Charge injection in study of ferroelectric film properties

A model of a capacitor with a two-layer insulator has been considered. The current density exponentially depends on voltage in one of layers and is negligible in the other layer. The dependences of current on the time of voltage action and the charge-voltage characteristics of the two-layer capacitor have been calculated. The results obtained can be used to detect and study charge injection during polarization of ferroelectrics.     

Development of dual-polarization reflectometry facility for Uragan-2M torsatron

The dual-polarization reflectometry facility developed for torsatron U-2M uses the extraordinary wave in addition to the ordinary wave. This is possible because the magnetic field of U-2M is produced by external conductors, is independent of plasma parameters, and is therefore a known quantity. The plasma probing is carried out simultaneously in a large number of pairs of close frequencies, which makes it possible to use superheterodyne circuits and, hence, considerably improves noise protection of the system and accuracy of measurement of phase shifts. The use of the extraordinary wave considerably broadens the range of the densities being measured in the given frequency band of generators. To reconstruct the density profile of the plasma from the frequency dependence of the phase shift of probing waves, original iterative algorithms have been developed for solving integral equations that are stable to experimental errors.     

Joint deformation of a circular inclusion and a matrix

An elastic infinite plane containing a circular inclusion with given jumps of tractions and displacements along the interface and nonzero conditions at infinity is considered. Explicit expressions are derived for the Goursat-Kolosov complex potentials of this problem. The solution constructed can be used to examine various circular interfacial defects, including interfacial cracks and rigid parts of the interface. The problem under consideration is fundamental for the superposition method, which solves many problems in which a circular region is an element of a polyphase elastic medium. In such cases, the well-posedness of the problem, which depends on the interrelation between the jumps of tractions and displacements, follows from the very superposition method. The application techniques of this method are demonstrated for singular problems on the action of a point force and an edge dislocation located inside an inclusion or in the matrix. Computational results for the tractions arising at the interface under the action of a point force concentrated in the inclusion are given.     

A monopole mass filter with a hyperbolic V-shaped electrode

In this article we compare the classical monopole mass filter of von Zahn and the monopole mass filter with a hyperbolic V-shaped electrode. The experimental results and those of computer simulation for both mass spectrometers are presented. We show that the replacement of a conventional 90 degrees V-shaped electrode by an electrode with a hyperbolic profile substantially improves the peak shape of any given mass, and increases the mass resolution by a factor of 3-4 and the abundance sensitivity by a factor of 100. The potential of high analytical performance combined with electroforming techniques for electrode manufacture indicate future practical uses of such instruments. Copyright 1999 John Wiley & Sons, Ltd.     

Dependence of the properties of polycaproamide obtained in the presence of benzhydrazide on the symmetry type of the unit cell

The structure and properties of polycaproamide obtained in the presence of benzhydrazide have been studied. They are shown to depend on the duration of application of pressure in the mold. Under tensile deformation a transition from hexagonal to monoclinic polycaproamide takes place in the neck.Lugansk Machine-Building Institute. Institute of the Chemistry of High-Molecular Compounds, As UkrSSR, Kiev. Translated from Mekhanika Polimerov, Vol. 4, No. 6, pp. 1125–1127, November–December, 1968.     

Ultraviolet-light generation in nitrogen-doped silica fiber

Nonlinear light transformations were observed in a nitrogen-doped silica fiber pumped with a Nd:YAG laser (lambda=1.06 microm) . Light generation in the spectral range 355-430nm was obtained with an efficiency of up to 2x10(-4) . The UV light was found to be the result of third-harmonic generation, stimulated Raman scattering of the third harmonic, and third-harmonic generation from the Stokes components of the pump light. Lasing based on the color centers of nitrogen-doped silica was observed in the range 380-430nm.     

Quantum-chemical calculations of thermodynamic parameters of the synthesis of tris(hydroxymethyl)phosphine

Thermodynamic characteristics of the process of tris(hydroxymethyl)phosphine synthesis are calculated by the Hartree-Fock-Roothaan method in the basises LANL2DZ and 6–31G. From the calculated data degrees of accumulation are found of the target product that correlate with experimental data. This fact can be taken into account at the choice of conditions for producing tris(hydroxymethyl)phosphine.     

Synthesis of some polyureas based on diamino derivatives of bis-1, 3, 4-oxadiazole

Ortho-, meta, and para-nitrobenzoyl derivatives of the dihydrazides of succinic, glutaric, adipic, and azelaic acids are prepared, from which are obtained nitro and amlno derivatives of bis-1,3,4- diazole. Various conditions for synthesizing these compounds are investigated. A series of polyureas is obtained by reacting diamino derivatives of bis-1,3,4-oxadiaole with diisocyanates, and some of their properties are investigated.