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951.
B. K. Kardashev Yu. A. Burenkov B. I. Smirnov A. R. de Arellano-Lopez J. Martinez-Fernandez F. M. Varela-Feria 《Physics of the Solid State》2004,46(10):1873-1877
The effect of the vibration strain amplitude on the Young modulus and ultrasonic absorption (internal friction) in biomorphic SiC ceramics is investigated in the temperature range 116–296 K. The biomorphic SiC ceramics is prepared through pyrolysis of eucalyptus with subsequent infiltration of silicon. It is demonstrated that the vibration loading of samples in air and under vacuum is accompanied by a number of unexpected effects. The behavior of the studied ceramics is governed by at least two mechanisms, which, to a large extent, are responsible for the elastic and inelastic properties of the material. One mechanism is associated with the adsorption-desorption of environmental molecules (hypothetically, owing to the presence of pores and residual carbon), and the other mechanism involves microplastic deformation due to the motion of dislocations or other (similar) structural units. 相似文献
952.
The crystallization of nickel nanoclusters is investigated using a molecular dynamics simulation with tight-binding potentials. The formation of a cluster structure depends on the cooling conditions. Slow cooling results in the formation of a face-centered cubic structure, whereas fast cooling, according to the data obtained in 40% of the simulation experiments, leads to the formation of an icosahedral structure. The molecular dynamics simulation experiments demonstrate the possibility of controlling the formation of a structure of nickel nanoclusters during crystallization. 相似文献
953.
In terms of the standard thermodynamic approach (the Debye-Grüneisen model of solid and the Landau theory of second-order phase transitions), approximate conditions providing the constancy of the volumetric thermal expansion coefficient (the Invar effect) and of the bulk modulus (the Ellinvar effect) of a ferromagnet are established. Conditions under which a ferromagnet may exhibit Invar and Ellinvar properties simultaneously are found. Interaction between the magnetic, phonon, and electron subsystems of a ferromagnet is shown to be a crucial factor in the occurrence of the Invar and Ellinvar effects. 相似文献
954.
Yu. A. Morozov 《Technical Physics》2004,49(5):603-608
The effect of random frequency fluctuations due to spontaneous emission and generation-recombination noise on the shape of
the emission line of a semiconductor laser with pseudorandom modulation of the pump current is studied numerically. The roles
of spontaneous emission and chirp modulation in forming the lasing spectrum are separated out. The dependence of the output
spectral characteristics of the laser on the parameters and type of modulation is analyzed. 相似文献
955.
956.
957.
Yu. V. Pyatkov V. V. Pashkevich W. H. Trzaska G. G. Adamian N. V. Antonenko D. V. Kamanin V. A. Maslov V. G. Tishchenko A. V. Unzhakova 《Physics of Atomic Nuclei》2004,67(9):1726-1730
An analysis of the preferable fission path manifesting itself as a fine structure of the total kinetic energy-mass distribution of the fission fragments compelled us to put forward an absolutely new shape of the fissioning system on the descent from the fission barrier. It is a multicomponent nuclear molecule constituted by two magic clusters and a torus-like neck between. 相似文献
958.
A. N. Aleev N. S. Amaglobeli V. P. Balandin O. V. Bulekov I. M. Geshkov T. S. Grigalashvili E. A. Goudzovski D. K. Guriev D. D. Emelianov S. V. Eremin A. I. Zinchenko Z. M. Ivanchenko I. M. Ivanchenko M. N. Kapishin A. A. Loktionov V. D. Kekelidze Z. I. Kozhenkova V. V. Korenkov I. G. Kosarev N. A. Kuzmin A. L. Ljubimov D. T. Madigozhin V. G. Maznyj A. S. Mestvirishvili N. A. Molokanova A. N. Morozov R. E. Pismenyj V. D. Poze I. A. Polenkevich A. K. Ponosov T. Ponta Yu. K. Potrebenikov F. M. Sergeev L. A. Slepets V. N. Spaskov 《Physics of Atomic Nuclei》2004,67(8):1513-1522
The features of the associated production of φ mesons with Λ0 hyperons in neutron-carbon interactions were investigated. The experiment was performed with the aid of the EXCHARM spectrometer at the Serpukhov accelerator in a neutron beam of energy in the interval 20–70 GeV. The differential cross section for inclusive associated φΛ0 production was measured. 相似文献
959.
V. K. Voronkova R. T. Galeev S. Shova G. Novitchi C. I. Turta A. Caneschi D. Gatteschi J. Lipkowski Yu. A. Simonov 《Applied magnetic resonance》2003,25(2):227-247
New compounds, [Cu3Ln2(ClCH2COO)12(H2O)8]·2H2O with Ln = Nd3+ (I), Sm3+ (II), Pr3+ (III), built up of pentanuclear clusters were synthesized and studied by means of X-ray analysis and electron paramagnetic
resonance (EPR). X-ray data show that all compounds are isostructural and the pentanuclear clusteres may be considered as
a linear system with alternating Cu(II) and Ln(III) ions: Cu(2)-L1-Ln-L2-Cu(1)-L2-Ln-L2-Cu(2) with L1 and L2 being bridging fragments and Cu(1) and Cu(2) being structurally nonequivalent copper complexes. EPR studies demonstrate that
in the temperature range of 100–293 K the signals due to only one type of the copper complexes are observed in the spectra
of I–III. AtT<100 K the spectral temperature dependence is nontrivial. AtT<30 K new signals are detected in the spectra of I and II. The temperature dependence of the EPR spectra is interpreted under
the assumption that the parameter of the exchange interaction Cu(2)-Ln considerably exceeds the parameter of the interaction
Cu(1)-Ln. EPR spectra are calculated for the fragments of five paramagnetic centers in the frames of the model taking into
account the nonequivalence of two copper complexes, short longitudinal and transverse paramagnetic relaxation times of the
rare-earth ions at room temperature and the change of the relaxation rates when the temperature decreases. The results of
the calculations show that it is possible to obtain information about the interactions in the system on the basis of the analysis
of the temperature dependence of the EPR spectra of the central copper complex. The parameter of the isotropic part of the
exchange interaction between copper and neodymium ions (for the interaction Cu(2)-Nd) is estimated as about 15 cm−1. A considerable rearrangement of the spin states when the temperature changes is found for all complexes. 相似文献
960.
The classes ofL
1-matrices,L
2-matrices,L
3-matrices andW-matrices are introduced to study solvability of a linear complementarity problem via solving a linear program. Three sufficient
conditions are presented to guarantee that a linear complementarity problem is solvable via a linear program. The new sufficient
conditions are weaker than the ones introduced by Mangasarian. This fact is also illustrated by an example.
Partially supported by NSFC.
This author is also with College of Business Administration of Human University as a Lotus chair professor. 相似文献