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Experimental investigation has been carried out for laser ignition and combustion of nanothermites based on aluminum and oxides of copper, bismuth and molybdenum. Ultrasonic mixing of nanosized powders was used to produce compositions. For thermite ignition, initiating laser pulse with a maximum intensity of 770 W/cm2 was generated by a laser diode with a wavelength of 808 nm. The ignition delay times, the minimum initiation energy density, and the average burning rate at various thermite densities and mass fractions of components were determined by recording the emission of radiation of the reaction products using a multichannel pyrometer jointly with a high-speed video camera. The effect of adding carbon black on the threshold parameters of a laser pulse was also studied. Based on the obtained results, certain assumptions were put forward with regard to the mechanism of nanothermites’ ignition by laser radiation and their burning. In particular, the assumptions were made on the two-stage process of the reaction initiation and jet burning mechanism of porous nanothermites.

The basic information on the functional properties of combined minced meat, developed on the basis of a combination of products of animal and vegetable origin, in one culinary product is presented. This mutual addition of the formulation with various components allows you to create a product that best meets the needs of the body according to nutritional value. The purpose of research is the development of technology and formulations of minced meat products with dietary supplements. The objects of study in the development of recipes and technology for minced meat products were: beef, beef and lamb; banana puree, rice flour, carrot and pumpkin powder as a dietary supplement. As a plasticizing additive used butter. The use of additives of plant origin allows you to stabilize the functional and technological properties of raw materials, increase biological value, emphasize the organoleptic characteristics of the finished product. Mashed potatoes, flour and powder are rich in minerals and vitamins, dietary fiber, proteins, polyunsaturated fatty acids. The rare chemical composition of the presented additives helps to improve the taste and increase the nutritional and biological value of the combined meat culinary products. We used standard and generally accepted sensory, rheological, physicochemical and microbiological methods for studying raw materials, semi-finished products, and finished products. Mathematical processing of the research results was carried out using the software package Curve Expert Ver. 1.34. The method of selecting components revealed promising combinations for enriching traditional formulations with plant components. Meat steamed meatballs have been developed both with the addition of vegetables (white cabbage, carrots and pumpkin), and without adding. The mass fraction of moisture of a steam crate with beef, lamb and cabbage is 12% higher than that of a steam cue with beef and pumpkin, and 10% more than a steam cue with beef and carrots. The mass fraction of fat in a chicken meat parrot with beef and pumpkin is 15% higher than that of a steam chicken with beef, lamb and cabbage and 4% than in a steam chicken with beef and carrots. The most corrected amino acid composition in meatballs of steam with beef and mutton.

