Computing-experimental method of verification of operability of composite porous package for protection of thin-walled constructions from non-stationary one-sided loadings is proposed. A set of ...explosive devices for generate loads of the required space-time distributions is described. Two new explosive devices for generation of low-pulse loads of microsecond duration with low difference in loading time at the surface of the tested composite constructions are considered. Time deformation profiles of glass-plastic cylindrical shell under low-impulse load of microsecond duration are given. It is received that use of wire or foil sensors for measurement of deformations give close results when the shell stage of deformation of glass-plastic thin-walled constructions is investigated.
This is the first report of the control of the structural and optical functional characteristics of integrated GaAs/Si(001) heterostructures due to the use of misoriented Si(001) substrates with ...protoporous sublayer. The growth of the epitaxial GaAs layer on silicon substrates without formation of the antiphase domains can be performed on substrates deviating less than 4°–6° from the singular (001) plane or without the use of a transition layer of GaAs nano-columns. Preliminary etching of the silicon substrate with protoporous Si sublayer formation facilitated the acquisition of an epitaxial GaAs film in a single-crystalline state with a considerably less residual strain factor using MOCVD, which has a positive effect on the structural quality of the film. These data are in a good agreement with the results of IR reflection spectroscopy as well as PL and UV spectroscopy. The optical properties of the integrated GaAs/Si (001) heterostructures in the IR and UV spectral regions were also determined by the residual strain value.
•The structural and optical characteristics of GaAs/Si(100) depends on the use of preliminary etched misoriented Si (100).•The growth of the epitaxial GaAs layer on Si substrates without formation of the antiphase domains.•Formation of protoporous Si sublayer has a positive effect on the structural quality of the GaAs film.
•Identification of oil product class based on the Identification Kurtz-Lorentz map.•Visualization is carried out on map based on properties of raw and final materials.•Alkanes in straight-run ...fractions correlate with molar vaporization enthalpies.•Method assessing group composition of straight-run oil fractions was proposed.•Polymethylene center of the map is linked with the “Water” point by 1-alkanols.
The technique is proposed for visualizing the product compositions and the refractodenses (trajectories) of oil refinery processes, based on measuring the refractive index and density of the liquid product flows of operating procedures, computing the specific refraction and refraction intercept, and constructing a Kurtz-Lorentz identification map, the center of which is the “polymethylene center”. Trajectories-refractodenses of the processes of atmospheric-vacuum distillation of oil, catalytic reforming, hydrocracking of vacuum and heavy gas oil, products of secondary oil refining (motor gasoline, diesel fuel, catalytic cracking gasoline, light catalytic cracking gas oil) and their fractional distillation have been constructed. An express method is also proposed for evaluating the group hydrocarbon compositions of straight-run oil fractions, upon which we propose a three-digit composition marking of straight-run fractions. It is shown that the logarithms of isomeric alkanes contents in straight-run oil fractions are linearly correlated with their molar enthalpies of vaporization.
The thermophysical properties of shock-compressed porous iron oxide at pressures up to 1 TPa were determined for the first time. The results agree well with earlier static and dynamic measurements in ...the pressure range up to 0.2 TPa. An equation of state for the high-pressure phase of iron oxide was constructed and compared with data at high pressures and temperatures.
The purpose of the study is to investigate the effect of a new type of compliant substrates based on an AlGaAs superstructure layer (SL) and a protoporous Si (proto-Si) layer formed on a crystalline ...Si (
c
-Si) layer on the optical properties of an epitaxial GaAs layer grown by metal–organic chemical vapor deposition. It is for the first time shown that the low-temperature growth of high-quality epitaxial GaAs films can be conducted using SL/proto-Si compliant substrates. The introduction of a SL layer in addition to proto-Si into the composition of the compliant substrate makes it possible to mitigate a number of negative effects of low-temperature growth, to reduce the level of strains in the epitaxial layer, to protect it from self-doping with Si atoms, to reduce the number of technological operations of the growth of transition buffer layers, to improve the structural and morphological characteristics of the epitaxial layer, and to attain good optical characteristics of the layer. The GaAs/Si heterostructures are studied by Raman spectroscopy, photoluminescence measurements, and optical transmission–reflection spectroscopy. The data will serve as an important material for understanding the fundamentals of the physics and technology of integrated III–V/Si heterostructures and for facilitating their use in optoelectronic devices.
Light-emitting devices of modern photonics are based on the semiconductor structures containing layers with various physical parameters. To preserve initial parameters during focused ion beam (FIB) ...lithography, it is necessary to take into account the processes of radiation defect formation. Radiation-induced defects in target play role of nonradiative recombination centers leading to photoluminescence (PL) quenching. In our work, the FIB impact on the photoluminescence were examined using PL spectroscopy of milled Al
0.18
Ga
0.82
As/GaAs double heterostructure. In order to exclude photoexcited carriers losses in emitter layer, an experiment with subbarrier photoexcitation was organized. Finally, we compare our experimental findings with theoretical data proposed by stopping and range of ions in matter (SRIM) calculation.
The purpose of the study is to investigate the effect of a new type of compliant substrate based on an AlGaAs superstructure layer (SL) and a protoporous Si (proto-Si) layer formed on a crystal Si (
...c
-Si) layer on the practical implementation and specific features of the epitaxial growth of GaAs layers by metal–organic chemical vapor deposition. It is for the first time shown that the low-temperature growth of high-crystal-quality epitaxial GaAs films can be implemented due to the use of compliant SL/proto-Si substrates. The introduction of a SL into the composition of a compliant substrate in addition to proto-Si makes it possible to neutralize a number of negative effects of low-temperature growth, to reduce the level of stresses in the epitaxial layer, to protect it from self-doping with Si atoms, to reduce the number of technological operations of the growth of transition buffer layers, and to improve the structural and morphological characteristics of the epitaxial layer.
The equations of state for polycrystalline solids which are in region of compression are developed on experimentally defined shock Hugoniot adiabat and dependence of specific heat on density and ...temperature. These equations are convenient for the numerical solution of problems of continuous medium mechanics. The numerical method for definition of specific cold energy and the Gruneizen function at T = 0 K depending on compression ratio is proposed. Results of comparison for temperatures behind shock wave in sapphire by means of the developed equations of state and other methods are given.
The effect of ion energy in a focused ion beam in the range 12–30 keV on the formation depth of nonradiative recombination centers during etching of the Al
0
.
18
Ga
0
.
82
As/GaAs/Al
0
.
18
Ga
0
.
...82
As double heterostructure has been studied. It is shown that an increase in the ion energy leads to an increase in the concentration and propagation depth of radiation defects. It was found that during etching of focused ion beam with ion energies above 15 keV, the depth of formation of radiation defects exceeds 900 nm, which does not correspond to the calculations in the Stopping and Range of Ions in Matter.
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