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  • 1
    Electronic Resource
    Electronic Resource
    Frequency of the F508 deletion in cystic fibrosis patients from the European part of the USSR (1991)
    Springer
    Human genetics 〈Berlin〉 87 (1991), S. 61-64 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The frequency of the F508 deletion (ΔF508) has been analyzed in 189 cystic fibrosis (CF) patients from the European part of the USSR, viz. 127 nothern Slavonians (Leningrad region), 30 southern Slavonians (the Ukraine), 10 central Slavonians (Moscow region), 14 Moldavians (Kishenev region) and 8 Lithuanians (Vilnius region). The distribution of CF+ chromosomes with and without ΔF508 varied significantly in the different ethnic groups studied and correlated with the clinical manifestation of CF. The overall frequency of ΔF508 in Slavonian patients is equal to 62.5%, approximately 90% of them being heterozygous or homozygous for this mutation. The frequency of the deletion among 99 Slavonian patients with severe disease manifestation (pancreatic insufficiency, PI) is equal to 67.5%, only 12 patients having pancreatic sufficiency (PS, 17.5%). The highest value of ΔF508 (77.4%) is registered in PI/CF patients of the southern Slavonian group; it is much less frequent (about 57%) in relevant groups of Slavonians from the northern and central parts of the country. Unusually low frequencies (24% and 26%) of ΔF508 are detected in a few samples of Lithuanian and Moldavian CF patients, respectively. All ΔF508+CF-chromosomes of Slavonian origin are associated with haplotypes 2.2.2. defined by the restriction fragment length polymorphism sites KM19/PstI, CS.7/Hin6I and MP6d-9/MspI, although a high proportion (about 25%) of unknown mutations is associated with the same haplotype. Haplotype B (allele 1XV2c/TaqI; allele 2 KM19/PstI) accounts for 91% of ΔF508+CF chromosomes. Our data are consistent with the hypothesis of a single origin and subsequent diffusion of this major CF mutation; however, its interpopulational dissemination in Eastern Europe does not follow the suggested south-east to north-west gradient in Western Europe. The significance of these data for prenatal diagnosis and carrier screening of CF mutations is briefly discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01213094
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  • 2
    Electronic Resource
    Electronic Resource
    Lase action on resonant molecular flows through capillaries (1988)
    Springer
    Applied physics 47 (1988), S. 61-65 
    Details
    ISSN: 1432-0649
    Keywords: 82.65-I ; 82.65.MY ; 82.65NZ
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract New experimental results are reported pointing to the possibility of a laser control of the resonant gases transit through capillaries in the Knudsen and intermediate regimes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00696210
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  • 3
    Electronic Resource
    Electronic Resource
    Identification of biphonons from prominent features of the angular and energy dependences of the inelastic-scattering cross section of biphonon-splitting neutrons (1998)
    Springer
    Physics of the solid state 40 (1998), S. 670-675 
    Details
    ISSN: 1063-7834
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The dispersion relations and wave functions of biphonon and dissociated two-phonon states of anharmonic crystals are used to determine the cross section of inelastic scattering of neutrons that split biphonons into unbound phonons, which scatter each other as a result of their anharmonicity. Prominent features are found of the angular and energy dependences of the cross section, useful for analyzing experimental data to identify biphonons; it is possible that these features can also be used for subsequent, potentially major modification of the system of existing criteria, based solely on energy-balance considerations for the classification of series of spectral resonances, supposedly corresponding to bound multiphonon states of various multiplicities. For a fixed, large loss of neutron energy, the cross section is a maximum in a “nonhead-on” neutron-biphonon collision with a lobe-shaped angular scattering diagram; for intermediate energy losses the cross section has the largest of all possible values at all collision angles; and, for small energy losses, the cross section is a maximum for “head-on” collision in a narrow range of angles. For a fixed angle the energy dependence of the cross section has a resonance peak, which exists at the low-energy edge of a finite energy band for large angles and, as the angle decreases, gradually increases as it shifts toward the high-energy edge of the band, which becomes narrower and shifts into the low-energy region. However, when the angle decreases below a critical value, the still-increasing resonance maximum changes direction and shifts back toward the low-energy edge. It is shown that, despite strong oscillations of the biphonon wave function in the presence of negative phonon dispersion, the cross section does not depend on the sign of the dispersion, i.e., the universal law of independence from this sign, established previously for the dispersion relation and the biphonon damping constant, appears to carry over to the cross section.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1130377
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  • 4
    Electronic Resource
    Electronic Resource
    The dislocation anharmonicity in silicon (2000)
    Springer
    Technical physics letters 26 (2000), S. 974-976 
    Details
    ISSN: 1090-6533
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The effect of the dislocation anharmonicity on the Young modulus in bending silicon single crystals was studied. It is shown that changes in the Young modulus are caused by the contribution of dislocations to the fourth-order elasticity moduli. It is revealed experimentally that the bending deformation in both donor and acceptor silicon crystals favors the appearance mainly of the edge dislocations with the axes forming an angle θ∼90° with the Burgers vector.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1329688
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  • 5
    Electronic Resource
    Electronic Resource
    Electric current and heat induced acoustic emission in cadmium sulfide (2000)
    Springer
    Technical physics letters 26 (2000), S. 996-999 
    Details
    ISSN: 1090-6533
