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Coefficients of the expansion of electrical energy in the ferroelectric phase near phase transition temperature are determined from an even power series according to polarization by studying the dynamics of repolarization in A2BX4 group crystals according to the Landau–Ginzburg–Devonshire theory. Experimental results are compared to the theoretical concepts of the Landau–Ginzburg–Devonshire theory describing dependences in static. [ABSTRACT FROM AUTHOR]

Deformation behavior of ZrO2−Y2O3 ceramics under conditions of diametral compression has been studied by method of digital image correlation. Spatiotemporal patterns of strain localization along the axis of a deformed sample (εxx(x)) and across this axis (εyy(y)) were obtained. It is established that the εxx and εyy deformations accumulated during the diametral compression test are inhomogeneously distributed over the sample. This is manifested by variation of the microstructure characteristics such as the size of the coherently diffracting domains of a tetragonal phase and microstresses and leads to the tetragonal–monoclinic phase transformation. This pattern of strain localization is correlated with the observed inhomogeneity of microstresses arising in the material volume. [ABSTRACT FROM AUTHOR]

The values of the energy expansion coefficients in a series of polarization even powers on the base of study of the Rb2ZnCl4 crystal repolarization dynamics according to the theory of Landau-Devonshire are determined. The comparison of experimental results in the dynamics with theoretical concepts of the Landau-Devonshire theory describing dependencies in static is obtained. [ABSTRACT FROM AUTHOR]

Values of the expansion coefficients of electrical energy Wc in a series with respect to even powers of polarization Pc are determined using the Landau-Devonshire theory by studying the repolarization dynamics of an Rb2ZnCl4 crystal. Experimental results obtained from the dynamics are compared to theoretical representations of the Landau-Devonshire theory that describe the dependences of Wc(Pc) in statics. [ABSTRACT FROM AUTHOR]

A staging analysis was carried out for deformation curves and the evolution of local deformation fields in defective and defect-free specimens of welded joints of grade VSt3sp steel that were made using manual arc and manual pulsed arc welding. Stages of elasticity, microplasticity, nucleation and motion of Chernov-Luder's bands, and parabolic deformation strengthening were considered. The parameters of acoustic-emission signals during tension of specimens with a welded seam were analyzed. [ABSTRACT FROM AUTHOR]

Considered is the possibility of using the MODIS spectroradiometer database for the determination of the level of atmospheric in stability for thunderstorm forecasting over West Siberia. Three indices computed from the data of the satellite and radiosondes are compared as instability characteristics: LIFT, TOTL, and KIND. It is revealed that two indices correlate well, namely, LIFT and TOTL. It is demonstrated that the results of MODIS sounding enable identifying the spatial position of deep convective cells and specifying the thunderstorm forecast. [ABSTRACT FROM AUTHOR]

Harmonic analysis of repolarization in A BX-group crystals in the ferroelectric phase near phase-transition temperature T is used to separate the contributions to the harmonic-component amplitudes in the output signal of a Sawyer-Tower circuit from charging the reference capacitor with capacitive and conductive current through such a crystal. Harmonic analysis of dielectric hysteresis loops obtained by placing a specimen in an electric field with harmonically changing strength reveals general regularities in the evolution of the domain walls of A BX-group crystals. It is established that the domain structure affects the nonlinear polarization properties of our specimens. The dependence of the potential relief of ferroelectric ion motion in a harmonically changing electric field is plotted on the basis of the experimental results. [ABSTRACT FROM AUTHOR]

Harmonic analysis of the dielectric hysteresis loops near the phase transition temperatureTcobtained under application of harmonic electric field with intensity above the intensity of the coercive field is presented. It is shown that, the direction of polarization reverses when the field value satisfies conditionEc=Emsin ϕ0. The increase inEcwhile approachingTcis shown to be the reason for the anomalous temperature independent behavior ofEcoer. [ABSTRACT FROM AUTHOR]