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The influence of the ratio of the initial components on the combustion parameters and modes of mixtures of aluminum with copper oxide has been studied. It has been shown that under normal conditions, such mixtures can burn stably when they contain not less than 30% copper oxide. Moreover, with an increase in the content of copper oxide to the stoichiometric ratio, there is a regular change in combustion mode: self-oscillatory, spin, combined convective and multi-hotspot, flame, and fireball combustion modes. In addition, the effect of the ratio of the components on the combustion of copper oxide–aluminum–titanium ternary mixtures was studied, and concentration regions were determined for four main modes of their combustion: the self-oscillatory, hotspot, flame, and fireball modes. It has been shown that the hotspot combustion of such mixtures can proceed in five different modes: a spin mode, a multi-hotspot mode, a combined convective and multi-hotspot mode, a multi-hotspot mode with the formation of a counter front, and a multi-hotspot mode with periodic ejection of combustion products. Depending on the ratio of the initial components, the condensed combustion products of mixtures of copper oxide with aluminum and titanium were found to contain copper, Al3Ti, Ti3Al, and CuAl5Ti2 intermetallic compounds, and Al2O3, TiO2, TiO, Cu2O, Al2TiO5, and Cu3Ti3O oxides.

The effect of the ratio of the components of mixtures of nickel (II) oxide with titanium on the combustion modes and burning rate of compositions based on them is studied. It is found that under normal conditions, a change in the mass content of nickel oxide from 75 to 30% leads to a regular change in combustion mode: a flame, a multi-hotspot mode, and a self-oscillating mode with a periodic separation of combustion products from the burning surface. It is shown that the maximum burning rate of such mixtures (82 mm/s) is achieved at equal mass proportions of nickel oxide and titanium. In the condensed combustion products of a mixture of nickel oxide with titanium, Ti2Ni intermetallic and Ni2Ti4O $$_{x}$$ binary oxide were identified.

Thermochemical transformations of potential precursors for nanoparticles of Mn, Cr, and V in the wave of flameless combustion (smoldering) of RDX in ballasted systems were explored. No full reduction to a metallic state was detected. In the wave of flameless combustion, manganese carbonate was found to yield manganese(II) oxide with a particle size of 0.1–0.5 μm; ammonium dichromate, chromium(III) oxide with a particle size of 0.2–0.3 μm; while ammonium vanadate, vanadium(III) oxide in the form of platelets 20–30 nm thick and 0.5–1.0 μm in size at a specific surface of 18.6 m2/g.

The influence of tropical cyclones on the thunderstorm activity on the Kamchatka peninsula for winter thunderstorms in the 2008–2018 period is studied. The temporal variations of the quasi-static electric field and meteorological values at the Paratunka Observatory of the Institute of Cosmophysical Research and Radio Wave Propagation (IKIR) of the Far Eastern Branch of the Russian Academy of Sciences (φ = 52.97° N; λ = 158.25° E) and data on the solar, seismic, and cyclonic activities available on the INTERNET are used as an indicator of thunderstorm activity. It is shown that, in addition to from solar flares, which are accompanied by increased radiation in the visible and infrared spectra, the infrared radiation from a series of closely located epicenters of average-intensity earthquakes, as well as distant tropical cyclones in the Pacific Ocean, can be a source of powerful flows of warm and humid air for the formation of thunderstorm activity.

The effect of comparatively small changes in the free carrier concentration in a heavily doped p‑type single-crystal silicon on the structural parameters of porous layers formed as a result of its anodic etching has been found. The pronounced influence exerted by the hole concentration on the structural porous silicon parameters being studied is explained on the basis of the concept of electrochemical pore-formation in silicon crystals as a self-organized cooperative process accompanied by the injection of electrons from the region of the chemical reaction at the propagation front of pores.

