Browsing by Issue Date, starting with "1994-06-06"

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TUNABLE DUAL-WAVELENGTH OPERATION OF A DIODE-ARRAY WITH AN EXTERNAL GRATING-LOADED CAVITY
(1994-06-06)
WANG, CL
;
PAN, CL
;
光電工程學系
;
Department of Photonics
A novel grazing-incidence grating cavity has been developed for simultaneous generation of laser output at two wavelengths. The gain section is a commercial laser diode array. By moving vertically with respect to the optical axis V-shaped double slit at the end mirror, we demonstrate tuning of the spectral separation of the dual-wavelength laser output from 3.52 to 11.29 nm. The side-mode suppression ratio is 10-20 dB. Examination of the far-field patterns reveal that the laser mode at the two wavelengths corresponds to a different order of the array modes.
GROWTH OF HIGHLY ORIENTED ZRTIO(4) THIN-FILMS BY RADIOFREQUENCY MAGNETRON SPUTTERING
(1994-06-13)
CHANG, DA
;
LIN, P
;
TSENG, TY
;
材料科學與工程學系
;
Department of Materials Science and Engineering
ZrTiO4 thin films on Si(100), metals [Al, Ti and Pt coated on Si(100)] and glass were prepared by radio-frequency magnetron sputter deposition. All films on crystalline substrates exhibited a highly preferred orientation in [020], which were evidenced by the full width at half-maximum (less-than-or-equal-to 0.046-degrees) of the associated rocking curves. The structure of the films on glass, depending on the substrate temperature, was either amorphous or random polycrystalline Good stoichiometric quality and thermal stability have been observed in films on silicon. The X-ray diffraction and transmission electron microscopy selected-area diffraction studies indicated that, after a sequence of annealing up to 650-700-degrees-C, the distributions of Zr and Ti ions in the octahedral cation sites of crystal structure of the films remained disordered.
蚊子離一點騷
(1994-06-13)
管管
鋼琴女人女人的奶子和奶子的嘴　
(1994-06-15)
管管
鋼琴女人女人的奶子和奶子的嘴　
(1994-06-15)
管管
CATION SOURCE DEPENDENCE OF GA0.5IN0.5P GROWTH-RATE BY LOW-PRESSURE METALORGANIC CHEMICAL-VAPOR-DEPOSITION
(1994-06-15)
WU, JW
;
CHANG, CY
;
LIN, KC
;
CHAN, SH
;
CHEN, HD
The Ga0.5In0.5P epilayer was grown by low-pressure metalorganic chemical vapor deposition. Trimethylgallium and triethylgallium were used as the gallium source's, while trimethylindium and ethyldimethylindium were used as the indium sources. The use of triethylgallium incorporated with trimethylindium enhanced the growth rate of Ga0.5In0.5P as compared to incorporation with ethyldimethylindium. While the use of trimethylgallium incorporated with ethyldimethylindium enhanced the growth rate of Ga0.5In0.5P significantly, as compared to incorporation with trimethylindium.
鋼琴女人女人的奶子和奶子的嘴　
(1994-06-15)
管管
鋼琴女人女人的奶子和奶子的嘴　
(1994-06-15)
管管
DIFFERENTIAL CROSS-SECTIONS FOR PLASMON EXCITATIONS AND REFLECTED ELECTRON-ENERGY-LOSS SPECTRA
(1994-06-15)
TUNG, CJ
;
CHEN, YF
;
KWEI, CM
;
CHOU, TL
;
交大名義發表
Electron differential inverse mean free paths for volume-plasmon excitations and differential probabilities for surface-plasmon excitations have been calculated using dielectric response theory. A model dielectric function which satisfied sum rules and agreed with optical data was established for these calculations. In surface-plasmon calculations, we considered electron-impact emissions of the reflected electron-energy-loss spectroscopy. Formulations were made for obliquely incident electrons with the recoil effect and without the small-scattering-angle assumption. For volume-plasmon excitations, we evaluated corrections due to the exchange and Z1(3) effects. Comparison between calculated results and experimental data extracted from reflected electron-energy-loss spectra showed good agreement. Calculated differential cross sections have been used to solve the transport equation for the angular and energy flux spectra of reflected electrons. Contributions to the spectra from single and plural plasmon excitations were analyzed. It was found that calculated spectra were in good agreement with measured data.
