Browsing by Issue Date, starting with "1996-08-10"

Now showing 1 - 20 of 85174

Adsorption characteristics of iron-cyanide complex on gamma-Al2O3
(1996-08-10)
Cheng, WP
;
Huang, CP
;
環境工程研究所
;
Institute of Environmental Engineering
The adsorption behavior of ferrocyanide and ferricyanide toward aluminum oxide with a 0.01 M NaClO4 background electrolyte at 25 degrees C was investigated. Results obtained from different pH values demonstrated that the adsorption of these complex ions could be described by a modified Langmuir isotherm in the concentration range 0.5 X 10(-4) to 4 X 10(-4) M. This modified Langmuir isotherm developed here could accurately predict the equilibrium partition between solid and liquid phases while taking proton competition into account. Also, the apparent equilibrium constant (K-app) derived from the Langmuir equation for ferrocyanide or ferricyanide adsorption on aluminum oxide was compared with the intrinsic constant (K-int) calculated by triple-layer model simulation. This comparison revealed a strong correlation between the apparent equilibrium constant and the intrinsic constant. Moreover, in comparing K-app with K-int, we can infer that the adsorption of either ferrocyanide or ferricyanide complexes onto aluminum oxide is achieved through outer-sphere complexation. (C) 1996 Academic Press, Inc.
On the computation of the distribution of the square of the sample multiple correlation coefficient
(1996-08-10)
Ding, CG
;
管理科學系
;
Department of Management Science
Two computationally simple methods are proposed to evaluate the distribution function and the density of the square of the sample multiple correlation coefficient. No auxiliary routine is required. The accuracy of recursive computations can be effectively controlled. The distribution function and the density can be evaluated concurrently because their computing formulas are closely related. This property can enhance efficiency of Newton's method for computing the quantiles of the distribution. The corresponding algorithms are provided in a step-by-step form.
Adsorption characteristics of iron-cyanide complex on gamma-Al2O3
(1996-08-10)
Cheng, WP
;
Huang, CP
;
環境工程研究所
;
Institute of Environmental Engineering
The adsorption behavior of ferrocyanide and ferricyanide toward aluminum oxide with a 0.01 M NaClO4 background electrolyte at 25 degrees C was investigated. Results obtained from different pH values demonstrated that the adsorption of these complex ions could be described by a modified Langmuir isotherm in the concentration range 0.5 X 10(-4) to 4 X 10(-4) M. This modified Langmuir isotherm developed here could accurately predict the equilibrium partition between solid and liquid phases while taking proton competition into account. Also, the apparent equilibrium constant (K-app) derived from the Langmuir equation for ferrocyanide or ferricyanide adsorption on aluminum oxide was compared with the intrinsic constant (K-int) calculated by triple-layer model simulation. This comparison revealed a strong correlation between the apparent equilibrium constant and the intrinsic constant. Moreover, in comparing K-app with K-int, we can infer that the adsorption of either ferrocyanide or ferricyanide complexes onto aluminum oxide is achieved through outer-sphere complexation. (C) 1996 Academic Press, Inc.
On the computation of the distribution of the square of the sample multiple correlation coefficient
(1996-08-10)
Ding, CG
;
管理科學系
;
Department of Management Science
Two computationally simple methods are proposed to evaluate the distribution function and the density of the square of the sample multiple correlation coefficient. No auxiliary routine is required. The accuracy of recursive computations can be effectively controlled. The distribution function and the density can be evaluated concurrently because their computing formulas are closely related. This property can enhance efficiency of Newton's method for computing the quantiles of the distribution. The corresponding algorithms are provided in a step-by-step form.
Effect of rapid thermal annealing on carrier lifetimes of arsenic-ion-implanted GaAs
(1996-08-12)
Lin, GR
;
Chen, WC
;
Ganikhanov, F
;
Chang, CS
;
Pan, CL
Femtosecond time-resolved reflectivity measurements, structural, and electrical analyses have been performed to investigate the effect of rapid thermal annealing (RTA) on GaAs implanted with 200 keV arsenic ions at 10(16) ions/cm(2). Ultrashort carrier lifetimes from 0.48 fs to 2.3 ps were observed for samples annealed at temperatures between 600 and 800 degrees C. The time constants are somewhat shorter than those of RTA-annealed low-temperature molecular-beam epitaxy grown material, while following the same trend of longer time constants and recovery of resistance at higher annealing temperatures. Arsenic precipitates were not observed. (C) 1996 American Institute of Physics.
