Home – Home – Jornals – Journal of Applied Mechanics and Technical Physics 2016 number 5

The possibility of improving the parameters of semiconductor integrated circuits by replacing the silicon layer in a metal-insulator-semiconductor transistors by a material with higher mobility of charge carriers. It is shown that for the totality of properties, germanium is best suited for this purpose. Recent developments in this area made in different laboratories both in Russia and abroad are discussed.

A new technological route for fabricating Ge based metal-oxide-semiconductor (MOS) transistors has been developed based on materials research of dielectric layer compositions. Unwanted impurities were encapsulated by using the gate-first process and a modified thermal GeO₂ layer with increased viscosity at the interface with the Ge substrate. Increasing the density of the oxide layer near germanium interaction with the deposited Si₃N₄ film hindered diffusion of impurities into adsorbed by the substrate surface into the transistor channel. This made it possible to increase the electron mobility in the MIS transistor and prevent its decrease at cryogenic temperatures.

Nanowire field-effect transistors are high-sensitivity sensor elements intended for the qualitative and quantitative analyses of biological and chemical substances. Optimization of the sensor operation is one of the key ways of increasing their sensitivity. An algorithm for choosing the operation mode of sensors based on silicon-on-insulator transistors is proposed which provides their maximum response during conductivity monitoring in the detection of target particles.

The current-voltage characteristics (CVC) of PbSnTe:In films with a tin content of x ≈ 0.29 at helium temperatures under conditions of unipolar injection from contacts and restriction by a spatial charge in a magnetic field of up to 4 T have been studied. Analysis of the CVC has shown that the observed CVC features change as the magnetic field is increased from 0 to 4 T. The relationship between these features and the presence of a multilevel system of traps located in the band-gap zone is validated.

Negative differential resistance in an UV laser InGaN/GaN diode is demonstrated. Switching between the lower and upper branches of the S-shaped current-voltage characteristic leads to a change in the optical radiation power by six orders of magnitude as the current is increased from 3 to 15 mA.The occurrence of a negative differential resistance is explained by superlinear injection of charge carriers of the same sign into a high-resistivity InGaN quantum well.

This paper describes the design and characteristics of the three-spectrum multielement photodetector with a sensitivity range from 0,6 to 12,0 μm, which consists of three lines of photodetectors with the sensitivity ranges from 0,6 to 0,9, from 3 to 5, and from 8 to 12 μm. The methods for manufacturing the lines, the photodetecting device in general, and its photoelectric characteristics are described.

This paper presents a brief review of experimental works in the field of quantum cryptography and quantum key generation by means of single photons in the atmospheric and fiber quantum communication lines. This paper given the description of two experimental devices for quantum key generation, which were designed at the Rzhanov Institute of Semiconductor Physics, Siberian Branch, Russian Academy of Sciences. The results of the study of the dependence of the speed of the quantum key generation on the average number of photons $\mu$ in the laser pulse are given. There is a discrepancy between theory and experiment found for $\mu>0.3$, which may be due to nonzero probability of occurrence of multiphoton pulses in the quantum transmission, which are detected by the single photon detectors as single-photon pulses. When it comes to sieving the quantum key, the cases with simultaneous triggering of several single-photon detectors are ignored because the measurement result is not determined.

This paper presents the review of studies of photoelectric properties of the PbSnTe:In films obtained by molecular beam epitaxy and the photosensitive structures of the far infrared and submillimeter ranges based on these films. The parameters of this type of multielement photodetectors and the detectors based on doped semiconductors and superconductors. Ruled (2 x 128 elements) and matrix (128 x 128 elements) multielement PbSnTe:In based photodetectors with a sensitive edge equal to ~22 m and an operating temperature of T ≤ 16 K are implemented. In the background-free conditions, the power equivalent to the noise reached MES ≤ 10^-18 W/Hz^0.5 for T = 7 K for the radiation source of the absolute black body type at T_ABB = 77 K. The submillimeter region of the spectrum had sensitivity to laser radiation with a wavelength λ ≤ 205 μm and the value of MES ≤ 10^-12 W/Hz^0.5 without optimization of the layout design of the photosensitive member and minimization of the measurement circuit noise. The directions of the development of PbSnTe:In based radiation detectors are considered.

This paper describes the model of Poisson's composite compound distribution for photon statistics with regard to their grouping in the Fock, thermal, and many other states. The method of generating functions is used to calculate the distribution of probabilities, moments, and correlation functions. The parameters of the conditional states arising from the subtraction of photons by splitting the beam are determined. The problem of state reconstruction through quadrature quantum measurements is considered. The research is aimed at developing high-precision methods for generating and controlling optical quantum states.

