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In the practice of magnetic flux leakage non-destructive testing the problem of distinguishing signals generated by dangerous internal defects from signals generated by surface flaws is very acute. In this paper on the basis of three-dimensional computer simulation it was shown that at significant inspection speed the area of the maximum magnetization of the most remote from the surface metal layers under the influence of emerging eddy currents is shifted behind the rear pole of the magnetizing system. Studies of magnetic induction distributions in the testing object in the form of a rail from speed, from the distance of the section under consideration relative to the rear pole and from the depth of the layer are carried out. Also, the distributions of the field in the presence of two types of defects – surface and internal – are studied. It was found that the magnetic field distribution behind the rear pole differs significantly from the distribution in the interpole space. Two contrary magnetic fluxes are formed behind the rear pole: in the bulk of the object the magnetic flux moves in one direction and near the surface magnetic flux flows in the opposite one. Since the flux directions are opposite, the signals from surface and internal defects have different polarity, which can be used to differentiate them.

The search for ferroelectric materials capable of producing high electric charge and power densities is important for developing a new generation of autonomous ferroelectric megawatt power supplies and ultrahigh-power-density ferroelectric energy storage devices. Here we report the results of experimental investigations of the mechanism for stress-induced depolarization of adiabatically compressing rhombohedral Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–PbTiO3 (PIN–PMN–PT) single crystals. The important finding is that the geometric dimensions of PIN–PMN–PT crystals and the direction of adiabatic compression relative to the crystallographic orientation have significant impacts on the depolarization dynamics and the generated charge density. Based on the analysis of experimental results, we conclude that a basic depolarization mechanism is associated with stress-induced lattice distortion, which leads to the phase transformation from a polar rhombohedral R3m to a nonpolar Rc phase accounting for the complete depolarization of the crystals. We experimentally demonstrated that PIN–PMN–PT crystals are capable of releasing electric charge with a record high density, 0.47 C m−2, which is not achievable in other ferroelectric materials. The produced power density in the external load is 0.53 MW cm−3, being 2.4 times greater than that of the state-of-the-art Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric ceramics used in high-power systems. Therefore, PIN–PMN–PT crystals are very promising ferroelectric materials for high-power applications.

In This paper is dedicated to the examination of one of the most relevant and significant problems of Russian society – illegal trafficking of items and materials, carried out using mass media andinformation and telecommunication networks. Top officials of the state raise the issue of the importance of special control in this area by law enforcement agencies. Despite this attention, comprehensive study on the criminal-legal significance of the use of mass media and information and telecommunication networks in illegal trafficking has not been yet undertaken in the frame of criminal law of Russia. The author examines the concept of «illegal traffic», analyses the texts of the articles of the criminal code of the Russian Federation, which explicitly criminalize illicit trafficking. The author makes a conclusion about the reasonableness of making changes to certain articles of the criminal code of the Russian Federation, in regard to the part concerning establishing stricter penalties for committing socially dangerous acts using mass media and information and telecommunication networks.

Research of magnetic flux leakage signals of rail non-destructive testing in a wide range of scanning speeds is carried out. The results of three-dimensional computer simulation show significant changes in the distribution of the magnetic field in the depth of the rail at high motion speeds of the magnetizer. The appearance of low magnetization zones in the places most distant from the surface of the rail due to the influence of eddy currents is predicted. It is concluded that to detect defects that lie deep under the surface of the rail, magnetic sensors should be shifted towards the rear pole. The simulation results are in correct agreement with the results of experimental studies carried out on railway tracks at testing speeds up to 60 km/h. The effect of the formation at high scanning speeds of a tail magnetic flux behind the rear pole of the magnetizer is considered. Registration of this flux leakage data is promising from the point of view of detecting deep-seated defects, as well as separating signals from surface and internal flaws at high inspection speeds.

