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891.
G. Marest A. Fontes M. Jeandin S. Fayeulle M. Vardavoulias M. Frainais 《Hyperfine Interactions》1998,112(1-4):39-42
Pearlitic grey iron was treated by means of a XeCl laser to remelt only a shallow layer. This process allows to modify the
heteregeneous surfaces of cast irons in order to improve their tribological behaviour. The energy density ranged from 0.3
to 3 J/cm2 and the number of shots from 4 to 40. It is shown that after laser irradiation austenite is formed in the melted layer; compressive
stresses at the surface were exhibited as well as the deposition of graphite and the formation of carbides. It is shown that
excimer laser processing highly decreases the coefficient of friction and the wear rate.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
892.
A. B. Drovosekov N. M. Kreines D. I. Kholin V. F. Meshcheryakov M. A. Milyaev L. N. Romashev V. V. Ustinov 《JETP Letters》1998,67(9):727-732
The excitation spectrum in an [Fe/Cr]n multilayer structure with non-collinear magnetic ordering was studied by the ferromagnetic resonance (FMR) method in the
frequency interval 9.5–37 GHz at room temperature. Besides an acoustic branch, several additional modes were observed under
parallel excitation of resonance. The FMR spectrum was calculated analytically in a biquadratic exchange model, neglecting
in-plane anisotropy, for an infinite number of layers in the structure and numerically for a finite number of layers contained
in real samples. It was shown that the observed modes correspond to excitation of standing spin waves with wave vectors perpendicular
to the film plane.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 9, 690–695 (10 May 1998) 相似文献
893.
The thermodynamic and transport properties of normal disordered conductors are strongly influenced by the proximity of a superconductor.
A cooperation between mesoscopic coherence and Andreev scattering of particles from the superconductor generates new types
of interference phenomena. A field theoretic approach is introduced which is capable of exploring both the averaged properties
and mesoscopic fluctuations of superconductor/normal-metal systems. As an example the method is applied to the study of the
level statistics of a SNS junction.
Pis’ma Zh. éksp. Teor. Fiz. 67, No. 1, 21–26 (10 January 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
894.
895.
A microscopic theory of the Efetov supermatrix sigma-model type is constructed for the low-lying electron states in a mixed
superconductive-normal system with disorder. This technique is used for the study of the localized states in the core of a
vortex in a moderately clean superconductor with τ
−1≫ω
0∼Δ2/E
F
. At low energies ε≪ω
Th∼ (ω
0/τ)1/2, the energy level statistics is described by the “zero-dimensional” limit of this supermatrix theory, and the result for
the density of states is equivalent to that obtained within Altland-Zirnbauer random matrix model. Nonzero modes of the sigma
model increase the mean interlevel distance by the relative amount [2 ln (1/ω
0
τ)]−1.
Pis’ma Zh. éksp. Teor. Fiz. 68, No. 1, 78–83 (10 July 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
896.
We use integrals of Cauchy type and the complex potentials of S. G. Lekhnitskii to solve the problem of the stress-strain
state of a piecewise-homogeneous anisotropic rock during the working of a horizontal seam of mineral. We study the stress
distribution in the deloaded zones. Three figures, 1 table. Bibliography: 4 titles.
Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 27, 1997, pp. 81–86. 相似文献
897.
898.
The reactions of IO radicals with CH3SCH3, CH3SH, C2H4, and C3H6 have been studied using the discharge flow method with direct detection of IO radicals by mass spectrometry. The absolute rate constants obtained at 298 K are the following: IO + CH3SCH3 → products (1): k1 = (1.5 ± 0.2) × 10?14; IO + CH3SH → products (2): k2 = (6.6 ± 1.3) × 10?16; IO + C2H4 →products (3): k3 < 2 × 10?16; IO + C3H6 → products (4): k4 < 2 × 10?16 (units are cm3 molecule?1 s?1). CH3S(O)CH3 and HOI were found as products of reactions (1) and (2), respectively. The present lower value of k1 compared to our previous determination is discussed. 相似文献
899.
The 351 nm laser-damage thresholds (at 0.7 nm pulse length) of monomeric liquid crystals are reported and results from aromatic-core samples are compared with those from fully saturated systems. The role of π-electron conjugation is examined and identified as the key cause for laser damage. For UV laser compatibility of devices, the damage behaviour of an alignment-layer polymer (nylon 6/6) was also investigated. 相似文献
900.
A. F. Blinokhvatov O. V. Markovtseva M. N. Nikolaeva 《Chemistry of Heterocyclic Compounds》1992,28(3):266-268
Substituted 4H-pyrans were obtained in high preparative yields by the reaction of 1,5-diketones with acetic anhydride and boron trifluoride etherate in diethyl ether. It is assumed that the heterocyclization of 1,5-diketones includes a step involving the formation and transformations of an acyloxy carbonium ion.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 320–322, March, 1992. 相似文献