Contents Vol. 21 N1 >>

Principles of development of modern ion sources with surface thermoionization, for isotopic analysis in atomic industry have been discussed. It has been shown that only two configurations of multi-ribbon ion sources are important for modern commercial instruments: two and three-ribbon ones. Atomic physical-chemical processes on the ionization ribbon have been analyzed, and physical limitations for the sample utilization coefficient have been pointed out. It was concluded that an essential increase in accuracy of isotopic measurements by surface thermoionization can be achieved only through simultaneous atomic consideration of all ion processes in the instrument including its burn, transportation, mass-analysis, and registration.

¹Institute for Analytical Instrumentation RAS, Saint-Petersburg
²A.F. Ioffe Physical Technical Institute RAS, Saint-Petersburg

The review contains a brief description of polarization-optical methods of investigations of resonant interfaces, which are developing in the Institute for Analytical Instrumentation RAS. The selective reflection spectra under conditions close to the resonant total internal reflection and resonant Brewster reflection are presented. Comparison of selective reflection features of laser radiation with various orientations of a polarization plane is carried out. The possibilities for observation in conditions under study of the new nonlinear phenomena are discussed. Spectra of fluctuations of resonant-reflected light are analyzed.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

Research of dynamic force lithography (DFL) regime on thin (20 nm) Au film on the polycarbonate substrate has been conducted. One-dimensional model in elastic approximation has been suggested and calculations demonstrating existence of the DFL optimal regime have been carried out. Experimental results which have been reached in the NanoEducator scanning probe microscope with piezoresonance detector of force interaction and electrochemically edged W probe are presented. It is experimentally demonstrated that the W probe cuts the metallic film throughout and that the width of the cut is approximately 100nm and is determined by the radius of the probe. It is shown that the DFL regime in the system "metallic film—polymer" ensures creation of the 2D-nanostructures of various configuration. This regime is an easy way to create elements of nanoelectronics, nanophotonics and nanosensorics.

¹Saint-Petersburg State University of Information Technologies, Mechanics and Optics
²Institute for Analytical Instrumentation RAS, Saint-Petersburg

The practical analysis of quantitative measurement errors was realized by RT-PCR at various methods of threshold cycle calculation. The threshold cycle values were obtained on analyzers of nucleic acids АНК-32 and АНК-64, developed in St.-Petersburg Institute for Analytical Instrumentation RAS. Effects of various errors in threshold cycle measurements are discussed. Recommendations on optimization of quantitative measurements are given

Institute for Analytical Instrumentation RAS, Saint-Petersburg

Methods of carbon nanoparticles orientations in polymer matrix by various electromagnetic fields to produce nanocomposites with desirable properties of individual nanotubes as bulk properties are described in the article. Analytical expressions are obtained for the purposeful choice of a method taking into account physical and chemical properties of particles and field strengths.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

In the present paper, we propose a simple ellipsometric technique for measuring the wavelength of monochromatic radiation up to 10–3 nm. The method is based on measuring the phase shift between two orthogonal components of the electric vector in the light transmitted by an anisotropic plane-parallel plate versus wave-length. The technique was used to measure the temperature-induced shift of the emission spectrum of a light-emitting diode. The data obtained were verified by comparing them with spectrophotometric. The method can be easily implemented on commercially available ellipsometers and mini-ellipsometers.

Institute of Semiconductor Physics RAS, Novosibirsk

The scintillation properties of face screens of standard PMTs of FEU-167 type (boron-silicate glass) and FEU-167-1 type (potassium-containing glass) are studied. Three modifications of the developed test stand permitted to use both cosmic rays and 60Co radioactive source. Scintillation efficiency of these glasses is found to be of about 10–2 of a polystyrene scintillator (2 % terphenyl + 0.06 % POPOP) efficiency and does not depend on the potassium presence. It is suggested to produce PM tubes with the face screens made of scintillation-active (e.g., Ce-doped) glasses which can in certain cases make unnecessary use of separate outer scintillator.

Ioffe Physical-Technical Institute of RAS, Saint-Petersburg

With the purpose of diminution of thermal noises and heightening resolving ability of photomultiplying tubes the compact nitrogen cryostat for effective cooling of a photomultiplying tubes is made. The work is carried out within the framework of the Program of scientific instrument making of NAS of Ukraine, grant П2/09-40. PACS: 07.20Mc.

