Browsing by Issue Date, starting with "1994-03-07"

Now showing 1 - 20 of 88378

NMR-STUDY OF EPSILON-CAPROLACTAM IN VARIOUS SOLVENTS - GRAPHICAL DETERMINATION OF MONOMER SHIFT, DIMER SHIFT AND DIMERIZATION CONSTANT FROM THE DILUTION SHIFT DATA
(1994-03-07)
CHEN, JS
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交大名義發表
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應用化學系
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National Chiao Tung University
;
Department of Applied Chemistry
A graphical method for the simultaneous determination of the monomer shift, dimer shift and dimerization constant of a self-association system from the dilution NMR shift data is proposed. This method avoids the conventional extrapolation to infinite dilution to obtain the monomer shift. Three self-association systems: epsilon-caprolactam in [H-2(1)]chloroform, [H-2(3)]acetone and [H-2(3)]acetonitrile were studied at various temperatures. The enthalpy and entropy of dimerization were also determined from van't Hoff plots.
STUDIES ON CO[POLY(ETHYLENE TEREPHTHALATE-P-OXYBENZOATE)] THERMOTROPIC COPOLYESTER(IV) THERMAL HISTORY BY DIFFERENTIAL SCANNING CALORIMETRY
(1994-03-07)
SHINN, TH
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LIN, CC
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材料科學與工程學系
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Department of Materials Science and Engineering
A series of co [poly (ethylene terephthalate-p-oxybenzoate)] thermotropic copolyesters with various compositions were prepared by the copolymerization of either poly (ethylene terephthalate) polymer (PET) or its oligomer (OET) as moiety (II) and p -acetoxy-benzoic acid (POB) as moiety (I). The polymeric products obtained were then subjected to solid-state polymerization. The glass and melting transitions of the copolyesters obtained have been studied by differential scanning calorimetry (DSC). Effects of composition and solid-state polymerization on DSC are discussed. The melting point of copolyesters possesses a higher value if the PET polymer is used as PET moiety in the copolyesters. In the DSC scan of the POB rich composition, the endothermic peak shows obscurely and enthalpy of fusion becomes small due to the change in the crystalline morphology from isotropic to anisotropic. In general, the melting point of copolyesters is increased by the solid-state polymerization reaction. It is also found that both the melting temperature and enthalpy of fusion of the copolyesters can be increased simultaneously by the solid-state polymerization reaction only when the composition of POB / PET is 80 / 20. This phenomenum at this composition may be attributed to the annealing effect caused by the randomness of two moiety units on the backbone chain of copolyesters and the increased molecular weight as well. (C) 1994 John Wiley & Sons, Inc.
RUBBER TOUGHENING OF THE PC/PA BLENDS BY REACTIVE AND NONREACTIVE CORE-SHELL ELASTOMERS
(1994-03-13)
CHOU, DC
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CHANG, FC
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應用化學系
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Department of Applied Chemistry
THE ENHANCEMENT OF OPTICAL 3RD HARMONIC SUSCEPTIBILITY IN A PARABOLIC QUANTUM-WELL BY TRIPLE-RESONANCE
(1994-03-15)
HUANG, YM
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LIEN, CS
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
The third harmonic susceptibility for the finite parabolic quantum well (PQW) is studied theoretically. An important feature of the finite PQW is that the subband eigenenergies E(n) form an equally spaced energy-level ladder. Since the eigenenergy spacing hBARomega0 can be designed to resonate with the pumping source, the third harmonic susceptibility can be greatly enhanced through the triple resonance' A third harmonic susceptibility as high as 2000 (mm/V)2 could be achieved for the finite parabolic quantum well structure. This is a more than six orders of magnitude enhancement as compared to that of the bulk GaAs.
CAPACITIVELY COUPLED SI STRIP DETECTORS ON A 100 MM WAFER
(1994-03-15)
YEH, SC
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SU, S
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LU, JP
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Silicon strip detectors with single-sided readout were designed and processed on 100 mm silicon wafers. Detectors with integrated coupling capacitors and polysilicon bias resistors were tested by electrical measurements. A 200 nm gate oxide thickness was chosen to provide a coupling capacitance of 9.75 pF/cm. A full depletion voltage of 80 V and leakage currents of 0.29, 0.64, 0.97, and 1.01 nA/strip for strip lengths of 2, 5, 7, and 8 cm, respectively were measured.