The urgency of the problems of combating crime committed through the media and telecommunication networks has reached a high level. The present paper gives a detail analysis of the notions of “inducement” and “appeals” made by the Supreme Court of Russia, explanatory dictionaries as well as criminal law scholars. Based on the analysis the author suggests his own definitions of “inducement” and “appeals” in the Criminal law of the Russian Federation. The author solves the problem of qualifying an act in the case of competition rules, on the one hand, providing for participation in the commission of a crime, the objective side of which, among other things, can be performed by declination and appeals and, on the other hand, independent appeals and inducement to commit a crime. Using the example of article 212 of the Criminal Code of the Russian Federation, the author solves the problem of qualification of acts in the case of competition of criminal law norms. A comparison of punishments in the main part of the article and in the part where the act is carried out using the media or information and telecommunications networks is made. There are some articles of the Criminal Code of the Russian Federation in the dispositions of which inducement and appeals do not provide implementation with the use of mass media and telecommunication networks. It is concluded that such norms need to be analyzed to establish more severe penalties for the acts influenced by media and telecommunication networks.

Systems for nondestructive testing (NDT) of rails are multichannel and concurrently use several methods, including ultrasonic, magnetic flux leakage (MFL), visual, and others. Periodic inspection of rails does not allow easily monitoring the condition of rails and tracking the trend in the development of defects simultaneously through multiple (up to 14) channels based on several parameters of ultrasonic- and magnetic-testing signals. We propose approaches to developing a generalized (integral) parameter that takes into account the main characteristics of signals from defects concurrently through all testing channels (methods). Using this parameter, we have analyzed the development of various defects in the rail head during repeated (up to 17 times) inspections. As expected, longitudinal defects in the head develop over a rather long (up to 4 years) period of time. At the same time, transverse cracks, most dangerous due to the likelihood of a sudden break in the rail, develop quite rapidly (0.5–4 months). Attention is drawn to the significant instability of ultrasonic flaw-detection signals during repeated monitoring and to regular changes in magnetic-testing signals. It is shown that it is possible to monitor the development of rail defects and take proactive measures for the timely removal of dangerous defects. The proposed approaches can be used in monitoring the development of defects in other fields of NDT.

The impact of a polychromatic field on a two-level medium is considered in the limit of small amplitudes. In the indicated limit, we obtained asymptotic expansions of the polarization spectra of an arbitrary order of smallness. These polarization spectra were compared with the results of the numerical solution of the density matrix equation. Compared to numerical calculation methods, the asymptotic expansion offers an analytical estimation of the contribution of each individual component of a polychromatic field and a description of the intermode interaction. However, with an increase in the intensity of the driving field, the computational efficiency of the method decreases, since, to achieve the required accuracy, it is necessary to increase the order of the asymptotic expansion.

The ability of the Magnetic Flux Leakage (MFL) method to detect flaws in railway rails in two different ways has been studied. First, a three-dimensional computer simulation of the leakage of magnetic flux around a transverse crack in the rail head was carried out to determine the relationship between the main characteristics (size and depth) of the defect and the magnetic sensor signal. Second, signals were analyzed from more than 600 actually confirmed defects of the rail track, enabling statistically determined conclusions on the detectability of various types of flaws by magnetic and ultrasonic methods. It has been established that the MFL method detects rail head defects with the critical size at a depth of up to 20 mm under the upper rail edge. In general, the revealed defects constitute more than 90% of hazardous damage to rail head; this confirms the high efficiency of the MFL method in comparison with acoustic methods, which are also traditionally used in rail non-destructive testing.

we study the distortions in the dispersion and absorption spectra that arise when rotating wave approximation (RWA) is applied to multilevel atomic system driven by a polychromatic field. The density matrix equations are solved numerically without applying the RWA and when using it. The obtained polarization spectra are compared with each other in terms of maximum and frequency-averaged deviations.

The interaction between two-level media and a polychromatic field is considered in the limit of small field amplitudes. The obtained third-order corrections allow us to describe a nonlinear response to the field and intermodal interaction. The obtained polarization spectra are compared to numerical solutions to the density matrix equation in the rotating wave approximation. The results can be used in nonlinear comb spectroscopy.

Differential density matrix equations for a three-level atomic system driven by polychromatic fields are solved numerically. The polarization spectrum of the probe field is obtained. Ultra-narrow resonances in the polarization spectrum on the probe field frequency emerge at multiple harmonics and subharmonics.

