A numerical algorithm for fast search of the initial phase shift on phase images with arbitrary stepwise shifts is proposed. The algorithm is based on finding the minimum deviation of the model function from the measurement results. The interval search method used directly in the proposed approach made it possible to significantly reduce the computational complexity of the algorithm. The paper presents the results of measuring a three-dimensional profile by phase triangulation methods using the proposed algorithm. The obtained results confirm the efficiency and high practical value of the proposed phase image decoding algorithm.

Измерение характеристик калибровочной платформы КЛАД-11 Институт теплофизики им.С. С. Кутателадзе СО РАН, г.Новосибирск, Российская Федерация

A numerical algorithm for fast search of the initial phase shift on phase images with arbitrary stepwise shifts is proposed. The algorithm is based on finding the minimum deviation of the model function from the measurement results. The interval search method used directly in the proposed approach made it possible to significantly reduce the computational complexity of the algorithm. The paper presents the results of measuring a three-dimensional profile by phase triangulation methods using the proposed algorithm. The obtained results confirm the efficiency and high practical value of the proposed phase image decoding algorithm.

The mechanism of anode-initiated breakdown in liquid organic dielectrics with long molecular chains is proposed on the basis of the experimental data on high velocities of the breakdown channel propagation in organosilicon and organofluorine liquids (~10^{7} cm/s), which is comparable to that obtained earlier in crystals in the same conditions. The high velocities of the anode-initiated breakdown channel are satisfactory explained within the model of the cascade Auger transitions, developed for the crystalline materials. According to this model, velocity of the breakdown channel propagation is proportional to the electrical field strength. The time delay in breakdown channel formation relative to the voltage pulse front does not exceed ~5·10^{-10} s within the margin of error.

The mechanism of anode-initiated breakdown in liquid organic dielectrics with long molecular chains is proposed on the basis of the experimental data on high velocities of the breakdown channel propagation in organosilicon and organofluorine liquids (~107 cm/s), which are comparable to that obtained earlier in crystals in the same conditions. The high velocities of the anode-initiated breakdown channel are satisfactory explained within the model of the cascade Auger transitions, developed for the crystalline materials. According to this model, velocity of the breakdown channel propagation is proportional to the electrical field strength. The time delay in breakdown channel formation relative to the voltage pulse rise time does not exceed ~5·10-10 s within the margin of error Keywords: electrical breakdown in liquid, nanosecond breakdown, breakdown mechanism.

This work aims at creating a universal software package for the development and testing of triangulation methods using structured lighting for measuring the three-dimensional geometry of objects in difficult ambient lighting conditions. As a result, a software package meeting the stated requirements is created. Lighting is based on the Fong model. A method for preloading objects is implemented to optimize the operation of the software package. An accelerated method for creating shadow maps is proposed and implemented. The developed software package is shown to successfully perform all required functions.

This work deals with the development of the software for the system of synchronous control of the optical system of visual control over dynamic objects and the creation of algorithms for resolving conflicts of simultaneous illumination by several light sources. The software for the microcontroller for the system hardware is created as part of the work. An application for remote configuration of the device is developed. Algorithms for time-separation of signals for switching on lighting are implemented.

Current work is devoted to the development of a device for monitoring the dynamic shape of a power unit. The work is based on the FMCW method. The light source uses a low-coherence semiconductor laser diode. Signal processing is performed on an adapted Doppler processor. The paper describes the methods, hardware and signal processing algorithms.

Secondary ion mass spectroscopy, Fourier transformed infrared spectroscopy, ellipsometry, reflection high energy diffraction and transmission electron microscopy are used to gain inside into the effect of Ge on the formation of ultrathin 3C‐SiC layers on Si(111) substrates. Accompanying the experimental investigations with simulations it is found that the ultrathin single crystalline 3C‐SiC layer is formed on top of a gradient Si1–x–yGexCy buffer layer due to a complex alloying and alloy decomposition processes promoted by carbon and germanium interdiffusion and SiC nucleation. This approach allows tuning residual stress at very early growth stages as well as the interface properties of the 3C‐SiC/Si heterostructure. Useful yields of secondary ions of Ge in Si matrix and Si dimer are estimated.

We studied the onset of induced optical absorption in mono- and polycrystalline Y3Al5O12:Nd3+ samples upon irradiation by a nanosecond electron beam with electron energy of 250 keV and current density of 25A/cm2. We show that in such crystalline samples, the fast electrons produce induced absorption between 1 and 4.2 eV expressed as a superposition of six adjacent elementary lines. We found that the induced absorption is due to electron transitions from the valence band to a local level around an O−–hole center, while the initial-phase (10−7−10−4s) relaxation of the induced absorption is determined by quadratic recombination of conduction-band electrons with the O−–hole centers. The higher density of structural defects in the polycrystalline sample than the monocrystalline sample increases the band-electron lifetime against capture by O− centers.

