For the first time in protozoology, research was carried out on the fauna of testate amoebas in a city park. One hundred and nine species and infraspecific taxa of this group of free-living protozoa ...were found in various types of habitats in the Bitsevskii Les Park in Moscow. To assess the species diversity of testate amoebas, samples were taken from tree hollows; small oligo-mesotrophic swamps; epiphytic mosses from tree trunks; mosses on deadwood; bottom samples from reservoirs; and soil samples near tree trunks, as well as directly in the area of the Yasenevo Estate Park. Various ecological groups of testate amoebas have been identified; the richest communities of eurybionts inhabited soils, as well as mosses on deadwood. Bottom sediments of manor ponds were inhabited mainly by hydrophilic species of the genus
Difflugia.
A physical model is proposed, which makes it possible to determine the velocity distributions of antihydrogen atoms formed as a result of three-body recombination for the given parameters of an ...antiproton–positron plasma. Particle velocity relaxation is accounted for using the Derbenev–Skrinskii approach. The recombination rate is calibrated from the available results of molecular dynamics calculations. Good agreement with experimental results is achieved. The model makes it possible to estimate the efficiency of trapping of atoms in experimental conditions for obtaining antihydrogen.
Energy loss of a proton propagating through a low-temperature gas of magnetized electrons is studied by molecular dynamics method for the case when proton velocity is much more than electrons thermal ...velocity. Strong uniform magnetic field is considered when electron Larmor radius is much smaller than distance of closest approach (Coulomb radius). High electron density, and hence small values of the Coulomb logarithm, is considered. The dependence of energy loss on angle between the proton velocity and the magnetic field direction is studied. Results of calculations are compared to Derbenev and Skrinskii theoretical approach to average friction force.
A method for measuring cross sections at
colliders for the case where the center-of-mass frame of colliding particles moves in the laboratory frame is proposed. Within this method, the energy ...dependence of the cross section is extracted from the angular distribution of interaction products. The method applied to the
process is found to be sensitive. This method provides the possibility of studying the fine structure of the cross section near the threshold at scales much less than the energy spread of the beams used. Similar measurements may be implemented in experiments at the Super Charm-Tau Factory.
Post-Spinel Phases in the Earth’s Mantle Iskrina, A. V.; Bobrov, A. V.; Spivak, A. V.
Geochemistry international,
04/2022, Letnik:
60, Številka:
4
Journal Article
Recenzirano
Odprti dostop
—
The post-spinel phases include compounds with stoichiometry
and structures of the calcium ferrite CaFe
2
O
4
, calcium titanate CaTi
2
O
4
, and marokite CaMn
2
O
4
types. The structures with a ...centered
Cmcm
(
Bbmm
) and primitive
Pnma
(
Pmcn
) and
Pbcm
(
Pmab
) cells are distinguished in this family of topologically related compounds with a “marokite” channel formed by six octahedra. The sites A and B are occupied by various cations, in particular, Cr, Al, Mg, Fe, Ca, Ti, Fe, Na, and Si, which implies the formation of solid solutions of a wide compositional range. In nature, such high-pressure phases were found in meteorites, as inclusions in diamond crystals, and in rocks from some metamorphic complexes. This review provides a characterization of natural mineralogical finds, the results of an experimental study of post-spinel phases of various compositions and their solid solutions, as well as crystal chemical simulation and assessment of likely compositions and the areas of stability of compounds with a “marokite” channel. The discrepancy between the results of individual studies indicates the necessity to clarify the stability parameters and probable isostructural transitions, and, ultimately, to improve the classification of post-spinel phases.
