The production of the charm-strange baryon Ξc0 is measured for the first time at the LHC via its semileptonic decay into eΞ−+νe in pp collisions at s=7 TeV with the ALICE detector. The transverse ...momentum (pT) differential cross section multiplied by the branching ratio is presented in the interval 1<pT<8 GeV/c at mid-rapidity, |y|<0.5. The transverse momentum dependence of the Ξc0 baryon production relative to the D0 meson production is compared to predictions of event generators with various tunes of the hadronisation mechanism, which are found to underestimate the measured cross-section ratio.
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The formation of plasma on the surface of a current-carrying electrode of a high-current facility when a current flows through it with a linear density of up to 4 MA/cm and is coated with lead foil ...or ceramic is studied. The propagation velocity of a dense plasma from a stainless steel electrode is 2–10 km/s, and when the electrode is coated with lead, it is 1–6 km/s. In these experiments, there is no load typical for such facilities—a source of intense X-ray radiation. The plasma propagation from ceramic-coated electrodes starts 200 ns later than that for metal electrodes.
Three different precipitating agents (NaOH,
NH
4
(
H
)
CO
3
and
CO
(
NH
2
)
2
) have been applied for the hydrothermal synthesis of ZnO powder materials, aiming at obtaining various types of porosity ...and surface species on ZnO. The synthesis procedures were carried out in the presence and in the absence of tri-block copolymer Pluronic (P123, EO20PO70EO20). These materials were characterized by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM)–energy-dispersive X-ray spectroscopy (EDX), BET method and TG–differential thermal analysis (DTA) method, and their photocatalytic activities were tested in the removal azo dye Reactive Black 5 (RB5). The urea precipitant yields spongy-like surface forms and the greatest share of mesopores. It has the highest specific surface area, highest degree of crystallinity of wurtzite ZnO phase and largest content of surface OH groups in comparison with the other two precipitants. The zinc hydroxycarbonate intermediate phase is missing in the case of NaOH as precipitating agent; therefore, it manifests poorer textural characteristics. The morphology of P123-modified sample is different and consists of needle-shaped particles. The urea-precipitated samples display superior performance in the photocatalytic oxidation reaction, compared with the other precipitated samples. The other two precipitating agents are inferior in regard to their photocatalytic activity due to greater share of micropores (not well-illuminated inner surface) and different surface morphologies.
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Two novel aromatic thiophene-containing annulated compounds, viz. 2-methoxybnaphtho2,1-dthiophene and 1,3-dimethoxybnaphtho2,1-dthiophene, were synthesized via the Mallory-type ...photocyclization. Their optical, redox and photophysical properties have been studied along with phosphorescence spectra and lifetimes at 77 K. The first compound exhibited much higher charge mobility in thin films than the second one suggesting the former being prospective for molecular electronics applications
Relevance. Dental care for children diagnosed with cerebral palsy (CP) presents substantial challenges to dental practitioners. These children not only necessitate individualized care strategies but ...also face challenges in mouth opening due to masticatory muscle spasticity, which limits operational access during treatments. This study introduces a phased approach to debridement that is integrated with interventions aimed at alleviating hypertonia in the masticatory muscles through adaptive myogymnastics and the use of a pneumatic mouth expander. Materials and methods . A clinical and functional assessment of the orofacial region was conducted on 34 compliant CP patients aged 6-12 years, with the mean age being 9.6 ± 0.3 years. These assessments considered the extent of motor activity and movement limitations in daily activities. Follow-up evaluations were performed six months post-intervention. Results. The phased debridement plan demonstrated significant effectiveness, integrating diagnostic and therapeutic strategies with tailored visitation schedules based on the clinical conditions of the patients. Conclusion. Uniform diagnostic and therapeutic protocols are recommended to enhance dental health and restrain the prevalence of dental diseases among children with spastic cerebral palsy.
The structure of a new mononuclear nickel(II) complex with bis-azomethine Ni(H
2
L)
+
· CH
3
COO
–
· H
2
O, resulting from condensation of 1,3-diaminopropan-2-ol with 2-amino-3-formylpyridine (H
3
...L), was studied by X-ray diffraction (CIF files CCDC nos. 1562927, 1562928). Apart from the mononuclear complex, the reaction gave a minor amount of the trinuclear metal chelate Ni
3
L'(H
2
O)
2
+
· (CH
3
COO)
–
· CH
3
OH · H
2
O, where L' is N
5
O
2
-donor ligand containing two 3-(((2-aminopyridin-2-yl)methylene)amino)-1-aminopropan-2-ol moieties linked by a 2-aminopyridine-3-methylene group.
—
Ca
0.75 + 0.5
x
Zr
1.5
Fe
0.5
(PO
4
)
3 –
x
(SiO
4
)
x
(
x
= 0–0.5) solid solutions have been synthesized by a sol–gel process and characterized by X-ray diffraction, IR spectroscopy, and ...differential scanning calorimetry. As expected, the synthesized phosphatosilicates crystallize in a NaZr
2
(PO
4
)
3
-type structure (trigonal symmetry, sp. gr.
R
c
). The thermal expansion of the solid solutions has been studied by high-temperature X-ray diffraction in the temperature range from 25 to 800°C. Their thermal expansion parameters have been calculated and analyzed as functions of composition. High-density ceramics based on the Ca
0.875
Zr
1.5
Fe
0.5
(PO
4
)
2.75
(SiO
4
)
0.25
phosphatosilicate have been produced by spark plasma sintering and their structure and properties have been studied in detail.
The Komplast materials experiment was designed by Khrunichev State Research and Production Space Center together with Skobeltsyn Institute of Nuclear Physics, Lomonosov Moscow State University and ...other Russian scientific institutes, and has been carried out by Mission Control Moscow since 1998. The purpose of this experiment is to study the complex effect of the low Earth orbit environment on samples of various spacecraft materials. On November 20, 1998 the Komplast experiment began with the launch of the first International Space Station module Zarya, or Functional Cargo Block (FGB). Eight Komplast panels with samples of materials and sensors were installed on the outer surface of FGB module. Two of eight experiment panels were retrieved during Russian extravehicular activity in February 2011 after 12years of space exposure and were subsequently returned to Earth by Space Shuttle “Discovery” on the STS-133/ULF-5 mission in March 2011.
The article presents the results obtained from this unique long-duration experiment on board of the International Space Station.
Photoluminescence of Multiple GaN/AlN Quantum Wells Aleksandrov, I. A.; Malin, T. V.; Protasov, D. Yu ...
Optoelectronics, instrumentation, and data processing,
09/2021, Volume:
57, Issue:
5
Journal Article
Peer reviewed
Photoluminescence of the structures with multiple GaN/AlN quantum wells grown by molecular beam epitaxy has been investigated. The calculated dependence of the energy of the quantum well ...photoluminescence band peak on the GaN layer thickness has been compared with the experimental data for various ratios of the thickness of the GaN and AlN layers. The thicknesses of the GaN and AlN layers were determined by transmission electron microscopy. The calculations of the photoluminescence band peak energy were carried out in the 6-band
kp
-approximation with consideration of spontaneous and piezoelectric polarizations. According to the calculation results, the slope of the dependence of the emission energy on the GaN layer thickness decreases as the ratio of the GaN layer thickness to the AlN layer thickness increases in accordance with the decrease in the electric field in the GaN layer. In quantum wells of sufficiently large thickness, the observed photoluminescence band peak energy is higher than the calculation result for undoped structures due to unintentional doping of the quantum wells, which leads to screening of the built-in electric field.
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