Experiments and simulations are performed to study the formation of silicon nanocrystals (Si-NC) in multilayer structures with alternating ultrathin layers of SiO₂ and amorphous hydrogenized silicon (α-Si:H) during high-temperature annealing. The effect of annealing on the transformation of the structure of the α-Si:H layers is studied by methods of high-resolution transmission electron microscopy, Raman spectroscopy, and photoluminescence. The conditions and kinetics of Si-NC formation are analyzed by the Monte Carlo technique. The type of the resultant crystalline silicon clusters is found to depend on the thickness and porosity of the original amorphous silicon layer located between the SiO₂ layers. It is shown that an increase in the thickness of the α-Si layer in the case of low porosity leads to the formation of a percolation silicon cluster instead of individual Si nanocrystals.

The phase and elemental compositions of GeSi heterostructures deposited on non-refractory substrates are analyzed by using a non-destructive express technique, i.e., the Raman spectroscopy. It is shown that application of pulsed laser annealing allows one to vary the elemental composition and size of nanocrystals formed from solid alloys of germanium and silicon.

The formation of an absorption layer on the Si(111) surface under conditions of sublimation at temperatures of 1000-1100 °C and subsequent quenching at T = 750 °C is studied by methods of in situ superhigh-vacuum reflection electron microscopy and ex situ atomic force microscopy. The distribution of the concentration of adatoms on an extrawide (~60 μm) atomically smooth terrace is determined for the first time, and the diffusion length x_s = 31 ± 2 μm at T = 1000 °C is obtained. The analysis of the temperature dependence of the equilibrium concentration of adatoms near a monatomic step allows pioneering measurements of the energy necessary for the adatom to pass from the step to the terrace E_ad ≈ 0,68 eV. Based on these results, the energy parameters for some atomic processes on the Si(111) surface are estimated.

A Monte Carlo grid model is proposed to describe the formation of semiconductor nanostructures by the vapor-liquid-crystal growth mechanism. This model is used to simulate the growth of GaAs nanostructures by the method of droplet epitaxy in the temperature range from 500 to 600 K in As₂ flows with intensity of 0.005-0.04 ML/s. The morphology of the resultant structures is demonstrated to depend on the growth parameters. Etching of the GaAs substrate by a gallium droplet is studied. The ranges of temperature and As flow rates necessary for the formation of GaAs nanorings are determined. The conditions of the formation of single and double concentric rings are analyzed.

A method is presented to be used in a computational experiment aimed at studying the internal structure of nano-mesoscopic objects, i.e., conducting subsystems and quantum phenomena in solid submicron objects, which demonstrate an individual behavior of low-temperature resistance.

Publications dealing with the study of methods of reducing a three-dimensional problem of the elasticity theory to a two-dimensional problem of the theory of plates and shells are reviewed. Two approaches are considered: the use of kinematic and force hypotheses and expansion of solutions of the three-dimensional elasticity theory in terms of the full system of functions. Papers where a three-dimensional problem is reduced to a two-dimensional problem with the use of several approximations of each sought function (stresses and displacements) by segments of the Legendre polynomials are also reviewed.

This paper describes the study of the influence of a microstructure characterized by directed or chaotic distribution of nanoinclusions and strain rate on the deformability of a nanocomposite. It is revealed that, under identical load conditions, crack formation occurs in nanocomposites whose structural elements are mostly directed in the same way at lower strain rates than in nanocomposites with chaotic distribution of the hardener. It is shown that, as the strain rate increases, the influence of the structural order on the limit deformation reduces due to transition from shear strain to rotational strain. No cracks are formed in bonding metals and nanocomposites by explosion welding. The experimental results obtained in the study of transverse bending of two-layer welded beams and the structure in the vicinity of the weld reveal that the obtained metal - nanocomposite compound has a uniform structure retained in deformation, with fracture occurring in the nanocomposite.

Different approaches to the determination of the carrying capacity of bars and shells under elastoplastic deformation and creep deformation conditions.

This paper presents the results of an experimental study of the elastic and viscoplastic properties of alloys using elastoplastic theory. The need to study complex loading of materials, consider the microstructure evolution during deformation, and develop an appropriate theory of experiment and adequate constitutive relations is highlighted.

