Improvement of accuracy of interferometric measurement of wedge angle of plates

A method is proposed for improving the accuracy of measuring the wedge angle of transparent plates using a lateral-shear holographic interferometer. Consecutive processing of a pair of interferograms with doubled number of interference fringes leads to reduction of the observational error by a factor of two compared to traditional interferometric methods. Data on the experimental validation of the method are presented.     

Distribution of zeros of the partition function of the lattice gases of fisher and of temperley

The distributions of zeros of the partition function of lattice gas models of Fisher (at some temperature) and of Temperley are obtained. The former is a closed loop crossing the real axis and the latter is a part of the negative real axis.     

Stability of families of probability distributions under reduction of the number of degrees of freedom

We consider two classes of probability distributions for configurations of the ideal gas. They depend only on kinetic energy and they remain of the same form when degrees of freedom are integrated out. The relation with equilibrium distributions of Tsallis’ thermostatistics is discussed.     

Calculation of energy characteristics of adsorption of metals

Within the framework of the electron density functional, a technique is developed for calculation of the adsorption energy and variation in the electron work function for metal substrates due to metal atom adsorption. The corrections to the local density approximation, which are associated with non-uniformity of the electron density in the subsurface region and discontinuous ion charge distribution over the crystal lattice sites, are included into consideration. It is shown that adsorption of alkali metal atoms results in lower electron work function, while that of transition metals (cobalt, iron, and chromium) might both decrease and increase the electron work function. Formation of a variety of adsorption structures from metal atoms depending on the temperature is discussed. __________ Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 14–19, July, 2007.     

Evidence of electrolysis of water of crystallisation

Electrolysis of interlayer water of crystallisation has been established by a direct d.c. electrolysis experiment on molybdic acid. The dihydrate MoO₃middot; 2H₂O gets converted into its monohydrate. This is confirmed by IR and Laser Raman Spectra. The increase in a.c. electrical conductivity with increasing d.c. bias, a.c. signal level and ambient humidity also supports the above viewpoint.     

Amenability of discrete subgroups of the group of diffeomorphisms of the circle

The amenability of several discrete subgroups of the group of diffeomorphisms of the circle is proved.     

BSA-SDS-Ag聚合物纳米微粒的制备及其水凝胶性质的研究（Ⅰ）

报道了BSA－SDS－Ag聚合物纳米微粒的制备及水凝胶的性质,用X射线衍射（XRD）、透射电镜（TEM）、傅里叶变换红外（FT－IR）光谱考察了这种聚合物微粒的结构,微粒粒径32nm左右,用UV／Vis光谱及SEM考察了冰凝胶的性,表明Ag^ 离子先与BSA产生化学键合,再学原了Ag粒,进行聚合成网状结构的聚合物。     

Equations of the general theory of plasticity of crystals

Equations are formulated for the elastic-plastic strains of crystals experiencing an inelastic flow of crystallographic shears. Local invariant relationships, including creep and active plasticity, are constructed. To take account of the microstresses a method of effective field is used. All the relationships are derived in a tensor formulation with reliance on representations about the physical regularities of the development of deformation. The derived system of equations describes a broad class of problems of the physics and mechanics of plasticity of an almost unbounded degree of complexity.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 73–78, June, 1988.     

X-ray interferometric method of determination of parameters of permolecular structure of polymers

A new method for determining the density of polymer materials based on determination of the path-length differences in moiré patterns is proposed. The method is characterized by simplicity and accuracy of results. The densities of polychloropren and polystirol have been determined with high accuracy. Knowledge of the dependence of the polymer density on the stretching degree enables one to reveal the dynamics of changes in the permolecular structure at deformation of polymers.     

Role of interactions of triplets of atoms in the formation of elastic properties of cubic crystals

It is widely known that the interaction of triplets of particles (which are not reducible to the sum of pair interactions) play an important role in formation the nonlinear and anisotropic properties of crystals. The aim of this work is to establish a general form of the dependence of these properties on interactions of triplets of atoms that is dependent only on the structure of the crystals. To separate the interactions of triplets of atoms from those of quadruples, we assume that the energy of triplets of interacting atoms depends only on the characteristics of a triangle whose vertices are the centers of gravity of interacting atoms. In this model, the internal energy must therefore be invariant upon rearrangement of the numbers of interacting atoms and any rotation of the triangle in isotropic space, P(3) × O(3). To specify the form of energy dependence on characteristics of selected triangles, we constructed an integral rational basis of invariants in dependence on the components of the vectors connecting the vertices of each triangle. Using the example of a simple dependence of the energy on basic invariants, we show how to move from the assumed energy dependence on invariants to the dependence of energy on lattice sums.     

