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151.
We show that (ℚω, +, σ, 0) is a quasi-minimal torsion-free divisible abelian group. After discussing the axiomatization of the theory of this structure, we present its ω-saturated quasi-minimal model. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
152.
广义拟牛顿算法对一般目标函数的收敛性 总被引:2,自引:0,他引:2
本文证明了求解无约束最优化的广义拟牛顿算法在Goldstein非精确线搜索下对一般目标函数的全局收敛性,并在一定条件下证明了算法的局部超线性收敛性。 相似文献
153.
Ju Myung Kim 《Journal of Mathematical Analysis and Applications》2006,320(2):619-631
This paper is concerned with compactness for some topologies on the collection of bounded linear operators on Banach spaces. New versions of the Eberlein–Šmulian theorem and Day's lemma in the collection are established. Also we obtain a partial solution of the dual problem for the quasi approximation property, that is, it is shown that for a Banach space X if X** is separable and X* has the quasi approximation property, then X has the quasi approximation property. 相似文献
154.
155.
无穷级拟亚纯映射的充满圆及Borel方向 总被引:4,自引:0,他引:4
对于平面上的K-拟亚纯映射,文献^[1]里证明了有限正级K-拟亚纯映射必定存在充满圆序列及Borel方向;本文进一步证明了对于平面上无穷级K-拟亚纯映射也存在充满圆序列及Borel方向. 相似文献
156.
Solutions of α-cyclodextrin, 4-methylpyridine and water undergo a reversible liquid–solid phase transition on heating (“inverse freezing”). In this paper quasi elastic neutron scattering (QENS) measurements are reported, from which the diffusive dynamics of different components in the liquid and solid phases is determined. Results imply that, in solution, α-cyclodextrin is contained in a solvation shell of 4-methylpyridine molecules, while in the crystal phase, the majority of the cell contents are immobilized on the nanosecond timescale. This information will be important in evaluating the entropy of the system in its different phases and in understanding the unusual phase transition. 相似文献
157.
Second-harmonic scattering (SHS) of light by laminar ferroelectric domains of the orthorhombic phase of RbH2PO4 below Tc=147 K is studied in detail. CCD images of the far-field SHS pattern reveal up to six off-axis distinct intensity maxima in a plane normal to the ferroelectric axis c. These scattering maxima are interpreted on the basis of the quasi-phase matching (QPM) conditions for the three sets of polarizations allowed by the nonvanishing elements of the second-order nonlinear susceptibility tensor. On this assumption scattering angles of the three SHS modes calculated from crystal optics are shown to fit well the experimental data for any incidence of the pump beam normal to c. Scattering intensities of the two most intense modes are also measured versus the component of the wave vector perpendicular to the modulated structure. A stochastic model giving the intensity as a function of the density probability of domain widths is developed and is shown to give a good fit of the scattered intensity. Moreover, it permits the evaluation of the mean and dispersion of the ferroelectric domain widths, which are found to be, respectively, 2.6 and 0.7 μm in the crystal under study. This is consistent with the domain size of the ferroelastic counterpart revealed by polarization microscopy. 相似文献
158.
159.
Lin Feng Wang 《Differential Geometry and its Applications》2013,31(3):337-348
We study τ-quasi Yamabe gradient solitons on complete noncompact Riemannian manifolds. We prove several scalar curvature estimates under some conditions and get a non-local collapsing result based on the gradient estimate of the potential function. We also derive a decay theorem and a finite topological type result. 相似文献
160.
This consideration is a conjunction of two processes: generation of recoil products and selective detection. A new type of plasma is carried out. The electron energy function distribution of the ion-guide source plasma is calculated and discussed. The properties of a laser ionization scheme detecting recoil atoms are analyzed using an optogalvanic approach. The Resonant Laser Ionization (RLI) in low temperature currentless plasma, formed by accelerated particle beam propagating through gas, will be used for the above mentioned separation. A tuned dye laser excites the studied atoms and the fast electrons ionize them. This process exceeds in cross-section the ionization from ground state which provides selectivity of IGS. The latter produces ions of almost all chemical elements. It can be used for investigating processes flowing in low temperature currentless plasma which presents a specific interest. These functions impart to the IGS the role of an Optogalvanic (OG) element, to be precise, of hollow cathode discharge used as an OG detector [1]. In this paper the IGS is analyzed as an OG detector in a quasi OG scheme. The investigation is a step simulating the IGS properties. The Electron Energy Distribution Function (EEDF) and the most important processes are analyzed and discussed as a first step in this field. The results obtained contribute to the efficiency of the RLI method. 相似文献