Purpose. To solve the problem of the allocation of contact vertical normal tensions along the sole of a rigid round stamp, located in an elastic isotropic half-space at a certain depth h 0. To ...compare the obtained solution with the well-known classical result for h = 0, to check the obtained results for adequacy. Methodology. Based on the analysis of the decision on the stress-strain state of the base, inside which there is a vertical arbitrary load distributed over the area of the circle, the necessary formulas are obtained to solve the problem. An algorithm for constructing an approximate solution has been developed, the essence of which is to use a combination of the boundary element method and the iteration process by S.N.Klepikov. For a number of depths, approximate solutions of the considered problem are obtained. Findings. The proposed algorithm for the approximate solution of the problem of indenting a round rigid stamp into the upper boundary of an elastic isotropic half-space has good agreement with the exact solution and can be used to solve contact problems. The outlines of the contact stress diagrams depend on the depth at which they are determined – the greater the depth, the flatter the outlines of the diagrams are, while starting from a certain depth, the diagrams of contact stresses practically coincide. The greater the depth is at which the stamp is located, the more force must be applied to obtain equal displacements of the stamp. Originality. The obtained research results significantly expand the possibilities of solving various problems of soil mechanics and foundation engineering, make it possible to obtain absolutely new results. In particular, a clear dependence of the contact stresses along the sole of a rigid round stamp on the depth at which it is located was identified. In addition, the presented data allow us to designate an absolutely new direction in the calculation of the foundations of ground anchors, namely, the calculation of their deformations. Practical value. For engineering practice, it is important that the greater the value of Poisson’s ratio of the base is, the greater the contact stresses are, other things being equal.
This study provides a comparative characterization of the structural parameters and cytotoxicity of zinc halide and copper(II) bromide complexes with caffeine (caf) of the composition Zn(caf)(H
2
O)X
...2
(X = Cl, Br, I) and Cu(caf)
2
Br
2
(1).
The cytotoxicity of the complexes is dose-dependent in all cell lines. The concentrations of the complexes, at which they are more cytotoxic against cancer cells (MCF-7) than against stem cells (DPSC), were determined. The synthesized complexes exhibited synergism of cytotoxicity.
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Dyes and pigments with high reflectance in the near-infrared (NIR) region can extensively control the heat buildup. Perylene-based pigments exhibit considerable reflectance in the NIR region. The ...reflectance of a material depends upon a number of factors, such as particle size, concentration of the reflective material, the distribution of particles within the material and the material’s refractive index. The refractive index, in turn, depends on the electronic structure of the material. Therefore,differently substituted perylene compounds are expected to exhibit different reflectance in the NIR region. To elaborate this point, different perylene bisimide derivatives have been synthesized, and their ability to reflect in the NIR region has been determined and compared to the results for commercially available pigments. Significant variation in the relative reflectance is observed in the NIR region for differently substituted perylene bisimide compounds. The NIR reflectance of different perylene tetracarboxy diimide derivatives (PCIs) was also compared to the reflectance of 3,4:9,10-perylenetetracarboxylic dianhydride (PTCA), the precursor from which the PCIs are commonly synthesized. PTCA exhibits significantly higher relative reflectance in the given region than any of the diimide derivatives synthesized from it in this study.
► Relative reflectance of different perylene derivatives in the near-infrared (NIR) region is reported. ► Significant variation in the relative reflectance in the NIR-region is observed among different
N,N′ disubsubstituted perylene-3,4:9 10-bis(dicarboximide)s (PCIs). ► 3,4:9,10-perylenetetracarboxylic dianhydride (PTCA) has shown significant higher reflectance in the NIR-region than any of the PCI synthesized from it in this study. ► All the 3,4:9,10-perylenetetracarboxylic bisiimide samples are thermally stable up to 330 °C.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Iron polyhydrides have been synthesized at pressures of 77–157 GPa and temperatures up to 2000 K by the laser heating of an iron–borazane (ammonia borane NH
3
BH
3
) sample in diamond anvil cells. ...X-ray spectra of the synthesized products indicate the formation of several FeH
x
phases, in which (in two cells) reflections of FeH
iron hydride with the tetragonal
phase are reliably detected. The magnetic and electronic properties of FeH
x
compounds have been studied by nuclear forward scattering spectroscopy on Fe-57 nuclei at high pressures in the temperature range of 4–300 K in external magnetic fields up to 5 T. The nuclear forward scattering data indicate at least seven FeH
x
compounds with very different electronic and magnetic properties. The Néel temperature
T
N
determined for the FeH
2
phase at a pressure of 82 GPa is about 174 K. One of the striking results is the observation of the FeH
x
phase remaining magnetically ordered at a pressure of 128 GPa in the entire temperature range of 4–300 K. Such a high pressure is characteristic of the boundary between the lower mantle and the outer core of the Earth. The existence of a magnetic phase of an iron compound at such a record high pressure is unique and has not yet been observed.