Challenges the European economy began to face 12 years ago raised the question about actions European Central Bank (ECB) have to undertake to maintain the financial sustainability, considering its ...objective to ensure price stability while coping with a changed economic environment. Provision that the ECB is obliged to take efforts to ensure financial stability as well as potentially serious consequences of crisis’ impact on the banking system and industrial production, led to an expansion of its role beyond standard monetary policy measures, with the unconventional steps being taken in addition to conventional to combat the adverse impact of the financial crisis. While reducing the interest rate, ECB also provided a cheap financial capital for banks via fixed-rate “Long Term Refinancing Operations” (LTROs), and three “Covered Bond Purchase Programmes” (CBPP). Purchases of debt securities were also conducted via “Securities Market Programme” (SMP) and, later, with then ECB’s President Mario Draghi declaring that ECB will do “whatever it takes to preserve the euro”, possibility of their increase was announced with the start of “Outright Monetary Transactions” (OMT) Programme. A mere announcement of the OMT was enough to calm financial markets, as none of the eurozone countries applied for financial support within this programme’s framework. Then ECB proceeded with a full-fledged quantitative easing, starting to buy sovereign bonds under its Public Sector Purchase Programme (PSPP), having spent 2.6 trillion € on its implementation. Understanding that a monetary union without an efficient banking union is unacceptably dangerous, the European Banking Union, under which supervision of largest eurozone banks has transferred directly to the ECB, was progressively established. While ECB’s anti-crisis policies achieved their goals, prolongation of the strategy it adopted may create new risks for the financial stability of the euro area, such as excessive dependence of credit institutions on monetary support and excessive inflationary risks under a zero interest-rate policy. Still, EU institutions’ coordinated financial management played an important role in overcoming the existing turbulence, with fiscal and monetary policy measures reinforcing each other.
This paper presents issues of identification of various AE sources in order to increase the information value of AE method. This task is especially relevant for complex objects, when factors that ...affect an acoustic path on an object of testing significantly affect parameters of signals recorded by sensor. Correlation criteria, sensitive to type of AE source in metal objects is determined in the article.
Abstract
We demonstrate a wide distribution and abundance of hybrids between the river species
Ranunculus aquatilis
,
R
.
fluitans
and
R
.
kauffmannii
with the still water species
R
.
circinatus
(
...Batrachium
, Ranunculaceae) in rivers of two postglacial landscapes of East Europe, i.e., Lithuania and Central European Russia. The
Batrachium
species and hybrid diversity is higher in the rivers of Lithuania (4 species and 3 hybrids vs. 2 and 1) and represented mainly by western
R
.
aquatilis
,
R
.
fluitans
and their hybrids whereas in Central European Russia, the East European species
R
.
kauffmannii
and its hybrid are the only dominant forms. Hybrids make up about 3/4 of the studied individuals found in 3/4 of the studied river localities in Lithuania and 1/3 of the individuals found in 1/3 of the localities in Central European Russia. Such extensive hybridization in river
Batrachium
may have arisen due to the specificity of rivers as open-type ecosystems. It may have been intensified by the transformation of river ecosystems by human activities and the postglacial character of the studied landscapes combined with ongoing climate change. Almost all hybrids of
R
.
aquatilis
,
R
.
fluitans
and
R
.
kauffmannii
originated from unidirectional crossings in which
R
.
circinatus
acted as a pollen donor. Such crossings could be driven by higher frequency and abundance of
R
.
circinatus
populations as well as by some biological mechanisms. Two hybrids,
R
.
circinatus
×
R
.
fluitans
and
R
.
circinatus
×
R
.
kauffmannii
, were formally described as
R.
×
redundans
and
R.
×
absconditus
. We found a hybrid which most likely originated from additional crossing between
R
.
aquatilis
and
R
.
circinatus
×
R
.
fluitans
.
This paper highlights advances made using the 4-bora-3a,4a-diaza-s-indacene (BODIPY) as a fluorophore in design and application of fluorescent sensors for microenvironment polarity. Sections of the ...paper cover broad analysis of a range of fluorescent indicators immobilized in ethyl- and methyl cellulose matrices. The present study demonstrates that BODIPY-based fluorescent materials could be successfully utilized for ratiometric detection of ethanol and acetone in gas phase. The achieved limit of detection value equals 0.02 mg/ml for acetone and 0.08 mg/ml for ethanol, whereas obtained sensoric materials are reusable without regeneration required.
This paper reports the comparison results obtained for temporal variations in atmospheric pressure and soil radon concentration measured in loose sediments at three monitoring stations in the Baikal ...region for the period of three relatively strong earthquakes such as Bystrinskii (September 21, 2020,
K
= 14.6), Kudarinskii (December 9, 2020,
K
= 14.0), and Khubsugulskii (January 11, 2021,
K
= 16.0). According to the emanation monitoring data, radon release is controlled in this region by variations in atmospheric pressure. As first identified by the formalized statistical analysis, this relationship is subjected to irregularities in the course of each seismic activation studied. They are related to the earthquake preparation processes. Upon expanding the monitoring network, this discovery opens up real opportunities for developing the emanation approach to medium-term forecasting.
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