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841.
Zsolt Patakfalvi 《Discrete Mathematics》2008,308(12):2351-2365
A graph is called normal if its vertex set can be covered by cliques Q1,Q2,…,Qk and also by stable sets S1,S2,…,Sl, such that Si∩Qj≠∅ for every i,j. This notion is due to Körner, who introduced the class of normal graphs as an extension of the class of perfect graphs. Normality has also relevance in information theory. Here we prove, that the line graphs of cubic graphs are normal. 相似文献
842.
申改英 《科技情报开发与经济》2007,17(2):281-282
介绍了太岗线柳林河1#隧道内直线地段的扣件和螺栓锈蚀问题,分析了病害原因,提出了具体的整治措施。 相似文献
843.
Thomassen [Reflections on graph theory, J. Graph Theory 10 (1986) 309-324] conjectured that every 4-connected line graph is hamiltonian. An hourglass is a graph isomorphic to K5-E(C4), where C4 is a cycle of length 4 in K5. In Broersma et al. [On factors of 4-connected claw-free graphs, J. Graph Theory 37 (2001) 125-136], it is shown that every 4-connected line graph without an induced subgraph isomorphic to the hourglass is hamiltonian connected. In this note, we prove that every 3-connected, essentially 4-connected hourglass free line graph, is hamiltonian connected. 相似文献
844.
Firstly, the analysis of [A. Büyükaksoy, G. Cinar, A.H. Serbest, Scattering of plane waves by the junction of transmissive and soft-hard half planes, ZAMP 55 (2004) 483-499] for the scattering of plane waves by the junction of transmissive and soft-hard half planes is extended to the case of a line source. The introduction of the line source changes the incident field and the method of solution requires a careful analysis in calculating the scattered field. The graphical results are presented using MATHEMATICA. We observe that the graphs of the plane wave situation [A. Büyükaksoy, G. Cinar, A.H. Serbest, Scattering of plane waves by the junction of transmissive and soft-hard half planes, ZAMP 55 (2004) 483-499] can be recovered by shifting the line source to a large distance. Subsequently, the problem is further extended to the case of scattering due to a point source using the results obtained for a line source excitation. The introduction of a point source (three dimensions) involves another variable which then requires the calculation of an additional integral appearing in the inverse transform. 相似文献
845.
A modified PRP conjugate gradient method 总被引:4,自引:0,他引:4
This paper gives a modified PRP method which possesses the global convergence of nonconvex function and the R-linear convergence
rate of uniformly convex function. Furthermore, the presented method has sufficiently descent property and characteristic
of automatically being in a trust region without carrying out any line search technique. Numerical results indicate that the
new method is interesting for the given test problems.
This work is supported by Guangxi University SF grands X061041 and China NSF grands 10761001. 相似文献
846.
Liu Deming 《沈阳师范大学学报(自然科学版)》1999,(1)
讨论了多项式系统 极限环的存在性和唯一性,其中a为正的奇数,彻底解决了(1)的极限环个数和分 布问题。 相似文献
847.
C. Corsi F. D'Amato M. De Rosa G. Modugno 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》1999,6(3):327-332
Fundamental spectroscopical parameters of CO2 are reported using a high resolution, direct absorption spectrometer, based on a distributed feed-back diode laser emitting
at 2 μm. Line intensity, self- and foreign broadening and shift, with N2 and O2 as foreign gases, have been measured with high accuracy in the combination band of CO2, for 13 lines of the R branch, from R(22) up to R(46). Comparison with available data is made, when possible, and a generally
good agreement has been found.
Received: 24 April 1998 / Received in final form: 28 October 1998 相似文献
848.
The Fourier-transform absorption spectrum of 15N14N16O-enriched nitrous oxide has been recorded at the Doppler limited resolution in the spectral range 3500-9000 cm−1. More than 15 000 transitions of 15N14N16O were observed and assigned based on the global effective Hamiltonian model. The band-by-band analysis led to the determination of the ro-vibrational parameters of a total of 133 bands. Among these bands, 103 were newly observed, and the rotational analysis of 30 others were significantly extended and improved. 相似文献
849.
The present work is concerned with the free vibration analysis of an elastically supported cracked beam. The beam is made of a functionally graded material and rested on a Winkler–Pasternak foundation. The line spring model is employed to formulate the problem. The method of differential quadrature is applied to solve it. The obtained results agreed with the previous similar ones. Further, a parametric study is introduced to investigate the effects of the geometric and elastic characteristics of the problem on the values of natural frequencies and mode shape functions. 相似文献
850.
本文通过分析共用接地极特点,提出了共用接地极的接线方案。在共用接地极进线处装设隔离开关,并根据实际工程条件选择了隔离开关的型式和参数。通过计算共用接地极的电位升分布,对接地极线路检修提出了建议。 相似文献