ZnSe epilayers have been grown by photo-assisted MBE on GaAs substrates at various substrate temperatures and under various molecular beam intensity ratios of group VI to group III element. A He-Cd laser with 441.6 nm...
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ZnSe epilayers have been grown by photo-assisted MBE on GaAs substrates at various substrate temperatures and under various molecular beam intensity ratios of group VI to group III element. A He-Cd laser with 441.6 nm wavelength was used as a light source. From the temperature dependence of the photo-desorption rate constants, the activation energies of photo-desorption of Zn and Se adatoms from the physical adsorption state (E(Zn)P, E(Ss)P) and from the chemical adsorption state (E(C)) are obtained, that is E(Zn)P = 7.8 kcal/mol, E(Se)P = 6.7 kcal/mol and E(C) = 16.1 kcal/mol. Thus, the photo-desorption observed in photo-enhanced "thermal" desorption. ZnSe epilayers have been successfully grown at a temperature as low as 150-degrees-C. A sharp and strong free-excition emission is observed in photoluminescence spectra at 11 K in the low-temperature grown samples, which shows that the crystallinity is almost comparable with that of the unirradiated epilayer grown at 340-degrees-C (the optimum growth temperature without irradiation).
The crystallinity of 3C-SiC on Si by CVD is significantly influenced by B2H6, trimethylaluminum (TMA) and triethylgallium (TEG) addition at relatively low temperatures. These acceptor doping agents lower the epitaxial...
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The crystallinity of 3C-SiC on Si by CVD is significantly influenced by B2H6, trimethylaluminum (TMA) and triethylgallium (TEG) addition at relatively low temperatures. These acceptor doping agents lower the epitaxial temperature and doped 3C-SiC is epitaxially grown at 1100-1150-degrees-C without buffer layer formation. Below 1150-degrees-C, TMA addition affects the growth rate and decreases the activation energy for the deposition of 3C-SiC from 34.7 kcal/mol for undoped growth to 8.7 kcal/mol for Al-doped growth.
Experimental conditions for high fidelity electron spectroscopy are discussed when digitized sweep generator is used to drive spectrometer with lock-in signal detection and computerized data acquisition/processing. Sp...
Experimental conditions for high fidelity electron spectroscopy are discussed when digitized sweep generator is used to drive spectrometer with lock-in signal detection and computerized data acquisition/processing. Spectral quality were evaluated in terms of signal to noise ratio (S/N ratio) and full width at the half-maximum (FWHM) in N(E) mode or energy separation of peak maxima in differential mode. Optimums of following terms were discussed from points of noise reduction ability and due time for measurement: (1) nature of noise signal;(2) sweep mode and repeat times of measurement;(3) parameters of the lock-in amplifier and scanning speed;(4) numerical treatment on spectral data.
作者：
Kamijo, MasayoshiToba, EijiScience University of Tokyo
Suwa College Department of Management and System Science 5000-1 Toyohira Chino Nagano391-02 Japan Shinsyu University
Faculty of Textile Science and Technology Department of Textile System and Engineering 3-15-1 Tokida Ueda Nagano386 Japan
Since the light propagation property of the currently produced single mode optical fiber couplers has not become clarified, there are various problems with their production method, namely in terms of their operability...
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A simple approach is presented for simultaneous on-line identification of the time delay and the system parameters of continuous-time systems based on discrete-time measurements. The linear integral filter is used bot...
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A simple approach is presented for simultaneous on-line identification of the time delay and the system parameters of continuous-time systems based on discrete-time measurements. The linear integral filter is used both to construct the derivatives of input-output signals and to avoid estimating the unknown initial conditions. The time delay and the system parameters are directly estimated by an on-line algorithm which is derived using Newton’s method. Severed identification methods such as the bias-compensating method and the instrumental variable methods are applied for eliminating the asymptotic bias of the parameter estimates in noisy situations. The present algorithm is applicable to the case when the time delay is not an integral multiple of the sampling interval, and can also be used for model reduction.
An advanced mathematical model of a shape memory alloy (SMA) useful for designing SMA micro-devices is proposed and applied to coil spring theory to analyze the appropriate mechanical and electrical characteristics. T...
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An advanced mathematical model of a shape memory alloy (SMA) useful for designing SMA micro-devices is proposed and applied to coil spring theory to analyze the appropriate mechanical and electrical characteristics. This model can handle three phases of the SMA: the parent phase, the martensitic phase, and the R-phase. of three steps. First, the mechanical properties of the three phases are modeled at the solid mechanics level. Second, a model of thermoelectric transformation is obtained at the thermodynamic level. Finally, the first and second steps are combined. The model was applied to coil spring theory and was verified successfully by experiments under general conditions.< >
A unique transmission mechanism using a non-contact magnetic gear (NCMG) is proposed for micro and miniature electromechanical systems. A miniature NCMG has been produced and the basic characteristics were evaluated e...
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A unique transmission mechanism using a non-contact magnetic gear (NCMG) is proposed for micro and miniature electromechanical systems. A miniature NCMG has been produced and the basic characteristics were evaluated experimentally. The theoretical approach for analyzing the transmittable torque of the NCMG was developed and verified experimentally. It is concluded that the NCMG system has great potential for use in safe miniature transmission mechanisms for medical applications and in micro transmission systems for microelectromechanical systems.< >
This paper describes an installation of the fringe scanning method into a shadow-type Moire Topography. The result is a high-precision three-dimensional measuring system and automatic fringe order measuring system usi...
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The phase analysis of fringes by apptying moife techniques to the interferometer is well-known. Since this method is based on 2-D subtraction method in the incoherent optics, the distortion of the optical system is ea...
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