The creep rupture strength of tensile bars in an aggressive environment is studied analysis. The time to rupture of the bars is analyzed as function of the shape of their cross section. It is shown that the influence of the aggressive environment on the creep rupture strength of the bars is determined by the diffusion of its elements into the bar material, resulting in a decrease of its creep rupture strength. The diffusion of the aggressive environment into the bar is studied using an approximate method of solving the diffusion equation taking into account the motion of the diffusion front. Bars with different cross-sectional shapes are considered using Rabotnov kinetic theory. It is shown that under the same tensile stress, the bar with a circular cross-section has minimum time to failure.

It is shown that, in the planar case, the system of constitutive equations of the linear elasticity theory should contain five independent equations. n the classical theory, only three equations are formulated, while the other two are contained in implicit form in the postulate of diffeomorphism, which the assumption of smoothness of the displacement field. A closed elasticity model is constructed without the assumption of diffeomorphism, and it contains a structural parameter having a dimension of length. It is shown that, in a static version, macrodeformations depend on stresses and the second derivatives of stresses by the coordinates, while there is dispersion of longitudinal and transverse waves in the dynamics.

The generalized rheological method is used to construct a mathematical model of small deformations of a porous media with open pores. Changes in the resistance of the material to external mechanical impact at the moment of collapse of the pores is described using the Mises~--- Schleicher strength condition. The irreversible deformation is accounted for with the help of the classic versions of the von Mises - Tresca - Saint-Venant yield condition and the condition that simulates the plastic loss of stability of the porous skeleton. Within the framework of the constructed model, this paper describes the analysis of the propagation of plane longitudinal compression waves in a homogeneous medium accompanied with plastic strain of the skeleton and densification of the material. A parallel computational algorithm is developed for the study of the elastoplastic deformation of the porous medium under external dynamics loads. The algorithm and the program are tested by calculating the propagation of plane longitudinal shock waves of compression and cylindrical cavity of in an infinite porous medium. The calculation results are compared with exact solutions, and it is shown that they are in good agreement.

This paper presents the results of a study of the shapes of axisymmetric bodies with minimum penetration resistance and maximum depth of penetration into the plastic soils. Optimum shapes of bodies of revolution of predetermined length and cross-sectional radius with generatrices represented by line segments are obtained by a modified method of local variations. The problem is solved using a binomial quadratic model of local interaction, including inertial and strength terms containing constant and Coulomb frictions. The resistance forces and the depth of penetration of cones and the obtained bodies of optimal shape are determined at different penetration velocities.

A mathematical model is developed for an inhomogeneous thermoelastic prestressed half-space consisting of a stack of homogeneous functionally graded layers rigidly attached to a homogeneous base.аEach component of the inhomogeneous medium under an initial mechanical stress and temperature.аConsistent linearization of the constitutive relations of nonlinear mechanics of a thermoelastic medium is performed using the theory of superpositionа of small deformations on finite deformations with the inhomogeneity of the medium taken into account.аIntegral formulas for studying dynamic processes in inhomogeneous prestressed thermoelastic media are derived.

A study of the sorption properties of a composite sorbent prepared from pseudoboehmite and synthetic sodium-borosilicate glass microspheres was performed with the aim of using the sorbent in membrane-sorption processes of helium extraction from natural gas with its simultaneous drying. Experimentally, permeability of the composite sorbent under study with respect to helium and its impermeability to air and methane has been demonstrated. Under experimental conditions, the absolute moisture content of the gas mixture having passed through the sorbent has reduced from 21.1 to 0.013 g/m³. The rate of helium adsorption by the composite sorbent has increased nearly by two orders of magnitude in comparison with the initial microspheres. It was found that the degree of saturation of the sorbent with water vapor had almost no influence on the rate of helium adsorption. A possibility of optimal use of the composite sorbent by combining the process of natural-gas drying from water vapor and the process of helium extraction from natural gas is shown. This possibility permits shortening of the process sequence for natural gas pre-conditioning prior to helium extraction.

The relevance of applying the methods of energy recovery from exhaust gases is substantiated. The principle of operation of a thermoelectric generator is described, the variant of its design is proposed, and the efficiency of various design methods of heat exchange intensification is compared. Designs are compared with a baseline configuration without heat transfer intensifiers in terms of coefficients of gas dynamic resistance ξ/ξ₀ and the ratio of dimensionless criteria Nu/Nu0. The results of comparative analysis have proved the applicability of the methods of heat exchange intensification in the design of thermoelectric generators of various vehicles.

The article presents the results of theoretical and experimental studies of the production of high-temperature silicate melts using the energy of low-temperature plasma in a conceptually new setup. A mathematical model of unsteady regimes of convective heat and mass transfer is developed and numerically implemented under the assumption of non-Newtonian nature of flow in the melting furnace with plasma-chemical synthesis of high-temperature silicate melts. Experiments on melting silicate containing materials were carried out using the energy of low-temperature plasma. The dependence of dynamic viscosity of various silicate materials (basalt, ash, waste of oil shale) was found experimentally.