We apply two complementary techniques for the characterization of mobile dislocations in samples of hcp $$^4\hbox {He}$$ 4 He with the concentration of $$^3\hbox {He}$$ 3 He $$\sim 3\times 10^{-7}$$ ∼ 3 × 10 - 7 , grown by the blocked capillary method at molar volume 19.5 $$\hbox {cm}^3\,\hbox {mol}^{-1}$$ cm 3 mol - 1 , before and after annealing at temperatures 1.8–2.0 K, and also after work hardening by high-amplitude twisting at 0.03 K and successive recovery at 0.5–1.0 K. The first technique relies on the elastic response of solid helium to oscillatory twisting at frequencies 161 Hz and 931 Hz at temperatures below 1 K, where this response is affected by the presence of mobile dislocations with variable amounts of trapped $$^3\hbox {He}$$ 3 He impurities. Monitoring the non-equilibrium amplitude dependence after moderate forcing allows to compute the length distribution n(L) of mobile dislocations (Iwasa in J Low Temp Phys 171:30, 2013; Fefferman et al. in Phys Rev B 89:014105, 2014). We also test methods of determining n(L) from the equilibrium temperature dependence of either real or imaginary part of the shear modulus at small strain amplitudes, based on the values of the damping force measured by Fefferman et al. [2]. The second technique utilizes measurements of thermal conductivity at temperatures below 0.4 K, i.e., of the dislocation-limited mean free path of thermal transverse phonons (Greenberg and Armstrong in Phys Rev B 20:1049, 1979; Armstrong et al. in Phys Rev B 20:1061, 1979). During a prolonged AC-twisting at a high amplitude of strain exceeding the yield stress, long dislocations disappear being replaced by many short ones which remain mobile. However, upon stopping this twisting, the majority of dislocations become immobilized until the sample is warmed up above 0.5 K to speed-up the recovery of dislocations to their mobile state (Day et al. in Phys Rev B 79:214524, 2009; Beamish and Franck in Phys Rev B 26:6104, 1982). This is different from the immobilization of dislocations by trapped $$^3\hbox {He}$$ 3 He impurities, routinely observed at smaller strain amplitudes, which is characterized by much shorter relaxation times to effectively un-trap $$^3\hbox {He}$$ 3 He atoms and make dislocations mobile again. We investigated the dynamics of the recovery of cold-worked samples, during which short segments quickly disappear, while the longest one appear after longer annealing times; the activation energy was estimated to be 22 K—pointing at the thermal vacancy-assisted process. A complementary characterization by the scattering rate of thermal transverse phonons off crystalline defects rules out non-interacting mobile dislocations as the dominant scatterer. The main conclusion is that while many properties of the sample are consistent with the theory of Granato and Lücke of isolated gliding dislocations (Granato and Lücke in J Appl Phys 27:583, 1956), several observations at low temperatures ($$^3\hbox {He}$$ 3 He -independent immobilization of dislocations after stopping high-amplitude twisting, sporadic avalanche-like relaxation of strain, flat temperature dependence of the phonon scattering rate) point at the presence of interacting dislocations, probably arranged into dislocation walls.

The influence of cerium oxide on the thermal properties and the glass structure has been studied for the Li2O–(Na2O–K2O)–B2O3–SiO2 system. It has been established that cerium is completely soluble in the quenched glass during the synthesis if addition of CeO2 is 0–10 mol%. The cubic ceria phase is formed in glass either during the synthesis if addition of CeO2 is 20 mol% or after thermal treatment (annealing) if the glass contains 10–20 mol% of CeO2. The studied lithium borosilicate glasses have low thermal stability and demonstrate significant difference in the crystal phase formation for Ce-free and Ce-containing glasses after annealing. The lithium–sodium and lithium–potassium glasses have much higher thermal stability toward crystallization regardless of Ce content. The obtained results are relevant for improving the properties of matrix materials of similar borosilicate systems used for immobilization of radioactive waste.

The development of instability of gravity-capillary waves on the surface of water excited by two perpendicular plungers has been experimentally observed. As a result of a four-wave process, waves with a frequency of 8 Hz scatter in pairs into waves with frequencies of 3.92 and 4.08 Hz, as well as 11.98 and 12.02 Hz. The amplitude of low-frequency waves increases exponentially with a characteristic time of about 90 s which exceeds the time of viscous wave damping almost by an order of magnitude. Along with the main pumping mode, the appeared low-frequency harmonics, propagating on the surface of water at an angle of 15° to each other, form large-scale vortex flows on the surface of water. The wave energy is transferred from the pumping region directly to vortices with a size comparable to the length of a bath wall. In a vortex system, a direct energy cascade with the energy distribution close to E(k) ~ k–5/3 is formed from the region of low wave vectors.

The paper deals with the issues of international trade as the main indicator of the state open economy. The authors proved that international trade is an integral part of the country in the age of economic globalization and affects the global economy development. International trade characterizes the country’s foreign economic activity. The research on international trade is based on the comparison and statistical methods, and mathematical analysis. The main indicators of international trade, such as trade exports and imports, as well as changes in the country’s external turnover, were analyzed. The structure of trade exports was studied. Promising areas of Russia’s foreign economic activity were identified. The authors of the paper considered the GDP dynamics at purchasing power parity and analyzed the volume of net exports in relation to GDP.

The generation of a vortex flow by waves on a water surface, which simulate an energy cascade in a system of gravity waves at frequencies of 3, 4, 5, and 6 Hz, has been studied experimentally. It has been found that pumping is accompanied by the propagation of waves on the surface at different angles to the fundamental mode and by a nonlinear interaction between waves resulting in the generation of new harmonics. It has been shown that large-scale flows are formed by modes of the lowest frequency of 3 Hz intersecting at acute angles. The energy distribution of the vortex motion can be described by a power-law function of the wavenumber and is independent of the energy distribution in a system of surface waves. The energy coming to large-scale vortex flows directly from the wave system is transferred to small scales. A direct rather than inverse energy flux is established in the system of vortices.