Compact autonomous megawatt-power systems based on shock depolarization of ferroelectric materials are capable of producing kiloampere currents and ultrahigh-voltage pulses with amplitudes exceeding 100 kV. Herein, we report the results of experimental investigations of the generation of ultrahigh voltage by poled Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 and Pb0.99(Zr0.52Ti0.48)0.98Nb0.01O3 ferroelectrics subjected to shock loading at different shock vector/polarization vector configurations. Our experiments demonstrated that under loading perpendicular to the polarization vector (transverse stress mode) the ferroelectrics are capable of generating high voltages exceeding 400 kV, while the loading parallel to the polarization vector (longitudinal stress mode) causes a distortion of the depolarization process in ferroelectrics of large thicknesses, resulting in inefficient generation of ultrahigh voltage. It was shown that for transverse semi-planar shock waves, the presence of the longitudinal component of stress due to non-perfect planarity of the shock front can cause a complex electric field distribution in the shock front area, resulting in energy losses in ferroelectrics operating in the ultrahigh-voltage mode. The important finding is that a cylindrical, radially expanding shock wave results in no significant distortion of the depolarization process and energy losses during ultrahigh-voltage generation by transversely shock-compressed ferroelectrics. The experimental results indicate that the voltage amplitude generated by transversely shock-compressed ferroelectrics is directly proportional to the ferroelectric thickness in the range from 6 to 230 mm. We found that over the full range of investigated thicknesses the breakdown-field-on-thickness dependence of shocked ferroelectrics is described by a power law and the mechanism of initiation of electric breakdown does not significantly change with ferroelectric thickness.

A numerical solution has been obtained for a two-level atomic system interacting with a 101-component polychromatic field. The analytical method of recurrence relations has confirmed the numerical calculations. The resonance in the polarization spectrum follows the transition frequency.

A new type of energy storage devices utilizing multilayer Pb(Zr0.95 Ti0.05 )0.98 Nb0.02 O3 films is studied experimentally and numerically. To release the stored energy, the multilayer ferroelectric structures are subjected to adiabatic compression perpendicular to the polarization direction. Obtained results indicate that electrical interference between layers (10-120 layers) during stress wave transit through the structures has an effect on the generated current waveforms, but no impact on the released electric charge. The multilayer films undergo a pressure-induced phase transition to antiferroelectric phase at 1.7 GPa adiabatic compression and become completely depolarized, releasing surface screening charge with density equal to their remnant polarization. An energy density of 3 J cm-3 is successfully achieved with giant power density on the order of 2 MW cm-3 , which is four orders of magnitude higher than that of any other type of energy storage device. The outputs of multilayer structures can be precisely controlled by the parameters of the ferroelectric layer and the number of layers. Multilayer film modules with a volume of 0.7 cm3 are capable of producing 2.4 kA current, not achievable in electrochemical capacitors or batteries, which will greatly enhance the miniaturization and integration requirements for emerging high-power applications.

In this paper the approaches to processing temporal data is considered. The problem of the anomaly detection among sets of time series is setting up. The algorithms TS-ADEEP and TS-ADEEP-Multi for anomaly detection in time series sets for the case when the learning set contains examples of several classes are proposed. The method for improving the accuracy of anomaly detection, due to “compression” of these time series is used.

The results are reported herein of experimental investigations of the mechanism of electric breakdown and the generation of high voltage and energy by shock-compressed rhombohedral (1-y-x)Pb(In1/2Nb1/2)O3-yPb(Mg1/3Nb2/3)O3-xPbTiO3 (PIN-PMN-PT) ferroelectric single crystals cut and poled along the [111]c crystallographic direction. PIN-PMN-PT crystals were shock-compressed in a direction perpendicular to the polarization, in either the [1 1 ¯0]c or [11 2 ¯]c crystallographic directions. Our experiments demonstrated that shocked crystals with thicknesses ranging from 1 to 5 mm are capable of producing high voltage amplitudes of 9–37 kV, with the amplitudes being directly proportional to the crystal thickness. The experimental results indicate that the shock loading direction does not have a significant effect on the generated voltage amplitude. The important finding is that the breakdown fields of adiabatically compressed crystals strongly depend on the crystal thicknesses, and this dependence obeys a power law similar to the one for solid dielectrics at ambient conditions. We found that high electric fields have significant impacts on the dielectric permittivity of poled PIN-PMN-PT crystals and a corresponding effect on the generated energy density. Our experimental results made it possible to determine the relationship between the energy density generated by crystals under shock loading and the crystal thickness. The energy density generated by shocked PIN-PMN-PT crystals is greater by a factor of three than that for high-energy-density Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric ceramics currently used in high-power systems, making these crystals very promising ferroelectric materials for high-power applications.