Winter thunderstorms in Kamchatka are a rare meteorological phenomenon. Temporal variations of the quasi-static electric field and meteorological values at the Paratunka observatory of the Institute of Cosmophysical Research and Radio Wave Propagation, Far East Branch, Russian Academy of Sciences (φ = 52.97° N; λ = 158.25° E), as well as data on solar, seismic and cyclonic activities available on INTERNET, are used to study the nature of this phenomenon. It is shown that powerful solar flares accompanied by increased radiation in the visible and infrared spectra, as well as the infrared radiation from the Earth that enters the atmosphere before powerful earthquakes with a magnitude of M > 8 may serve as an additional heat source in the surface atmosphere of Kamchatkan for the formation of thunderstorm activity. The contribution of tropical cyclones to these processes with weak seismic activity is not clearly defined and requires further detailed study.

The conditions of occurrence, nature, size, and shape of combustion hotspots of energetic condensed systems and the spatial dynamics of the hotspot combustion wave are discussed. A model for the propagation of hotspot combustion waves in condensed systems is briefly described based on the cellular automata method. A possible explanation for the occurrence of unsteady effects in the combustion of solid rocket propellants is proposed.

In this paper, we discuss causes of the multidirectional effect of changes in the concentrations of free charge carriers in silicon crystals of p- and n-type conductivity on the transverse dimensions of pores formed as a result of anodic etching in hydrofluoric acid solutions, as well as the effect of anodic current density on pore size. The observed dependences are explained based on the concepts of electrochemical pore formation in semiconductor crystals as self-organizing cooperative processes accompanied by the injection of electrons from the chemical reaction region at the pore advancement front. Differences in the size of pores forming at the same current density in crystals differing in type and concentration of free charge carriers are associated with the effective temperature of the front of the cooperative chemical reaction at the bottom of germinating pores. This temperature, in turn, correlates with the power density of thermal energy released in the near-surface region of the etching crystal, either due to recombination processes for a p-type semiconductor or direct or indirect energy transfer from hot electrons to lattice vibrations in the case of a n-type semiconductor. The characteristic relaxation times of injected nonequilibrium electrons were calculated depending on the concentrations of the majority charge carriers in silicon crystals of both types of conductivity and the corresponding thicknesses of the regions of relaxation energy release. The revealed patterns of concentration changes in the power density of heat release in the near-frontal region of etching silicon crystals of p- and n-type conductivity are in good agreement with observed changes in the size of germinating pores.

A Ti–Zr alloy was prepared by magnesiothermic reduction from TiO2–ZrO2–Mg mixtures followed by acid leaching and the influence of leaching conditions on the quality of final product was explored. For nitric and hydrochloric acids as leaching agents, conditions for complete removal of MgO from crude TiZr–MgO combustion product had been optimized. The resistance of combustion-synthesized Ti–Zr alloy to elution with nitric acid was higher than that with hydrochloric acid.

A brief review and results of experimental investigation of the properties of energy-saturated nanoporous silicon-based composites are presented. Various types of oxidants used in the composites are examined. Calcium perchlorate has been used as an oxidant. The energy-saturated composite under study is shown to exceed in several parameters the primary explosive, mercury fulminate and brisant explosive, RDX.

The nitration of hyperbranched polyglycidols was studied. It was confirmed that there is no destruction of the polymeric chain when the nitration reaction is performed. The influence exerted by the molecular mass of polyglycidols on the degree of substitution of hydroxy groups in polyglycidol by nitrate groups was determined. The dependences of the degree of substitution of hydroxy groups on the reaction conditions and duration were found. It was shown that the fundamental aspects found in the study can be used to synthesize polyglycidyl nitrates with controllable degree of substitution from polyglycidols with various molecular masses.

Technologically viable principles have been developed for the preparation of titanium and zirconium powders via reduction of metal oxides. We have studied the effect of synthesis conditions (starting-mixture composition and relationships between reactants) on the composition, structure, and particle size of the powders. The results demonstrate that the addition of excess magnesium to the starting mixture leads to the complete reduction of the oxides and that reducing the combustion temperature of the starting mixture leads to an increase in the percentage of zirconium oxide in the final product. The titanium and zirconium powders prepared in the combustion regime with a reduction stage consist of agglomerates of particles ranging widely in size: from large (several microns) to ultrafine and nanoscale particles. The use of magnesium perchlorate as a heating additive leads to the formation of a titanium–zirconium solid solution. The composition of the powders has been determined by chemical analysis, microstructural analysis, and X-ray diffraction.