A technique that allows simultaneous measurements of vortex and wave motions of fluids is described. To record the vortex motion, a liquid surface is decorated with light particles of PA-12 polyamide with an average diameter of 30 μm and video filming of the motion of these particles is performed. The wave motion on the water surface is recorded using an improved method that we proposed earlier for spatial recording of waves on the surface of a transparent liquid; this involves video filming of a contrast stencil lying on the bottom of an experimental pool. The distortion of the video image of the stencil through the transparent liquid layer allows the vertical velocity component to be reconstructed.

The evolution of a vortex flow excited by an electromagnetic technique in a thin layer of a conducting liquid was studied experimentally. Small-scale vortices, excited at the pumping scale, merge with time due to the nonlinear interaction and produce large-scale structures—the inverse energy cascade is formed. The dependence of the energy spectrum in the developed inverse cascade is well described by the Kraichnan law k–5/3. At large scales, the inverse cascade is limited by cell sizes, and a large-scale coherent vortex flow is formed, which occupies almost the entire area of the experimental cell. The radial profile of the azimuthal velocity of the coherent vortex immediately after the pumping was switched off has been established for the first time. Inside the vortex core, the azimuthal velocity grows linearly along a radius and reaches a constant value outside the core, which agrees well with the theoretical prediction.

The detonation properties of mechanically activated mixtures of ammonium perchlorate and aluminum were studied. The deflagration-to-detonation transition for low-density charges was investigated. Dependences of the detonation velocity of pressed charges with different types of aluminum on the activation time, density, and diameter of the charges were obtained. For compositions with nanosized aluminum, it is was found that the detonation velocity depends nonmonotonically on the inverse charge diameter and remains almost unchanged in a certain range of charge diameters. It is shown that the joint use of mechanical activation and nanosized components of the composite explosive significantly increases the detonability, reduces the critical diameter, and shifts the maximum of the detonation velocity as a function of density to higher charge densities.

Experiments on the decay instability of gravity-capillary waves excited by alternating electric fields with frequencies of 14–30 Hz on a charged liquid hydrogen surface in a rectangular cell are reported. An exponential increase in the amplitudes of the subharmonics caused by decay of the wave at the pump frequency is found. For the first time, the experimentally observed growth rate of the decay instability and damping coefficient for the surface waves in the rectangular cell yield an estimate of the coefficient for three-wave interactions of gravity-capillary waves in liquid hydrogen.

The mass-transport induced by crossed surface waves consists of the Stokes and Euler contributions which are very different in nature. The first contribution is a generalization of Stokes drift for a plane wave in ideal fluid and the second contribution arises due to the fluid viscosity and it is excited by a force applied in the viscous sublayer near the fluid surface. We study the formation and decay of the induced mass-transport theoretically and experimentally and demonstrate that both contributions have different time scales for typical experimental conditions. The evolution of the Euler contribution is described by a diffusion equation, where the fluid kinematic viscosity plays the role of the diffusion coefficient, while the Stokes contribution evolves faster, feeling the additional damping near the system boundaries. The difference becomes more pronounced if the fluid surface is contaminated. We model the effect of contamination by a thin insoluble liquid film presented on the fluid surface with the compression modulus being the only non-zero rheological parameter of the film. Then the Euler contribution into the mass-transport becomes parametrically larger and the evolution of the Stokes contribution becomes parametrically faster. The parameter is the same in both cases and it is equal to the quality factor of surfaces waves, which is modified by the presence of a surface film. We infer the value of the compression modulus of the film by fitting the results of transient measurements of eddy currents and demonstrate that the obtained value leads to the correct ratio of amplitudes of horizontal and vertical velocities of the wave motion and is in reasonable agreement with the measured dissipation rate of surface waves.

