The method of digital parametric measurement of the phase shift of signals with slowly varying amplitudes of the same slowly varying instantaneous frequencies was proposed. The numerical simulations and experiments on the developed hardware and software system were carried out. The error of measurement the phase difference of harmonic signals in the experiments were not more than 0,00001 radian. The method can be used in applications where the measured value is expressed in terms of the phase difference of quasi-harmonic signals.
Keywords: quasi-harmonic signal, phase shift, real time measurements, hardware and software system
In this paper a systematic study of individual single-walled and multi-walled carbon nanotubes was performed by Raman spectroscopy and high-resolution electron microscopy. We have presented the geometrical and electronic structure analysis on the examples of two tubes: individual single-walled and double-walled nanotubes. The role of different environmental effects and their influence on the final structure assignment are discussed. Moreover, we have shown that the Raman spectroscopy gives reliable estimations of the nanotube diameters and the conductivity. Given a non-destructible character of Raman spectroscopy, we may conclude that it is one of the most efficient methods for structure analysis of carbon nanotubes.
Keywords: Carbon nanotubes, Raman spectroscopy, electron microscopy
Proposed by parallel implementation structures aloritmicheskih simulating year-round circulation of water bodies. The research evaluation of computation time, find the optimal algorithm for the implementation of independent calculations for multi-core processors to reduce the computation time.
Keywords: parallelization of computations, thermohydrodynamics modeling of water objects, multi-core processors
This article describes the model of the pseudorandom sequences (PRS) generator developed in OrCAD program suite.The described model is applicable for radio systems modules circuits simulation that are using in the operation a PRS. The PRS generator implementation in OrCAD make possible to change PRS parametres immediately in the program, without using other software. A model specificity is that it is parametrised. Parametrization facilitates model control and that is reduce to a minimum necessary manipulations for changing of PRS type. The model is constructed on the basis of circuitry implementation of the linear feedback shift register (LFSR). For adjustment of model it is enough to instal code words setting starting state a LFSR, parametres of a signal of a clock source and to specify register tap output. As an example, used a 16-bit LFSR to create maximum length PRS, tap sequence {0, 5, 9, 13}. Emulation results are presented.
Keywords: pseudorandom sequence, PRS generator, LFSR, OrCAD, circuit simulation
The represented approach of dynamic process modeling is based on the technology of automatical semantic text analysis. An associative network is forming during text processing. Its key notions, including lexical and psycholinguistic markers of the analyzed process, are ranked by theirs semantic weight. The weight being multiplied by marker status value at the scale of “good-bad” gives its contribution to the process stage characteristic. Transformation of the accumulated for all of the markers process characteristic from one period of time to another one is characterize a direction of the process.
Keywords: automatical text processing, associative (homogenous semantic) network, process dynamic modeling, social processes, lexical and psycholinguistic markers
The results of a patent search in the field of shut-off valve constructions for nuclear power plants, thermal power plants and main piping are given.
Keywords: Nuclear power plants, shut-off valve, construction, main piping
This article considers the causes of halitosis and methods of the diagnosis. Halitosis, syndrome of bad breath caused by pathological condition of the oral cavity or internal organs and systems, has a significant impact on the patient's social life. Analysis of the composition of exhaled air may become a promising way to diagnose halitosis, as the direct relationship between the compositions of molecules of oxygen, carbon dioxide, nitrogen oxides, ammonia etc. and the causes of halitosis were found. The article's authors review and analysis the methods of measurement of qualitative and quantitative composition of exhaled air. The most common methods include the use of electrochemical, optical sensors, infrared spectrometers and mass spectrometers. The latter method is positioned as the most optimal method of analysis of exhaled air due to its high accuracy, selectivity and sensitivity. The authors' portable mass spectrometer being developed is represented. At this stage it can detect traces of oxygen and carbon dioxide, which inject into the device through the capillary system or membrane one, in gas samples in real-time mode.