Flameless combustion of 40% Fe2O3 – 40% RDX – 20% HDI (mix I) and 30% CoCO3 – 15% iron formate – 40% RDX – 15% HDI (mix II) systems was explored by time-resolved X-ray diffraction (TRXRD). In case of mix I, the reaction was found to proceed via the formation of FeO intermediate: Fe2O3 → FeO → Fe3O4. Variation in the extent of iron reduction was associated with dynamic temperature change and a reductant content of the reaction zone. The reduction proceeded as a solid-state reaction, without amorphization of the structure. The process in system II involved the formation of CoO and FeO intermediates. Further reduction – up to metals – takes place behind the combustion front and yields a mixture of nanosized Co, Fe, and Co0.7Fe0.3 particles. Exposure of hot reaction products – nano-sized Co and Fe – to the air leads to their self-ignition and formation of Co3O4 and Fe3O4, respectively.

Nitration of α-, β-, and γ-cyclodextrins with nitric acid of various concentrations was studied. The nitration occurs similarly for all the three cyclodextrins studied. The influence of the reaction conditions on the degree of substitution of hydroxy groups in cyclodextrin by nitrate groups was examined. The composition and degree of substitution of the nitration products depend not only on the nitric acid concentration, but also on the molar ratio of HNO3 to OH groups. The results obtained allow optimization of the procedure for preparing cyclodextrin nitrates with definite topology of substitution of cyclodextrin hydroxy groups.

The extraction of Ti powder from SHS-produced Ti–MgO–Mg(–CaO) cakes by treatment in leaching solutions (HNO3, HCl, and NH4Cl) was explored and optimized in relation to such factors as concentration of leaching agent, leaching temperature, chemical resistance of target Ti powder, and extent of byproducts extraction. The type of leaching solution was found to affect the size, structure, and morphology of resultant Ti powder. Best results were obtained at 70°C with aqueous solutions of: (1) the nitric acid taken in a 6-fold excess to the Mg content of combustion product and (2) the ammonium chloride taken in a 20-fold excess to nominal Mg content.

This paper describes the study of the effect of physical and chemical properties of powder titanium and the equivalence ratio on the burning parameters of its mixtures with copper oxide. It is shown that the linear burning rate of such mixtures is significantly dependent on the brand of used titanium. Under normal conditions, the mixtures can stably burn with the content of copper oxide of not smaller than 13%. With an increase in the content of copper oxide to a stoichiometric ratio, there is a change of combustion regimes: multifocal, multifocal with detachment of solid residue, combination of convective and multifocal, multifocal with melt formation, flaming combustion, and fireball. It is determined that, in this system, there may be convective burning under atmospheric pressure in the absence of outer reinforcement.

Fine Ti powders were prepared through magnesiothermic reduction in TiO2–Mg–Ca mixtures under 4 MPa of Ar followed by acid leaching (with HCl or HNO3) and characterized by XRD, SEM/EDS, and chemical analysis. Thus prepared Ti powders exhibited the specific surface ranging between 7.0 and 30.0 m2/g. The produced Ti powders can find their application in pyrotechnics, powder metallurgy, and as raw material for SHS of inorganic compounds.

The diurnal variations in electrical (quasistatic electric field and electrical conductivity) and meteorological (temperature, pressure, relative humidity of the atmosphere, and wind speed) parameters, measured simultaneously before strong earthquakes in Kamchatka region (November 15, 2006, М = 8.3; January 13, 2007, М = 8.1; January 30, 2016, М = 7.2), are studied for the first time in detail. It is found that a successively anomalous increase in temperature, despite the negative regular trend in these winter months, was observed in the period of six–seven days before the occurrences of earthquakes. An anomalous temperature increase led to the formation of “winter thunderstorm” conditions in the near-surface atmosphere of Kamchatka region, which was manifested in the appearance of an anomalous, type 2 electrical signal, the amplification of and intensive variations in electrical conductivity, heavy precipitation (snow showers), high relative humidity of air, storm winds, and pressure changes. With the weak flow of natural heat radiation in this season, the observed dynamics of electric and meteorological processes can likely be explained by the appearance of an additional heat source of seismic nature.