The experimental results of studying wave turbulence in a system of capillary waves on the surface of water in a cylindrical vessel are presented. Waves on the surface are excited by vertical vibrations of the water-filled vessel with accelerations below the parametric-instability threshold at a fixed frequency f p or in the frequency band from 30 to 50 Hz. The deviation of the surface from equilibrium is recorded by a laser beam reflecting from water. It is shown experimentally that the position of the high-frequency boundary of the inertial range f b of the turbulent cascade is shifted towards high frequencies with an increase in the pump amplitude А and described by the power function f b ~ A β with index β equal to 1.2 ± 0.1 for monochromatic pumping and 1.10 ± 0.15 for broadband pumping. The value of the index β for monochromatic pumping is close to the theoretical estimate; for broadband pumping, it is less by a factor of 2.5. In the dissipation region f > f b , the turbulent distribution is damped exponentially with the characteristic frequency f d depending on the amplitude and spectral characteristic of the excitation force. It follows from the amplitude dependences that the frequency f d is proportional to the frequency of the boundary of the inertial range f b .

The formation of a vortex flow in a vessel with a liquid undergoing harmonic oscillations in a vertical direction has been studied experimentally. It has been found that the vortex flow does not occur in a cylindrical vessel until the amplitude of the oscillations exceeds a threshold value, at which the Faraday parametric instability develops and azimuthal modes emerge on the surface. The vortices appear in a square vessel and in a cylindrical vessel with broken symmetry at amplitudes below the parametric instability threshold. The formation of a vortex flow is presumably caused by the interaction of surface waves propagating at an angle with respect to each other.

Formation of low frequency harmonics on turbulent distribution in the system of waves on the surface of liquid hydrogen has been studied in the frequency range 1–100 Hz (capillary-gravity waves). It is shown that the geometry of the experimental cell has a significant influence on the direct cascade of capillary waves generated by monochromatic force as well as on the direction of the wave energy transfer from the range of pumping towards that of dissipation. Besides a direct turbulent cascade, single half-frequency harmonic generation was observed in a cylindrical cell under high pump power. In a square cell we observed not only a half-frequency harmonic but a number of low frequency harmonics below the driving frequency generated by the nonlinear threewave interaction. In the case of a rectangular cell we observed formation of incommensurate low frequency harmonics caused by the three-wave interaction of capillary waves and generation of a wave mode of ~1 Hz in the frequency range of gravity waves which could be attributed to the four-wave interaction.

Two-dimensional wave turbulence on the charged surface of liquid hydrogen in a rectangular cell has been studied. It has been found that, after intense monochromatic pumping at frequencies of 14–30 Hz in an electric field partially compensating the gravitational field of the Earth, incommensurate subharmonics at low frequencies until 0.8 Hz can be observed on the surface of the liquid with a certain time delay in addition to the direct turbulent cascade of Kolmogorov-Zakharov capillary waves. The nonlinear interaction of these subharmonics with each other and with a wave excited at the pump frequency results in the appearance of additional combination waves in the direct turbulence spectrum.

The generation of a large-scale vortex flow by gravity waves on the water surface has been experimentally studied. It is shown that large-scale flows are formed as a result of the interaction between nonlinear low-frequency modes which intersect at small angles. The amplitude of vorticity at large scales increases with increasing angle between pump waves. The experimental data agree well with the developed theoretical model.

A method for recording standing waves on the surfaces of transparent liquids is proposed. A contrast pattern (grid) is placed on the bottom of a liquid-filled transparent cell and is photographed through a liquid layer in transmitted light. The shape of the vibrating liquid surface can be reconstructed from the distortions in the pattern image.

The effect of addition of aluminum powders, including nanosized powders, on the acceleration ability of explosive compositions as studied by standard methods is examined. The analysis is based both on literature data and results obtained at the Semenov Institute of Chemical Physics RAS. A brief description of the methods and criteria for evaluating the acceleration ability, including the Gurney velocity, is presented. It is shown that the addition of highly dispersed aluminum can increase the acceleration ability of compositions as compared to that of individual HEs. Nanosized aluminum also improves the acceleration ability, but the observed increase is somewhat lower than for micron-sized aluminum because of a high content of alumina in nanoparticles. The possibility of increasing the acceleration ability by adding nanosized aluminum to CL-20 powerful HE is considered.

