Nitrogen-doped ZnSe and lattice-matched ZnSSe were grown on GaAs substrates by MBE using NH3 gas as a dopant source. The epilayers were characterized by photoluminescence. ZnSe was rather easily doped, and samples in ...
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Nitrogen-doped ZnSe and lattice-matched ZnSSe were grown on GaAs substrates by MBE using NH3 gas as a dopant source. The epilayers were characterized by photoluminescence. ZnSe was rather easily doped, and samples in which the acceptor-bound exciton line was a major line in the exciton emission region at 11 K were obtained. ZnSSe was less readily doped with nitrogen at the same NH3 effective pressure. However, the free-to-acceptor omission at 60 K was stronger in ZnSSe than in ZnSe, due to the effect of lattice matching.
ZnSSe epilayers were grown by MBE with light irradiation using a Hg-Xe lamp. The free-exciton-emission intensities increased in the photoluminescence spectra of the light-irradiated epilayers, and the sulfur compositi...
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ZnSSe epilayers were grown by MBE with light irradiation using a Hg-Xe lamp. The free-exciton-emission intensities increased in the photoluminescence spectra of the light-irradiated epilayers, and the sulfur composition also increased. However, the surface morphologies were rough. The irradiated-photon-energy dependence of the above irradiation effects was investigated for the first time, and it turned out that the photons of energy larger than the band-gap energy of the epilayer were responsible for the light-irradiation effects.
Al2O3 thin films have been prepared by photo-CVD under oxygen atmosphere for the first time using aluminum-tri-isopropoxide as a source material. The light source was a low-pressure Hg lamp. Without UV irradiation the...
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Al2O3 thin films have been prepared by photo-CVD under oxygen atmosphere for the first time using aluminum-tri-isopropoxide as a source material. The light source was a low-pressure Hg lamp. Without UV irradiation the deposition rate had a maximum at a particular oxygen-flow rate, which suggests the Langmuir-Hinshelwood surface-reaction mechanism. With UV irradiation, the deposition rate increased largely at a substrate temperature of less than 300°C. The activation energy of deposition reaction was as small as 1.5 kcal/mol. It was confirmed that the 185-nm light played an important role in the photodeposition. The dielectric dissipation factor ( tan δ) decreased in the samples prepared by photo-CVD, especially at a low substrate temperature of less than 300°C; that is, the film quality was improved by photo-CVD.
Basic research for the micro actuator using TiNi Shape Memory Alloy (SMA) is conducted from the crystallographic point of view. SMA (TiNi) thin film is fabricated by sputtering deposition. First, the influence of subs...
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作者：
Suzuki, HiroshiKyushu Institute of Technology
The Faculty of Information Science & Engineering The Department of Mechanical System Engineering 680-4 Kawatsu Fukuoka Iizuka820 Japan
Basic research for the micro actuator using TiNi shape memory alloy (SMA) is conducted from the crystallographic point of view. SMA (TiNi) thin film is fabricated by sputter deposition. First, the influence of substra...
