Browsing by Author "CHANG, HL"

Now showing 1 - 17 of 17

DISAGGREGATE MODEL OF HIGHWAY ACCIDENT OCCURRENCE USING SURVIVAL THEORY
(1989-10-01)
JOVANIS, PP
;
CHANG, HL
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
DOUBLE RESONANT BEHAVIOR OF MICROSTRIP RING-RESONATOR IN TL-BASED HIGH T-C SUPERCONDUCTING FILMS
(1994-12-19)
WU, SC
;
YEH, CY
;
CHEN, FH
;
TSENG, TY
;
WANG, C
EFFECT OF SN ON THE SUPERCONDUCTIVITY OF THE DYBA2CU3O7-DELTA SYSTEM
(1989-12-01)
WANG, C
;
CHEN, LT
;
CHANG, HL
;
CHU, ML
;
HSU, FW
EFFECTS OF MAGNETIC-FIELD AND TEMPERATURE ON THE CRITICAL CURRENT HYSTERESIS IN TL-CA-BA-CU-O THIN-FILMS
(1990-11-01)
CHANG, HL
;
JUANG, JY
;
LIOU, SH
;
UEN, TM
;
GOU, YS
EFFECTS OF ZRO2 ON THE TEXTURING AND PROPERTIES OF MELT-PROCESSED Y1BA2CU3O7-DELTA
(1994-04-25)
JUANG, JY
;
WU, CL
;
WANG, SJ
;
CHU, ML
;
WU, KH
The addition of ZrO2 is found to be very effective as the nucleation sites to promote the oriented growth of Y1Ba2Cu3O7-delta (YBCO) during peritectic solidification. Extended regions of well-textured YBCO grains with superior superconducting properties of the YBCO bulk are readily obtained by a single-step melt process at much lower process temperatures. At 77 K, the platelike Josephson weak-link behaviors observed in pure melt-processed YBCO have been effectively eliminated, indicating that the coherency between the spherulitic superconducting YBCO grains may have been greatly improved by ZrO2 additions.
FLUX LINE DYNAMICS CROSSOVER IN THE TL-BA-CA-CU-O THIN-FILM
(1990-11-01)
WANG, CY
;
CHANG, HL
;
CHU, ML
;
JUANG, JY
;
GOU, YS
By extending the observation of the current-voltage characteristics to a much higher dissipative state, the flux-line motion experiences at least two stages of crossover, namely, from glassy hopping to creep-dominating, and finally an abrupt transition into the flow regime.
FORMULATING ACCIDENT OCCURRENCE AS A SURVIVAL PROCESS
(1990-10-01)
CHANG, HL
;
JOVANIS, PP
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
LOW-FIELD SCALING BEHAVIORS OF GLOBAL FLUX PINNING IN TL-BA-CA-CU-O THIN-FILMS
(1992-07-01)
JUANG, JY
;
WANG, SJ
;
UEN, TM
;
GOU, YS
;
CHANG, HL
The scaling behaviors of global pinning force density (F(p) = J(c) X B) in dc sputtered TI-Ba-Ca-Cu-0 superconducting thin films as functions of both the reduced magnetic field and temperature were investigated by direct transport measurements for fields up to 4 kOe. It was found that, depending on the film granularities (originating from different deposition and annealing conditions and characterized by the temperature and magnetic-field dependencies of critical currents), vastly different scaling behaviors were manifested. For films with very high critical current densities, where the intragranular behaviors prevailed, the conventional surface core pinning by some high-density normal pinning centers combined with a significant flux creep appeared to be the predominant limiting mechanisms for the critical current densities, whereas in more granular films, suggestive collective-pinning effects arising from the weakly pinned fluxoids in the intergranular networks were observed.
OBSERVATION OF A POSSIBLE FRINGING FIELD-EFFECT ON THE THRESHOLD VOLTAGE VARIATION OF THE SHORT-CHANNEL MOSFET
(1980)
CHANG, HL
;
YU, SY
;
交大名義發表
;
電控工程研究所
;
National Chiao Tung University
OBSERVATION OF THE VORTEX-GLASS TRANSITION IN THE TL-BASED SUPERCONDUCTING THIN-FILMS
(1992-08-01)
WANG, CY
;
CHANG, HL
;
JUANG, JY
;
GOU, YS
;
UEN, TM
The current-voltage characteristics (IVC) of Tl-based superconducting thin films as well as the magnetization of the Tl-based bulk sample were investigated. A crossover similar to the prediction of the vortex-glass to vortex-liquid phase transition in the IVC of Tl-based superconducting thin films was clearly demonstrated. More significantly, striking scaling behavior was found in the IVC which is only sample dependent and is irrelevant to the applied magnetic fields. By comparison to dc magnetization measurements on similar bulk samples, it is found that the phase boundary is not the irreversibility line commonly encountered in the flux-creep scenario.
