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Natural diamonds are studied by Fourier-transform IR (FTIR) spectroscopy, and it is shown that B2 centers in them form through intermediate stages, which are accompanied by the appearance of absorption bands with maxima
near 1550 and 1526 cm−1. The concentration of interstitial carbon atoms in the centers responsible for these bands may be several times higher than
the concentration of the interstitials in B
2 defects. 相似文献
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A. Raicu Th. Ionescu-Bujor A. Pantea V. Valeanu J. Badalec K. Jakubka VI. Kopecký J. Stöckel M. Valovič F. Žáček 《Czechoslovak Journal of Physics》1987,37(7):850-861
The start-up phase of discharge in a TM-1-MH tokamak has been investigated. We present a simple model describing the time evolution of electron density in a time interval where the bulk of electron distribution function is already Maxwellian and thermal ionization of neutral gas dominates. Comparison of the computed results with experimental data proved the validity of this model and allowed us to determine the electron temperature during this period of the discharge. The role of the run-away electron production during the start-up phase is discussed. 相似文献
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V.V. Kocharovsky VI.V. Kocharovsky 《Physica C: Superconductivity and its Applications》1992,200(3-4):385-402
The Green's function method and diagram technique for umklapp electron-electron scattering mediated by the screened Coulomb interaction in layered anisotropic conductors are examined. Gor'kov-type equations and their general solution for anomalous and normal temperature Green's functions are derived taking into account umklapp scattering of all orders. Explicit equations for dielectric and superconducting order parameters, including coexistent Bragg and BCS pairing, are found. The possibility of the first-order phase transition to the superconducting state is discussed. The theory elucidates the origin of Bragg-Coulomb high-Tc superconductivity, proposed by the authors. 相似文献
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