The thermal decomposition of the energetic component and chemical reactions occurring at elevated temperatures in a flameless combustion wave of systems based on hexogen (filled with iron(II) formate and polyisocyanurate binding agent) afford a mixture of iron oxides and iron nitride as nanosized particles. The purposeful change in the ratio of the indicated basis components can provide individual Fe2O3, Fe3O4, or FeO in the conversion products. Additives of anthracene and hydroquinone to the initial composition can result in the formation of predominantly iron carbide in the products, whereas mainly iron nitrides are formed upon the addition of guanidine nitrate or 5-aminotetrazole. The addition of aluminum hydride components to the initial mixture results in the reduction of iron to the zero-valence state in the form of iron—aluminum intermetallic compounds.

The sensitivity of an energy-packed compound based on nanoporous silicon and calcium perchlorate to a high-current electron beam is studied. The initiation of explosive transformations in a mixture of potassium picrate with a highly dispersed powder of boron-doped silicon by means of a high-voltage discharge is examined. It is shown that explosive transformation modes (combustion and explosion) appear in the energy-packed compound under study upon its treatment with an electron beam. A relationship is established between the explosive transformation modes and the density of the energy-packed compound and between the breakdown (initiation) voltage and the mass fraction of the silicon powder.

The enthalpy of combustion of hexamethylenetetrammonium dodecahydro-closo-dodecaborate is determined via combustion in a KL-5 calorimeter and is found to be‒17660 kJ/mol. Its standard enthalpy of formation is calculated using the obtained experimental data (−538 kJ/mol).

The dependence of the combustion parameters of cellulose nitrate (nitrocellulose, NC) mixtures with magnesium oxide on the content of the energetic component was studied to reveal peculiarities of the combustion of NC in ballasted systems. It is experimentally shown that the combustion occurs in the flameless low-temperature region at the NC content in a mixture with magnesium oxide lower than 60%, and the reactive smoke reaction products can be ignited by a secondary thermal igniter heated to the temperature higher than 770 K. For the NC content in the initial mixture higher than 60%, a critical increase in the combustion temperature and velocity is observed due to the ignition of the reactive smoke products of NC decomposition inside the sample. The combustion of NC in the flame and flameless regimes is characterized by an intermediate isothermal stage at the temperature about 440 K corresponding to the temperature of onset of the fast NC decomposition. Thus, ballasting of a power material with an inert filler makes it possible to reveal and characterize the spatial and time stage character of its thermal decomposition under the combustion conditions.

The impact sensitivity of the energy systems based on nanoporous silicon, obtained by electrochemical etching of monocrystalline silicon wafers in an HF-containing electrolyte, and calcium perchlorate was studied using a modified Weller—Ventselberg technique (estimation of the impact sensitivity of initiating explosives). The impact sensitivity of these systems is shown to be determined by both the presence of hydrogen, which is stored on the porous silicon surface during the preparation of the latter, and also the influence of other factors, including the specific surface of porous silicon. The composition, amount of the generated gas, and gas evolution rate during nonisothermal and isothermal calcination of porous silicon in a temperature range of 60—120 °С were determined using methods of thermal gravimetry (TG), measurement of the gas volume, and mass spectrometry. The generated gas almost completely consists of hydrogen, and its content in the studied samples of porous silicon achieved ~3.8 wt.%. The calculated activation energy of the hydrogen evolution process in vacuo was 103.7±3.3 kJ mol–1. The dependences of the impact sensitivity of the energy composition based on porous silicon and heat of combustion of porous silicon on oxygen on the hydrogen content were established. The impact sensitivity of the energy system decreases with a decrease in the hydrogen content in porous silicon and its specific surface.

