Here, the energy spectrum of prompt neutron emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission ...Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.
The article is devoted to the creation of an intelligent software complex of a self-learning automated expert system for registering, accounting and executing incidents based on artificial ...intelligence. The creation of the software complex includes the development of an advisory support expert system based on a semantic processor for speech recognition and synthesis, which allows implementing the first line advisory support based on artificial intelligence. The obtained expert system consists of the following blocks: an input data flow module-GSM (voice address); a semantic processor-the system core in which, using special designed algorithms, the input data flow is converted into the language understood by the system for subsequent intelligent processing set by the specified skills, based on self-learning algorithms; a semantic processor language module with a protocol of recognition, analysis and extraction of input and output data context; an incident registration module with the accounting system in the Redmine platform; PostgreSQL skills database; a manual learning module and an output data flow module. The developed expert support digital ecosystem will allow to completely automate the receipt, processing, registration, accounting and decision-making of incoming requests. The complex implementation can replace first line support call centers and will have a significant economic effect on retail, banking, and consulting systems.
Using the Geant4 software package, a numerical simulation of a neutron source of the time-offlight spectrometer GNEIS created on the basis of the SC-1000 synchrocyclotron with 1 GeV proton energy at ...the NRC Kurchatov Institute—PNPI (Gatchina) has been carried out. The influence of the structural features of the neutron source of the spectrometer on the spatial and energy distributions of neutrons has been studied. The intensity and spectral characteristics of the neutron flux in the range of 1–1000 MeV have been determined on the basis of the obtained information and detailed allowance for all elements of the neutron beam guide system. It is found that the best agreement between the experiment and calculation performed by means of Geant4 is observed when using the QGSP_INCLXX_HP model. In the neutron energy range of 1–200 MeV, the difference between the experimental and calculated shapes of the spectra is less than 25%.
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•Fe3O4-Ag nanoparticles were synthesized by solvothermal method using different duration of the thermolysis process.•The nanoparticles morphology depends on the thermolysis ...duration.•Correlations between morphology and adsorption properties have been found.•Nanoparticles demonstrate high catalytic activity for degradation of organic dyes.
The morphology and magnetic properties as well as adsorption capacity and catalytic activity of Fe3O4-Ag nanoparticles synthesized by the solvothermal method were studied in dependence on the duration of the thermolysis process (3, 6, and 8 h). X-ray diffraction, transmission electron microscopy, and energy-dispersive spectroscopy measurements showed that the morphology of nanoparticles changed strongly as the duration of thermolysis increased. At 6 and 8 h duration, Fe3O4 nanocrystals grow and assemble into porous spherical globules with an Ag core (samples 2 and 3). These samples demonstrate high magnetization value and very low coercivity. The adsorption capacity of nanoparticles was studied with respect to two organic dyes: cationic methylene blue (MB) and anionic Congo red (CR). The particles showed preferential adsorption of the cationic dye. High catalytic activity towards four dyes: MB, methyl orange (MO), CR, and Rhodamine C (RhC) at the presence of NaBH4 is the remarkable property of these samples. The rate constant of the catalytic reaction was 1.4 min−1. Simultaneous exposure of CR and MO dyes to nanoparticles and NaBH4 caused their irreversible 100 % degradation while in the case of MB and RhC, a transition to their leuco form occurred.
The cross section for the neutron-induced fission of
238
U nuclei has been measured using the time-of-flight spectrometer of the GNEIS neutron complex at the Petersburg Nuclear Physics Institute, ...National Research Center Kurchatov Institute, in the neutron energy range of 0.3–500 MeV. Fission fragments have been detected by low-pressure position-sensitive multiwire proportional counters. The cross section for
238
U(
n
,
f
) fission has been measured with respect to the cross section for
235
U(
n
,
f
) fission, which is an accepted international standard. Data on the energy dependence of the anisotropy of the angular distribution of fragments of neutron-induced
238
U nuclei are also presented. The data obtained have been compared to previous experiments carried out using both similar and significantly different methods.