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Basic research for the micro actuator using TiNi shape memory alloy (SMA) is conducted from the crystallographic point of view. SMA (TiNi) thin film is fabricated by sputter deposition. First, the influence of substrate temperature on crystal structure is verified by measuring resistivity-temperature curve and X-ray diffraction. Though high temperature substrate conditions make TiNi film in regular crystal, an amorphous structure appears at low substrate temperature. Next optimal composition of sputtered SMA thin film is found by SSQ. The negative slope of the resistivity curve due to phase transformation between R-phase and parent phase is observed. Finally, annealing methods are examined to crystallize amorphous TiNi.< >
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：
ZITZMAN, LHFALATKO, SMPAPACH, JLDr. Lewis H. Zitzman:is the group supervisor of the Advanced Systems Design Group
Fleet Systems Department The Johns Hopkins University Applied Physics Laboratory (JHU/APL). He has been employed at JHU/APL since 1972 performing applied research in computer science and in investigating and applying advanced computer technologies to Navy shipboard systems. He is currently chairman of Aegis Computer Architecture Data Bus and Fiber Optics Working Group from which many concepts for this paper were generated. Dr. Zitzman received his B.S. degree in physics from Brigham Young University in 1963 and his M.S. and Ph.D. degrees in physics from the University of Illinois in 1967 and 1972 respectively. Stephen M. Falatko:was a senior engineering analyst in the Combat Systems Engineering Department
Comptek Research Incorporated for the majority of this effort. He is currently employed at ManTech Services Corporation. During his eight-year career first at The Johns Hopkins University Applied Physics Laboratory and currently with ManTech Mr. Falatko's work has centered around the development of requirements and specifications for future Navy systems and the application of advanced technology to Navy command and control systems. He is a member of both the Computer Architecture Fiber Optics and Data Bus Working Group and the Aegis Fiber Optics Working Group. Mr. Falatko received his B.S. degree in aerospace engineering with high distinction from the University of Virginia in 1982 and his M.S. degree in applied physics from The Johns Hopkins University in 1985. Mr. Falatko is a member of Tau Beta Pi Sigma Gamma Tau the American Society of Naval Engineers and the U.S. Naval Institute. Janet L. Papach:is a section leader and senior engineering analyst in the Combat Systems Engineering Department
Comptek Research Incorporated. She has ten years' experience as an analyst supporting NavSea Spa War and the U.S. Department of State. She currently participates in working group efforts under Aegis Combat System Doctrin
This paper sets forth computer systems architecture concepts for the combat system of the 2010–2030 timeframe that satisfy the needs of the next generation of surface combatants. It builds upon the current Aegis comp...
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This paper sets forth computer systems architecture concepts for the combat system of the 2010–2030 timeframe that satisfy the needs of the next generation of surface combatants. It builds upon the current Aegis computer systems architecture, expanding that architecture while preserving, and adhering to, the Aegis fundamental principle of thorough systems engineering, dedicated to maintaining a well integrated, highly reliable, and easily operable combat system. The implementation of these proposed computer systems concepts in a coherent architecture would support the future battle force capable combat system and allow the expansion necessary to accommodate evolutionary changes in both the threat environment and the technology then available to effectively counter that threat. Changes to the current Aegis computer architecture must be carefully and effectively managed such that the fleet will retain its combat readiness capability at all times. This paper describes a possible transition approach for evolving the current Aegis computer architecture to a general architecture for the future. The proposed computer systems architecture concepts encompass the use of combinations of physically distributed, microprocessor-based computers, collocated with the equipment they support or embedded within the equipment itself. They draw heavily on widely used and available industry standards, including instruction set architectures (ISAs), backplane busses, microprocessors, computer programming languages and development environments, and local area networks (LANs). In this proposal, LANs, based on fiber optics, will provide the interconnection to support system expandability, redundancy, and higher data throughput rates. A system of cross connected LANs will support a high level of combat system integration, spanning the major warfare areas, and will facilitate the coordination and development of a coherent multi-warfare tactical picture supporting the future combatant command st
A numerical simulation is made of a cylindrical hollow cathode glow discharge in helium gas. Electrons are assumed to consist of two or three groups of different temperatures. Calculations are made for the following c...
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A numerical simulation is made of a cylindrical hollow cathode glow discharge in helium gas. Electrons are assumed to consist of two or three groups of different temperatures. Calculations are made for the following conditions: gas pressure of 0.24 kPa, cathode fall potential of 260 V and discharge current of 33 mA. Numerical results present number densities of electrons, ions and excited atoms of 64 excited levels as a function of the radial distance r. Experimentally determined population densities of excited atoms are also presented as a function of r. Agreement of calculation with experiment is good for densities at the center of the cathode. Calculated densities, however, have a larger peak near the edge of the negative glow than measured densities.
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