ORGANOMETALLIC VAPOR-PHASE EPITAXIAL-GROWTH OF ALASXSB1-X FILMS USING TERTIARYBUTYLARSINE
(1994-03-15)
CHEN, WK
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OU, J
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LEE, WI
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交大名義發表
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電子物理學系
The deposition of AlAsxSb1-x films is studied systematically using an organometallic vapor phase epitaxy growth technique. It is found that the growth of AlAsSb films requires a low V/III ratio to enhance the incorporation of antimony into the solid. The composition of the alloy also depends strongly on the growth temperature. Experimental data shows that films grown at higher temperatures yield much higher AlSb contents in the AlAsxSb1-x alloys. This is contrary to the results reported for GaAsSb films. In our study, we are able to grow metastable AlAsxSb1-x epitaxial films throughout the entire range of the solid composition for temperatures above 550-degrees-C.
FEMTOSECOND SOLITON PROPAGATION IN ERBIUM-DOPED FIBER AMPLIFIERS - THE EQUIVALENCE OF 2 DIFFERENT MODELS
(1994-03-15)
CHI, S
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CHANG, CW
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WEN, S
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光電工程學系
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Department of Photonics
The femtosecond soliton propagation in erbium-doped fiber amplifiers (EDFA) was calculated by using the coupled Maxwell-Bloch equations and the modified nonlinear Schrodinger equation with a complex lorentzian pin profile, respectively. Two results are found to be almost identical for the practical parameters of the EDFA. Therefore, accurate results can be obtained using the complex lorentzian gain profile, and it is much more time saving.
CONFIGURATION TRANSITION OF A CLOSED-CYLINDER NEMATIC LIQUID-CRYSTAL IN AN EXTERNAL ELECTRIC-FIELD
(1994-03-15)
CHEN, SH
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WEI, JG
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交大名義發表
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光電工程學系
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National Chiao Tung University
This study reports on the director-field configurations of a closed-cylinder nematic liquid crystal with negative dielectric anisotropy in an external electric field. Raising the applied voltage causes the director orientation with a volume point defect to be transformed from a normal to a twisted configuration. The voltage at which the configuration is transformed depends on the aspect ratio of the cylinder.
ON PRIME LABELINGS
(1994-03-15)
FU, HL
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HUANG, KC
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應用數學系
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Department of Applied Mathematics
Let G = (V, E) be a graph. A bijection f:V--> {1, 2,...,V} is called a prime labelling if for each e = {u, v} in E, we have GCD(f(u),f(v)) = 1. A graph admits a prime labelling is called a prime graph. Around ten years ago, Roger Entringer conjectured that every tree is prime. So far, this conjecture is still unsolved. In this paper, we show that the conjecture is true for trees of order up to 15, and also show that a few other classes of graphs are prime.
STRONG ACCUMULATION OF AS PRECIPITATES IN LOW-TEMPERATURE INGAAS QUANTUM-WELLS GROWN BY MOLECULAR-BEAM EPITAXY
(1994-03-21)
CHENG, TM
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CHIN, A
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CHANG, CY
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HUANG, MF
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HSIEH, KY
Low temperature InGaAs strained quantum wells have been grown by molecular beam epitaxy and annealed at 600-900-degrees-C for 10 min. For an optimized annealing condition, arsenic precipitates can be successfully confined in the InGaAs wells and completely depleted in the GaAs barriers. The strong accumulation of As precipitates shows that the phenomena are not due to the strain effect but may be explained by the difference of interfacial energy between precipitate and matrix. The ability to control the As precipitates into two-dimensional quantum wells in LT materials has unique applications in a wide variety of devices.
