The properties of azido-acetylenic derivatives of s -triazine containing various combinations of propynyloxy, propynylamino, N-methyl-propynylamino, and azido groups have been studied, and their enthalpy of formation in the condensed phase, density, and impact and friction sensitivities have been determined. Based on these data, the energy parameters of detonation, combustion, and adiabatic transformation for individual compounds and their compositions with the binder SKI-3 isoprene rubber have been calculated. The results of the integrated experimental and theoretical studies suggest a high heat of combustion of the investigated individual compounds and compositions based on them.

The explosive properties of cyclodextrin nitrates with different degrees of substitution of nitrate groups in cyclodextrins for hydroxyl groups have been estimated by calculation and experiment. It is shown that charges of  $$\beta$$ -cyclodextrin nitrate with 100% substitution at a density of 1.576 g/cm3 detonate with a relative explosion impulse equal to 96.4% of its value for the 50/50 TNT/RDX composition with a density of 1.66 g/cm3, whose impulse is taken as 100%. In this case, the detonation velocity is 7.15 km/s. It is concluded that the substance belongs to powerful blasting explosives. The sensitivity of cyclodextrin nitrates to mechanical stimuli was studied as a function of the degree of substitution. The obtained values of the explosive properties and sensitivity of cyclodextrin nitrates to impact and friction are compared with those of nitrocellulose.

The results of investigation of the detonation waves structure, the critical diameter, detonation parameters and the dependence of detonation velocity on the charge diameter for pressed hydrazine nitrate (HN) charges in the density range of 1.40–1.68 g/cm3 are presented. It was found that the critical diameter drops with the initial density decrease. Under steady-state detonation conditions at an initial density of 1.68 g/cm3, a high detonation velocity of 8.92 km/s is observed in HN charges. The change of the detonation velocity with variation of the initial density is not monotonous, but has a characteristic s-shape.

The results of the crush method applied to the experimental determination of the concentration limit of detonation for binary systems based on tetranitromethane and fluoronitromethane are generalized. A universal line (for the class of standard explosives with the atomic composition CaHbNcOdFe) dividing the plane of pairs of dimensionless parameters (heat of explosion, coefficient of oxidizer excess) into regions of detonating solutions and those unable of detonation was found.

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.

The X-ray crystallographic analysis of 1,7-difluoro-1,1,3,5,7,7-hexanitro-3,5-diazaheptane has been carried out. We have also determined its sensitivity to mechanical actions and a set of calculated and experimental data on explosion characteristics.

The impact sensitivity of some groups of nitrates and cubane derivatives has been correlated with their heat of explosion and chemical structure. These correlations show the ways of reducing explosion hazard in handling these compounds. It is currently impossible to construct a reference series of compounds that would allow explosives with preset sensitivity to be synthesized on the basis of a preliminary energetic prediction. New opportunities to enhance safety in handling explosives can be provided by investigating their detonation ability.

The results of experimental studies of the structure of the reaction zone for steady-state detonation of nitromethane and its mixtures with methanol. For pure nitromethane, the characteristic reaction time and detonation parameters were determined. For a nitromethane/methanol mixture, a dependence of the detonation parameters of the mixtures on methanol concentration is presented. It is shown that in pure nitromethane and with small additions of methanol, the detonation front is stable, or the size of the inhomogeneities of the front is less than 1 m. At a methanol concentration of 10% or higher, instability of the front is observed.

A set of data characterizing the detonation process in mixtures of nitromethane with nitrobenzene is determined with the use of an electromagnetic method. The dependence of the pressure of detonation products on nitrobenzene concentration is established. Information on the effect of dilution ratio of nitromethane by nitrobenzene on detonability was obtained in experiments on mixture explosion. The results are compared with the results of previous similar studies of mixtures of nitromethane and methanol.

Detonation in mixtures of nitromethane with methanol as an inert (nonexplosive) diluent is studied. Ignition experiments with mixtures in steel tubes of various diameters provided information on the effect of the degree of dilution on detonability. Mass velocity profiles with a chemical spike characteristic of detonation waves were recorded at the unsteady detonation front in all mixtures studied. This made it possible to distinguish the Chapman-Jouguet state and obtain a fairly complete set of detonation parameters. The dependence of the pressure in the detonation products on the methanol concentration is determined, which is required, in particular, to find the true (absolute) limit of detonation propagation for the concentration of diluted liquid explosives using the method proposed and validated by A. N. Dremin. Some results were found to be inconsistent with one-dimensional detonation theory.