The ability of ferroelectric materials to generate high voltage under shock compression is a fundamental physical effect that makes it possible to create miniature autonomous explosive-driven pulsed power systems. Shock-induced depolarization releases an electric charge at the electrodes of the ferroelectric element, and a high electric potential and a high electric field appear across the element. We performed systematic studies of the electric breakdown field, $E_{b}(d)$ , as a function of the ferroelectric element thickness, $d$ , for Pb(Zr0.95Ti0.05)O3 (PZT 95/5) and Pb(Zr0.52Ti0.48)O3 (PZT 52/48) ceramics compressed by transverse shock waves (shock front propagates perpendicular to the polarization vector) and established a relationship between these two values: $E_{b}(d) = \textrm {const}\cdot d^{-\xi }$ . This law was found to be true in a wide range of ferroelectric element thicknesses from 1 to 50 mm. This result makes it possible to predict ferroelectric generator (FEG) output voltages up to 500 kV and it forms the basis for the design of ultrahigh-voltage FEG systems.

The comparison of residual Magnetic Flux Leakage (MFL) with traditional MFL method was carried out as applied to rail nondestructive testing. The mechanisms for the residual magnetization of rails are considered. It is concluded that the traditional Magnetic Flux Leakage method is more effective as compared with one based on а rail remanence.

The efficiency of a flaw detector magnetizing system using wheels as magnetic poles was studied. To obtain information on the emerging magnetic field distributions, three-dimensional computer simulation and research on an experimental model were carried out. The rail was used as a test object. It is shown that with the same magnetomotive force of the electromagnet, the wheel magnetizing system provides a higher magnetization of the test object compared to the traditionally used U-shaped magnetizing system.

A ferroelectric depolarized by high strain-rates induced by the passage of adiabatic shock waves releases a high-density electric charge, initiating the generation of high voltage and megawatt power levels. Additionally, this depolarization process alters physical and mechanical properties that might cause energy and electric charge losses in the ferroelectric materials. We report, herein, the results of an experimental study of electric charge losses in Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 and Pb0.99(Zr0.52Ti0.48)0.99Nb0.01O3 ferroelectrics subjected to shock compression. We found that electric charge losses mainly occur in the compressed zone of ferroelectric elements; i.e., shock compression is an essential part of the charge loss mechanism. Based on our analysis of the experimental results, charge losses are explained by the leakage current flowing through microscopic conductive pathways (conductive channels), which are formed due to the effects of high magnitude stress and high electric fields in compressed zones of ferroelectric elements. It is shown that the Joule heating of conductive channels by the leakage current increases their temperature and conductance, eventually short-circuiting the electrodes of the shocked ferroelectric element and causing electric breakdown. The leakage current density, jleak, and breakdown delay time, tcr, can be described by the relationship, j leak 2 t c r = β (where β is the material dependent constant), over a wide range of delay times. The breakdown criterion we propose is based on the integral of specific current action and can be used to characterize the electric breakdown in a broad range of shock-compressed ferroelectric materials.

