作者：
M. SteslickaM. RadnyS. G. DavisonQuantum Theory Group
Department of Applied Mathematics and Department of Physics University of Waterloo Waterloo Ontario Canada N2L?1 and Guelph-Waterloo Program for Graduate Work in Physics University of Guelph Guelph Ontario Canada N1G?1
The effective-range approximation is adopted to study surface states of a linear array of scattering centers. It is shown that, depending on the values of the scattering length and effective range for the surface atom...
The effective-range approximation is adopted to study surface states of a linear array of scattering centers. It is shown that, depending on the values of the scattering length and effective range for the surface atom, two, one, or zero surface states can exist in the forbidden energy gap. The possibility of a smooth transition from true (stationary) surface states to virtual (decaying) states is discussed. A comparison is also made with the crystal-potential approach.
The distribution of interstellar extinction and early-type stars to A5 in the field (l, b) = (253°, −7°) has been studied toV∼ 12 mag. The space density of B5, B8–A0 and A2–A5 stars is normal for a field ...
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The distribution of interstellar extinction and early-type stars to A5 in the field (l, b) = (253°, −7°) has been studied toV∼ 12 mag. The space density of B5, B8–A0 and A2–A5 stars is normal for a field outside the galactic plane, following a relationship of the formψ(r) =ψ0exp [− (rsinb)/β], where (ψ0,β) = (2.1 × 10−5stars pc−3, 60 pc), (17 × 10−5, 90) and (22 × 10−5, 140) for the three stellar groups respectively. The stellar and extinction data indicate that the direction (l, b) = (253°, −7°) lies out of the matter plane of the Milky Way at least to 3 kpc,|$(\langle E(B-V)\rangle = 9.25 \enspace\text{mag})$|. However, the higher extinction of Bochum 15 (4.4kpc,|$\langle E(B-V)\rangle = 0.5$|) and the absence of background galaxies suggests the possible presence of the galactic warp at −7° at distances beyond ∼ 5 kpc (z∼ 0.6 kpc), as well as a total higher extinction than the maximum ofE(B–V) = 0.53 ford> 10 kpc found at (l, b) = (245°, 0°).
We present a catalogue of photoelectric UBV photometry and some spectral types for 610 stars in a field in Puppis centred at (l, b) = (245°, 0°). This catalogue reports results taken from the literature, as ...
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The objective of the program reported in this paper was to assess the explosion and fire hazard associated with the crude-oil offloading facility proposed for the Deep Water Port, Galveston, Texas. Explosion damage es...
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The objective of the program reported in this paper was to assess the explosion and fire hazard associated with the crude-oil offloading facility proposed for the Deep Water Port, Galveston, Texas. Explosion damage estimates were made for two conditions;the ″worst case,″ which involved 36 percent of the tanks of the largest tanker. Fire effects were investigated on the basis of six fire scenarios. Fire-control techniques were postulated and equipment characteristics and quantities were defined. The inert-gas system (IGS) was evaluated in terms of operational characteristics, reliability, failure modes and effects, and controls.
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