Polycrystalline samples of hcp 4He of molar volume Vm = 19.5 cm3 with small amount of 3He impurities were grown in an annular container by the blocked-capillary method. Three concentrations of 3He, x3, were studied: isotopically purified 4He with the estimated x3

We report on the experimental observation of energy accumulation near the high frequency boundary of the inertial range in the spectrum of turbulence in a system of capillary waves on the surface of liquid hydrogen driven by a harmonic force. The effect is manifested as a local maximum in the spectrum of pair correlation function of the surface elevation. This phenomenon is dynamical and can be seen only during reconfiguration of the turbulent cascade caused by waves generation of below the driving frequency.

Polycrystalline samples of hcp 4He of molar volume 19.5 cm3 with small amount of 3He impurities were grown in an annular container by the blocked-capillary method. Three concentrations of 3He, x3, were studied: isotopically purified 4He with the estimated x3≤10−10, ‘well-grade’ helium with x3∼3×10−7 and a specially prepared mixture with x3=2.5×10−6. The torsional oscillator response and thermal conductivity were investigated before and after annealing. The temperature and width of the torsional anomaly increase with increasing x3. Annealing resulted in an increased phonon mean free path but often in little change in the torsional oscillator response. While the magnitude of the torsional anomaly and phonon mean free path can be very different in different samples, no correlation was found between them; this implies that these two properties are controlled by different types of crystal defects. It seems plausible that the mean free path of thermal phonos at ∼200 mK is controlled by vibrating dislocations while the magnitude of the frequency shift of torsional oscillations is governed by static defects such as pinned dislocations and grain boundaries.

In the dissipative range at frequencies above the inertial frequency range, the turbulent cascade of capillary waves on the surface of liquid helium and hydrogen decays according to an exponential law. The characteristic frequency of the quasi-Planck distribution is determined by the spectral characteristic of an exciting force. In the case of harmonic pumping on the surface of superfluid helium in the discrete turbulence regime, energy condensation is observed near the high-frequency edge of the inertial range. The effect is due to the influence of discreteness in the spectrum of the eigenfrequencies of surface excitations and in the turbulence distribution on the energy transfer through the cascade.

We report the first observation of “quasi-Planck” spectra of capillary turbulence on the surface of liquid hydrogen in the dissipation domain. Capillary waves have been driven by low-frequency random force. We have observed that the frequency spectrum of surface elevation changes its dependence from power-like 〈|ηω2|〉 ∼ ω−2,8 at middle-frequency domain to “quasi-Planck” distribution ∼eω/ωd at higher frequencies. The frequency ωd is proportional to the boundary frequency between inertial interval and dissipation domain and it is scaled up with the increase of driving force.

Based on the literature data and the results of studying aluminized high explosives, the effects of the particle size of the components and the charge structure on the pressure and temperature of the detonation products are analyzed. Trinitrotoluene-HMX-, RDX-, bis(2,2,2-trinitroethyl)nitramine-, nitroguanidine-, nitromethane, and isopropyl nitrate-based compositions are studied.

Based on published data and the results obtained at the Institute of Chemical Physics of the Russian Academy of Sciences, an analysis of the effect of the particle size of explosive base and additives and of the sample structure on the mechanical sensitivity and detonation velocity of various explosive materials was performed.

Recent results of the experimental study of capillary turbulence on superfluid helium-4 surface are presented. For the first time wave energy accumulation was observed in the wave turbulent spectrum at high frequencies when the surface was excited by harmonic pumping. We suggest a qualitative explanation of this phenomenon in the frames of weak wave turbulence approach that takes into account discreteness of the eigenfrequencies spectrum of surface oscillations in the cylindrical resonator.

