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991.
We study the equilibrium statistical mechanics of classical two-dimensional Coulomb systems living on a pseudosphere (an infinite surface of constant negative curvature). The Coulomb potential created by one point charge exists and goes to zero at infinity. The pressure can be expanded as a series in integer powers of the density (the virial expansion). The correlation functions have a thermodynamic limit, and remarkably that limit is the same one for the Coulomb interaction and some other interaction law. However, special care is needed for defining a thermodynamic limit of the free energy density. There are sum rules expressing the property of perfect screening. These generic properties can be checked on the Debye–Hückel approximation, and on two exactly solvable models, the one-component plasma and the two-component plasma, at some special temperature. 相似文献
992.
I. N. Koprinarov U. Müller-Jahreis P. Thiele 《Applied Physics A: Materials Science & Processing》1996,62(6):565-570
The crystalline-amorphous transition in GaAs induced by Ar ions (energy 1–3 keV) has been investigated using single-wavelength ellipsometry. The experiments have been performed in-situ at room temperature. Ion damage straggling, amorphization threshold and critical energy density have been derived by means of a simple analytical model for the growth of the amorphous layer. This model is discussed and the corresponding calculations are found to be in satisfactory agreement with experimental data. 相似文献
993.
D. Abbaneo P. Antilogus T. Behnke S.C. Blyth M. Elsing R. Faccini R.W.L. Jones K. Mönig S. Petzold R. Tenchini 《The European Physical Journal C - Particles and Fields》1998,4(2):185-191
Measurements of the forward-backward production asymmetry of heavy quarks in Z decays provide a precise determination of
. The asymmetries are sensitive to QCD effects, in particular hard gluon radiation. In this paper QCD corrections for and are discussed. The interplay between the experimental techniques used to measure the asymmetries and the QCD effects is
investigated using simulated events. A procedure to estimate the correction needed for experimental measurements is proposed,
and some specific examples are given.
Received: 26 February 1998 / Published online: 2 June 1998 相似文献
994.
We investigate the role of the torsion field at the quantum level. One-loop counterterms are calculated in the theory with terms quadratic in the torsion field. We have shown that the theory is finite at the one-loop level. 相似文献
995.
This paper presents the results of plasma temperature and pressure calculations in the parallel plate accelerator during the accelerating process. The plasma pressure is calculated by means in Dalton's law. 相似文献
996.
997.
998.
Esarey E. Ting A. Sprangle P. Umstadter D. Liu X. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1993,21(1):95-104
A linearly polarized, ultraintense laser field induces transverse plasma currents which are highly relativistic and nonlinear, resulting in the generation of coherent harmonic radiation in the forward direction (i.e., copropagating with the incident laser field). A nonlinear cold fluid model, valid for ultrahigh intensities, is formulated and used to analyze relativistic harmonic generation. The plasma density response is included self-consistently and is shown to significantly reduce the current driving the harmonic radiation. Phase detuning severely limits the growth of the harmonic radiation. The effects of diffraction are considered in the mildly relativistic limit. No third-harmonic signal emerges from a uniform plasma of near-infinite extent. A finite third-harmonic signal requires the use of a semi-infinite or finite slab plasma. For an initially uniform plasma, no second-harmonic radiation is generated. Generation of even harmonics requires transverse gradients in the initial plasma density profile 相似文献
999.
Demin D. L. Dzhelepov V. P. Filchenkov V. V. Grafov N. N. Grebinnik V. G. Migachev D. V. Konin A. D. Rudenko A. I. Sidorov V. T. Zhestkov Yu. G. Zinov V. G. Davies J. D. Bom V. R. van Eijk C. W. E. 《Hyperfine Interactions》1996,101(1):13-19
The ddµ molecule formation rate is experimentally measured for the two hyperfine states of the dµ-atom in the temperature range of 5–30 K. Results are consistent with a preliminary measurement by the TRIUMF group and contradict theoretical predictions. The work has been performed on the JINR phasotron (Dubna). 相似文献
1000.
The Fourier transform infrared spectrum of monoisotopic SC80Se has been investigated in the ν2, ν3, 2ν2, 2ν3, and ν1 regions with a resolution between 3 and 4 × 10−3 cm−1. In addition, the millimeter-wave spectrum has been studied in the region 150 to 320 GHz, and ground and ν2 = 1 excited state transitions have been measured. Ground state constants, B0 = 2043.285 4(4) MHz and D0 = 146.53(5) Hz, have been determined from a merge of millimeter-wave data and ground state combination differences spanning J values up to 77 and 143, respectively. The band centers ν2 = 352.341 075(9) cm−1 and ν3 = 505.480 06(5)cm−1 have been determined. The rovibrational parameters of numerous overtone and combination levels (ν1νl22ν3) = 0200, 0220, 0310, 0330, 0400, 0420, 0002, and 0003 have been obtained from polynomial analyses whose standard deviations ranged from 0.7 to 3.5 × 10−4 cm−1. The 1000 level, νeff 1435.840 cm−1, is anharmonically perturbed by the 0400 level, with an avoided crossing at J = 55, and W12222 = 0.963 09(1) cm−1. Transitions to both the upper (E+) and lower (E−) sublevels of the dyad were observed for 1 ≤ J′ ≤ 117 and 4 ≤ J′ ≤ 171, respectively, and the deperturbed wavenumbers ν1 = 1435.542 76(2) and 4ν02 = 1432.725 00(3) cm−1 were derived. Furthermore, a local crossing of the E− and 0420 levels involving l-type resonance was observed at J = 91. 相似文献