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91.
92.
93.
The co-degrees of irreducible characters 总被引:1,自引:0,他引:1
LetG be a finite group. The co-degree of an irreducible character χ ofG is defined to be the number |G|/χ(1). The set of all prime divisors of all the co-degrees of the nonlinear irreducible characters ofG is denoted by Σ(G). First we show that Σ(G)=π(G) (the set of all prime divisors of |G|) unlessG is nilpotent-by-abelian. Then we make Σ(G) a graph by adjoining two elements of Σ(G) if and only if their product divides a co-degree of some nonlinear character ofG. We show that the graph Σ(G) is connected and has diameter at most 2. Additional information on the graph is given. These results are analogs to theorems
obtained for the graph corresponding to the character degrees (by Manz, Staszewski, Willems and Wolf) and for the graph corresponding
to the class sizes (by Bertram, Herzog and Mann). Finally, we investigate groups with some restriction on the co-degrees.
Among other results we show that ifG has a co-degree which is ap-power for some primep, then the corresponding character is monomial andO
p
(G)≠1. Also we describe groups in which each co-degree of a nonlinear character is divisible by at most two primes. These results
generalize results of Chillag and Herzog. Other results are proved as well.
The paper was written during this author’s visit at the Technion and the University of Tel Aviv. He would like to thank the
departments of mathematics at the Technion and the University of Tel Aviv for their hospitality and support. 相似文献
94.
Ohne Zusammenfassung 相似文献
95.
In this paper we prove that every element in the finite Abelian groupZ
p
×Z
p
,p>3,p prime, can be written as a sum over a subset of the setA, whereA is any set of non-zero elements ofZ
p
×Z
p
with |A|=2p–2.Dedicated to Professor E. Hlawka on the occasion of his seventieth birthday 相似文献
96.
New results on elements 111 and 112 总被引:1,自引:0,他引:1
S. Hofmann F.P. Heßberger D. Ackermann G. Münzenberg S. Antalic P. Cagarda B. Kindler J. Kojouharova M. Leino B. Lommel R. Mann A.G. Popeko S. Reshitko S. Śaro J. Uusitalo A.V. Yeremin 《The European Physical Journal A - Hadrons and Nuclei》2002,14(2):147-157
Experiments on the synthesis and identification of the nuclei 272111 and 277112 were performed in order to confirm previous results. Three additional decay chains were measured in the reaction 64Ni + 209Bi →273111*. The study revealed considerably improved data on the decay chain originating from 272111. One additional chain was measured in the reaction 70Zn + 208Pb →278112*. The decay properties of the chain starting at 277112 are in excellent agreement with the second chain of the first experiment down to 265Sg, where the new chain ends by a previously unknown spontaneous-fission branch. A re-analysis of all the data on elements
110, 111, and 112 measured at GSI since 1994 (a total of 34 decay chains was investigated) revealed that for 2 chains (the
second chain of 269110 measured in 1994 and the first chain of 277112 measured in 1996) the results of the new analysis differed from the previous one. In all other cases the earlier data
are exactly reproduced.
Received: 21 December 2001 / Accepted: 15 January 2002 相似文献
97.
The ξ-carbide, also described as Fe2MoC and MaCb, has been identified at ferrite grain boundaries in 1Cr-0.5Mo steels exposed to elevated temperatures (500–530°C) for prolonged periods (65,000–170,000 hr). The structure and composition of the phase have been characterized using electron microdiffraction and energy-dispersive X-ray spectroscopy (EDXS) respectively. Analysis of microdiffraction patterns supports the proposal that the ξ-carbide has a monoclinic unit cell, rather than the orthorhombic unit cell first proposed. The ranges of metallic element concentrations in the ξ-carbide (i.e. 48–59 at.% Fe, 22–29 at.% Mo, 7–16 at.% Cr, 4–7 at.% Mn and 3–6 at.% Si) are unique compared to those of other carbide precipitates identified in the 1Cr-0.5Mo steels, which means that the ξ-carbide may be identified rapidly on extraction replicas using qualitative EDXS. 相似文献
98.
C. M. Mann D. N. Matheson M. R. B. Jones 《International Journal of Infrared and Millimeter Waves》1989,10(9):1043-1049
A double diode subharmonically pumped mixer is described. A diode-whisker contacting arrangement has been developed which avoids many of the problems associated with whisker contacts. Early tests indicate that the circuit structure is rugged and capable of good electrical performance. 相似文献
99.
Ki Mann Jee Dong Chul Park 《International Journal of Infrared and Millimeter Waves》2003,24(12):2105-2117
A spurious-suppressed transversal filter using the multiple-coupled line is proposed. The frequency characteristics of the multiple-coupled line are analyzed in detail. In order to compare the performances, the novel spurious-suppressed transversal filter using triple-coupled half-wavelength directional couplers is designed at 30 GHz. The spurious-suppression characteristics of the proposed transversal filter are verified by the full wave analysis and the measurement. The spurious response of the fabricated filter is effectively suppressed and the large attenuation is obtained in the stopband. 相似文献