The electrical and thermal characteristics of plasma-resistive furnace in the drying zone at a recycling man-made waste were studied. The dependences of power output in the drying zone at different specific electrical resistances of the charge were derived. It is shown that introduction of additional resistance heating in the drying zone reduces the load on plasmatorch, increasing the lifetime of electrodes.

The paper presents experimental data on the laminar-turbulent transition in the nanofluid flow in the pipe. The transition in the flows of such fluids is shown to have lower Reynolds numbers than in the base fluid. The degree of the flow destabilization increases with an increase in concentration of nanoparticles and a decrease in their size. On the other hand, in the turbulent flow regime, the presence of particles in the flow leads to the suppression of small-scale turbulent fluctuations. The correlation of the measured viscosity coefficient of considered nanofluids is presented.

The application of the weighted residuals method is considered for the calculation of heat transfer in flowing thin liquid films. As an example, the problem of the film moving under the action of the gas flow on the heated horizontal wall is solved. The solution demonstrates good agreement with the numerical one obtained by the finite-difference method.

Comparative study of 3D numerical simulation of fluid flow and coal-firing processes was applied for flame combustion of Kansk-Achinsk brown coal in a vortex furnace of improved design with bottom injection of secondary air. The analysis of engineering performance of this furnace was carried out for several operational modes as a function of coal grinding fineness and coal input rate. The preferable operational regime for furnace was found.

August 7, 2016 is the 70th Anniversary of Professor Anatoly A. Maslov, a noted scientist, specialist in viscous gas dynamics, and Doctor of physical and mathematical sciences.

September 8, 2016 is the 50th Anniversary of Alexander N. Shiplyuk, a noted scientist, researcher in the field of high-velocity aerogasdynamics and experimental methods of studying gas flows, doctor of physical and mathematical sciences, corresponding member of the Russian Academy of Sciences.

Professor Anatoly M. Kharitonov, an outstanding researcher in the domain of fluid mechanics, doctor of technical sciences, Honored scientist of the Russian Federation, winner of the Prize of the Council of Ministers of the USSR and of the Prize named after Professor N.E. Zhukovskii, and Deputy Editor-in-Chief of our journal, deceased on August 13, 2016.

Objective: To evaluate the contribution of IL1β gene polymorphisms rs1143634 and rs16944 in the development of myocardial infarction (MI) and multivessel coronary artery disease in patients with CAD. Material and Methods: 303 patients with stable coronary artery disease were included in the study. Serum IL1β levels were measured with commercial kits (Bender MedSystems, Austria). TaqMan genotyping assays were performed in 96-well plate. Results: Women, who were homozygous carriers of the IL-1β rs1143634 G major allele, had a 4-fold decreased risk of developing multivessel coronary artery disease (p = 0.046) as well as a 2-fold decreased risk of myocardial infarction (p = 0.0198). The variable site of the IL1β rs1143634 was significantly (p = 0.0025) associated with a reduced risk of MI according to the dominant inheritance pattern (OR = 0.48, 95% CI = 0.29- 0.77), and rs16944 - with a five-fold increased risk (p = 0.0022) according to the co-dominant model (OR = 5.12, 95% CI = 1.82-14.42). The risk of myocardial infarction in men, who were homozygous carriers of the IL1β rs16944 T minor allele, was six times higher than that in women (p = 0.0093). The AC haplotype (rs1143634- rs16944) was associated with a 2-fold reduced risk of myocardial infarction and PICS (OR = 0.49, 95% CI = 0.29-0.81, p <0.0059), with the most pronounced effects in the age of 65 years (p = 0.0031). However, the GT haplotype rs1143634-rs16944 in younger patients (<65 years) was associated with the development of myocardial infarction (p = 0.0074). Conclusion: Genetic markers should be taken into consideration as an independent predictors of myocardial infarction and multivessel coronary artery disease.