Records of the coastal mareographs during the December 26, 2004, tsunami are used to study the fine structure of the tsunami wave power spectra. It is shown that a series of maxima is observed in their spectra near the source in a range of internal gravity wave frequencies of 0.2–1.2 mHz, which coincides with the frequencies of the natural oscillations of the Earth. This experimental finding enables us to propose a possible physical mechanism for the formation of tsunami waves as a result of oscillations in the sea bottom at these frequencies. Internal gravity waves in the Earth’s atmosphere excited in this way are found in the variations of the total electron content that resulted from this powerful earthquake.

At present, cellulose and nitrocellulose components used in the field of ammunition are manufactured from a cotton linter or a wood. However, over the last decade the raw material characteristics, including for the nitrocellulose production for special purposes, have changed significantly both in connection with the loss of the traditional source of the cellulose raw material (the cotton linter) and with the deterioration of the quality of cotton cellulose. The new types of cellulose materials (a flax, a hemp, oats and etc.) have appeared on the market in due to the cotton deficit, intended for the special-purpose nitrocellulose. If we take into account the need to develop a component base based on the available domestic annually renewable sources of raw materials, then there is no doubt that the flax should be considered as a promising one.. In this connection, the possibility of an application of the flax pulp and NC based on it when manufacturing the combustible articles was investigated.

Cyclodextrin nitrates with different degrees of substitution of hydroxy groups by nitrate groups were synthesized. A procedure based on analysis of 1H NMR spectra was developed for determining the degree of nitration and the composition of the product mixtures obtained.

Combustion enthalpies of chitosan dodecahydro-closo-dodecaborate corresponding to −13194 kJ/mol are measured via combustion in an AKS-3M automatic calorimeter. The standard enthalpy of formation corresponding to −5223 kJ/mol is calculated from the resulting experimental data.

This work presents the most important results, some of which have been previously unknown, of long-term experimental studies of signals and emission in the ELF and VLF ranges carried by Ya.I. Likhter during ground-based and satellite observations. In addition, the possibility of using the research results obtained for the diagnostics of parameters and the state of the near Earth’s plasma is shown.

The data of hourly measurements of ionospheric parameters in Petropavlovsk-Kamchatsk are analyzed for the period 1998-2002. In the vertical component of nearsurface atmospheric quasistatic elec� tric field Ez, earthquake precursors in the form of anomalous negative bays have been found earlier. In some cases, anomalously high sporadic layer Es, interpreted as an ionospheric precursor of an earthquake, was observed simultaneously with anomalous negative bays in Ez. All these cases were correlated with earth� quakes of different magnitudes which occurred with a significant time delay (more than five days) after the precursor appearance. Based on the whole data set (including those for simultaneously measured Es and Ez), empirical dependences linking the prediction time of a precursor, earthquake magnitudes, and the distance from the observation point to the epicenter, are presented. It is shown that these dependences are close to those obtained earlier for longterm earthquake precursors in nearsurface geophysical fields of the same seis� moactive region. Estimates of the prediction time for earthquake precursors on the boundaries of preparation zones are presented.

It has been shown that the polymerization of oxetanes with azidomethyl substituents initiated by boron trifluoride etherate in the absence and the presence of ethylene glycol proceeds via chain termination with fluorine atom transfer. This reaction results in the formation of a polymer that is monofunctional with respect to hydroxyl groups and contains a fluorine atom at one of the chain ends. With the use of 19F NMR spectroscopy, the number-average functionality of polymer with respect to fluorine atoms was studied. The methods of suppressing the aforementioned reaction, whose intensity decreases during a decrease in the polymerization temperature and an increase in the ethylene glycol concentration, were considered. In the absence of ethylene glycol, the chain termination with fluorine atom transfer is the main reaction of chain-propagation restriction.