OXIDATION OF GAAS SURFACE BY OXYGEN PLASMA AND ITS APPLICATION AS AN ANTIREFLECTION LAYER
(1991-07-15)
LOONG, WA
;
CHANG, HL
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The optical reflectivity of a GaAs wafer is found to decrease from about 45% down to about 5% for both the g-line and i-line by oxidation in low-power oxygen plasma at 300-degrees-C for 4 hours. The oxide layer on the GaAs top surface used as an in situ antireflection layer for optical microlithography is demonstrated to be effective.
PREPARATION OF TL2CA2BA2CU3OX SUPERCONDUCTING THIN-FILMS BY DC SPUTTERING
(1989-04-01)
CHANG, HL
;
WANG, C
;
CHU, ML
;
UEN, TM
;
GOU, YS
SYNTHESIS AND CHARACTERIZATION OF SIDE-CHAIN LIQUID-CRYSTALLINE POLYMETHACRYLATES CONTAINING FLUORINATED DIPHENYLDIACETYLENE SIDE-GROUPS
(1994)
LU, YH
;
TSAY, KT
;
HSU, CS
;
CHANG, HL
;
應用化學系
The synthesis of four side-chain liquid crystalline polymethacrylates containing either 4-alkanyloxy-4'-flourodiphenyldiactylenes or 4-alkanyloxy-3',4'-difluorodiphenyldiacetylenes side groups is presented. The phase behavior of both monomeric and polymeric liquid crystals was characterized by differential scanning calorimetry and optical polarizing microscopy. All synthesized polymethacrylates present nematic mesomorphism. The glass transition temperature of the obtained polymers decreases as the spacer length increases. The mesomorphic behavior of the prepared polymers depends very much on the degree of substitution of the mesogenic side groups on the polymer backbones.
SYNTHESIS OF SIDE-CHAIN LIQUID-CRYSTALLINE POLYOXETANES CONTAINING 4-DODECANYLOXYPHENYL TRANS-4-ALKYLCYCLOHEXANOATE SIDE-GROUPS
(1994-05-01)
LU, YH
;
CHANG, HL
;
HSU, CS
;
應用化學系
;
Department of Applied Chemistry
The synthesis and characterization of side-chain liquid crystalline polyoxetanes containing 4-dodecanyloxyphenyl trans-4-alkylcyclohexanoate side groups are presented. All the obtained monomers exhibit smectic B mesomorphism, while all the obtained polymers present smectic A, smectic B and smectic G mesophases. A longer terminal alkyl group is leading to the formation of a more stable mesophase.
SYNTHESIS PROCESS OF THE HIGH-TC SUPERCONDUCTOR IN THE TL2CA2BA2CU3OX PHASE
(1989-04-01)
WANG, C
;
CHANG, HL
;
CHU, ML
;
GOU, YS
;
UEN, TM
THE MAGNETIC AND TRANSPORT-PROPERTIES OF HIGH-CRITICAL-CURRENT TL2BA2CA2CU3OX SUPERCONDUCTING THIN-FILMS
(1991-08-26)
CHU, ML
;
CHANG, HL
;
WANG, C
;
JUANG, JY
;
UEN, TM
Highly c-axis-oriented Tl2Ba2Ca2Cu3O(x) superconducting thin films with the critical current density as high as 1 X 10(7) A/cm2 at 87 K were obtained by single-target dc sputtering on LaAlO3 (100) substrates followed by encapsulated compensate annealing. The strong linear temperature dependence of zero-field critical current at low temperatures suggests a creep-dominated behavior. Preliminary field dependence studies on the critical current density in low-field regime (< 2 kOe) shows no evidence of hysteresis commonly encountered in films with higher granularity. The scaling behavior of the global pinning force density exhibits strong resemblance to conventional type-II superconductors with the pinning force density of the same order of magnitude as that in strong pinned NbN thin films.
THE SCALING BEHAVIORS OF PINNING IN TLBACACUO SUPERCONDUCTING THIN-FILMS
(1992-08-01)
CHANG, HL
;
WANG, C
;
JUANG, JY
;
UEN, TM
;
GOU, YS
The scaling behaviors of global pinning force density in dc sputtered TlBaCaCuO superconducting thin films as functions of both reduced magnetic fields and temperatures were investigated by direct transport measurements with applied fields perpendicular to the film surface. The pinning mechanisms which were depicted by the scaling behaviors of the Tl-based thin films were found to be strongly dependent on the superconducting properties of the films. For films with high critical current densities the conventional flux line shear pinning appeared to be the predominant limiting mechanism for the current carrying capability. Whereas in more granular film that did not scale well when normalized by the extrapolated Hc2, an astonishing scaling behavior by taking a reversible field H* as the normalization parameters was observed.