In this paper, we consider the need to assess the influence of the parameters of a linear time-invariant causal system in the processing of quadrature amplitude modulation signals of various ...positionality and constellation diagram irregularity. We describe the equations that determine the energy balance of a radio line and the total losses arising in route. We have developed mathematical expressions to assess the equivalent energy losses caused by the irregularity of amplitude-frequency and phase-frequency characteristics of the frequency selection filters. We propose a procedure to assess the non-noise losses in the frequency selection filters when designing high-speed radio systems for transmitting the information.
Heterostructures with thin Hg(Cd)Te/CdHgTe quantum wells (QWs) are attractive for the development of mid-infrared interband lasers. Of particular interest are room-temperature operating emitters for ...the short-wavelength infrared range (SWIR, typically defined as 1.7–3 μm). In this work, we report on the observation of stimulated emission (SE) in the 2.65–2.75 µm wavelength range at room temperature in an optically pumped HgCdTe QW laser heterostructure. We study a series of three samples with lengths ranging from 2.5 to 7 mm and discuss the effects related to the non-uniformity of the excitation beam profile. SE threshold intensity and the magnitude of pump-induced carrier heating are found to be effectively dependent on the chip size, which should be accounted for in possible designs of HgCdTe-based optical converters. We also pay attention to the problem of active medium engineering in order to push the SE wavelength towards the 3–5 µm atmospheric window and to lower the SE threshold.
The dispersed oxide fillers of different chemical composition were investigated: rutile (TiO2), alumina (Al2O3), calcite (CaO) and hematite (Fe2O3). The mineral composition, surface morphology, ...particle size and specific surface of the fillers were investigated using modern physicochemical methods. It has been established that the acid-alkaline properties of the active surface centers (ASC) and hydroxyl-hydrate layer (HHL) depend on the chemical and mineral nature of the fillers. It is established that with decreasing acidity of the oxide, the desire for its surface to adsorb water molecules from the air increases. As the alkalinity of the oxide increases, the thickness of both the hydroxyl and hydrate surface layers increases in proportion. It is shown that the acid-alkaline properties of the surface correlate with the acid-alkaline properties of the oxides included in the fillers.
In this paper, we analyze the correlations between the mean transverse momentum and the multiplicity of charged particles in proton–proton collisions using four different models: EPOS, SMASH, PHSD ...and UrQMD. Three strongly intensive quantities, as well as second- and third-order cumulants of transverse momentum, were chosen as variables for the resaerch. In the dependences of strongly intensive quantities on energy, discrepancies between the models were found. In the model SMASH, both for strongly intensive quantities and for cumulants, a certain ‘‘wave’’ arise, which can become evidence of a transition from the resonance regime to strings. Such a nontrivial behavior of
correlations in
collisions as ‘‘baseline’’ may later cause difficulties in explaining the results for
collisions. All models coincide with the prediction of the hydrodynamic model. Experimental results obtained at MPD/NICA can clarify this model analysis.
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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
Th
e
paper presents results on multiplicity correlations in two rapidity intervals and mean transverse momentum vs event multiplicity correlation function calculated in the developed Monte-Carlo ...model of multi-particle production run for
p
+
p
interactions at
and
GeV. The model is based on interacting colour strings approach with longitudinal and transverse strings dynamics. Results are compared with the ALICE data and PYTHIA 8.3 simulations.
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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
We study the initial states of p+p interactions and their influence on the correlation and fluctuation observables that are sensitive to them by considering the processes of multipomeron exchange and ...stretching of color QCD strings. We discuss the full string dynamics, their longitudinal motion due to the deceleration of the string ends, and the transverse motion caused by attraction due to the exchange of sigma mesons with subsequent fusion. We calculate the coefficient of rapidity correlations and the strongly intensive variables constructed for the multiplicity of charged particles,
, and the total transverse momentum
for inelastic p+p interactions at the energy of
GeV.
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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 paper studies the possibility to correct strongly intensive quantities ΔPT, N, £PT, N, and £NF, NB for detector inefficiencies by means of RooUnfold package. Several tests of applying Unfolding ...technique to 1D- and 2D-dimensional distributions were done on Monte-Carlo generated data in NA61/SHINE acceptance. Results reveal that several aspects of this analysis have to be improved.
The paper aims at development of mathematical model of interaction process between forest machine rover and soil, the properties of which change during the interaction process. The study bases on the ...off-road operation theory and methods of mathematical analysis. The basis of the mathematical model includes equation of interaction between a mover die and deformable soil mass of specified thickness placed on a rigid non-deformable base. The model uses power dependence of the mass deformation modulus on its density, which is changed under the impact of the mover die following the relative compression of the soil. The equation solution for sinkage is obtained in form of Taylor polynomials, this allows obtaining the rut depth caiculated value without iterations, which simplifies development of automated workplaces designed to evaluate forestry machines and cutting sites soils interaction at timber harvesting planning stage. Using an example of interaction between forest machine mover and weak forest soils, the paper shows the difference between rut depth calculated values, obtained using proposed mathematical model, and the values, obtained with a constant value of the deformation modulus. With a contact pressure in range of 0.06-0.1 MPa, rut depth predicted values are lower by 30-60%. In conclusion the paper notes prospective areas of further research, which include studying the changes of soil physical and mechanical properties, characterizing its shear resistance, and development of mathematical models that take into account the soil bearing capacity, the value of which also changes during compaction.
We calculate the strongly intensive variables Σ and Δ that suppress trivial volume fluctuations and are constructed for the charged particle multiplicity n and the total transverse momentum
P
t
in a ...modified multipomeron exchange approach for proton-proton interactions in the range of collision energies attainable with the SPS and LHC accelerators. In this approach, the interaction between the color quark-gluon strings formed from cut pomerons are effectively taken into account; in this case, the role of these interactions increases as the collision energy increases. The inequalities Σ(
P
t
,
n
) > 1 and Δ(
P
t
,
n
) < 1, which agree with the experimental data, are the main result of the calculations for energies attainable at the SPS. We show that as the energy increases, Σ(
P
t
,
n
) behaves nonmonotonically and Δ(
P
t
,
n
) increases.
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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 high-frequency asymptotic approach to diffraction by strongly elongated bodies is generalized to the case of the impedance boundary conditions. However, this is done only in the limiting case of ...infinitely flat elliptic cylinder. The representations for the field in the boundary layer near the surface of the strip and for the radar cross section in the case of small scattering angles are derived and tested.
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