The mutual solubility of polymers based on the azide-containing oxetane monomers 3,3-bis(azidomethyl)oxetane and 3-azidomethyl-3-methyloxetane is studied. The temperatures of melting, crystallization, glass transition; the upper critical solution temperature; and the compositions of coexisting phases for blends of polymers with different molecular masses are determined via differential scanning calorimetry and multiple-beam microinterferometry. On the basis of these data, the phase diagrams of blends are constructed. The melting regions and the metastable and heterogeneous states are determined. The studied systems are shown to have a complex amorphous-crystalline equilibrium and to differ in the location of boundary curves on the phase diagram, depending on the molecular mass of the components. Amorphous separation below the liquidus line in the metastable region with respect to the crystalline equilibrium is experimentally detected. The motion of the figurative point in different regions of the diagram is thoroughly considered. The specifics of structural and morphological organization of systems are examined via electron microscopy.

The kinetic features of the dibutyltin dilaurinate-catalyzed and noncatalyzed reactions of 1,6-hexamethylene diisocyanate with azide-containing oligodiols of various structures and molecular masses are studied. The accelerating effect of azide groups on urethane formation, which is determined by the possibility of activation of free hydroxyl groups via complexation with azide-containing fragments of side chains of oligomers, is established.

A method for the preparation of new representatives of polynitrogen hyperbranched polymers of heterocyclic series was developed involving polymerization of monomeric 2,4-diazido-6-propynyloxy-1,3,5-triazine by 1,3-dipolar cycloaddition. Kinetics of polymerization of diazidoacetylene monomer was compared with the kinetic data of polymerization of its closest analog, 2-azido-4,6-bis(propynyloxy)-1,3,5-triazine monomer. Properties of hyperbranched poly(1,2,3-triazole-1,3,5-triazine)s with terminal azide groups and terminal triple bonds were compared, as well.

The features of flameless low-temperature wave conversion (LWC) of some energetic materials in filled systems were studied experimentally and analyzed theoretically. The results attest to an relay-race mechanism of process propagation in the initial composition. An important role of the filling material in stabilization of the LWC wave of the energetic component is revealed. In the presence of mono- or oligomeric binders, flameless LWC of the energetic component affords strong highly porous composite materials. The possibility of using this method for preparing new high-performance grinding materials and catalysts containing nanosized particles of transition metals and their derivatives is demonstrated.

The synthesis of polyurethane block based on oligoesterdiols 4,4′-methylene-bis(phenylisocyanate), and various chain elongating agents was studied. The properties of these copolymers were compared (using literature data) with selected properties of polyurethanes obtained by the reactions of oligoetherdiols, viz., oligo-3,3′-bis(azidomethyl)oxetanediol and oligo-3-azidomethyl-3′-methyloxetanediol with diisocyanates. The complex of rheological and physicomechanical properties of the initial and plasticized polyurethane block copolymers was studied. Regularities of their deformation behavior were established. The process of mutual solubility was studied by the microinterference method for a wide range of systems block copolymers—plasticizers. On the basis of the data obtained, the phase diagrams were constructed for limitedly compatible systems.

Natural disasters, the processes of their origin and large-scale technogenic catastrophes are accompanied by anomalous physical phenomena in near-Earth space (NES). In order to reveal such phenomena, record and investigate them, complex NES monitoring is required with the use of specially designed research equipment onboard a low-orbiting spacecraft. This work presents the results of flight tests of the small Vulkan-Compass-2 satellite with research equipment specially designed for orbital monitoring of the ionosphere and search for abnormal phenomena caused by large-scale catastrophes of different nature.

The thermal decomposition of new heteroaromatic polyazides 2,6-diazido-3,5-dicyanopyridine, 2,4,6-triazido-3,5-dicyanopyridine, and 2,3,4,5-tetraazido-6-cyanopyridine was studied by thermogravimetry, volumetry, mass-spectrometry, and IR spectroscopy. Reaction kinetic parameters were determined. The only gaseous product of the thermal decomposition of all the azides studied was nitrogen, its degree of purity was 99.0–99.8 vol %. 2,6-Diazido-3,5-dicyanopyridine and 2,4,6-triazido-3,5-dicyanopyridine had thermal stability and thermal decomposition parameters close to those of the majority of aromatic azides. The mechanism of thermal decomposition of these azides includes the splitting off of the nitrogen molecule at the initial limiting process stage. Subsequent intermolecular reactions with the participation of nitrenes result in the formation of an amorphous substance containing polyconjugated fragments with sp 2 hybridization, which form planar two-dimensional networks. 2,3,4,5-Tetraazido-6-cyanopyridine has very low thermal stability; the rate of nitrogen release during its decomposition is almost 1000 times higher than with 2,6-diazido-3,5-dicyanopyridine and 2,4,6-triazido-3,5-dicyanopyridine at comparable temperatures. This was explained by the presence of the ortho azido group (there is no ortho arrangement of azido groups in 2,6-diazido-3,5-dicyanopyridine and 2,4,6-triazido-3,5-dicyanopyridine).