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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
.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The review is compiled on the basis of the results of operation of the total ozone (TO) monitoring system in the CIS and Baltic countries 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 being 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 first quarter of 2021 and for the first quarter. Data of routine observations of surface ozone values in the Moscow region are also presented.
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The magnetic and electronic states of iron in the hexagonal close-packed ε-Fe phase have been studied by synchrotron Mössbauer spectroscopy on Fe-57 nuclei (nuclear forward scattering method) at ...pressures of
GPa in the temperature range of 4–300 K in external magnetic fields up to 5 T. It has been found that Fe atoms are in a nonmagnetic state in the entire studied
P
–
T
region. Theoretically implied magnetic instability and quantum spin fluctuations, which can be stabilized by magnetic perturbation (e.g., external magnetic field), have not been confirmed by our measurements of nuclear forward scattering spectra in an external magnetic field. It has been established that the isomer shift
IS
(
P
) has a nonlinear pressure dependence and reaches a colossal value of about –0.8 mm/s at a maximum pressure of 241 GPa, indicating a very high electron density on the Fe nucleus. A sharp change in the electron density on the Fe nucleus at temperatures of 100–200 K indicates a phase transition with a change in the electronic structure, which can be due to an abrupt increase in the conductivity or even to the appearance of superconductivity.
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—
Planctomycetes are common inhabitants of northern wetland ecosystems. In this study, a new planctomycete of the genus
Paludisphaera
, strain Pla2
T
, was isolated from a boreal fen in Russia. The ...novel isolate was represented by nonmotile, pink-pigmented, spherical cells that multiplied by budding and occurred singly or were assembled in small aggregates. Strain Pla2
T
was a chemoorganotrophic, psychrotolerant mesophile with a growth optimum at pH 5.5‒6 and 15‒20°C. The preferred growth substrates were polysaccharides, including xylan, xanthan gum, and phytagel, as well as some sugars. The 16S rRNA gene sequence of strain Pla2
T
displayed the highest similarity (97.9%) to that of ‘
Paludisphaera soli
’ JC670
T
isolated from highland soil of the western Himalayas. With other members of the genus
Paludisphaera
, ‘
P. rhizosphaerae
’ JC665
T
and
P. borealis
PX4
T
, this similarity was 97.0 and 93.8%, respectively. The genome of strain Pla2
T
was 8.21 Mb in size and contained about 6500 protein-coding genes and 3 copies of the rRNA operon. The DNA G + C content was 67 mol %. The average nucleotide identity between the genome sequence of strain Pla2
T
and those of previously described members of the genus
Paludisphaera
was between 79.4 and 82.6%. This genotypic distance as well as several phenotypic differences allowed classifying the new planctomycete from a fen as representing a novel species of the genus
Paludisphaera
,
Paludisphaera mucosa
sp. nov. with the type strain Pla2
T
(=KCTC92668
T
= VKM B-3698
T
).
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The review is compiled from the results of operation of the total ozone (TO) monitoring system in Russia and adjoining territories that functions 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 controled based on the OMI satellite equipment observations (NASA, USA). Basic TO observation data are generalized for each month of the third quarter of 2021 and for the third quarter. Data of routine observations of surface ozone values in the Moscow region are also presented.
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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 electronic structure of a clean molybdenum surface oxidized in air and upon sodium Na adsorption at submonolayer coating have been studied by photoelectron spectroscopy in situ in an ultrahigh ...vacuum. The photoemission spectra from the valence band and O 1
s
, O 2
s
, Mo 4
s
, and Na 2
p
core levels are studied at the synchrotron excitation in the photon energy range 80–600 eV. The spectrum of oxygen core levels related to the substitution of sodium atoms for hydrogen atoms in the hydroxyl group is found to be changed. The surface topography and the cathodoluminescence of the molybdenum oxide has been studied.
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