Ferroelectrics are capable of producing megawatt power levels under shock loading due to stress-induced phase transformations, resulting in depolarization of the ferroelectric materials. This power can be used for generation of high voltages, high currents, or ultrahigh-power electromagnetic radiation. The results are reported herein on an experimental study of limitations on energy harvested from shocked Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 and PbZr0.52Ti0.48O3 ferroelectrics and transferred to external electrical systems. The experimental results indicate that one of the limits to the energy transfer is electric breakdown that occurs within ferroelectric specimens during shock wave transit and depolarization, interrupting the energy transfer process and resulting in energy losses. It was revealed that the mechanism for breakdown in shocked ferroelectrics differs depending on the energy transfer time range, making a significant impact on the energy transfer process. High-speed photography and analysis of outputs for the two ferroelectrics indicate that for energy transfer times exceeding eight microseconds, the mechanical fragmentation of the ferroelectric material caused by the shock and resulting release waves following the shock wave front plays an important part in the breakdown process, while a thermal runaway dominates the breakdown at shorter energy transfer times. The heretofore disregarded mechanism of electric breakdown of the mechanically fragmented dielectric media is an unavoidable time-limiting factor for energy transfer from ferroelectrics under shock loading. The results obtained in this study are important for understanding the behavior of ferroelectrics during shock wave transit under high electric fields and for ultrahigh-power applications of ferroelectric materials.Ferroelectrics are capable of producing megawatt power levels under shock loading due to stress-induced phase transformations, resulting in depolarization of the ferroelectric materials. This power can be used for generation of high voltages, high currents, or ultrahigh-power electromagnetic radiation. The results are reported herein on an experimental study of limitations on energy harvested from shocked Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 and PbZr0.52Ti0.48O3 ferroelectrics and transferred to external electrical systems. The experimental results indicate that one of the limits to the energy transfer is electric breakdown that occurs within ferroelectric specimens during shock wave transit and depolarization, interrupting the energy transfer process and resulting in energy losses. It was revealed that the mechanism for breakdown in shocked ferroelectrics differs depending on the energy transfer time range, making a significant impact on the energy transfer process. High-speed photography and analysis of out...

For three-level system of atoms interacting with polychromatic fields, the system of differential equations of the density matrix is analytically solved and the polarization spectrum of the components of the probe field is calculated. Supernarrow resonances in polarization spectrum at the frequency of the probe field occur at multiple harmonics, subharmonics, and on a frequency that is mirror-to-field.

The paper considers the possibility of using artificial intelligence methods in information security tasks: methods for generating inductive concepts for analyzing network traffic, as well as methods of argumentation for automated security decision support systems. The approach proposed in the work allows giving quantitative assessments of the quality of the recommendations developed by the system, thereby helping to solve an important task - the task of choosing the way of responding to suspicious activity in the system. Examples of handling dangerous situations occurring in the system are also presented.

The numerical solution for polarization for two-level atom in polyharmonic field has been made. The analytical solution for partial case of symmetrical case relative to the frequency of the homogeneously broadened transition confirmed numerically. The results can be used in the nonlinear comb spectroscopy.

Relaxor ferroelectric single crystals have triggered revolution in electromechanical systems due to their superior piezoelectric properties. Here the results are reported on experimental studies of energy harvested from (1-y-x)Pb(In1/2Nb1/2)O3–(y)Pb(Mg1/3Nb2/3)O3–(x)PbTiO3 (PIN-PMN-PT) crystals under high strain rate loading. Precise control of ferroelectric properties through composition, size and crystallographic orientation of domains made it possible to identify single crystals that release up to three times more electric charge density than that produced by PbZr0.52Ti0.48O3 (PZT 52/48) and PbZr0.95Ti0.05O3 (PZT 95/5) ferroelectric ceramics under identical loading conditions. The obtained results indicate that PIN-PMN-PT crystals became completely depolarized under 3.9 GPa compression. It was found that the energy density generated in the crystals during depolarization in the high voltage mode is four times higher than that for PZT 52/48 and 95/5. The obtained results promise new single crystal applications in ultrahigh-power transducers that are capable of producing hundreds kilovolt pulses and gigawatt-peak power microwave radiation.

The limiting detection depth of subsurface defects is considered as an important efficiency factor of Magnetic Flux Leakage (MFL) method of railway nondestructive testing. This issue is particularly topical since magnetizing systems of new type with increased interpole distance are implementing. The speculative limit of detection depth is investigated by numerical simulation. Test data of NDT facilities equipped with new magnetizing system are presented.

