The changes of microstructure in Al and Cu thin film lines due to electromigration have been studied using transmission electron microscopy. Grain boundary migration, inclination and dislocation activity were found to...
The changes of microstructure in Al and Cu thin film lines due to electromigration have been studied using transmission electron microscopy. Grain boundary migration, inclination and dislocation activity were found to be critically involved in the electromigration induced hillock formation that can be described as three dimensional grain growth.
Plasma parameters of Ar/SiH4 plasma were measured as a function of de bias in a double-tubed coaxial line-type microwave plasma chemical vapor deposition (CVD) apparatus. The results indicate that it is possible to co...
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Plasma parameters of Ar/SiH4 plasma were measured as a function of de bias in a double-tubed coaxial line-type microwave plasma chemical vapor deposition (CVD) apparatus. The results indicate that it is possible to control the ion bombardment energy without affecting either the gas phase reaction or ion flux density incident to the substrate. Hydrogenated amorphous silicon films were deposited as a function of the ion bombardment energy and characteristics of the deposited films were investigated. The results indicate that the ion bombardment improves film density, bonding characteristics of hydrogen, and optical band gap but increases the concentration of dangling bonds due to Ar ion implantation. The ion bombardment not only causes the heating of the films but also induces sputtering and ion implantation.
Gamma-ray bursts are short but powerful pulses of electromagnetic radiation coming from space. Specially equipped satellites have observed the arrival of several hundred bursts during the past two decades. The origin ...
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Gamma-ray bursts are short but powerful pulses of electromagnetic radiation coming from space. Specially equipped satellites have observed the arrival of several hundred bursts during the past two decades. The origin of these bursts, whether from near the earth, across the galaxy, or out of the deep cosmos, has become a major question for astronomers. At the heart of this question lies a statistical puzzle relating to familiar issues in survival analysis Kaplan--Meier-type curves, data truncation, hazard rate analysis, Mantel--Haenszel statistics, and so on. Survival analysis is used here to critically examine two different models that have been proposed for the gamma-ray burst data. The analysis contradicts one of these models.
The influence of a laterally inhomogeneous electrostatic potential of an adsorbate-covered surface on the resonant charge transfer in ion-surface scattering is investigated by means of the time-dependent Anderson-Newn...
The influence of a laterally inhomogeneous electrostatic potential of an adsorbate-covered surface on the resonant charge transfer in ion-surface scattering is investigated by means of the time-dependent Anderson-Newns Hamiltonian. The adsorbate-induced random modulation of the projectile orbital energy level is treated as a stochastic process, and its role in the charge transfer is evaluated analytically, in the Gaussian-process approximation, for low projectile speeds and low surface coverage by alkali atoms.
Measurements were made of the magnetic susceptibility in the temperature range 2K-10K of twenty-nine samples of materials and components used in the construction of cryogenic instruments. The use of SQUID-based superc...
Characteristics of both thermoplastic and thermoset composite materials as they pertain to marine vehicle applications are discussed. Comparison of various material selection factors such as strength, damage and moist...
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Characteristics of both thermoplastic and thermoset composite materials as they pertain to marine vehicle applications are discussed. Comparison of various material selection factors such as strength, damage and moisture resistance, and flammability and toxicity as well as cost and availability of thermoset and thermoplastic composite materials are presented. Methods for testing and reducing the flammability and toxicity are discussed. Many commercially available composite systems are reported to provide favorable characteristics for marine applications. Although there seems to be a need for improved production technology for thermoplastics, they present potential advantages in physical properties over thermoset composites.
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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