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991.
The electronic band structure of YbRhSn has been calculated using
the self-consistent full potential nonorthogonal local orbital minimum
basis scheme based on the density functional theory. We investigated
the electronic structure with the spin-orbit interaction and on-site
Coulomb potential for the Yb-derived 4f orbitals to obtain the correct
ground state of YbRhSn.
The exchange interaction between local f electrons and conduction
electrons play an important role in the heavy fermion characters of them.
The fully relativistic band structure scheme
shows that spin-orbit coupling splits the 4f states
into two manifolds, the 4f7/2 and the 4f5/2 multiplet. 相似文献
992.
基于神经网络的钞票真假识别研究 总被引:3,自引:1,他引:2
利用神经网络与光电检测的技术研制了钞票真假识别系统.介绍了系统的结构组成、工作原理、软件系统、神经网络的优化设计、实验及测试结果.经实践验证,其识别结果稳定可靠,可应用于金融智能防伪点钞机与ATM机中. 相似文献
993.
The magnetoelastic plane strain problem of an interfacial Griffith crack between two dissimilar soft ferromagnetic elastic materials subjected to a uniform magnetostatic field is considered within the framework of linear magnetoelasticity. By making use of the Fourier integral transform technique, the mixed boundary problem is then reduced to a pair of singular integral equations of the second kind. Solutions of the singular integral equations are obtained numerically by means of a Jacobi polynomial expansion method. Effects of the magnetic field, the combinations of the magnetic properties of materials and the geometric parameters on the magnetoelastic stress intensity factors in the vicinity of crack tip are shown graphically. 相似文献
994.
The paper presents an analysis of some recently proposed improvements of the water hammer equations, which concern the friction term in the momentum equation. A comparison of the experimental data and numerical results shows that the required damping and smoothing of the pressure wave cannot be obtained by modification of the friction factor only. In order to evaluate the significance of the introduced improvements into the momentum equation, the accuracy of the numerical solution has been analysed using the modified equation approach. The analysis shows why the physical dissipation process observed in the water hammer phenomenon cannot be reproduced with the commonly used source term in Darcy–Weisbach form, representing friction force in the momentum equation. Therefore, regardless of the proposed form of the friction factor for unsteady flow, the model of water hammer improved in such a way keeps its hyperbolic character. Consequently, it cannot ensure the expected effects of damping and smoothing of the calculation head oscillations. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
995.
B. G. M. Vandeginste G. Kateman J. K. Strasters H. A. H. Billiet L. de Galan 《Chromatographia》1987,24(1):127-134
Summary The mathematical resolution of overlapped chromatographic peaks obtained in HPLC with a diode array UV detector has received
considerable attention recently. The purpose of the proposed methods is the quantitation and identification of unknown solutes
in complex mixtures by an efficient use of all available data.
Basically two approaches have been proposed: the first one resolves the concentration profiles and calculates the pure spectra
by applying a minimal number of assumptions, which is denoted self-modeling-curve resolution. The second one is based on a
match of pure spectra available in a spectral library with the measured mixture spectra.
In this paper both approaches are evaluated with respect to their performance to provide the pure spectra and an accurate
quantitation of the concentrations. 相似文献
996.
The single longitudinal mode (SLM) characteristics of narrow linewidth long-external-cavity semiconductor lasers has been improved significantly by using a multisegment composite-cavity configuration. In this paper, the mode selectivities of two-segment, three-segment and four-segment cavity semiconductor lasers have been analysed and compared. In experiments, a four-segment composite cavity laser exhibits SLM oscillation with side-mode suppression ratio of 30 dB even for total external cavity length of 75 cm. The oscillation linewidth is less than 200 kHz. 相似文献
997.
N. Mazars 《商业与工业应用随机模型》1989,5(3):179-201
Binary coherent system theory has played an important part in reliability. Its extension to (‘degradable’ or ‘multistate’ or) multinary systems has recently been considered in various papers, through various definitions. This paper lays the foundations of a unified theory for coherent systems by first giving unified arguments to apply and to investigate further binary and multinary systems. Monotone binary systems are introduced and examined by generalizing classic deterministic and probabilistic results. Applications of monotone coherence to the multinary case are proposed in a companion paper with a unified viewpoint on multinary coherent systems. As an indication, monotone constraints are defined with a partition of the component set and some total orderings imposed on the elements of the concerned partition. The discrete partition retrieves the classic theory of (free) binary coherent systems; some constraints defined from component levels lead to multinary coherent systems; some other constraints apply to systems submitted to some ‘common stresses’, e.g. the organizing system of a monotone coherent decomposition. 相似文献
998.
N. Mazars 《商业与工业应用随机模型》1989,5(3):203-231
Binary coherent system theory has played an important part in reliability. Its extension to (‘degradable’ or ‘multistate’ or) multinary systems has recently been considered in various papers, through various definitions. This paper studies the most general model for multinary systems, proposes a unified viewpoint on multinary coherent systems and gives unified arguments to apply and to investigate further the binary and multinary cases. In a more detailed way, the ‘helpful bridge’ lately proposed by Block and Savits1 between the binary and multinary cases is completed and multinary systems then can be studied in terms of monotone binary coherent systems, introduced in a companion paper.2 Through various results, multinary systems are examined in terms of structure functions and of life functions; fundamental relations for their analysis are obtained with their set characterizations; the main axis that can be retained among the numerous types of coherence is emphasized, in a unified way, through relevance; reliability models are examined through performance processes, life lengths and performance functions; and Birnbaum's factors of importance are thoroughly extended to the multinary case. Fundamental results proposed in previous studies are thus completed with a shorter unified approach. 相似文献
999.
磁脉冲压缩器用脉冲变压器的设计 总被引:4,自引:3,他引:1
本文简要说明了磁脉冲压缩器的工作原理。着重介绍了其输入、输出脉冲变压器的等效回路设计法。并将该方法用于实例进行验证。结果说明,这种设计方法是非常成功的,而且可以推广到一般情况下的脉冲变压器的设计。 相似文献
1000.