Application of new methods of interpretation of meteor observations at the Institute of Astrophysics of Tajikistan

New methods of interpretation of meteor observations were developed and published in [1?C9]. The interpretation of ground-based observations of meteors and bolides available today in the scientific literature all over the world suffers from serious contradictions. Observers use the so-called photometric approach for determination of extra-atmospheric masses of meteoric bodies. This approach is based on the formula proposed in 1933 [10] and very simple ideas of how to describe the interaction between the atmospheric air and the surface of a meteoric body. These ideas are provisionally suitable to describe the flow around a body in a free molecular regime. Subsequently, the photometric approach was applied to all the meteor events including bolides. The main effort aimed to elaborate the approach included a choice of new formulas for the radiative efficiency.     

Measurement of degree of polarization of fluorescence of pure anthracene crystalline film

The polarization ratio (I _b/I_a) of fluorescence of a monocrystalline film of pure anthracene is measured correcting for all probable errors. Comparison with decay-time data brings out that deviation from the value obtained from absorption measurements is due to a loss of intensity in the a-polarized fluorescence as compared to what is expected from absorption data. This is interpreted as an evidence that anthracene crystal fluorescence is emitted from regions of local lattice imperfections. It is confirmed that the first electronic transition takes place along the short axis of the anthracene molecule.     

Analysis of Calculation of the Critical Temperature of Metals

General considerations on the form of the real equation of state make it possible to assume that the ratio of the melting temperature to the critical temperature is constant for each group of elements. This assumption is verified for two groups of elements, the critical temperatures of which are measured. It is shown that, for certain groups of elements, the critical temperatures of which are calculated instead of being measured, this assumption is also valid. The critical temperatures of certain elements are calculated or refined.     

Symmetry of Lagrangians of nonholonomic systems of non-Chetaev’s type

This paper studies the symmetry of Lagrangians of nonholonomic systems of non-Chetaev's type. First, the definition and the criterion of the symmetry of the system are given. Secondly, it obtains the condition under which there exists a conserved quantity and the form of the conserved quantity. Finally, an example is shown to illustrate the application of the result.     

Kinetics of Macrolocalization Patterns of Plastic Flow of Metals

The features of the macroscopic inhomogeneity of plastic deformation in the form of autowaves with a pulsating amplitude are analyzed, and data on the localization of sources of acoustic emission at different stages of plastic flow in the stretching of fcc mono- and polycrystals are presented. The relationship between the local components of the plastic distortion tensor in the strain localization zone is traced. The role of acoustic phenomena accompanying the localization of plastic strain in the development of the process of plastic deformation is considered.     

Optical investigation of dynamics of phenomena of laser-based lithotripsy

Using time-resolved high-speed shadowgraphy, the dynamics of phenomena due to laser-based lithotripsy is studied. Collapsing mechanism of bubble formed therein is investigated. In order to study the mechanism, the optically implemented mathematical morphology is applied. The study of the shape of the plasma and the collapsing region of the bubble of fluid that we are studying can possibly be used for practical application for laser-based lithotripsy.     

Formation of One-Dimensional Distributions of Values of Correlators of Network Traffic Aggregates

Russian Physics Journal - A mathematical model of the flow of aggregated load characteristics of network traffic data packets in the form of a set of analytical signals is proposed. The real parts...     

Features of Ion-Beam Polishing of the Surface of Sapphire

The effect of an argon ion beam on the surface of sapphire is studied at different technological parameters: the ion energy, and the angle α between the sapphire surface and the ion-beam axis. The roughness of the sapphire surface is analyzed before and after ion polishing. The optimum ion-beam parameters are determined, at which the surface roughness after polishing decreases to 0.8 nm. At angles α = 20°–30°, the relief of the sapphire surface is found to become wavy. The study of the impact of the ion energy on the roughness of the sapphire surface in the 400–1200-eV range reveals that an increase in the energy of the ion beam to 1200 eV is accompanied with a decrease by 8.8 times in the roughness which falls below the level of 3 nm.     

Methods of analysis of the structure of materials on the basis of orthogonal transformations of microscopic images

Some methods for studying the structure of materials on the basis of microscopic images are considered. The images are analyzed using various orthogonal transformations: Fourier, cosine, Hartley, and continuous wavelet transformations.     

Some aspects of the kinetics of formation of triatomic halogenides of rare gases

The formation of triatomic excimer molecules Rg₂X and Rg’RgX by VUV excitation of mixtures of halogens with rare gases is discussed. The remarkable simplicity of the electronic structure and kinetics of these molecules offers interesting possibilities for studying the role of different collisional processes in recombination in the high-and low-pressure limits.