The aim of this study was to investigate the connection between coronary atherosclerosis severity, measured on a scale of the SYNTAX with psychosocial factors in patients with acute coronary syndrome who live in the North. The study involved 269 consecutive patients (n = 203, 21.2% female, n = 66, 78.8% - men) with acute coronary syndrome with the average age of 56,0 ± 6,1 years (45-64 years). It revealed a high level of alcohol consumption on the AUDIT scale in patients with severe coronary disease compared with mild and moderate (p = 0.03). Direct correlation among severity of coronary lesions, a total cholesterol (r = 0,15, p <0,05) and low density lipoprotein cholesterol (r = 0,15, p <0,05) in patients with severe coronary disease were found out. With the help of binary logistic regression it was stated that the low level of instrumentally support increases in 2,16 times the risk of presence of acute coronary syndrome ona scale of the SYNTAX (p = 0,02), however, the age (p = 0.06) and male gender (p = 0 94) did not significantly influence the dependent variable above.

Objectives: to investigate the prevalence and determinants of AF in cross-sectional study in a population sample 45-69 age (Novosibirsk). Materials and methods: a random population sample of men and women 45-69 years old (y. o.) (n=9360) was examined in Novosibirsk (project HAPIEE). We used standard epidemiological methods. As optional study ECG was registered participants and estimated by Minnesota code (n=9255). They were included for current analysis (grant RSF 14-45-0030). Results: in studied population sample the prevalence of AF was 1.6% (1.1% in women and 2.1% in men). The frequency of AF increased with age: from 0.3% in age group of 45-49 y. o. in both sexes to 4.0% in men and 2.8% in women in the oldest age group (65-69 y. o.), p<0.001. In unadjusted analysis, in men AF was associated with elder age, heart rate (HR) (р<0,001), diastolic blood pressure (р=0,003), body mass index (BMI) (р<0,001), presence of cardiovascular disease (CVD), hypertension (HT) (р<0,001) and diabetes mellitus (DM) (р=0,002). When we have compared laboratory parameters, the patients with AF had lower level of total cholesterol (TC) (р=0,001), low-density lipoprotein cholesterol (LDL-C) (р=0,005) and higher level of gamma-glutamyltranspeptidase (GGT) (p <0.001). The significant difference of alcohol consumption measures in relation to AF we did not identified in population sample. In women were similar results in the studied risk factors and cardiometabolic diseases. In multivariate regression, AF in men was positively associated with age, HR, BMI (p<0.001) and negatively related to level of triglycerides (p=0.019) and LDL-C level (p=0.001). Women had a positive association of AF with age, HR, BMI (p<0.001), GGT (p=0.002) and negative - to LDL-C level (p<0.001). Conclusions: in a population sample 45-69 y. o. of Novosibirsk the prevalence of AF was 1.6%, which is close to indicators in other populations. Determinants of AF were CVD, HT, DM, HR, BMI, increasing age (for both sexes) and GGT level in women. We did not find the direct relationship between AF and the atherogenic lipid profile; these results are likely to be associated with the modulating contribution of cardiometabolic factors.

Clinical examination in our country has a long history. National health care has significant experience in the clinical examination of the population and its separate contingents. Cardiovascular disease is one of the priorities for preventive measures among the population. During the event, using the experience, formed the modern concept of the clinical examination of the adult population.

Atherosclerosis concept defines the key role of inflammation in the occurrence and progression of atherosclerosis. Hemostatic system is an integral part of the inflammatory response. At all stages of atherogenesis, starting from the early stages, there is part of hemostasis factors. In recent years researchers attract most interest to the questions of intercellular interaction between platelets and leukocytes. Combined evaluation of leukocyte-platelet responses reflect the clinical and laboratory picture of atherothrombotic events in unstable angina and myocardial infarction. Monocyte-platelet interaction plays a significant role in the development of heart failure, blood platelets are capable of inducing apoptosis. The individual testing the risk of hemorrhagic complications increase the efficiency of drug prevention and therapy of antithrombotic drugs. Changing the pattern of atherosclerosis observed in recent years, also requires the introduction of new approaches in the prevention of atherosclerosis, enhancing the protection of the endothelium. This review focuses on the research, covering the role of hemostasis in the pathogenesis of atherosclerosis.

This article is devoted to discussion about statin’s using in patients with atherosclerosis-associated disease, arterial hypertension, diabetes mellitus, chronic kidney disease, familial hypercholesterolaemia, rheumatoid arthritis, systemic lupus erythematosus, nonalcoholic fatty liver disease and gallstone disease.

The 84rd European Atherosclerosis Society (EAS) Congress was held in Innsbruck, Austria, 28 May-1 June 2016. The Congress program discussed the latest scientific data and clinical studies. Angiogenesis and vascular metabolism, familial hypercholesterolemia, obesity, lifestyle and cardiovascular diseases, personalized medicine were the main topics of the discussion. The review was prepared based on the EAS Congress 2016 materials and the websitehttp://www.eas2016.kenes.com/.