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131.
Summary The energy spectrum of sea level muons in the range (102÷104) GeV has been calculated from the latest directly measured JACEE primary spectrum using Fermilab results on pp→π± X and pp→K± X inclusive reactions. The conventional pion atmospheric diffusion equation after Bugaevet al. has been used in this analysis to account the flux of muons emerged from the multiple generation of mesons in air. The derived
muon spectrum has been compared with the earlier magnetic spectrograph data of Durham and Kiel groups. The latest BAKSAN scintillator
telescope data is well in agreement with the calculated integral spectrum originated from the meson decays in the range (1÷104) GeV. 相似文献
132.
B. Aronov A. R. Davis T. K. Dey S. P. Pal D. C. Prasad 《Discrete and Computational Geometry》1998,19(4):553-574
We extend the concept of the polygon visible from a source point S in a simple polygon by considering visibility with two types of reflection, specular and diffuse. In specular reflection a light ray reflects from an edge of the polygon according to the rule: the angle of incidence equals
the angle of reflection. In diffuse reflection a light ray reflects from an edge of the polygon in all inward directions.
Several geometric and combinatorial properties of visibility polygons under these two types of reflection are described, when
at most one reflection is permitted. We show that the visibility polygon Vs(S) under specular reflection may be nonsimple, while the visibility polygon Vd(S) under diffuse reflection is always simple. We present a Θ(n
2
) worst-case bound on the combinatorial complexity of both Vs(S) and Vd(S) and describe simple O(n
2
log
2
n) time algorithms for constructing the sets.
Received September 27, 1995, and in revised form October 24, 1997. 相似文献
133.
Warm plasma theory is used to investigate the propagation of electromagnetic waves in a plasma filled parallel plate waveguide with one boundary plate corrugated. Dispersion relations for TE- and TM-modes are derived and it is found that the propagation of TE-modes is unaffected by corrugation of one boundary plane while the propagation of TM-modes is affected by it. For TM-modes the wave numberk depends on the frequency ta as well as on the distance through which the wave is propagated.The authors take the opportunity to thank Professor M. L. Ghosh, Department of Mathematics, North Bengal University for suggesting the problem and one of the authors (S. K. Ghosh) wishes to express his thanks to the University of North Bengal for financial support. 相似文献
134.
A simple method for the amperometric estimation of N-cyclohexyl-2-benzothiazole sulphenamide, N-dicyclohexyl-2-benzothiazole sulphenamide, 2-(morpholinothio)benzothiazole and N-tert.-butyl-2-benzothiazole sulphenamide is reported. The results are obtained within 5 min and are correct within +/- 2.0%. 相似文献
135.
136.
Magnetic properties and structural chemistry of ternary silicides (RE,Th, U)Ru2Si2 (RE = RARE EARTH)
K. Hiebl C. Horvath P. Rogl M.J. Sienko 《Journal of magnetism and magnetic materials》1983,37(3):287-296
Ternary silicides (RE, Th, U)Ru2Si2 have been synthesized from the elements. All the compounds (RE = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were found to be isotypic and to crystallize with the structure type of ThCr2Si2 (ordered derivative of the BaAl4-type). The magnetic behavior of these alloys was studied in the temperature range 1.5 K < T < 1100 K. Magnetic susceptibilities at temperatures T > 300 K closely follow a typical Van Vleck paramagnetism of free RE3+-ions. In the case of CeRu2Si2 susceptibilities are well described for 20 K < T < 1100 K by a Van Vleck paramagnetism of widely spaced multiplets; the observed effective paramagnetic moment μeff = 2.12 BM indicates a high percentage (85%) of Ce3+. SmRu2Si2 yields an effective moment μeff = 0.54 BM, which compares reasonably well with the Hund's rule J = 5/2 ground level for free Sm+ and a low-lying excited level with J = 7/2. For temperatures T > 15 K the magnetic susceptibility as a function of temperature follows the “Van Vleck behavior” for free Sm3+. At low temperatures ferromagnetic ordering was encountered for (Pr, Nd, Ho, Er, Tm)Ru2Si2, whereas antiferromagnetic ordering was observed for (Sm, Gd, Tb, Dy)Ru2Si2. The ordering temperatures are generally below 55 K. No superconductivity was found for temperatures as low as 1.8 K. 相似文献
137.
W.E. Cleland A. Delfosse P.-A. Dorsaz J.-L. Gloor M.N. Kienzle-Focacci G. Mancarella A.D. Martin M. Martin P. Muhlemann C. Nef T. Pal J. Rutschmann H. Zeidler 《Nuclear Physics B》1982,208(2):228-261
The mass and momentum transfer spectra of the charged system produced in the reaction π±p→Ks0K±p are analyzed. The data have been collected at the CERN SPS with the Geneva-Lausanne two-arm, non-magnetic spectrometer at 30 and 50 GeV/c incident momenta. The general features of the reactions at these energies and the results of partial-wave analyses of the two kaon system are presented.The channel is dominated by the diffractive production of even spin resonances. The spin 4 recurrence of the A2(1320) is clearly observed at 2040 MeV (Γ=380 MeV. A new resonance is observed with a mass M=2450MeV and a width Γ=400 MeV; the quantum numbers of this state are found to be IG(JPC)=1?(6++). The analysis also shows the decay of the decay of the meson ?′(1600) through the channel at both energies.The production amplitudes are determined both as a function of the effective mass and of the momentum transfer. Isoscalar natural parity exchange is dominant. The energy dependence between 10 and 50 GeV/c is shown to be well described by a Regge pole model based on the f-dominated pomeron hypothesis. We compare the production mechanisms of the 2+ resonances A2(1320) and K1(1430). Finally, we estimate the branching ratios of the spin 4 A2(2040) and spin 6 A2(2450) resonances. 相似文献
138.
139.
Emphasis is laid on the fact that the peak in the static structure factor S(k) observed in a recent experiment at k≈2kF for conduction electrons in beryllium agrees well with the one predicted by us theoretically some time back. The error in the calculation of the pair correlation function g(r) using the experimental data on S(k) is pointed out. The position of the peak obtained in our g(r) clearly indicates that the effect of electron correlation is to condense into a Wigner lattice at a distance equal to the average interparticle separation rather than making a Mott type transition to an atomic-like state. 相似文献
140.