The heats of combustion of three compounds, members of a new series of N-spiranes were measured by combustion calorimetry. The molecules of the title compounds comprise condensed and N-spirofused heterocycles as well as nitroxy groups that are both NO-donors and explosophores. The enthalpies of formation and the heats of explosive transformation of these compounds are calculated. Two compounds belong to explosives with low heat of explosive transformation, whereas the third compound is inert.

This paper gives the results of experimental studies of the reaction zone structure during steady detonation in bis-(2-fluoro-2,2-dinitroethyl)-formal (FEFO, C(5)H(6)N(4)O(10)F(2)) and its mixtures with nitrobenzene (NB). For pure FEFO, the pressure and particle velocity at the Chapman-Jouguet point and the characteristic reaction time were measured. For FEFO/NB, the dependence of the detonation parameters of the mixture on the NB concentration was determined, and the detonation front was shown to be unstable in pure and in mixtures containing more than 30% NB.

The experimental investigation of reaction zone structure was conducted for steady-state detonation in tetranitromethane (TNM), nitromethane (NM), TNM/methanol (TNM/M), and NM/methanol (NM/M) solutions. A VISAR laser interferometer was used. As the result of measurements, particle velocity profiles with clearly defined Von Neumann spikes were determined. For TNM and NM reaction time, parameters in Von Neumann spike and in Chapman-Jouguet point were determined.

Results of a study of a two-stage laboratory technique for nicorandil synthesis from nicotinic acid ethyl ester are presented. The process for nicorandil synthesis is fundamentally improved.

The dependence of detonation parameters for (bis-(2-fluoro-2,2-dinitroethyl) formal)/nitrobenzene solution (FEFO/NB) on NB concentration was defined. Velocity profiles of the boundary between HE and water window were recorded by laser interferometer VISAR. It was found that particle velocity in a pure FEFO was strongly oscillating with the oscillation amplitude similar to 50 m/s. It means that detonation front is unstable and heterogeneities size is about 10 mu m. The average velocity profile corresponds to ZND model. The reaction time is equal to similar to 400ns, C-J pressure and particle velocity are 24 GPa and 2.0 km/s respectively. For FEFO/NB solution it was found that at low NB concentrations (10-20%) oscillations disappeared and detonation front was stable. When the NB concentration increased up to 30.% high-frequency oscillations appeared again. The measurements of reaction zone structure up to critical concentration were conducted, it was about 45%. At average particle velocity profiles Von Neumann spike was distinctly registered. It was shown that in a pure FEFO and in solutions with NB concentration exceeding 30% detonation front was unstable.

Electromagnetic method of registration of partical velocity profile U(t) has been used for investigation of nitromethane/methanol mixtures of different concentration including mixtures in which weigh ratio is close to the detonation limits concentration. In all mixtures in the experimental records of U(t) a typical spike was registered, this enables to locate the Chapman-Jouguet state, and to determine a set of detonation parameters including the pressure PC-J data which are necessary for finding of true detonation limits on concentration according to methods proposed by Dremin recently. Attention was given to some disagreements with one-dimensional ZND detonation theory.

Aim of the work was to study effect of nicorandil [N-(2-nitrooxiethyl) nicotinamide, SG75] on blood pressure (BP), heart rate (HR) and rhythm disturbances during regional ischemia and reperfusion of the heart in rats in vivo and its ability to limit acute myocardial infarction (MI). Nicorandil was obtained by nitrating nicotinamide ethanol using produced by industry ethylnicotinate. MI in Wistar rats was modeled by 40-min occlusion of anterior descending coronary artery (ADCA) and subsequent 60-min reperfusion. Nicorandil (3,2 mmol/kg) was administered intravenously before occlusion. Nitroglycerine was used as preparation of comparison; it was administered in the same dose. MI area and zone at risk (ZR) were measured by computer planimetry after staining of left ventricular sections with 2, 3, 5-triphenyltetrazolium chloride. Lowering of mean BP under influence of nicorandil during ADCA occlusion and subsequent reperfusion were deeper and longer than under influence of nitroglycerine. Contrary to nitroglycerine administration of nicorandil did not cause decrease of HR. Administration of both drugs postponed origination of rhythm disturbances during ischemia but did not affect their duration. MI dimension assessed by MI/ZR ratio after administration of nicorandil and nitroglycerine was significantly lowered down to 22 +/- 4 and 32 +/- 3%, respectively, compared with 47 +/- 3% in control. The results obtained evidence that in this model of ischemic and reperfusion damage of the heart vasodilating properties of nicorandil combined with decrease of postischemic loss of cardiomyocytes in ZR are comparable with effects of nitroglycerine.