The ability of ferroelectric materials to generate high voltage under mechanical stress is widely used in transducer applications. The high strain-rate adiabatic compression of poled ferroelectrics results in their complete depolarization, the release of surface charges, and the generation of up to hundreds of kilovolts of electric potential that is an order of magnitude higher than in the low-strain piezoelectric mode. Electric breakdown within adiabatically compressed ferroelectric specimens is one of the factors that affect the generation of a high voltage by ferroelectric materials under extreme stress. We report herein the results of experimental investigations of the generation of high voltages by PbZr0.95Ti0.05O3 doped 2% Nb and PbZr0.52Ti0.48O3 doped 1% Nb2O5 poled ferroelectric ceramics adiabatically compressed by explosive-driven shock waves in a direction perpendicular to the direction of polarization. An important finding is the dependence of the ferroelectric breakdown field, Ebreak, upon breakdown delay time, td, for the two ferroelectrics, which is described by a power law: Ebreak(td) = β × td−η. This law can be used to characterize electric breakdown in adiabatically compressed ferroelectrics, for the prediction of voltage generated by ferroelectric materials under high strain rate loading, and for optimization of the ferroelectric materials properties for ultrahigh-power applications. The parameters of the power law indicate the possibility of an impulse thermal constituent in the mechanism for electric breakdown of adiabatically compressed ferroelectric ceramics. The Ebreak(td) relationships obtained in this study are important for theoretical consideration of mechanisms of breakdown in adiabatically compressed ferroelectrics and for ultrahigh-power applications of ferroelectric materials.

Ferroelectric (FE) films are widely used in electronic devices and low-power FE transducers. There is significant interest in expanding the usage of FE films to ultrahigh-power systems. The results are reported herein on experimental investigations of stress-induced depolarization of single-layer PbZr0.95Ti0.05O3 doped 2% Nb (PZT 95/5) poled FE films subjected to uniaxial adiabatic compression perpendicular and antiparallel to the direction of polarization. It was found that at a stress of 2.4 GPa, the 32-μm-thick films underwent a pressure induced transition to a nonpolar antiferroelectric phase and became completely depolarized in both modes of high strain rate loading. The experimental results indicate that the behavior of stress-induced current generated by longitudinally compressed films is more complicated than under transverse stress. This complex behavior may be caused by the short stress wave transit distance through the film, that is, comparable with the thickness of the stress wave front. The important result is that the specific electric charge released by PZT 95/5 films under stress, 104 μC/cm3, is more than an order of magnitude higher than that released by bulk PZT 95/5 ceramic specimens. It was experimentally demonstrated that transversely compressed miniature PZT 95/5 film specimens with volume less than 1 cm3 are capable of producing pulses of hundreds of amperes of current. This study promises FE film applications in ultrahigh-power systems.Ferroelectric (FE) films are widely used in electronic devices and low-power FE transducers. There is significant interest in expanding the usage of FE films to ultrahigh-power systems. The results are reported herein on experimental investigations of stress-induced depolarization of single-layer PbZr0.95Ti0.05O3 doped 2% Nb (PZT 95/5) poled FE films subjected to uniaxial adiabatic compression perpendicular and antiparallel to the direction of polarization. It was found that at a stress of 2.4 GPa, the 32-μm-thick films underwent a pressure induced transition to a nonpolar antiferroelectric phase and became completely depolarized in both modes of high strain rate loading. The experimental results indicate that the behavior of stress-induced current generated by longitudinally compressed films is more complicated than under transverse stress. This complex behavior may be caused by the short stress wave transit distance through the film, that is, comparable with the thickness of the stress wave front. The i...

The problem is inductive concept formation in the case of the processing of incomplete, inaccurate, and inconsistent information stored in real data sets. In order to generalize information from real databases it is proposed to use production models and decision trees. Models of noise are presented and the effect of noise on the operation of the proposed generalization algorithms is examined. The results of the program modeling are given.

Two methods were applied to compute the 2-level atom driven by a polychromatic field. The first method is a direct numerical solution of the density matrix equations and the second one is a harmonic basis decomposition resulting in an infinite linear algebraic equation system. It is showed the resonance frequency mostly follows the transition frequency. But some frequency pulling or pushing is observed depending on the transition frequency inside the field component bounds or not.

One of the basic problems arising under processing temporal dependencies is the analysis of time series. The various approaches to processing of temporal data are considered. The problem of anomaly detection among sets of time series is setting up. The algorithm TS-ADEEP-Multi for anomaly detection in time series sets for the case when the learning set contains examples of several classes is proposed. The method for improving the accuracy of anomaly detection, due to “compression” of these time series is used. Modelling results for anomaly detection in time series are produced.

A numerical solution for the polarization of two-level atoms that interact with a polyharmonic field was obtained. An analytical solution for the particular case of a symmetrical position of carrier frequency relative to transition frequency is possible. The results showed that nonlinear effects occur in a polarization spectrum at the small amplitudes of comb components and small frequency distances between them. Consequently, it is necessary to take into account nonlinear effects in comb spectroscopy.