PRECRACK HYSTERESIS ENERGY IN DETERMINING ITS DUCTILE-BRITTLE TRANSITION .3. EFFECT OF TEMPERATURE
(1994-06-27)
CHANG, FC
;
HSU, HC
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
A temperature variable has been used to correlate the precrack hysteresis energy and the corresponding ductility in terms of ductile-brittle transition behavior for polycarbonate. When the precrack plastic zone exceeds a critical value, crack extension thereafter will be effectively contained within the domain of the plastic zone and result in ductile fracture. Whether a specimen will fail in a ductile mode or a brittle mode is actually already being decided before the onset of crack initiation. The precrack elastic storage energy, total input energy minus hysteresis energy, is the major driving force to strain the crack tip for crack initiation. A higher testing temperature with lower yield stress converts a greater fraction of the input energy into the precrack hysteresis energy and relieves the storage strain energy available for crack initiation. A polycarbonate-toughening mechanism of increasing temperature is very similar to the presence of rubber by reducing yield stress and increasing the precrack plasticity. (C) 1994 John Wiley & Sons, Inc.
HIGH-RESOLUTION X-RAY CHARACTERIZATION OF LOW-TEMPERATURE GAAS/AS SUPERLATTICE GROWN BY MOLECULAR-BEAM EPITAXY
(1994-06-27)
CHENG, TM
;
CHANG, CY
;
CHANG, TC
;
HUANG, JH
;
HUANG, MF
High-resolution x-ray analysis of Si delta-doped GaAs grown by molecular-beam epitaxy at a low substrate temperature (230-degrees-C) is presented. Superlattice satellite peaks in the rocking curve are observed for the sample annealed at 700-degrees-C for 10 min. The peak intensity increases with increasing postgrowth annealing temperature and reaches the maximum value for the 900-degrees-C annealed sample. The evolution of the x-ray rocking curves can be explained consistently by the formation of a GaAs/As superlattice during the annealing period based on the transmission electron microscope observations.
CHARACTERISTICS OF DIELECTRIC-LINE-LOADED CONDUCTOR-BACKED SLOTLINE (CBS)
(1994-07-01)
HUANG, JW
;
TZUANG, CKC
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
The mode-coupling phenomenon prevents the conventional shielded conductor-backed slotline (CBS) from broadband applications. This paper proposes a modified CBS by adding a dielectric line of higher dielectric constant on the top of the dot region to circumvent the mode-coupling problem. The dispersion characteristics of the resultant dielectric line-loaded CBS are studied by using the full-wave space-domain Green's impedance. function approach. The theoretic results show that the particular modified CBS significantly reduces mode-coupling phenomenon and is suitable for broadband applications. Furthermore, it is possible to adjust the values of the propagation constant and the characteristic impedance by changing the thickness of the dielectric line on top of the slot region. Finally, the design curves for the dielectric line-loaded CBS are provided for potential applications.
SIMULTANEOUS NULLING FOR MONOPULSE ARRAY WITH PARTIALLY ADAPTIVE WEIGHTS
(1994-07-01)
LEE, TS
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
;
Institute of Communications Engineering
A new simple method is described for synthesizing low-sidelobe sum and difference patterns with partially adaptive weights. By partially adaptive, we mean that only part of the weights are adapted for simultaneous nulling. These adaptive weights are shared by the sum and difference channels, leading to a significant reduction in the number of variable attenuators/phase shifters used, as compared to the fully adaptive implementation. An objective function is derived that yields different configurations of the shared adaptive weights. Numerical examples are presented to ascertain the efficacy of the new method for both point and extended interference.
EFFECT OF CROSS-PHASE MODULATION ON OPTICAL-PHASE CONJUGATION IN DISPERSION-SHIFTED FIBER
(1994-07-01)
WEN, SF
;
CHI, S
;
CHANG, TC
;
光電工程學系
;
Department of Photonics
The temporal effect of optical phase conjugation in dispersion-shifted fiber is studied numerically. Frequency chirping is induced in the conjugate pulse by the signal pulse and the pump wave through cross-phase modulation, which increases with the signal power and may distort the pulse shape when the conjugate pulse propagates in the standard fiber. It is also shown that, when the signal power is low, the optical phase conjugation is nearly ideal.