Forecasting enrollments based on fuzzy time series
(1996-08-12)
Chen, SM
;
資訊工程學系
;
Department of Computer Science
This paper presents a new method to forecast university enrollments based on fuzzy time series. The data of historical enrollments of the University of Alabama shown in Song and Chissom (1993a, 1994) are adopted to illustrate the forecasting process of the proposed method. The robustness of the proposed method is also tested. The proposed method not only can make good forecasts of the university enrollments, but also can make robust forecasts when the historical data are not accurate. The proposed method is more efficient than the one presented in Song and Chissom (1993a) due to the fact that the proposed method uses simplified arithmetic operations rather than the complicated max-min composition operations presented in Song and Chissom (1993a).
Forecasting enrollments based on fuzzy time series
(1996-08-12)
Chen, SM
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
;
Department of Computer Science
This paper presents a new method to forecast university enrollments based on fuzzy time series. The data of historical enrollments of the University of Alabama shown in Song and Chissom (1993a, 1994) are adopted to illustrate the forecasting process of the proposed method. The robustness of the proposed method is also tested. The proposed method not only can make good forecasts of the university enrollments, but also can make robust forecasts when the historical data are not accurate. The proposed method is more efficient than the one presented in Song and Chissom (1993a) due to the fact that the proposed method uses simplified arithmetic operations rather than the complicated max-min composition operations presented in Song and Chissom (1993a).
Preparation of poly(2,5-thienyleneethylene) and poly(2,5-furyleneethylene) by vapor phase pyrolysis of (5-methyl-2-thienyl)methyl benzoate and (5-methyl-2-furyl)methyl benzoate
(1996-08-12)
Lu, YH
;
Hsu, CS
;
Chou, CH
;
Chou, TH
;
應用化學系
The synthesis-of poly(2,5-thienyleneethylene) and poly(2,5-furyleneethylene) by vapor deposition polymerization is presented. (5-Methyl-2-thienyl)methyl benzoate and (5-methyl-2-furyl)methyl benzoate were subjected to vapor phase pyrolysis above 650 degrees C to form 2,5-dimethylene-2,5-dihydrothiophene and 2,5-dimethylene-2,5-dihydrofuran. Upon condensation, both compounds spontaneously polymerize, respectively, at a temperature higher than -25 degrees C to produce poly(2,5-thienyleneethylene) and poly(2,5-furyleneethylene). The obtained poly(2,5-thienyleneethylene) is soluble in chloroform above 60 degrees C. It is a semicrystalline polymer and displays a glass transition at around 25 degrees C and a melting transition at around 160 degrees C. The synthesized poly(2,5-furyleneethylene) is insoluble in tetrahydrofuran, chloroform, dimethylformamide (DMF), and dimethyl sulfoxide (DMSO) at room temperature and only swells in DMF and DMOS above 100 degrees C. Solid-state NMR studies show that the poly(2,5-furyleneethylene) is cross-linked. The poly(2,5-furyleneethylene) is also a semicrystalline polymer exhibiting a glass transition at around 20 degrees C and a melting transition at around 110 degrees C. Solution polymerizations of 2,5-dimethylene-2,5-dihydrothiophene and 2,5-dimethylene-2,5-dihydrofuran were also carried out, respectively, in THF to yield poly(2,5-thienyleneethylene) and poly(2,5-furyleneethylene). Finally, the relative merits for the polymerization of 2,5-dimethylene-2,5-dihydrothiophene and 2,5-dimethylene-2,5-dihydrofuran by both methods are compared.
Characterization of antenna effect by nondestructive gate current measurement
(1996-08-15)
Lin, HC
;
Chien, CH
;
Huang, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A novel method is proposed for the effective characterization of plasma-charge-induced damage on thin gate oxides. We have found that the gate current measured at V-g(gate voltage) = V-th(threshold voltage) under a low drain bias (e.g., 0.1 V) is a good indicator of the damage. Since the proposed method requires only low bias voltages, it does not cause additional damage to the devices. The proposed gate current measurement is also easy to incorporate to device measurement routines without an extra stressing step, and thus provides a simple and efficient damage indicator for studying plasma-charge-induced damage.
Differential matched filter architecture for spread spectrum communication systems
(1996-08-15)
Lin, WC
;
Liu, KC
;
Wang, CK
;
電信工程研究所
;
Institute of Communications Engineering
The authors present a new digital matched filter architecture: digital differential matched filter (DDMF), that employs novel schemes to reduce the number of multiplications and accumulations (M and A). Theoretical analysis shows that the DDMF saves half of the M and A hardware in comparison with the conventional filter, and maintains identical processing gain. This makes the proposed DDMF more suitable for direct sequence spread spectrum (DSSS) communication systems and low power VLSI implementations.