This work is aimed at finding and developing new ways to improve and optimize the characteristics of transparent conductive electrodes based on SWCNT by forming a texture in a continuous layer by ...combination of lithography and oxygen plasma treatment. A theoretical and an experimental justification for choosing thickness of a textured pattern, together with the experimental results of optical and electrophysical measurements were presented. The resistance of the textured electrode was 187.5 Ohm/sq, which is 17.5% lower than resistance of the electrode made from a continuous SWCNT layer with a same transparency of 95%. An analytical calculation showed that the use of extremely absorbing SWCNT films for texturing allows to obtain ∼ 54% gain in the resistance of a textured electrode compared to a continuous SWCNT's layer.
Layered two-dimensional materials, whose properties dramatically differ from their bulk precursors, are of great theoretical and applied importance. Recently, a layered 2D material, an analog of a ...natural mineral, valleriite, in which quasi-monoatomic Cu−Fe−S sheets alternate with brucite-like ones, has been prepared using a simple hydrothermal synthesis procedure. The features of the electronic structure of these materials make it possible to propose them as new materials for a wide field of applications such as (electro)photocatalysis, high-capacity batteries, etc. In this work, nanocomposite materials have been prepared via immobilization of gold nanoparticles (AuNPs) from citrate hydrosols on the surface of the synthesized valleriites having different compositions of hydroxide layers, which control the surface charge density. According to X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), energy-dispersive X-ray microanalysis (EDX), and selected area electron diffraction (SAED) data, AuNPs are immobilized on valleriite nanoflakes, which have lateral sizes of 150–200 nm and thicknesses of several tens of nanometers, as isolated metal nanoparticles with an average diameter of 11 nm. A small amount of aggregates indicates a high affinity of AuNPs for the valleriite surface. The amounts of immobilized gold are the same on all studied valleriites (~0.2%). This finding may be related to the simultaneous sorption of free citrate ions from the AuNP hydrosols, with these ions, according to zeta potential measurements, charging the surfaces of all studied valleriite samples to nearly the same negative value of –40 mV. According to the XPS data, the AuNPs immobilization markedly decreases the magnesium and oxygen contents on the surfaces of the synthesized valleriites due to the partial degradation/dissolution of the brucite layer. In addition, the amount of Fe
3+
ions bound to OH groups decreases with a simultaneous increase in the fraction of Fe
3+
–O species. The TEM data have confirmed the preservation of the layered structure of valleriites after the immobilization of AuNPs.
The anodes based on the nickel oxide and yttria-stabilized zirconia are developed by the method of hybrid inkjet 3D-printing with laser treatment. The granulometric composition of the NiO/Zr
0.9
Y
...0.1
O
2
-composite and the rheological characteristics of its based printing pastes are determined. The printing of three-dimensional test objects using the developed ceramic paste is studied experimentally. The influence of the pore formers—graphite and potato starch—added to the paste composition on the rheological characteristics of the paste is studied. The obtained samples of supporting anodes were studied by a complex of physicochemical methods to determine their morphological and structural characteristics.
Due to their unique properties, organosols of silver nanoparticles are widely used in optical and semiconductor devices, to produce electrically and thermally conductive films, as catalysts, ...antibacterial materials, etc. This work proposes a simple and highly productive method for the preparation of silver organosols, which have a metal concentration as high as 1800 g/L and contain spherical nanoparticles with low polydispersity and a median size of 9.1 nm. The method consists in the initial preparation of silver nanoparticle hydrosols with a concentration of higher than 30 g/L followed by the transfer of the NPs into an organic phase of
o
-xylene. A set of physical research methods has been employed to study the regularities of the extraction of silver nanoparticles with
o
-xylene in the presence of cetyltrimethylammonium bromide (CTAB) and ethanol and to determine the optimal process conditions, under which the extraction degree is as high as 62.5%. It has been found that bromine anions contained in CTAB molecules cause the aggregation of some amount of silver nanoparticles with the formation of silver metal sediment in the aqueous phase. According to X-ray photoelectron spectroscopy data, the sediment contains bromide ions (up to 4 at %) on the particle surface. Organosols synthesized under optimal conditions are stable for more than 7 months and withstand repeated cycles of drying and redispersing. Silver organosols have been used to obtain metal films with an electrical conductivity of about 68 500 S/cm, which increases to 412 000 and 509 500 S/cm (87.8% of the electrical conductivity of bulk silver) after thermal treatment at 150 and 250°C, respectively.
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