REDUCTION OF STRINGY SCATTERING-AMPLITUDES THROUGH MASSIVE WARD IDENTITIES
(1994-07-01)
LEE, JC
;
交大名義發表
;
電子物理學系
;
National Chiao Tung University
;
Department of Electrophysics
It is shown that the scattering amplitudes of some degenerate massive string states can be expressed in terms of that of higher spin states at the same mass level. This phenomenon is discussed from sigma-model point of view and demonstrated explicitly by using massive Ward identities generated by zero-norm states at D = 26. The subtlety of the scalar propagating state is briefly pointed out. We also compare our on-shell gauge symmetry derived from sigma-model with off-shell gauge symmetry of covariant string field theo
FLUX-FLOW OF ABRIKOSOV VORTICES IN TYPE-II SUPERCONDUCTORS
(1994-07-01)
CHEN, JL
;
YANG, TJ
;
電子物理學系
;
光電工程研究所
;
Department of Electrophysics
The theory of flux flow developed by Bardeen and Stephen (BS) is modified and extended to the high-field case. The Clem model and Wigner-Seitz circle-cell approximation for vortices are used in our approach. The distinct boundary of the normal core of a vortex in BS theory is removed and treated naturally. Several interesting results come out as a consequence. The Lorentz force is determined by the normal current rather than the supercurrent. But the supercurrent can sustain the magnetic-field distribution of flux quanta. From energy dissipation considerations, the Lorentz force is equal to viscosity force automatically without assumption as made in BS theory. An expression for the viscosity is also obtained.
DEPOSITION OF MOLYBDENUM CARBONITRIDE THIN-FILMS FROM MO(NBUT)2(NHBUT)2
(1994-07-01)
CHIU, HT
;
HO, WY
;
CHUANG, SH
;
交大名義發表
;
應用化學系
Mo(NBut)2(NHBut)2 is used as a single-source precursor to deposit thin films of cubic phase molybdenum carbonitride, MoC(x)N(y), (x: 0.2-0.55, y: 0.1-0.47), by chemical vapor deposition on silicon substrates. in general, the C/Mo ratios increased from 0.2 to 0.55 and the N/Mo ratios decreased from 0.47 to 0.1 with increasing the temperature of deposition from 773 to 923 K. Based on the elemental composition and the composition of the gas phase products, it is proposed that the carbon atoms were incorporated through beta-methyl activation of the ligands.
PERFORMANCE OF FAST FH MFSK SIGNALS IN JAMMED BINARY CHANNELS
(1994-07-01)
SU, YT
;
CHANG, RC
;
電信工程研究所
;
友訊交大聯合研發中心
;
Institute of Communications Engineering
Soft-decision decoded performance of fast frequency-hopped (FH) M-ary FSK signals over partial band noise jammed binary channels is studied. The effects of metrics conversion, quantization, and the presence of regenerative nodes on the system's cutoff rate performance are investigated. It is found that the conversion from an M-ary metric to a binary one suffers only negligible degradations. For communication links without regenerative nodes, as expected, the infinite-bit soft-decision is the optimal metric, followed by finite-bit soft decision and then hard-decision. For those with regenerative nodes, however, the infinite-bit soft-decision is outperformed by the hard-decision, but the finite-bit soft-decision decoder still keeps its edge over the latter. The issue concerning the order of metric conversion and diversity combining is also analyzed. Numerical results indicate that the conclusion obtained by an earlier simulation report addressing a similar design alternative in fading channels is valid for jammed binary channels, as well. That is, the precombining metric conversion technique gives up only minor performance degradations when compared to the more sophisticated postcombining metric conversion technique.
MULTIOBJECTIVE DECISION-MAKING APPROACH TO ENERGY SUPPLY MIX DECISIONS IN TAIWAN
(1994-07-01)
TZENG, GH
;
SHIAU, TA
;
TENG, JY
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
This article proposes an integrated multiobjective decision-making (MODM) model to deal with energy supply mix problems in Taiwan based on its characteristics. The analytical framework integrates multiobjective programming (MOP), multicriteria decision making (MCDM), and group decision making (GDM) methods and considers decision dependencies existing in the time horizon. The integrated model has the advantages of flexibility, reasonableness, and robustness. The analyzed outputs, including alternatives, the preferred solution, and the best compromise solution, are provided as a basis for decision making.
A QUARTER-WAVE PLATE USING SUBSTRATE-MODE HOLOGRAMS
(1994-07-01)
SU, DC
;
YOO, JC
;
TSAI, YK
;
HUANG, YT
;
電子工程學系及電子研究所
Based on the phase shifts due to the total internal reflection and the grating diffraction, a new type of quarter-wave plate using substrate-mode holograms is presented. A sample of this device was fabricated to demonstrate its function.