Browsing by Issue Date, starting with "1995-12-11"

Now showing 1 - 20 of 86564

SPONTANEOUSLY FORMED LONG-RANGE AL-RICH AND GA-RICH ALXGA1-XAS/ALYGA1-YAS SUPERLATTICE AND OPTICAL-PROPERTIES ENHANCEMENT IN (111)A ALGAAS
(1995-12-11)
CHIN, A
;
LIN, BC
;
GU, GL
;
HSIEH, KY
;
電子工程學系及電子研究所
Spontaneously formed long-range Al-rich and Ga-rich AlxGa1-xAs/AlyGa1-yAs superlattice in(111)A was demonstrated. This was observed by cross-sectional transmission electron microscopy (TEM) in 0.75 mu m Al0.30Ga0.70As grown on (111)A GaAs substrates at 640 degrees C. In contrast, none of the above superstructure was observed by TEM on a side-by-side grown (100) oriented substrate. 15 K photoluminescence (PL) showed a 31 meV redshift and six times peak intensity enhancement in layers grown on (111)A substrates to that on (100). A reduced long-range compositional modulation can be achieved by growth at higher temperatures and is shown in the finer and moderately modulating (111)A Al0.40Ga0.60As grown at 700 degrees C. A 15 K PL linewidth of 17 meV was achieved in 700 degrees C grown (111)A A(0.40)Ga(0.60)As that is the narrowest reported linewidth for (111)A AlGaAs. (C) 1995 American Institute of Physics.
STUDIES ON CO[POLY(ETHYLENE TEREPHTHALATE-P-OXYBENZOATE)] THERMOTROPIC COPOLYESTER - THERMOMECHANICAL AND THERMODYNAMIC PROPERTIES
(1995-12-12)
SHINN, TH
;
LIN, CC
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A series of co[poly(ethylene terephthalate-p-oxybenzoate)] thermotropic copolyesters were prepared by the copolymerization of poly(ethylene terephthalate) (PET) as moiety (II) and p-acetoxybenzoic acid (POB) as moiety (I). The polymeric products obtained were subjected to solid-state polymerization. Characterization of the copolyesters by thermomechanical analysis shows that properties such as the coefficient of thermal expansion, transition temperature, and maximum softening rate temperature varied directly as a function of composition as well as did solid-state polymerization time. All thermomechanical data were found to increase with the solid-state polymerization time due to the increase in the degree of polymerization and the effect of annealing. The coefficient of thermal expansion behaves in a manner that is interpretable by the crystalline state of the copolyester. The relationship between the free-volume fraction and thermodynamic properties is further correlated for a more comprehensive discussion on its molecular arrangements. (C) 1995 John Wiley & Sons. Inc.
管管作品三首
(1995-12-15)
管管
Modification on the surface of superconducting YBa2Cu3O7-x films by microwave plasma-enhanced pulsed laser deposition
(1995-12-15)
Huang, CS
;
Tseng, TY
;
Chung, BC
;
Tsai, CH
;
Hsu, SS
Superconducting YBa2Cu3O7-x films having smooth surfaces were successfully synthesized by a microwave plasma-enhanced pulsed laser deposition (PEPLD) process. Particulates that frequently occurred in films grown by the conventional PLD process were effectively eliminated. The films were epitaxial-like. The c-axis was perpendicular to the films' surface, the a and b axes were aligned in the films' plane, and the onset and zero of the transition temperature were at T-c=90 K and T-c0=86 K, respectively. Optical emission spectroscopy indicated that the presence of oxygen plasma not only reexcited the laser-induced species via the collision process, but also produced abundant atomic oxygen in PEPLD process. The surface reaction kinetics for the formation of the thin-film process was thus greatly enhanced, which substantially improved the thin-film quality. (C) 1995 American Institute of Physics.
THE EFFECT OF NB-ADDITION ON THE LL(2) PRECIPITATES OF RAPIDLY-SOLIDIFIED AL-CR-ZR ALLOY
(1995-12-15)
CHUANG, MS
;
TU, GC
;
交大名義發表
;
材料科學與工程學系
;
National Chiao Tung University
管管作品三首
(1995-12-15)
管管
管管作品三首
(1995-12-15)
管管
管管作品三首
(1995-12-15)
管管
Effects of oxygen-argon mixing on the electrical and physical properties of ZrTiO4 films sputtered on silicon at low temperature
(1995-12-15)
Chang, DA
;
Lin, P
;
Tseng, TY
;
材料科學與工程學系
;
電子工程學系及電子研究所
Zirconium titanate (ZrTiO4) thin films (200-260 nm) on p-type (100) Si substrates were prepared using radio-frequency sputter deposition at room temperature in atmosphere of various O-2/Ar mixing ratio (from 0/100 to 20/80). All films exhibited a (020) preferred orientation and small grain size with increasing O-2/Ar ratio, as shown by x-ray diffraction. The variations of dielectric constant, fixed oxide charge, and interface trapped charge with O-2/Ar ratio are studied with an Al/ZrTiO4/Si structure. The refractive index and dielectric constant varied in ranges 2.34-2.26 and 20-16 for the as-deposited films. Within the range investigated, crystallinity appears to have a stronger influence on the densities of charge-trapping centers in the films than oxygen stoichiometry, and the latter may determine the leakage current density. A remarkable two orders of magnitude decrease in leakage current to 5.6X10(-9) A/cm(2) at 0.1 MV/cm and an increase in breakdown field beyond 1.2 MV/cm are observed in the film deposited without oxygen after a 400 degrees C annealing in air for 1 h. The current transport in ZrTiO4 film is dominated by the Poole-Frenkel mechanism. (C) 1995 American Institute of Physics.
