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111.
Bill Jackson 《Journal of Graph Theory》1988,12(3):429-436
We apply proof techniques developed by L. Lovász and A. Frank to obtain several results on the arc-connectivity of graphs and digraphs. The first results concern the operation of splitting two arcs from a vertex of an Eulerian graph or digraph in such a way as to preserve local connectivity conditions. The final result is concerned with orienting the edges of a mixed graph (consisting of vertices, undirected edges, and directed arcs) in such a way that the resulting digraph is as arc-connected as possible. 相似文献
112.
We observed the two-dimensional plasmons of the two-component electron plasma in the (001) Si-inversion layer resulting from simultaneous population of the [001] valley, E0, and the [010] valley, E0′, subbands under a compressional uniaxial stress along [010]. Our data show an onset of electron transfer from E0 to E0′ at X = (1.4 ± 0.1) kbar for n = 1.67 × 1012 cm?2 and X = (1.2 ± 0.2) kbar for n = 2.60 × 1012 cm?2, consistent with the theory of Takada and Ando that includes the electron-electron correlation effects. 相似文献
113.
Bill Sands 《Algebra Universalis》1977,7(1):211-217
A latticeL satisfies thebounded epimorphism condition if wheneverM is a lattce and ϕ:M →L is a bounded epimorphism, there exists a homomorphismι:L →M such that ιϕ=id
L
. we show that the class of finite lattices satisfying the bounded epimorphism condition is properly contained in the class
of finite lattices satisfying Whitman's condition (W). We also introduce a property defined for finite lattices that is sufficient
to imply the bounded epimorphism condition.
Presented by B. Jónsson. 相似文献
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115.
Given an m×n matrix M over E=GF(qt) and an ordered basis A={z1,…,zt} for field E over K=GF(q), expand each entry of M into a t×1 vector of coordinates of this entry relative to A to obtain an mt×n matrix M1 with entries from the field K. Let r=rank(M) and r1=rank(M1). We show that r?r1?min{rt,n}, and we determine the number b(m,n,r,r1,q,t) of m×n matrices M of rank r over GF(qt) with associated mt×n matrix M1 of rank r1 over GF (q). 相似文献
116.
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Morton Kaplan David J. Moses Dag Ø. Eriksen Mehmet Kildir Douglas R. G. Logan Michael S. Zisman Richard J. McDonald 《Zeitschrift für Physik A Hadrons and Nuclei》1983,313(1-2):31-37
Inclusive4He and4H energy spectra and heavy fragment coincidence correlations have been measured for reactions of 7.31 MeV/u238U with238U and?197Au targets. The H/He production cross sections are in the range 15–26 mb, and their emission spectra are very similar for the two systems. The observed strong kinematic shifts with angle are reproduced in shape and magnitude by Monte Carlo simulations of particle evaporation from projectile-like and target-like fragments, indicating competition between charged particle emission and sequential fission. No evidence is found for high energy charged particle emission associated with ultra-highZ composite systems. Heavy fragment measurements indicate an abundance of quasielastic and deeply inelastic reaction fragments, as well as sequential fission of target and projectile nuclei. For238U nuclei, the fission occurs predominantly in an asymmetric mode, reminiscent of fission at low excitation energy. For238+238U reactions in the vicinity of the grazing angle, the frequency of single sequential fission (with survival of the partner fragment) is twice as large as double sequential fission in which both the target and projectile undergo fission. In238U+197Au reactions, the survival probability of the heavy fragments is even greater. The surprisingly high survival probabilities of high-Z fragments imply a preponderance of very soft collisions in these very-heavy-ion reactions, at least at energies not very far over the Coulomb barrier. 相似文献
120.
Logan B. G. Dove W. F. Gerber K. A. Goldenbaum G. C. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1974,2(3):182-186
Information on the peak electron energy, angular spread, and current density of a relativistic electron beam propagating in a plasma column is obtained from measurements of two-absorber transmission ratios, anistropy, and intensity, respectively, of x-ray bremsstrahlung from thin target foils in the plasma. Measurements indicate a 10% loss in peak electron energy and a factor of two loss in peak beam intensity over the distance of the plasma column, and show a large angular spread in the beam. 相似文献