Institute of Physics of NAS of Ukraine, Kiev, Ukraine

Methods of noise squelch were systematized at processing of images on the basis of wavelet analysis. Approbation of the developed methods of processing images was performed on magnetic resonance tomograph General Electric Signa Infinity in SPb CDH "Pokrovsk City Hospital".

Saint-Petersburg State University of Information Technologies, Mechanics and Optics

The influence of the electron beams input angles on the form of the cylindrical energy analyzer apparatus function is investigated. It is shown that a choice of electron beams input angles in the energy analyzer it is possible to reduce a peaks trains considerably.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

For PCR realization it is necessary to ensured cyclic temperature change in correspondence with particular-linear law from 55 to 95 ºC within the predetermine time. This paper deals with estimation of heat-transfer dynamic in the object (reaction camera) with size 0.7–1.0 mm based on the calculated mathematic model. Temperature regulation is carried out by heaters, which are placed on the camera walls. Calculation results allow to estimate heat-transfer values for different schemes of temperature regulation. Basing on this information it is possible to minimize cycle-time and whole time of polymerase chain reaction, including molecular colony method.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

The problem of choice invariance of a tensor surface integration of impulse stream density in calculations of radiation pressure forces (RPS) in the field of monochromatic sound wave is discussed. Cases of homogeneous and heterogeneous ideal and viscous liquids are regarded separately. It is confirmed that in the case of homogeneous ideal or viscous liquid such invariance exists, the fact earlier described by some authors. In case of smooth or intermittent heterogeneity in liquid such invariance seems to be unjust in spite of the fact that formally the averaged divergence of tensor of impulse stream density in the heterogeneity may identically equal to zero. The cause may be the appearance of the field dispersed on this heterogeneity.

Institute for Analytical Instrumentation RAS, Saint-Petersburg

The work analyses features of the inverse problem of ellipsometry arising in determination of the whole set of parameters of a reflecting system with superthin superficial film. The way for the solution of the inverse problem is developed: the approach to the solution, representing consecutive passage of two stages is stated. Criterion for the choice of optimum values of the corresponding parameters is formulated for each stage. Optimum values of substrate parameters and value of the film parameters corresponding to a point of functional absolute minimum of an inverse problem are determined at the first stage. For superthin films these values are significantly different from the true values of the film parameters because of the experimental errors and because of experimental errors and discrepancies in the choice of the model of the object under study. The second stage is an obvious consequence of the first one and represents realization of the approach described in the previous work [1]. At this stage of the solution of the inverse problem the optimum values of substrate parameters defined at the previous stage are set and by means of criteria of selection offered in the work [1] optimum values of parameters of the film are determined. This approach to the solution of the mathematically incorrect inverse problem is successfully tested in the numerical experiment for different variants of experimental errors. Influence of the broken layer on substrate surfaces is also discussed in the work.

1Institute for Applied Physics NAS, Sumy, Ukraine 2Institute for Analytical Instrumentation RAS, Saint-Petersburg

Robust methods and related algorithms based on neural networks for signal mixture separation are considered. Form reconstruction for original signals, identification of mixture and separation matrixes are implemented practically without of errors for conditions of noise significant levels in the mixtures of original signals.

SPbSPU, Saint-Petersburg

Unceasing function of several variables in a form of weighted sum of univariate functions, determined on the generalized basis, formed as a linear superposition of arguments of the initial function is suggested. The given approach is adapted to the structure of the optimum filter and is a basis of the theory of spline-filtration, developed by the author, and can be used in solving the problem of signal reception on the background of noise and hindrances, described by nonlinear stochastic differential equations. The problem will be discussed in details in our future publications.

Popov Higher Naval Academy of Radio Electronics, Petrodvorets

Article is devoted to one of the actual problems in the field of creation of fuzzy-logic systems — hardware realization of devices which processing fuzzy information. Disadvantages of the present microprocessor devices fulfilling processing of the fuzzy information are considered. The attention is paid to the alternate method of hardware realization of processing fuzzy information devices on the basis of optic information technologies (for examples, the optic fuzzification device and optoelectronic defuzzification device are devoted). The main advantages of optic processing fuzzy logic information devices use are discussed.

Rostov State Transport University, Rostov-on-Don