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301.
In this paper, the authors characterize Carleson measures for the weighted Bergman spaces with B′ekoll′e weights on the unit ball. They apply the Carleson embedding theorem to study the properties of Toeplitz-type operators and composition operators acting on such spaces. 相似文献
302.
《Journal of magnetism and magnetic materials》1987,68(1):15-27
The 57Fe Mössbauer effects of Nd2Fe14B were measured in a temperature range of 4.2−300 K. Below the spin reorientation transition temperature Tsc = 148 K, the spectra were satisfactorily analyzed with twelve Zeeman sextuplets due to splitting of six crystallographic Fe-sites into twelve non-equivalent sites. It was shown that the magnetic moments of the Fe and the Nd atoms are non-collinearly coupled in the magnetic structure with canted moments below Tsc. The directions of the moments at 4.2 K are inclined at 27° for Fe and at 58° for Nd from the c-axis to the [110] direction. The average moments are 2.27μB for Fe and 3.3μB for Nd at 4.2 K. The increase of the average hyperfine field with decreasing temperature is suppressed below Tsc, and its value at 4.2 K is reduced by 1% from the value of 337 kOe which is observed in Y2Fe14B and also estimated for Nd2Fe14B by extrapolating the values above Tsc. On the other hand, the Nd moment increases abruptly around Tsc as the temperature decreases. The directions of the principal axes of electric field gradients on the six distinct Fe-sites were also obtained. The anomalous temperature dependence of quadrupole splittings and isomer shifts was observed around Tsc. They were discussed in a framework of the changes in the band structure and the lattice parameters incidental to the spin reorientation transition. 相似文献
303.
The enthalpy of formation of cubic (b.c.c., a0 = 1.0839 ± 0.0004 nm) Cf2O3, ΔfH° (298 K), has been determined to be −1652.6 ± 10.3kJ mol−1 by solution microcalorimetry. The magnetic susceptibilities of two samples have been measured between 1.5 and 300 K. Cf2O3 obeys the Curie-Weiss law between 90 and 300 K with eff = 9.7 ± 0.2 μB and gq = −80 ± 10 K. 相似文献
304.
《Fluid Phase Equilibria》1996,118(2):153-174
A generalized van der Waals equation of state, applied recently (Nguyen Van Nhu and Kohler, 1995) to the calculation of excess properties and phase equilibria for the mixture methane + ethane, is now extended to several nonpolar binary mixtures.Improved mixing rules for the van der Waals attractive term and for the correction term are proposed. With these mixing rules, the equation gives good agreement for vapour-liquid and liquid-liquid equilibria over a large temperature range for 29 binary mixtures. The agreement of mixture volumes and cross second virial coefficients is also satisfactory. 相似文献
305.
采用多能场复合微细电沉积加工技术,制备了微观结构渐变的多彩结构色磁性Al2O3-Co复合薄膜.在沉积电场和与之垂直的偏转电场作用下,复合薄膜的微观结构、光学特性和磁性沿偏转电场方向呈现渐变特征.通过建立微观结构等效模型,理论分析了复合薄膜微观结构变化机理.通过软件仿真定量分析了沿偏转电场方向Co离子沉积电流密度分布规律,仿真结果与理论研究和实验结果相吻合.研究发现,采用多能场复合的微细电沉积加工技术可以从微观角度调控复合薄膜微区结构,实现对薄膜微区磁学和光学特性的精细调控. 相似文献
306.
307.
《Physics letters. [Part B]》1987,188(1):129-132
The oscillations of a collisionless quark plasma are studied on the basis of the gauge covariant kinetic equations. The small oscillation approach provides the dispersion relations which coincide with those predicted by the finite-temperature QCD in one-loop approximation. 相似文献
308.
《Physics letters. [Part B]》1987,195(3):423-428
Spontaneous breaking of R parity in the standard supergravity model implies the existence of a majoron which is strongly constrained by astrophysics. This is suggested as the origin of the small parameter required for the resonant amplification of neutrino oscillations to take place in the sun. To a good approximation only one neutrino type (most likely the tau neutrino) acquires a mass. Therefore the form of the leptonic charged current is very much restricted: it is fully described by two mixing angles and there is no CP violation. As a result, matter can only amplify oscillations in one channel which, for small mixings, is vℓvτ. Agreement with the chlorine data on the one hand and the nonobservation of charged supersymmetric states in e+e- collisions on the other, tightly restricts the parameters of the model in a way that will be directly tested by collider experiments. 相似文献
309.
310.
《Optics Communications》1987,61(3):215-218
Modulated pumping of a Nd3+ doped silica monomode fibre laser has been investigated experimentally. For small modulation depths the laser exhibits a resonance at the relaxation oscillation frequency, providing pulses of a few microseconds duration at a repetition rate in the region of 10 kHz, dependent on the average pump level above threshold. As the pump modulation depth is increased, hysteresis is observed as a function of modulation frequency, along with optical bistability. For further increase in modulation depth, optical chaos and period doubling are observed. Gain-switching has also been demonstrated. 相似文献