Several approaches to generating temporal decision trees for diagnostic purposes and algorithms for generating decision trees are considered. The process of diagnostics based on information about possible faults is modeled. A multiagent approach is used for diagnostics in dynamics.

Systematic studies of the depolarization of Pb(Zr0.52 Ti0.48)O3 (PZT 52/48) poled piezoelectric ceramic samples were performed using thermal heating and explosive longitudinal-shock compression. The electric charge density that is released due to thermal heating at a rate of 0.9 K/min was consistent for all sample sizes (Q = 27.8 μC/cm2). The charge density that is released due to shock compression was practically equal to that released due to thermal heating. The PZT 52/48 samples were completely depolarized by longitudinal shock waves at shock front pressures of PSW = 1.5 ±0.2 GPa. The electric charge that the samples release can be transformed into pulsed power. Miniature explosive-driven ferroelectric generators containing PZT 52/48 ceramic elements with a volume of 0.35-3.5 cm3 are capable of converting the depolarization charge into pulses of high voltage with amplitudes of up to 22 kV and high power with a peak power of up to 0.35 MW within a time interval of 0.3-1.5 μs .

The quantum method of variable separation is applied to the spectral problem of the isotropic Heisenberg model. The Baxter difference equation is resolved by means of a special quasiclassical asymptotic expansion. States are identified by multiplicities of limiting values of the Bethe parameters. The string limit of the four-particle sector is investigated. String solutions are singled out and classified. It is shown that only a minor fraction of solutions demonstrate string behavior.

Ability of ferroelectric materials to generate high voltage under shock compression is fundamental physical effect that makes possible to create miniature autonomous explosive-driven pulsed power systems. As the result of shock induced depolarization, an electric charge is released at the electrodes of the ferroelectric element and a high electric potential and a high electric field appears across the element. We performed systematic studies of electric breakdown field, E b (d), as function of ferroelectric element thickness, d, for Pb(Zr 0.95 Ti 0.05 )O 3 (PZT 95/5) and Pb(Zr 0.52 Ti 0.48 )O 3 (PZT 52/48) ceramics compressed by transverse shock waves (shock front propagates across the polarization vector) and established a relationship between these two values: E b (d) = const·d−0.25. This law was found to be true in wide range of voltages from 4 to 150 kV and ferroelectric element thicknesses varied from 4.7 to 51 mm. This result makes it possible to predict the ferroelectric generator (FEG) output voltage and it forms the basis for design of ultrahigh voltage FEG systems.

Poled ferroelectrics are key components of autonomous explosive-driven pulsed power systems. Shock depolarization of ferroelectrics is a basic physical effect providing prime electrical power to autonomous systems. In this paper we report results of experimental studies of shock-induced and thermal-induced depolarization, and X-Ray diffraction of lead zirconate titanate ferroelectrics of two different compositions, PbZr 0.52 Ti 0.48 O 3 (PZT 52/48) and PbZr 0.95 Ti 0.05 O 3 (PZT 95/5). Specimens were shock loaded perpendicular to the polarization vector. The experimental results indicate that the shock induced depolarization mechanisms are different for these two compositions. Thus, the shock-induced charge released by PZT 52/48 is less than half of its remnant polarization. PZT 52/48 is transformed to a state with lower polarization, while PZT 95/5 under the same loading conditions undergoes a phase transition to a non-polar antiferroelectric phase and completely depolarized as a result of this phase transition.

The operating principles of the telescope-robot system MASTER (Mobile Astronomical System of Telescopes-Robots, http://observ.pereplet.ru), designed to search for fast transient phenomena in the optical range, are described. The robot-telescope includes the following: a Richter-Slefogt telescope with D=355 mm, F/D=2.4, a Richter-Slefogt telescope with D=200 mm, F/D=2.4, a Flugge telescope with D=280 mm, F/D=2.5, a TV camera with a field of 20x40 degrees, and three CCD cameras. A German mount with a slew rate of 8 deg/s is used. MASTER obtains images down to 19m in a field of 6 square degrees in a 1.5 minute exposure. We present some observations of the optical afterglow of cosmic gamma-ray bursts. MASTER was the first system in Europe to record optical emission from GRB030329.