Simulation of high-speed interaction between impactor and layered-spaced design involving explosive

In this paper we present calculating and experimental study of high-speed interaction between explosive content, protected by layered-spaced design, and the cermet impactor in wide speed range. An experimental technique and mathematical model of during the behavior of explosives, protected by layer-spaced design, by with high-speed impact. The process of the interaction between the cermet impactor and element of the protective design is customized and depends on the materials of the interacting bodies, the speed and angle of impact

Calculation and experimental study on high-speed impact of heat-resistant coating materials with a meteoric particle

The given article presents the conducted calculation and experimental study on destruction of heat-resistant coating material of an aircraft in the process of high-speed interaction of the steel spherical projectile. The projectile is imitating a meteoric particle. The study was conducted in the wide range of velocities. The mathematical behavioral model of heat-resistant coating under high-speed impact was developed. The interaction of ameteoric particle with an element of the protective structure has especially individual character and depends on impact velocity and angle, materials of the interacting solids

Intrusion features of a high-speed striker of a porous tungsten-based alloy with a strengthening filler in a steel barrier

The complex problem of increasing the penetrating power of strikers based on highly porous tungsten composites is considered by improving their strengthening properties by alloying the hardening components under high-speed collision conditions. Using the method of liquid-phase sintering, we fabricated samples of strikers based on a porous WNiFeCo alloy (tungsten + nickel + iron + cobalt), alloyed with tungsten carbide with cobalt (WCCo8) and titanium-tungsten carbide (TiWC). Dynamic tests of the strikers from the developed alloys were carried out at the collision velocity with a steel barrier of the order of 2800 m/s. The penetration depth of the striker based on a porous WNiFeCo alloy doped with tungsten carbides is 30% higher than the penetration depth of a striker of a monolithic WNiFe-90 alloy (tungsten + nickel + iron with a tungsten content of 90%)

High-speed impact of the metal projectile on the barrier containing porous corundum-based ceramics with chemically active filler

The paper presents a calculation-experimental study on high-speed interaction of the metal projectile with a combined barrier made of porous corundum-based ceramics filled with chemically active composition (sulfur, nitrate of potash) in the wide range of speeds. A mathematical behavior model of porous corundum-based ceramics with chemically active filler is developed within the scope of mechanics of continuous media taking into account the energy embedding from a possible chemical reaction between a projectile metal and filler at high-speed impact. Essential embedding of inlet heat is not observed in the considered range of impact speeds (2.5 … 8 km/s)

Using non-adiabatic excitation transfer for signal transmission between molecular logic gates

Molecular logic gates (MLG) are molecules which perform logic operations. Their integration into a computing system is a very difficult task which remains to be addressed. The problem lies in the field of signal exchange between the gates within the system. We propose using non-adiabatic excitation transfer between the gates to address this problem while absorption and fluorescence are left to communicate with external devices. Excitation transfer was studied using the modified Bixon-Jortner- Plotnikov theory on the example of the 3H-thioxanthene-TTF-dibenzo-BODIPY covalently linked triade. Several designs of the molecule were studied in vacuum and cyclohexane. It was found that the molecular logic system has to be planar and rigid to isolate radiative interfaces from other gates. Functioning of these gates is based on dark πσ∗-states in contrast to bright ππ∗-states of radiative interfaces. There are no fundamental difference between ππ∗ → πσ∗ and ππ∗ → ππ∗ transitions for cases when an exciton hopes from one gate to another. The rates of such transitions depend only on an energy gap between states and a distance between gates. A circuit is highly sensitive to the choice of solvent which could rearrange its state structure thereby altering its behavior. According to the obtained results, non-adiabatic transfer can be considered as one of the possible ways for transmitting a signal between MLGs

A simplified Bixon-Jortner-Plotnikov method for fast calculation of radiationless transfer rates in symmetric molecules

A simplified form of the Bixon-Jortner-Plotnikov (BJP) method is derived for calculation of internal conversion (IC) rate in a symmetrical molecule. The rate is a sum of contributions from individual transitions between vibronic states. For each transition, vibrational modes are divided into two groups, the promoting (one or two modes per electronic transition) and the surrounding ones. In the case of the non-totally symmetric transition in a symmetric molecule, the overwhelming majority of transitions do not contribute to the overall rate. Moreover, the promoting and surrounding modes belong to different symmetry representations and can be separated. It is proposed to deal with the promoting modes directly, while approximating the effect of the surrounding modes by a Pekarian function. The method was tested on polyacenes and it was shown that the calculated IC rates are in agreement with the experimental ones. The simplified method can be applied for calculating the rates of non-totally symmetric transition in a symmetric molecule, if its point symmetry group does not change after transition

Квадратуры со сверхстепенной сходимостью

The calculation of quadratures arises in many physical and technical applications. The replacement of integration variables is proposed, which dramatically increases the accuracy of the formula of averages. For infinitely smooth integrand functions, the convergence law becomes super power. It is significantly faster than the power law and is close to exponential one. For integrals with bounded smoothness, power convergence is realized with the maximum achievable order of accuracy.Вычисление квадратур возникает во многих физических и технических приложениях. В статье предложена замена переменных интегрирования, кардинально повышающая точность формулы средних. Для бесконечно гладких подынтегральных функций закон сходимости становится сверхстепенным. Он существенно быстрее степенного и близок к экспоненциальному. Для подынтегральных функций с ограниченной гладкостью реализуется степенная сходимость с максимально достижимым порядком точности

The Application of Electrophysical Effects in the Processing of Agricultural Materials

International audienc

Correct determination of electron concentration in n-GaSb by electrical measurements

The concentrations of conduction electrons in n-GaSb at 295 and 77 K have been calculated taking into account the non-parabolic deviation of the conduction band shape. We show that at T = 295 K the concentration of heavy electrons in the L-valley of the conduction band is higher than the concentration of light electrons in the Г-valley. On the contrary, at T = 77 K the conduction electrons are mostly concentrated in the Г-valley. Hall data for tellurium doped CZ n-GaSb specimens have been reported. Analysis of experimental data for T = 295 K requires the existence of two types of electrons be taken into account (the light and the heavy ones), the concentrations of which cannot be determined. The apparent increase in the electron concentration with a decrease in the temperature from 295 to 77 K is not true. The concentration of conduction electrons at T = 77 K can be measured correctly with the Hall method