A GLOBAL APPROACH FOR GENERAL 0-1 FRACTIONAL-PROGRAMMING
(1994-03-24)
LI, HL
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交大名義發表
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資訊管理與財務金融系註：原資管所+財金所
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National Chiao Tung University
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Department of Information Management and Finance
Current methods of general 0-1 fractional programming (G-FP) can only find the local optimum. This paper proposes a new method of solving G-FP problems by a mixed 0-1 linear program to obtain a global optimum. Given a mixed 0-1 polynomial term xy where x is a 0-1 variable and 0 < y less-than-or-equal-to 1, we develop a theorem to transfer the xy term into a set of mixed 0-1 linear inequalities. Based on this theorem, a G-FP problem can be solved by a branch-and-bound method to obtain the global solution.
管管的詩畫世界
(1994-03-24)
管管
管管的詩畫世界
(1994-03-24)
管管
管管的詩畫世界
(1994-03-24)
管管
管管的詩畫世界
(1994-03-24)
管管
A CONSTRAINT VARIATION TREATMENT FOR ROTATING NUCLEAR INTRINSIC STATES IN THE LABORATORY SYSTEM
(1994-03-28)
LIN, L
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交大名義發表
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電子物理學系
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National Chiao Tung University
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Department of Electrophysics
The cranking model describes nuclear rotation in the rotating frame. However, the physical experiments are performed in the laboratory system. In this article, a constraint variation treatment is suggested to generate a set of single particle orbitals with rotational characteristics. By using this set of basis vectors, we can obtain a rotating nuclear intrinsic state which is observed in the laboratory system.
COMPLEX-VALUED NEURAL-NETWORK FOR DIRECTION-OF-ARRIVAL ESTIMATION
(1994-03-31)
YANG, WH
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CHAN, KK
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CHANG, PR
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交大名義發表
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電信工程研究所
A complex-valued neural network for the implementation of a direction of arrival (DoA) estimator is presented. The network is based on the linear prediction method, with data processed fully in the complex domain. Simulation results are given to demonstrate the effectiveness of the network performances.
QUANTIZATION-ERROR CURVE - A MEASURE OF SIMILARITY BETWEEN REQUANTISED IMAGES
(1994-03-31)
CHU, CH
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HSUEH, YC
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資訊工程學系
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Department of Computer Science
A new similarity measure between a digital image and its quantised version is presented. By calculating the quantisation error on each of a sequence of subdomains, we can obtain a quantisation error curve as a similarity measure. This measure outperforms the commonly used measure for estimating the similarity between requantised images.
BINDING-ENERGIES OF D- ION IN GAAS QUANTUM-WELL
(1994-04-01)
CHANG, YH
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YEH, JJ
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SHEU, YM
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WANG, CC
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CHEN, TC
Magnetic field dependent binding energies of the D- ion in the center of a 210 angstrom GaAs quantum well are determined by temperature magneto-transport measurments. The binding energies increase from 2.1 meV at 2T to 4 meV at 8T, and are consistently higher than the transition energies ootained from magneto-optical measurements performed on the same sample. We conclude from these data that in the magneto-optical measurement the observed transitions are between ground and excited D- states.
NANOMETER THICK SI/SIGE STRAINED-LAYER SUPERLATTICES GROWN BY AN ULTRAHIGH-VACUUM CHEMICAL-VAPOR-DEPOSITION TECHNIQUE
(1994-04-01)
CHANG, TC
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CHANG, CY
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JUNG, TG
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TSAI, WC
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WANG, PJ
High quality Si/Si1-xGex superlattices having layers as thin as 1.5 nm have been grown by an ultrahigh vacuum/chemical vapor deposition system. High-resolution double-crystal x-ray diffraction, and conventional and high-resolution cross-sectional transmission electron microscopy were used to evaluate the crystalline quality of these superlattices. A dynamical x-ray simulation program was employed to analyze the experimental rocking curves. Excellent matches between experimental rocking curves and simulated ones were obtained for all superlattices with various periodicity. A cross-sectional transmission electron micrograph of an 80 period Si(4.2 nm)/Si0.878Ge0.122 (1.5 nm) superlattice, in which each individual layers was clearly resolved, demonstrated the capability of this growth technique for nanometer thick layer deposition.