A technique for producing ultrafine nitramine powders and aluminized nanocomposites based on them is described. Powders of RDX, HMX, and 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (HNIWor CL-20) with an average crystal size of about 1 µm were produced by spray drying of solutions. Results of x-ray phase analysis showed that resulting nitramine was formed in an unstable crystalline phase state and the time of relaxation to an stable phase state is several tens of days. Experimental batches of explosive aluminized nanocomposites were produced by spray drying of a suspension of nanoaluminum (nAl) in a solution of nitramines with a mass content of nAl of 5, 15, and 25%. The effect of the composition of the barrier coating on nAl surfaces (an oxide coating, an organic coating based on unsaturated carboxylic acid, an organosilicon coating based on organosilazanes) and the nAl particle size on the structure of the nanocomposite product was studied. The effect of the suspension spraying conditions on the structure of nanocomposites is discussed.

The modification of the turbulent cascade in a system of capillary waves on the surface of liquid hydrogen under a change in the spectral width of exciting noise has been experimentally studied. The correlation function I ω of the deviations of the surface of liquid hydrogen from equilibrium under broadband excitation is a monotonically decreasing function of frequency. The distribution I ω in the inertial range is well described by the power function ω−m with the exponent m close to 17/6. In the presence of narrowband excitation, a chain of peaks appears on the cascade I ω; the positions of the peaks are described by a power function of frequency with the exponent m = 3.8 ± 0.1.

The capillary turbulence on the surface of liquid helium with excitation of surface waves by a harmonic force at low frequency ωp is investigated. It is shown for the first time that at the transition of helium out of the superfluid into the normal state the high-frequency edge ωb of the inertial interval shifts in the direction of low frequencies. The magnitude of the shift is described well on the basis of the theory of weak wave turbulence. In the superfluid state the relative width ωb∕ωp of the inertial interval, where a developed turbulent cascade is established, can reach two decades.

The probability distribution density of the deviation of the surface of liquid hydrogen from the equilibrium plane state in the system of capillary waves has been analyzed. It has been shown that this probability distribution density for the case of the excitation of the surface oscillations by low-frequency noise in the turbulent regime is well reproduced by a Gaussian. When the oscillations are excited by a low-frequency harmonic force, the stochastization of the waves occurs after several scattering events.

The explosive characteristics of HMX compositions doped with 15% Al (by weight) were studied experimentally. The detonation velocity, pressure and temperature profiles, the velocity of endwise acceleration of plates, and the heat of explosion of dense pressed samples were measured. The results were compared for compositions based on mechanical mixtures of initial micron-size particles of HMX with aluminum powders of various sizes and for nanocomposites. The addition of nanoaluminum reduces the detonation velocity to a greater degree than the addition of micron-size aluminum. The mechanical mixtures have close detonation velocities, whereas in composites containing different types of nanoaluminum, they differ by almost 200 m/sec. For all compositions, except for the most homogeneous nanocomposite, two-peak pressure profiles are observed. For charges of a composite and a mechanical mixture with nanoaluminum of the same type, the second peak pressures almost coincide but are reached in different times. At the same time, the peak pressure increases with decreasing aluminum particle size. The temperature profiles agree qualitatively with the pressure profiles. The velocity of endwise acceleration of plates depends linearly on the activity of the aluminum powder used. Nanocomposites and mechanical mixtures containing the same aluminum powder have close heats of explosion. Nanoaluminum is almost completely oxidized during calorimeter bomb tests, and the major factor determining the heat of explosion of the compositions with nanoaluminum is also the content of active metal in the aluminum powder.

The techniques developed earlier for study of turbulence on the surface of liquid hydrogen was used for generation of nonlinear waves on the charged surface of liquid 4He. This permitted us to observe for the first time capillary turbulence on the surface of liquid 4He in normal and superfluid state, and to expand in a few times the relative width of the inertial interval, where the Kolmogorov-Zakharov spectrum of turbulence was observed.

We demonstrate that waves excited on a fluid surface produce local surface rotation owing to hydrodynamic nonlinearity. We examine theoretically the effect and obtain an explicit formula for the vertical vorticity in terms of the surface elevation. Our theoretical predictions are confirmed by measurements of surface motion in a cell with water where surface waves are excited by vertical and harmonic shaking the cell. The experimental data are in good agreement with the theoretical predictions. We discuss physical consequences of the effect.

