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51.
E. A. Bailov N. Temirgaliev 《Computational Mathematics and Mathematical Physics》2006,46(9):1515-1525
Sharp estimates (in the power scale) are obtained for the discretization error in the solutions to Poisson’s equation whose right-hand side belongs to a Korobov class. Compared to the well-known Korobov estimate, the order is almost doubled and has an ultimate value in the power scale. 相似文献
52.
Khalid KOUFANY 《数学学报(英文版)》2006,22(5):1467-1472
Let Ω be a symmetric cone. In this note, we introduce Hilbert's projective metric on Ω in terms of Jordan algebras and we apply it to prove that, given a linear invertible transformation g such that g(Ω) = Ω and a real number p, |p| 〉 1, there exists a unique element x ∈ Ω satisfying g(x) = x^p. 相似文献
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从立方抛物线谈起(1)--余弦型振动,椭圆余弦型振动与双曲线型非周期运动 总被引:1,自引:1,他引:0
从立方抛物线的特性谈起 ,用较初浅的方法 ,借助于雅可比椭圆函数求椭圆方程的解来说明一大类一维保守系统的余弦振动、椭圆余弦型振动与双曲线型非周期运动 .并以杜芬振子、单摆、倒摆、转动圆环上的小环运动为典型实例作了详细讨论 相似文献
57.
V. V. Kozlov 《Functional Analysis and Its Applications》2005,39(4):271-283
We discuss the symplectic geometry of linear Hamiltonian systems with nondegenerate Hamiltonians. These systems can be reduced to linear second-order differential equations characteristic of linear oscillation theory. This reduction is related to the problem on the signatures of restrictions of quadratic forms to Lagrangian planes. We study vortex symplectic planes invariant with respect to linear Hamiltonian systems. These planes are determined by the solutions of quadratic matrix equations of a special form. New conditions for gyroscopic stabilization are found. 相似文献
58.
Neodymium doped bismuth layer structure ferroelectrics (BLSFs) ceramics CaBi4−xNdxTi4O15 (x=0, 0.25, 0.50, 0.75) were prepared by solid-state reaction method. X-ray diffraction pattern showed that single phase was formed when x=0-0.75. The refined lattice parameters showed that a (b) axes decrease at x=0.25 and increase with more Nd3+ dopant. The effects of Nd3+ doping on the dielectric and ferroelectric properties of CaBi4Ti4O15 ceramics are studied. Nd3+ dopant decreased the Curie temperature linearly, and the dielectric loss, tan δ, as well. The remnant polarization of Nd3+ doped CaBi4Ti4O15 ceramics was increased by 80% at x=0.25, while more Nd3+ dopant decreased the remnant polarization. CaBi3.75Nd0.25Ti4O15 ceramics had the largest piezoelectric constant d33. The structure and properties of CaBi4−xNdxTi4O15 ceramics showed that Nd3+ may occupy different crystal locations when Nd3+ content x is less than 0.25 and more than 0.50. 相似文献
59.
This paper presents an enhanced version of the elasto-plastic model for partially saturated soil first proposed by Bolzon,
Schrefler and Zienkiewicz in 1996, “BSZ” model, which uses the effective stress tensor and suction as independent stress variables.
It is recalled that the effective stress tensor proposed by Lewis and Schrefler in 1982 is thermodynamically consistent and,
compared with other choices of stress tensors, results particularly suitable for partially saturated soil mechanics. A hydraulic
constitutive relationship and a hydraulic hysteresis are introduced in the model, to take into account the irreversible deformation
during cyclic drying and wetting until structural collapse. For this reason the plastic rate of strain is split into the sum
of two components: one depending on the effective stress tensor and the other one on suction. This is the new feature of the
BSZ model. This enhanced model is then cast into a thermodynamical framework at macroscopic level and it is shown that it
is possible to derive the constitutive law from the Helmholtz free energy and a dissipation function, both for associative
and non- associative plasticity. Finally the model predictions have been compared with experimental data for Sion slime, with
particular emphasis on the deviatoric part, and model predictions of hysteretic behaviour have been investigated in case of
a wetting and drying cycle on compacted betonite–kaolin. 相似文献
60.
We propose a unified method for deducing recursive relations for the canonical partition function of a system of noninteracting particles with charge conservation if the particles follow the Bose–Einstein, Fermi–Dirac, or Maxwell–Boltzmann statistics or parastatistics. For all these types of statistics, we find recursive relations for the partition function of a new statistical model of nuclear multifragmentation with electric charge and baryon number conservation, accounting for the internal degrees of freedom of the nuclear fragments. 相似文献