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  • 1
    Electronic Resource
    Electronic Resource
    Quasi-two-dimensional hydrodynamics and problems of two-dimensional turbulence (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Chaos 4 (1994), S. 299-304 
    Details
    ISSN: 1089-7682
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The principal problems of quasi-two-dimensional (Q2-D) hydrodynamics are discussed. Accounting for Q2-D flow vertical structure is shown to eliminate "genetic'' defects of the formal 2-D idealization of 3-D Navier–Stokes equations and allows under certain conditions to formulate corrected 2-D motion equations which adequately describe real hydrodynamic processes. The applicability of the approach is directly verified in laboratory experiments. Special attention is paid to the problem of 2-D turbulence. Its simulation on the basis of ordinary 2-D equations is unjustified because of the absence of the external Kolmogorov dissipation scale and reverse spectral energy flux. An alternative approach allows one to introduce the natural external scale of 2-D turbulence which depends only on physical properties of the system under consideration and to formulate the conditions under which the large scale vortex dynamics is expected to be universal at large Reynolds number, i.e., to be independent on the size and form of integration domain and lateral boundary conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.166009
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  • 2
    Electronic Resource
    Electronic Resource
    An advanced investigation of interaction of allocated quasi-two-dimensional vortices (1996)
    Woodbury, NY : American Institute of Physics (AIP)
    Chaos 6 (1996), S. 297-308 
    Details
    ISSN: 1089-7682
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This work should be regarded as a natural development of the investigations by Dolzhanskii, Krymov and Manin [Sov. Phys. Usp. 33, 495–520 (1990); J. Fluid Mech. 241, 705–722 (1992); Russ. J. Comput. Model. 1, 107–118 (1993)] of quasi-two-dimensional (Q2D) flows in which the linear and weakly nonlinear stability theory based on the 2D hydrodynamic equations with the Rayleigh (Ekman) friction term imitating the influence of the bottom on the motion of upper fluid layers was corroborated with laboratory and observational data. The applicability of the Q2D approach to describe self-oscillating supercritical regimes was even more vague as Batchaev's experiments [Izv. AN SSSR Fiz. Atmos. Okeana 25, 434–439 (1989); Z. Prikl. Mech. Tech. Fiz., No. 4, 85–91 (1990)] on modeling the four vortex self-oscillations in a thin fluid layer by the magnetohydrodynamics method (the so called hydrodynamical clock [Obukhov, Dolzhanskii and Batchaev, Topological Fluid Mechanics, Proceedings of the IUTAM Symposium, Cambridge, 13–18 August 1989 (Cambridge University Press, Cambridge, 1989), pp. 304–314]) did not find an appropriate theoretical explanation. To remove earlier uncontrolled effects the supplementary detailed measurements of the experimental flow characteristics were implemented, including the spatial spectral composition of the external vorticity sources and free surface 2D velocity fields. Satisfactory agreement is found between experimentally measured flow characteristics and the results of numerical simulations. The frequency of self-oscillations was found to be greatly susceptible to the spectral composition of the external vorticity sources and fluid layer thickness, which should be taken into account in designing laboratory experiments to simulate the natural Q2D processes observed in the ocean and atmosphere. Applicability conditions of the Q2D approach and the influence of geometrical parameters of vortices on their nonlinear interplay are also discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.166177
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  • 3
    Electronic Resource
    Electronic Resource
    Distribution function, population inversion and FIR gain of hot holes in germanium in crossed electric and magnetic fields (1991)
    Springer
    Optical and quantum electronics 23 (1991), S. S195 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The energy distribution function of hot heavy and light holes, the degree of population inversion and of the accumulation of light holes are determined from an investigation of near infrared light absorption in crossed magnetic and electric fields. Analysis of the data shows that inversion of the population is caused not only by accumulation of light holes, but also by weaker heating of light holes compared with heavy holes and drift in momentum space. The numeral value and spectral dependence of the FIR gain, are determined. The distribution function and optical gain are in good qualitative and quantitative agreement with the values calculated by the Monte Carlo method. The power of the far-infrared laser is estimated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00619765
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  • 4
    Electronic Resource
    Electronic Resource
    Narrowband tunable sub-millimetre hot hole injectionless semiconductor laser and its use for cyclotron resonance investigation (1993)
    Springer
    Optical and quantum electronics 25 (1993), S. 705-721 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A narrowband far-infrared laser on intersubband transitions of hot holes was constructed and investigated. Two methods were used: mode selection due to intercavity Fabry-Perot resonator and selection of a narrow spectral lasing region by special multilayer mirror. The emission spectra of the laser were determined. The radiation bandwidth measured was Δν≤0.2 cm-1 as compared with Δν≃15–30 cm-1 for nonselective resonator. Lasing with selective resonator could occur at any two wavelengths in the ranges 80–120 and 150–200 μm. The wavelength was modified by altering electric and magnetic fields. The radiation power was about 10 W and of the same kind as that of a laser without a mode selector. The narrowband laser was used in investigation of CR of electrons in n-InSb.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00430560
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  • 5
    Electronic Resource
    Electronic Resource
    Generation of far-infrared radiation by hot holes in germanium and silicon inE ⊥H fields (1991)
    Springer
    Optical and quantum electronics 23 (1991), S. S221 
    Details
