.
Materials and ...methods. 84 patients with coronary artery disease were examined. Of these, 39 people showed a moderate degree of atherosclerotic lesion of the coronary bed (less than or equal to 22 points) on the SYNTAX Score scale, 20 severe (2231 points), and 25 extremely severe (more than 32 points). Upon admission to the hospital, all patients underwent an echocardiographic study (Echocardiography, Acuson, Germany) with the calculation of the ejection fraction (EF) of the left ventricle (LV) to assess its systolic function. During a planned surgical intervention (coronary bypass surgery, CABG), adipocytes of subcutaneous, epicardial (EAT) and perivascular adipose tissue (PVAT) were taken. Adiponectin gene expression was evaluated by polymerase chain reaction (real-time PCR) using TaqMan probes. Statistical analysis was performed using Statistica 9.0.
Results. The maximum level of adiponectin expression was detected in adipocytes of PVAT, and the minimum EAT. With an increase in the degree of atherosclerotic lesion of the coronary bed, the expression of the adiponectin gene in adipocytes of local depots significantly decreases r=-0.82; p=0.023. Moreover, the low level of gene expression in EAT correlated with a decrease in LV EF by r=0.73; p=0.03. In adipocytes of subcutaneous and especially PVAT, gene expression was the highest in patients with a moderate degree of coronary lesion.
Conclusions. Low adiponectin gene expression in EAT is associated with an increase in the degree of atherosclerotic lesion of the coronary bed and a decrease in LV EF.
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