Keywords: diagnosis of halitosis, molecular biomarkers, analysis of exhaled air, portable mass spectrometer
Results of comparing the beamwidth and the concentration factor of receiving antenna wich were calculated using the metods of Bartlett and Prony when working on the background noise of the sea are considered. It was shown that efficiency parameter estimation signal sources using Prony methods is higher than when using the method of Bartlett.
Keywords: Prony algorithm, vector-scalar array,dynamc sea noise, the covariance, the flow of power
Possibility of receiving lungs self compacting concrete is considered. The technique of a choice of components of a raw mix is offered and are brought physics - mechanical characteristics of a ready construction materia
Keywords: Self-compacting concrete, the supersoftener, knitting, filler.
A mathematical model of heat transfer processes, the discrete model is based on the finite difference method, and the results of calculations of the temperature distribution also will be developed. In addition the program was created which allows to calculate the distribution of temperature over its entire length for given values of insolation, ambient air temperature and air velocity inside the collector
Keywords: mathematical modeling, finite difference method, heat transfer processes, solar collector
We consider the problem of the use of adaptive autonomous scripts in the decision of problems of management of information resources of computer systems. Developed a conceptual model of adaptive autonomous script with use of frames and apparatus of finite automata, which expands the possibilities of automation of complex problems of information resources management
Keywords: adaptive autonomous scripts, theory of finite automata, frame, slot, management of distributed information resources.
With the increase in the coefficient of friction is a growth of the torque transmitted by the lead pair of friction of the main friction, reducing torque is transmitted by the slave pairs of friction friction core group and a couple of extra friction of the friction. Load transfer in the adaptive friction clutches reduces spacer force and accelerate the growth of the torque transmitted by the friction pair of the main driving frictional group.
Keywords: the coefficient gain, a separate positive connection, the coefficient of friction, clutch, friction pair
The coefficient of friction, whereby the total nominal load adaptive clutch transmitted only the leading pair of friction friction basic group is less than the maximum value, which may take the coefficient of friction in actual operation of the coupling. Appearance and an increase in the strength of the spacer when the external load and increasing at an elevated value of the friction coefficient begins at a certain minimum value of the external load, which depends on the total number of pairs of friction of the friction core and the gain. The dependences of the distributions of the torque between the lead pair of friction friction main group and driven friction pairs of basic friction and friction pair of extra friction.
Keywords: the coefficient gain, a separate positive connection, the coefficient of friction, clutch, friction pair
The proposed method of designing hardware components optical switching systems simplifies prototyping and development of systems of optical switching and multi-core VLSI. This method allows to automatically set parameters of the optical system at the design stage, depending on the requirements. This method may be cost-effective at the stage of technical specifications of the project, as will reduce the time required for its coordination between the customer and the design engineer.
At the heart of developing a method of designing systems, optical switching elements is a comprehensive analysis of the equations and functions describing the electrical and optical properties of laser heterostructures, as well as electro-optic modulators and Fabry-Perrot resonators. Fundamental static and dynamic characteristics of semiconductor diode lasers can be calculated by using a set of kinetic equations describing the interaction of electrons, holes and photons in the active layer of the laser structure. At various stages of this method is processing, evaluation and calculation of the main characteristics of the elements of integrated optical switching systems.
Keywords: optical switching, integrated injection laser, quantum-scale heterostructure, amplitude modulation, terahertz range
In this work we have investigated the structure of individual single-walled and multi-walled carbon nanotubes by high-resolution electron microscopy and electron diffraction. To grow carbon nanotubes we used a catalytic chemical vapor deposition method. It was shown, that this synthesis protocol gave in general single-walled and double-walled carbon nanotubes with a high level of crystallinity. The diameters of the nanotubes were in the range 1.5 - 7 nm. We also observed that there was a certain level of amorphous carbon deposited on the nanotube surface during the growth. In this work we also present the structure analysis of the double-walled carbon nanotube by means of electron diffraction. We show that the structural date derived from electron microscopy and electron diffraction agree within the experimental error.
Keywords: Carbon nanotubes, electron diffraction, electron microscopy