The flow in a Ranque tube with a square cross-section channel has been studied using the hydraulic concept of strongly swirling flow with a circulation zone. Based on experimental data, it has been found that for flow in a vortex tube, the hydraulic condition of flow crisis is satisfied: the longitudinal velocity becomes equal to the velocity of propagation of centrifugal waves at the boundary between the vortex and the circulation zone. It has been shown that the temperature variation along the flow occurs mainly in the region of the working channel in which the ratio of the longitudinal velocity at the vortex boundary to the propagation velocity of centrifugal waves fluctuates about unity. The existence of a previously unknown energy separation mechanism due to the presence of hydraulic jumps in the development of internal waves in a Ranque tube was assumed.

In the framework of the proposed theoretical model crossover and scaling equations of state for near-critical multicomponent hydrocarbon mixture were obtained. To elaborate the equations of state the experimental data measured on the serial setup intended for comprehensive pressure-volume-temperature (PVT) research of a natural gas-condensate systems were used. The information concerning the mixture composition was not involved. The obtained equations describe the experimental data with the accuracy not exceeding the measurement inaccuracy. It has been shown that in extended range of thermodynamic parameters the crossover equation of state looks more reliable. The crossover model describes the transition from the scaling behavior to the mean-field behavior, which is typical for cubic and multiparameter equations of state. The model was extended for calculation of the volume fractions of gas and liquid phases needed for practical applications. In addition, the expression for isothermal compressibility has been derived. It was demonstrated that the isothermal compressibility has a cusp-like anomaly in the close vicinity of the critical point.

This paper is referred to the development of a method for measuring the geometry of rotating parts of power stations based on the effect of self-mixing of laser radiation. The method is based on spectral analysis of the photodiode signal using narrowband and threshold filtering in the frequency domain. A relative measurement error of 0.5% was achieved when measuring the surface of the rotating rotor modules of the power plant under laboratory conditions.

The implementation of the method expanding the dynamic range of photodetectors in hydrodynamic experiments based on the use of active optical shutters is presented. A method that allows using modern CMOS cameras as optical radiation receivers and laser emitters as illuminators has been developed. The attenuation coefficients of linearly polarized light on the photodetector has been measured. An experimental estimate of the expansion of the dynamic range in terms of the intensity of the received radiation in the presence of background highlights has been made.

Уравнение состояния околокритической углеводородной смесиМ.Ю.Беляков 1* , В

Abstract The fundamental scientific problem of this kind arises in mechanics, chemistry and catalysis in the intensification of mass transfer. The turbulent mass transfer characteristics were analyzed experimentally in a controlled rotational-divergent flow. The laser Doppler anemometry was used for turbulent mass transfer diagnostic. The verification of numerical calculations by computational hydrodynamics has been carried out according to the results of experimental studies. Calculation of turbulent kinematic is build on solving of a system of continuity and the Navier-Stokes equations. The fluid is incompressible and isothermal. For averaged equations closure, semi-empirical turbulence models were used: the k-ε model of turbulence and the Reynolds stresses transfer model. The calculation has showed the existanceof a near-wall jet after a rotating device and the generation of reverse flow zones. Comparison with experimental data has shown that all models of turbulence adequately model the rotational-divergent flow only until the formation of flow gaps and the formation of reverse flow zones. The discrepancy with the experiment occurs while controlling the flow to equalize the velocity profiles.

An approach for the reconstruction of the composition profiles of heterostructures with chemically modified interfaces is presented. It is based on the comprehensive simulation of the heterostructure growth stages and the compositional changes occurring at the depth profiling stage during sputtering by secondary ion mass spectrometry. Combining simulation of the growth and the concentration measurement process allows the calculation of the real concentration depth profiles of the heterostructure components. Within the framework of the proposed approach, the composition of the SiC:Ge/Ge/Si:Ge/Si heterostructure is analyzed and the real depth profiles were calculated.

A spectral method of detection of laser Doppler velocimeter signals in turbulent flows is proposed. The method is based on estimating the signal/noise ratio adapted to the width of the power spectral density of the signal and comparing its value with the recognition threshold. Numerical simulations show that the error of the signal/noise ratio estimates is 1% for different velocities of the turbulent flow. Physical experiments aimed at measuring turbulent aerodynamic processes show that the proposed method offers a possibility of eliminating the errors of calculating the mean value and the velocity deviation equal to 15 and 78% by means of eliminating the signals with low signal/noise ratios from the processing system. Application of the proposed method also ensures lower nonuniformity of the signal/noise ratio estimates than that ensured by the famous method developed by Tropea for a wide range of turbulent velocities.

AbstractThe process of changing the average deflection of the copper surface over cobalt subsurface clusters and the fraction of the surface occupied by the ensemble of clusters. Their time dependences were calculated, in good agreement with the experiment.