The hydrogenation of 1,3-pentadiene into pentenes over the commercial 0.5% Pd/Al2O3 catalyst and over a new catalyst containing 1.0% Pd and 3.7% Ag (μ-catalyst) has been investigated. The new catalyst has been prepared via the flameless wave conversion of cyclotrimethylenetrinitramine in a porous composite. The catalytic properties of the new composite in the hydrogenation reaction depend on the hydrogen/1,3-pentadiene ratio and on the catalyst activation temperature. The reaction conditions for selective 1,3-pentadiene hydrogenation have been optimized. The pentenes yield as a function of temperature passes through a maximum at any H2/C5H8 ratio between 1 and 2. The 2-pentene/1-pentene ratio in the reaction products increases as the temperature is raised.

The kinetics and products of the thermal decomposition of hexamethylenetetraammonium dodecahydro-closo-dodecaborate in air, argon, and a vacuum were studied using thermogravimetry, volumetry, mass spectrometry, and IR spectroscopy. According to the nonisothermal kinetic data, noticeable rates of the formation of volatile products were observed at temperatures higher than 150°C. The thermal decomposition of the salt occurred in stages. At 160–200°C, the thermal decomposition of hexamethylenetetraammonium dodecahydro-closo-dodecaborate could not be described by simple kinetic equations. The dependence of the initial reaction rates on inverse temperature (lnV0−1/K) was linear, which showed that the thermal decomposition of the salt obeyed the Arrhenius equation V0 = 109.4 ± 0.6exp[(−20500 ± 1800)/RT], %/min. The obtained temperature dependences of the kinetic parameters of thermolysis were used to predict the time of salt storage and the conditions of work with it. A comparison of the kinetics of the thermolysis of hexamethylenetetraammonium dodecahydro-closo-dodecaborate and free hexamethylenetetraamine in open and closed reaction systems showed that the thermolysis of hexamethylenetetraammonium dodecahydro-closo-dodecaborate was not accompanied by salt dissociation to hexamethylenetetraamine and dodecahydro-closo-dodecaborate acid. The products of its thermolysis volatile under normal conditions were trimethylamine with a small admixture of nitrogen. The solid residue after thermolysis was a high-porosity insoluble product, whose volume was 6–8 times larger than the volume of the initial sample. An analysis of the IR spectra of the solid thermolysis product showed that it had a well-defined salt character. The special features of the IR spectra of initial hexamethylenetetraammonium dodecahydro-closo-dodecaborate and the product of its thermolysis led us to suggest that an acid-base equilibrium of the type [R3N-H+] + A ↔ [R3N… H+…A] occurred in it and, probably, in the initial salt. Here, R3N is the tertiary amino group, and A is the borohydride acid residue. Indications of amorphization allowed us to suggest that polymer structures were formed as a result of intramolecular interaction between the borohydride anion and onium cation.

The preliminary results of observations of VLF electromagnetic signals (atmospherics) in the mountains of North Vietnam (Dien Bien Phu, 21°23′50″ N, 103°0′28″ E) are presented. Primarily, signals of typical atmospherics with a maximum in the frequency range of 4–9 kHz were observed; sometimes they were accompanied by so-called “tails” at frequencies less than 1 kHz, and also tweeks of usually short duration (about 10 ms) were observed. Several parameters of the ionosphere, as well as the distance to sources of atmospherics (in accordance to the data of the World Wide Lightning Location Network (TOGA)), were estimated by spectral-temporal characteristics of tweeks.