The FRAGM experiment is carried out on the basis of the ITEP–TWAC multipurpose accelerator complex, which generated proton and ion beams for various studies in the field of nuclear physics. A ...technique for identifying fragments in secondary ion beams based on the analysis of correlation distributions over the time of flight and signal amplitude from scintillation detectors is presented. The experimental data are obtained by fragmentation of a carbon beam with energy of 300 MeV per nucleon by scanning the rigidity of the magneto-optical channel with a step of 50 MeV/
c
. Differential cross sections for ion production are obtained using beryllium isotopes as an example. The results are compared with the predictions of the binary cascade model.
The results of searches for nucleon charge-exchange processes in the fragmentation of carbon ions are presented. The respective experimental data were obtained by means of the FRAGM facility at the ...TWAC-ITEP multipurpose accelerator complex with a 300-MeV/nucleon beam incident to a thin beryllium target. The experimental setup used, which was oriented at an angle of 3.5
with respect to the ion beam, possessed a hodoscope system, which ensured an accuracy of 0.4
in momentum measurements. The differential cross sections for the yields of isotopes
Be and
B produced upon single nucleon charge exchange were measured as a function of the fragment momentum. These experimental data were compared with theoretical predictions of two models of ion–ion interactions: the binary cascade (BC) model and the intranuclear cascade (INCL) model. In the above energy range, processes of nucleon charge exchange were measured for the first time.
In the FRAGM experiment at the heavy-ion accelerator
accumulator complex ITEP
TWA, yields of cumulative charged
mesons have been measured in a fragmentation of carbon ions with the energy of 3.2 ...GeV/nucleon on a beryllium target. The momentum spectra of
mesons cover four orders of the invariant cross section magnitude. They demonstrate the exponential fall with increasing energy. The measured inverse slope parameter is compared with similar measurements in nucleon–nucleus interactions and ion–ion collisions at lower energies. The energy dependence of the ratio of the yields of negative to positive
mesons is presented. This dependence is discussed in a connection with Coulomb and isotopic effects. The obtained data are compared with predictions of several ion–ion interaction models.
Abstract
Paper considers educational digital tools development results for university level within geo-information management paradigm during Industry 4.0 era under climate change and COVID-19. While ...research, authors used modern web-technologies for educational platforms design. Recently, the ways of geo-information support for environmental economics have distinct features of digitalization with new concepts in data obtaining and presenting. In paper, preference is given to the use of open online platforms, which integrate heterogeneous hardware and software resources with the use of web-technologies in distributed networks and wide application of cloud services. There are considered examples of presented digital tools using. The presented research results have significant scientific novelty can be used in training and educational purposes at university level, including the preparation of Master’s programs.
Abstract
The article contains the digitalization results for expert systems design in the framework of geoinformation management within Arctic while coronavirus and change of climate. Currently, the ...methods of designing expert systems within the framework of geoinformation management in the Arctic demonstrate the use of improved concepts of data collection and visualization. The article gives preference to the use of web constructors in distributed networks. An example of a working layout of an expert system for geoinformation support of the activities of a subarctic port in the conditions of ice waters is given. The results of the research can be useful in operational environmental activity and for university learning purposes, including Master’s programs.
The reaction of dibenzo
b
,
e
1,4dioxine-2,3-dicarbonitrile with sodium butoxide in butyl alcohol, followed by treatment with nitric acid, gave 1
H
-benzo5,61,4dioxino2,3-
f
isoindole-1,3(2
H
...)-dione, which was brought into the condensation with quinaldine to obtain (
E
,
Z
)-3-(quinolin-2-ylmethylidene)-2,3-dihydro-1
H
-benzo5,61,4dioxino2,3-
f
isoindol-1-one. Treatment of the latter with BF
3
·Et
2
O in the presence of triethylamine in toluene afforded a new unsymmetrical BODIPY analogue, (
Z
)-2-(difluoroboryl)-3-(quinolin-2-ylmethylidene)-2,3-dihydro-1
H
-benzo5,61,4dioxino2,3-
f
isoindol-1-one. The product showed luminescence in solution with a Stokes shift of 36 nm and a high relative fluorescence quantum yield (φ = 0.72). The obtained experimental data were supported by DFT and TD-DFT calculations.
Experimental data are presented on differential cross sections of the formation of
11
Be,
12
Be, and
12
B isotopes. The isotopes form upon the fragmentation of a carbon beam at 300 MeV/nucleon in the ...FRAGM experiment performed at the multipurpose ITEP−TWAC accelerating complex. The experimental data are compared to predictions made with the binary cascade and quantum molecular dynamic models of ion–ion interaction.
First results on
-dependence measurements in inclusive
meson production in
interactions (
, Al, Cu, Sn, and W) are presented at
GeV/
c
. The ratios of the differential cross sections of four of these ...nuclei to the differential cross section on aluminum were measured and the dependence of these cross sections on the atomic of the nucleus was studied. The measurements were carried out in the kinematic region of the Feynman variable
and transverse momentum
GeV/
c
.
mesons were detected in the decay mode
at the SPASCHARM experimental setup using negative charged beams at beamline 14 of the U-70 accelerator complex.
The T-P phase diagram of the Mo–H system studied earlier at hydrogen pressures up to 5.3 GPa and temperatures up to 1200 °C by in-situ X-ray diffraction Y. Fukai et al. Mater. Trans. 44 (2003) 1359 ...is re-examined at P ≤ 6 GPa and T ≤ 800 °C using a quenching technique. The formation of the high-temperature fcc MoH hydride at T > 480–570 °C is not confirmed. Instead, the stability region of the low-temperature hcp MoH1.1 hydride is found to grow with pressure. The temperature of its boundary with the region of diluted Mo–H solutions rises with pressure and reaches 800 °C at P ≈ 5.5 GPa.
•T-P diagram of the Mo–H system is re-examined at P ≤ 6 GPa and T ≤ 800 °C.•The formation of the fcc MoH hydride at T > 480–570 °C is not confirmed.•The stability region of the hcp MoH1.1 hydride is found to grow with pressure.
The use of chemically synthesized short interfering RNAs (siRNAs) is currently the method of choice to manipulate gene expression in mammalian cell culture, yet improvements of siRNA design is ...expectably required for successful application in vivo. Several studies have aimed at improving siRNA performance through the introduction of chemical modifications but a direct comparison of these results is difficult. We have directly compared the effect of 21 types of chemical modifications on siRNA activity and toxicity in a total of 2160 siRNA duplexes. We demonstrate that siRNA activity is primarily enhanced by favouring the incorporation of the intended antisense strand during RNA-induced silencing complex (RISC) loading by modulation of siRNA thermodynamic asymmetry and engineering of siRNA 3′-overhangs. Collectively, our results provide unique insights into the tolerance for chemical modifications and provide a simple guide to successful chemical modification of siRNAs with improved activity, stability and low toxicity.
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