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Acoustic emission (AE) induced by the electric current passing through a cadmium sulfide (CdS) single crystal was studied. In the temperature range T=300–450 K, the intensity of the AE signals excited in the CdS crystal exposed to a constant electric field increases with the current density. It is suggested that AE in CdS is due to the dislocations breaking off and moving under the action of direct electric current and thermoelastic stresses. The activation energy for this process (E a=0.35±0.5 eV) was estimated for a current density in the range of j=(1−7)×105 A/m2.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1329695
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  • 6
    Electronic Resource
    Electronic Resource
    Biphonons in quasicrystals (1997)
    Springer
    Physics of the solid state 39 (1997), S. 141-147 
    Details
    ISSN: 1063-7834
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The spectrum of coupled optical biphonon vibrations in quasicrystals with variation of the atom-atom interaction in accordance with the Fibonacci sequence is investigated. For two-phonon states with strong anharmonicity of the vibrations, a system of recursion equations, which is more complicated than the previously employed system for one-phonon states, is obtained. Calculations using this system made it possible to determine the spectrum of biphonon vibrations in a quasicrystal. It is shown that, on the low-frequency edge of the biphonon band, a scaling-type fine structure of the same form as in biphonon spectra of fractal lattices exists in the density of states. It is found that the energy dependence of the density of states is periodic on a logarithmic scale. The period of this dependence is determined. It is noted that the resonance structure in the density of states is of a nonstandard form in the high-frequency region of the biphonon band.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1129815
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  • 7
    Electronic Resource
    Electronic Resource
    Fermi resonance of optical one-phonon and acoustic two-phonon vibrations in light metals (1997)
    Springer
    Physics of the solid state 39 (1997), S. 472-475 
    Details
    ISSN: 1063-7834
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the anharmonicity of crystal lattice vibrations in light metals such as beryllium, can give rise to a Fermi resonance of optical one-phonon and acoustic two-phonon vibrations. New hybridized vibrational states are formed as a result of such a resonance interaction: biphonon and quasibiphonon vibrations and renormalized optical vibrations. Depending on the wave vector, these vibrational states can be both damped and stationary. The corresponding dispersion equation is obtained, whose solution made it possible to determine the spectrum of these vibrations (dispersion curves and the wave vector dependence of the damping for damped vibrations). It is shown that ultrafast damping of optical vibrations, similar to the well-known superradiance effect for Frenkel’ and Wannier-Mott excitons, is possible.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1129874
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  • 8
    Electronic Resource
    Electronic Resource
    Electrically stimulated movement of edge dislocations in silicon in the temperature range 300–450 K (2000)
    Springer
    Physics of the solid state 42 (2000), S. 2054-2060 
    Details
    ISSN: 1063-7834
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The movement of edge dislocations and the related acoustic emission of Si (111) carrying a direct current of density 0.5−5×105 A/m2 in the [110] direction are studied in the temperature range T=300–450 K. It is shown that the basic mechanism of dislocation movement is the electric wind determining the magnitude of the effective charge (per atom of the dislocation line) Z eff=0.06 (n-Si) and −0.01 (p-Si). Matching theory with experimental data has made it possible to determine the main contribution of edge dislocations to the acoustic-emission response of the silicon samples under investigation. The characteristic transition frequencies of dislocations in n-and p-Si from one metastable state into another are found to be f max=0.1–0.5 Hz. The numerical values of the diffusion coefficient for atoms in the dislocation impurity atmosphere are estimated as 3.2×10−18 m2/s (n-Si) and 1.5×10−18 m2/s (p-Si).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1324039
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  • 9
    Electronic Resource
    Electronic Resource
    Influence of magnetic field on acoustic emission in dislocation-containing silicon under current loading (2000)
    Springer
    Physics of the solid state 42 (2000), S. 1861-1864 
    Details
    ISSN: 1063-7834
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The influence of weak (〈1 T) magnetic fields on acoustic emission (AE) of dislocation-containing n-Si(111) under current loading j=(1−5)×105 A/m2 is investigated. It is found that the combined effect of the magnetic and electric fields leads to an increase in the acoustic emission response by a factor of 1.5 and is responsible for the emergence of an additional peak in the AE spectra at a frequency of 1.7–1.8 Hz. The result is explained by the influence of magnetic fields, which changes the energy state of paramagnetic stoppers. This facilitates the separation and motion of dislocations. Withdrawal of the magnetic field leads to the relaxation of acoustic emission processes, which is determined by the dynamics of excited point centers interacting with a dislocation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1318877
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  • 10
    Electronic Resource
    Electronic Resource
    A new type of local polariton at the interface of gyrotropic enantiomorphic crystals (1999)
    Springer
    Physics of the solid state 41 (1999), S. 302-305 
    Details
    ISSN: 1063-7834
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that a new type of local polariton can propagate at the interface of enantiomorphic twins—gyrotropic crystals with left-handed and right-handed rotation of the polarization plane. The wave function of these local polaritons oscillates strongly, with changes of sign, over lengths of the order of the lattice constant near the interface, and the period of the spatial oscillations grows with increasing distance from the interface. The local polariton term is detached from the band of delocalized states toward higher frequencies. Calculations of the radiation broadening of this term show that, for a local polariton, the effect of a giant increase of the decay (“superradiance”) is possible. The magnitude of the polarization rotation due to a local polariton has been found.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1134/1.1130772
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