The results of determination of the chemical composition of the main plutonic rock gabbro are presented. The chemical and mineral compositions were calculated by physicochemical modeling, as well as ...the composition of the components formed during its heating in a wide temperature range in different atmospheres. The results made it possible to create methods for modification of the composition of gabbro-basalt raw materials to obtain mineral fibers, stone casting products, and ceramics.
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Implementing the Dubna Radioactive Ion Beams project (DRIBs) a new, efficient fragment separator ACCULINNA-2 was installed recently at the primary beam line of the U-400M cyclotron in the Flerov ...Laboratory of Nuclear Reactions, JINR. Since 2017, radioactive beams have been obtained from this facility. The motivation for the new RIB complex, together with an overview of the RIB research conducted in Dubna and its correlation with the worldwide RIB activities, are given in this paper. The status of the ACCULINNA-2 setup, the nearest prospects for completing its equipment, and the planned first-stage experiments are presented.
A possible mechanism is considered for the formation of nanoscale oxides based on titanium and aluminum isopropoxides in a medium of supercritical CO
2
fluid. It is shown that because of ...intermolecular interactions and high pressure in the system, the supercritical fluid acquires the properties of a condensed medium, the main role of which is to restrain processes of hydrolysis. At the first stage of the hydrolysis of titanium isopropoxide, the water molecule is coordinated in the outer sphere of the central atom due to the formation of intermolecular hydrogen bonds. It is then coordinated into the inner sphere with the formation of a five-coordinate transition state and its destruction, creating a product substituted for the hydroxo group. The next steps proceed in a similar way. The described mechanism agrees with experimental findings and produces nanosized X-ray amorphous titanium oxide. (With aluminum isopropoxide, only the hydrolyzed hydroxo form can be produced.) Results suggest the production of nanosized oxides from isopropoxides in a medium of supercritical CO
2
fluid is possible for transitional
d
-elements.
To carry out the experiments with radioactive beams at the ACCULINNA-2 fragment separator in the Flerov Laboratory of Nuclear Reactions, a complex of cryogenic thin physical targets with isotopes H
2
..., D
2
, T
2
,
3
He, and
4
He is being created for the gas, liquid, and solid phase (for hydrogen). One of the three types of cryotargets created for nonhazardous gases in any phase at a temperature of 11–30 K is described. Requirements to the targets are formulated. A variety of available cells are presented, a concept of safe operation with the solid phase of hydrogen is given, and the gas–vacuum test bench for its implementation is described.
The H7 system was populated in the H2(He8,He3)H7 reaction with a 26 AMeV He8 beam. The H7 missing mass energy spectrum, the H3 energy and angular distributions in the H7 decay frame were ...reconstructed. The H7 missing mass spectrum shows a peak, which can be interpreted either as unresolved 5/2+ and 3/2+ doublet or one of these states at 6.5(5) MeV. The data also provide indications of the 1/2+ ground state of H7 located at 1.8(5) MeV with quite a low population cross section of ∼25 μb/sr within angular range θc.m.≃(17°-27°).
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Possible strategies of the development of low-energy nuclear physics in Russian Federation on the basis of the DERICA (Dubna Electron–Rare Isotope Collider fAcility ) project is examined. DERICA is a ...multiuser multipurpose facility for the production and study of radioactive isotopes (RI). In the research program of DERICA, emphasis is placed on studying RI in collector rings, but a stage-by-stage implementation of the program of DERICA would make it possible to address a wide range of fundamental problems at each stage of its development at the cutting-edge level. The ambitious goal of creating an
electron–radioactive ion
collider for studying basic properties of RI in electron–ion scattering is proposed for the final stage of development of DERICA.
The climatology of ozone produced by the Canadian Middle Atmosphere Model (CMAM) is presented. This three‐dimensional global model incorporates the radiative feedbacks of ozone and water vapor ...calculated on‐line with a photochemical module. This module includes a comprehensive gas‐phase reaction set and a limited set of heterogeneous reactions to account for processes occurring on background sulphate aerosols. While transport is global, photochemistry is solved from about 400 hPa to the top of the model at ∼95 km. This approach provides a complete and comprehensive representation of transport, emission, and photochemistry of various constituents from the surface to the mesopause region. A comparison of model results with observations indicates that the ozone distribution and variability are in agreement with observations throughout most of the model domain. Column ozone annual variation is represented to within 5–10% of the observations except in the Southern Hemisphere for springtime high latitudes. The vertical ozone distribution is generally well represented by the model up to the mesopause region. Nevertheless, in the upper stratosphere, the model generally underestimates the amount of ozone as well as the latitudinal tilting of ozone isopleths at high latitude. Ozone variability is analyzed and compared with measurements. The comparison shows that the phase and amplitude of the seasonal variation as well as shorter timescale variations are well represented by the model at various latitudes and heights. Finally, the impact of incorporating ozone radiative feedback on the model climatology is isolated. It is found that the incorporation of ozone radiative feedback results in a cooling of ∼8 K in the summer stratopause region, which corrects a warm bias that results when climatological ozone is used.
The features of methods for constructing recrystallization curves of the second and third kind and the dependence “average grain size (area) - strain intensity – temperature” are given. For alloys of ...various structural classes VZH159 and 14Cr17Ni2 using the above methods, a recrystallization curve and the recrystallization dependence for a temperature of 1100℃ are constructed. The advantages and disadvantages of the above methods are considered.
The results of uranium ion beam dynamics simulation in front-end and superconducting sections of the accelerator-driver LINAC-100 for the new rare isotope facility DERICA (JINR, Dubna) are presented. ...The optimum parameters are chosen for the buncher accelerator with radiofrequency quadrupole focusing (RFQ) for uranium ion beam acceleration from the ion source up to the energy of 570 keV/nucleon. LINAC-100 modular superconducting part layout for uranium beam acceleration from 3 to 100 MeV/nucleon is obtained. The energies for the stripper section installation are chosen.
This paper presents the results of a systematic study aimed at searching for organometallic molecules with a large dipole moment in order to create new film electret materials. A number of porphyrin ...complexes of transition metals, titanium, and vanadium and also complexes with bismuth(
iii
) iodide with an axial metal—oxygen bond were synthesized. The obtained compounds were identified by physicochemical methods (IR spectroscopy and X-ray photoelectron spectroscopy). The optimized geometry of the complexes, their vibrational spectra, dipole moments, and charge density distributions were evaluated by quantum chemical calculations. The Mulliken population analysis was performed. The maximum dipole moments were found for BiI etioporphyrin II (6.47 D) and BiI 5,10,15,20-tetrakis(pentafluorophenyl)porphyrin (3.87 D). The metal ion acts as a transmitter of electron density from nitrogen atoms to the counterion, resulting in an increase in the dipole moment of the molecule as a whole compared to the starting porphyrin ligands. The inclusion of porphyrin complexes under the action of an electric field resulted in the formation of polyvinyl acetate films. Copper layers 100 nm thick were deposited by magnetron sputtering onto both sides of these films. The dielectric properties and the temperature dependences of thermally stimulated depolarization currents of the obtained samples were studied. All samples were found to have a pronounced electret effect.
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