Investigations of nonlinear phenomena on the charged surface of liquid hydrogen are reviewed. It is demonstrated that excitation of the surface by a low frequency AC electric field results in the formation of capillary waves in the high-frequency domain, and that the latter exhibit turbulence. The quasi-adiabatic decay of this capillary turbulence has been studied both experimentally and theoretically. It is shown that the processes of formation and decay of the turbulence are both controlled by the same relaxation mechanisms. For spectrally narrow pumping, the application of an additional low-frequency driving force causes a decrease of wave amplitude in the high-frequency domain of the turbulent spectrum and correspondingly decreases the width of the inertial range of energy transfer.

The effect of the addition of Al on the detonation velocity of bis(2,2,2-trinitroethyl) nitramine (BTNEN) was studied experimentally. It is shown that the dependence of the detonation velocity of BTNEN on the initial density is nearly linear, and a 75/25 BTNEN/Al mixture is characterized by an increase in the slope of the dependence with increasing density. The addition of Al decreases the detonation velocity of BTNEN. The density range characterized by a maximum decrease in the detonation velocity is determined. A comparison of experimental detonation velocities of BTNEN/Al mixtures with literature data obtained by calculations taking into account a possible change in the phase state of Al2O3 showed that the thermodynamic model used in the calculations needs to be improved.

The dynamics of establishing steady-state turbulent cascade has been studied in a system of capillary waves on the surface of liquid hydrogen after additional pumping whose frequency is lower than the frequency of the main pumping is switched off/on. It has been found that, when the additional low-frequency pumping is switched on, the amplitude of waves in the high-frequency part of the turbulent spectrum decreases, which gives rise to the narrowing of the inertial frequency range. The experimental data qualitatively agree with the numerical calculations performed in the kinetic-equation approximation including the viscous damping of waves.

We communicate the results of numerical studies of acoustic turbulence in a system of nonlinear second sound waves in superfluid He-II in a resonator. It is shown that at sufficiently high amplitude of the external driving force the power-like energy distribution over frequency is formed in the system of second sound waves. This distribution is attributed to formation of the acoustic turbulence regime in the system. The energy distribution inside this interval is close to Eω ~ ω−2 and it does not depend on the sign of the coefficient, i.e. the coherent structures (shock waves) do not contribute into statistical properties of the second sound distribution in the turbulent state.

Free decay of a turbulent cascade of capillary waves was experimentally studied at the surface of liquid hydrogen after switching off harmonic pumping. It was found that the cascade starts to decay at the high-frequency side of the frequency spectrum and proceeds in the quasi-stationary regime. The characteristic relaxation time of the whole cascade proves to be close to the viscous-damping time of the wave, whose frequency coincides with the surface-excitation frequency.

Experiments were performed to study the effect of the species particle size and structure of aluminized mixture samples on the sensitivity and detonation parameters of HMX, nitroguanidine, bis(2,2,2‐trinitroethyl)nitramine, and their mixtures with an Al powder with a mean particle size of 0.1 – 150 μm. The addition of ultrafine Al to HMX and bis (2,2,2‐trinitroethyl)nitramine substantially increases the sensitivity to mechanical effects and decreases the detonation velocity. In compositions with nitroguanidine, the detonation velocity practically does not vary. For nitroguanidine, the width of the chemical‐reaction zone and Chapman–Jouguet parameters were determined by recording the detonation‐pressure profiles. The pressure profiles for bis(2,2,2‐trinitroethyl)nitramine show that detonation decomposition can occur in two stages. A two‐peak detonation‐wave structure was detected for mixtures of HMX with Al. Temperature measurements indicate that Al interacts with detonation products in the immediate proximity to the front. The highest temperature was recorded for compositions containing ultrafine aluminum and an aluminum dust.

Radiation from shock‐compressed water at pressures of 10.0–39.5 GPa loaded through targets made of various metals (Al, Mg, and Cu) is studied. It is shown that the radiation intensity depends on both shock pressure and the nature of the metal. At pressures below 25 GPa in the region of water transparency, the radiation intensity considerably exceeds the presumed level of thermal radiation. This effect can partly be explained by the interaction of the target material with water and by nonthermal radiation from shock‐compressed water. For comparison, some experimental data on shock‐induced radiation from a number of transparent materials (Kron‐8 optical glass, glycerin, AND sodium salt) are given.