    ISSN: 1572-817X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The experimental results obtained by the investigation of stimulated FIR emission from dopedp-type germanium andp-type silicon by hot holes in crossedE andH fields atТ = 10 and 80 K are reported. The analysis of the emission intensity fromp-type germanium as a function ofE andH fields permits us to draw a conclusion about the important role of quantization of the energy spectrum of light holes and the contribution of light hole transitions with Δn = 2 to the amplification of FIR radiation. A new region of generation is demonstrated inp-type germanium under uniaxial stress. The first experimental results on stimulated FIR emission fromp-type silicon are reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00619769
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  • 6
    Electronic Resource
    Electronic Resource
    Observation of segregation deposits in iron-nickel-titanium alloy using scanning tunneling microscopy (1999)
    Springer
    Technical physics letters 25 (1999), S. 134-135 
    Details
    ISSN: 1090-6533
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Scanning tunneling microscopy and electron microscopy were used to study the aging process of the fcc alloy Fe+36.5%Ni+2.5%Ti under annealing. The possibility of using scanning tunneling microscopy to study new-phase deposits formed during aging is examined. The sizes of the γ′-phase particles was determined.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1262377
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  • 7
    Electronic Resource
    Electronic Resource
    Insertion/deletion polymorphism in the angiotensin-I-converting enzyme gene is associated with coronary heart disease in IDDM patients with diabetic nephropathy (1995)
    Springer
    Diabetologia 38 (1995), S. 798-803 
    Details
    ISSN: 1432-0428
    Keywords: Key words Plasma angiotensin converting enzyme ; angiotensin-I-converting enzyme gene ; coronary heart disease ; diabetic nephropathy ; insulin-dependent diabetes mellitus.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Insulin-dependent diabetic (IDDM) patients with diabetic nephropathy have a highly increased morbidity and mortality from coronary heart disease. An insertion (I) /deletion (D) polymorphism in the angiotensin-I-converting enzyme (ACE) gene has been shown to be associated with coronary heart disease. Therefore, we have investigated the role of this ACE/ID polymorphism in 198 IDDM patients with diabetic nephropathy and 190 normoalbuminuric IDDM patients. The prevalence of myocardial infarction and other coronary heart disease was significantly elevated in patients with nephropathy, 19 % (38/198) vs 8 % (15/190), p 〈 0.001. In the nephropathic group 12 of 63 (19 %), 23 of 95 (24 %), and 3 of 40 (7.5 %) patients with the DD, ID and II genotypes, respectively had a history of coronary heart disease, II vs DD and ID, p 〈 0.05 when compared to nephropathic patients without coronary heart disease. Multiple logistic regression analysis of the risk factors associated with coronary heart disease in univariate analysis revealed that the II genotype acts as an independent protective factor against coronary heart disease, odds ratio II/DD + ID 0.27 (95 % confidence interval 0.07–0.97, p 〈 0.05). There was no difference in genotype or allele frequency (D/I) between patients with and without nephropathy, 0.56/0.44 in both groups, but plasma ACE concentration was elevated in patients with nephropathy 609 (151–1504) ng/ml as compared to patients with normoalbuminuria, 428 (55–1630) ng/ml, p 〈 0.001. We suggest that ACE/ID polymorphism may influence the frequency of life-threatening cardiac complications in IDDM patients suffering from diabetic nephropathy, a condition characterized by increased plasma ACE concentration. [Diabetologia (1995) 38: 798–803]
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s001250050355
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  • 8
    Electronic Resource
    Electronic Resource
    Transport of a passive scalar and Lagrangian chaos in a Hamiltonian hydrodynamic system (2000)
    Springer
    Journal of experimental and theoretical physics 91 (2000), S. 423-432 
    Details
    ISSN: 1090-6509
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract An experimental and numerical study is made of the chaotic behavior of Lagrangian trajectories and transport of a passive tracer in a quasi-two-dimensional four-vortex flow with a periodic time dependence of the Euler velocity field. Quantitative measurements are made of tracer transport between isolated vortices in physical space and in “action” variable space. The theory of adiabatic chaos is used to interpret the measurements. The simplest phenomenological models of liquid particle random walks are proposed to describe the anomalous transport in terms of the action.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1312003
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  • 9
    Electronic Resource
    Electronic Resource
    Characteristics of a far-infrared germanium hot-hole laser in the Voigt and Faraday field configurations (1997)
    Springer
    Semiconductors 31 (1997), S. 1273-1279 
    Details
    ISSN: 1063-7826
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract A far-infrared laser utilizing intersubband transitions of hot holes in germanium with a hole density of 2.5×1014 cm−3 is investigated in the Voigt and Faraday field configurations. New comparative data for both configurations are given on the field ranges in which lasing takes place, the emission intensity and spectra, and their dependence on the temperature of the crystal. The Voigt configuration is shown to be preferable, having a broader lasing field range, a higher working temperature, a richer emission spectrum, and a higher intensity. Prominent details of the laser characteristics are discussed, and a comparison is made with calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1187310
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  • 10
    Electronic Resource
    Electronic Resource
    Amplification of radiation in the far infrared range by hot holes in germanium in crossed electric and magnetic fields (1997)
    Springer
    Semiconductors 31 (1997), S. 1280-1283 
    Details
    ISSN: 1063-7826
    Source: Springer Online Journal Archives 1860-2000
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Notes: Abstract The results of direct gain measurements are reported for the amplification of polarized and unpolarized, long-wavelength, infrared radiation by hot holes in germanium in crossed electric and magnetic fields in the Voigt and Faraday configurations. The experimental data are compared with gain calculations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1187311
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