Parallel pixel processing using programmable gate arrays
(1996-08-15)
Budgett, DM
;
Tang, PE
;
Sharp, JH
;
Chatwin, CR
;
Young, RCD
A reconfigurable hardware design permits very fast feature extraction from high frame rate video images. By implementing parallel pixel processing paths in programmable gate arrays, a wide range of image processing algorithms can be implemented in realtime.
Characterization of antenna effect by nondestructive gate current measurement
(1996-08-15)
Lin, HC
;
Chien, CH
;
Huang, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A novel method is proposed for the effective characterization of plasma-charge-induced damage on thin gate oxides. We have found that the gate current measured at V-g(gate voltage) = V-th(threshold voltage) under a low drain bias (e.g., 0.1 V) is a good indicator of the damage. Since the proposed method requires only low bias voltages, it does not cause additional damage to the devices. The proposed gate current measurement is also easy to incorporate to device measurement routines without an extra stressing step, and thus provides a simple and efficient damage indicator for studying plasma-charge-induced damage.
Differential matched filter architecture for spread spectrum communication systems
(1996-08-15)
Lin, WC
;
Liu, KC
;
Wang, CK
;
電信工程研究所
;
Institute of Communications Engineering
The authors present a new digital matched filter architecture: digital differential matched filter (DDMF), that employs novel schemes to reduce the number of multiplications and accumulations (M and A). Theoretical analysis shows that the DDMF saves half of the M and A hardware in comparison with the conventional filter, and maintains identical processing gain. This makes the proposed DDMF more suitable for direct sequence spread spectrum (DSSS) communication systems and low power VLSI implementations.
Electron differential inverse mean free path for surface electron spectroscopy
(1996-08-20)
Chen, YF
;
Kwei, CM
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new, general expression for the position-dependent differential inverse mean free path (DIMFP) of an electron penetrating into vacuum from a solid is derived. This DIMFP can be divided up into a bulk and a surface term. It is found that the surface effect is restricted to a surface layer extending on both sides of the vacuum-solid interface. An extended Drude dielectric function, which allows the characteristic oscillator strength, damping constant, and critical-point energy for each subband of valence electrons, is employed to estimate electron DIMFPs near Al and Au surfaces. Our results are relevant to the understanding of inelastic electron scattering near a solid surface.
Thickness dependence of magnetic force and vortex creation in type-II superconducting thin film
(1996-08-20)
Wei, JC
;
Chen, JL
;
Horng, L
;
Yang, TJ
;
電子物理學系
We examined a single vortex line in an infinite type-II superconducting thin film with finite thickness. The thickness dependence of the magnetic force acting on a point dipole placed above a superconducting film is calculated as the negative of the gradient of the interaction energy, coupled to the London theory of superconductivity with electromagnetics. We also considered the situation of a single vortex creation in the thin film, caused by the field of the magnetic dipole tip itself. The thickness dependence of the critical position of the point dipole for creating the first vortex line in the thin film is calculated.
Electron differential inverse mean free path for surface electron spectroscopy
(1996-08-20)
Chen, YF
;
Kwei, CM
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new, general expression for the position-dependent differential inverse mean free path (DIMFP) of an electron penetrating into vacuum from a solid is derived. This DIMFP can be divided up into a bulk and a surface term. It is found that the surface effect is restricted to a surface layer extending on both sides of the vacuum-solid interface. An extended Drude dielectric function, which allows the characteristic oscillator strength, damping constant, and critical-point energy for each subband of valence electrons, is employed to estimate electron DIMFPs near Al and Au surfaces. Our results are relevant to the understanding of inelastic electron scattering near a solid surface.
Synthesis of ent-herbasolide
(1996-08-21)
Ho, TL
;
Liang, FS
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
ent-Herbasolide is synthesised by elaboration of (+)-10-camphorsulfonyl chloride which involves homologation at C-10 cleavage of the C-2/C-3 bond, oxidation at C-5 and chain extension at C-3 of the camphor skeleton.
Synthesis of ent-herbasolide
(1996-08-21)
Ho, TL
;
Liang, FS
;
應用化學系
;
Department of Applied Chemistry
ent-Herbasolide is synthesised by elaboration of (+)-10-camphorsulfonyl chloride which involves homologation at C-10 cleavage of the C-2/C-3 bond, oxidation at C-5 and chain extension at C-3 of the camphor skeleton.
Effect of lateral substituent on the mesomorphic properties of ferroelectric side-chain liquid crystalline polysiloxanes.
(1996-08-25)
Hsu, CS
;
Tsai, CT
;
應用化學系
;
Department of Applied Chemistry
Effect of lateral substituent on the mesomorphic properties of ferroelectric side-chain liquid crystalline polysiloxanes.
(1996-08-25)
Hsu, CS
;
Tsai, CT
;
應用化學系
;
Department of Applied Chemistry