管管作品三首
(1995-12-15)
管管
Wide bandwidth AlAs/AlGaAs tandem Bragg reflectors grown by organometallic vapor phase epitaxy
(1995-12-18)
Lee, WI
;
交大名義發表
;
電子物理學系
;
National Chiao Tung University
;
Department of Electrophysics
Wide bandwidth AlAs/Al0.6Ga0.4As tandem Bragg reflectors were grown by organometallic vapor phase epitaxy. Quarter-wave reflector stacks designed for different wavelengths were placed in cascade in epitaxially grown structures to expand the high reflectance bands. Intermediate low-index layers were put in between every two stacks to suppress the transmission peaks in the centers of the combined high reflectance bands. While a single-stack structure showed a full width half-maximum bandwidth of 500 Angstrom, the two-stack and the three-stack structures effectively doubled and tripled this bandwidth to approximately 1000 and 1500 Angstrom, respectively. (C) 1995 American Institute of Physics.
The first exclusive regioselective fragmentation of primary ozonides controlled by remote carbonyl groups
(1995-12-18)
Lin, CC
;
Wu, HJ
;
應用化學系
;
Department of Applied Chemistry
Ozonolysis of compounds 1a-1d in CDCl3 at -78 degrees C regioselectively and stereoselectively gave the corresponding final ozonides 2a-2d as the sole product, which, after treatment with triethylamine, gave the novel convex tetraquinane era-cages 9a-9d in high yields respectively.
Synthesis of furan-, thiophene- and pyrrole-fused sultines and their application in Diels-Alder reactions
(1995-12-21)
Chung, WS
;
Lin, WJ
;
Liu, WD
;
Chen, LG
;
交大名義發表
The synthesis of 1,4-dihydrofurano[3,4-d]-3,2-oxathiine 2-oxide 8, 5,7-dimethyl-1,4-dihydrothieno[3,4-D]-3,2-oxathiine 2-oxide 9 and 1,4-dihydro-6-tosylpyrrolo[3,4-D]-3,2-oxathiine 2-oxide 10, precursors for nonclassical heteroaromatic o-quinodimethanes, and their application in the Diels-Alder reactions are reported.
Recognition of handwritten similar Chinese characters by neural networks
(1996)
Fu, HC
;
Chen, JM
;
資訊工程學系
;
Department of Computer Science
清大有種會啄人的鳥
(文史哲, 1996)
沈定濤
Effects of oxygen content on the penetration depth in YBCO thin films
(1996)
Hsieh, MC
;
Tseng, TY
;
Fu, CM
;
Wu, KH
;
Juang, JY
By varying oxygen content of the microstrip line resonator of YBa2Cu3O7-x, the effective penetration depth was studied. Based on the two-fluid model, we fit the data of the resonant frequency by means of the inductance formula. It allows us to determine the zero-temperature penetration depth of the fully oxygenated,(O approximate to 7) and oxygen deficient (O = 6.8) states in the same strip to be 483.2 nm and 789.8 nm, respectively. The ratio of the superconducting carrier densities with different oxygen contents is then derived and found to be consistent with the result of Hall measurement. A correlation between oxygen contents and charge carriers of the samples will be obtained in our work as accurately as possible.
II-VI半導體量子點和微腔液滴之超快同調光譜研究
(1996)
謝文峰
;
HSIEH WEN-FENG
;
國立交通大學光電工程研究所
氫原子多光子過程之研究---有限元素動量空間解法
(1996)
江進福
;
JIANG TSIN-FU
;
國立交通大學物理研究所
本計劃擬用我們最近發展出來的"有限元素動量空間法",來解氫原子在強雷射場之下的多光子過程, 這種問題為量子非微擾性質,自從 1979年多光子實驗發表以來,雖然經過許多理論探討,但是從下列幾個引用之著名學者的最近論文來看,如果能夠將氫原子的多光子過程解決,將是一件很重要的工作:游離電子的運動範圍到無限遠,因此如果想要解好游離問題,習用之座標空間法,勢須改良;我們小組這幾年來也曾發表了若干方法,最近發展出結合 Finite Element Method (FEM) 與Momentum Space Method 的 "有限元素動量空間法",經過初部試探,已經可以處理這個問題,上述引證中所談到的困難,都可以克服, 我們覺得這個方法頗有價值,因此提出此一為期兩年的計劃,預備對氫原子的多光子過程,做全面性的研究.擬定研究項目如下 :
航站模擬模式之建立與應用
(1996)
汪進財
;
國立交通大學交通運輸研究所
不論就科技之進展、使用航站旅客之行為及各項服務設施服務特性之更動觀之,機場航站之運作均受到相當程度之衝擊,傳統機場航站規劃之標準與概念已有必要作一適度之檢討 ,以便能適當反應此等相關航站運作之差異.由於航站入境與出境作業是分開且獨立的,出境航站受到外在因素的影響較多,因此,本研究將僅針對中正機場航站之出境服務設施、作業方式、航站設施使用者行為及需求等相關因素建立模擬模式來評估出境航站服務水準,最終目的將利用該模擬模式建立一套出境航站設施規劃標準,以提供未來航站規劃或改善時之參考. 主要工作將包括:1.出境航站使用者行為分析2. 出境航站佈設及運轉方式分析3.模擬模式建立 4.航站設施服務水準分析5.航站設施空間需求標準之建立
台灣地區高程系統及其變遷之研究---子計畫三：應用地理資訊系統於重力地形改正及重力預估之研究
(1996)
史天元
;
SHIH TIAN-YUAN
;
國立交通大學土木工程學系