Browsing by Author "Huang, TH"

Now showing 1 - 14 of 14

2,8-Bis(3-phenylquinoxalin-2-yl)-5 lambda(6)-dibenzo[b,d] thiophene-5,5-dione
(2005-12-01)
Huang, TH
;
Whang, WT
;
Wen, YS
;
Lin, JT
;
材料科學與工程學系
The bond lengths and angles in the title compound, C40H24N4O2S, are normal. The dihedral angles between the dibenzothiophene-S,S-dioxide and two quinoxaline groups are 34.88 (1) and 45.86 (1)degrees.
2-phenyl-3-[6-(3-phenylquinoxalin-2-yl)-dibenzo[b,d]thiophen-3-yl]quinoxaline
(2005-12-01)
Huang, TH
;
Whang, WT
;
Wen, YS
;
Lin, JT
;
材料科學與工程學系
In the molecule of the title compound, C40H24N4S, the two benzene rings fused to the thiophene ring form a dihedral angle of 2.3 (2)degrees. In the crystal structure, there are no significant hydrogen-bonding interactions, but there are pi - pi stacking interactions between molecules.
A heuristic approach to generating file spanning trees for reliability analysis of distributed computing systems
(1997-11-01)
Chen, DJ
;
Chen, RS
;
Huang, TH
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
The reliability of Distributed Computing Systems (DCS) in terms of Distributed Program Reliability (DPR) and Distributed System Reliability (DSR) has been studied intensively. Current reliability algorithms available for the analysis of DPR and DSR include MFST, FARE, FST, and FST-SPR. This paper presents a reliability algorithm, called HRFST, that eliminates the need to search a spanning tree during each subgraph generation. The HRFST algorithm reduces both the number of subgraphs (or trees) generated and the actual execution time required for analysis of DPR and DSR. Examination of several sample cases shows that the HRFST algorithm is more efficient than the FST-SPR algorithm.
A heuristic approach to generating file spanning trees for reliability analysis of distributed computing systems
(1997-11-01)
Chen, DJ
;
Chen, RS
;
Huang, TH
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
The reliability of Distributed Computing Systems (DCS) in terms of Distributed Program Reliability (DPR) and Distributed System Reliability (DSR) has been studied intensively. Current reliability algorithms available for the analysis of DPR and DSR include MFST, FARE, FST, and FST-SPR. This paper presents a reliability algorithm, called HRFST, that eliminates the need to search a spanning tree during each subgraph generation. The HRFST algorithm reduces both the number of subgraphs (or trees) generated and the actual execution time required for analysis of DPR and DSR. Examination of several sample cases shows that the HRFST algorithm is more efficient than the FST-SPR algorithm.
Back-gate forward bias method for low-voltage CMOS digital circuits
(1996-06-01)
Chen, MJ
;
Ho, JS
;
Huang, TH
;
Yang, CH
;
Jou, YN
The back-gate forward bias method suitable for present standard hulk CMOS processes has been promoted for low-voltage digital circuit application, A CMOS inverter employing the method has experimentally exhibited the ability of electrically adjusting the transition region of the de voltage transfer characteristics. Transient measurement has further shown that the inverter with a back-gate forward bias of 0.4 V can operate at low supply voltages down to 0.6 V without significant loss in switching speed, Guidelines for ensuring proper implementation of tile method in a bulk CMOS process has been set up against latch-up, parasitic bipolar, impact ionization, and stand-by current, Following these guidelines, a cost-effective low-power, low-voltage, high-density mixed-mode CMOS analog/digital integrated circuits chip with both reasonable speed and improved precision has been projected for the first time.
Combustion synthesis of Ni-Zn ferrite powder - influence of oxygen balance value
(2005-01-01)
Hwang, CC
;
Tsai, JS
;
Huang, TH
;
Peng, CH
;
Chen, SY
In this study, Ni0.5Zn0.5FC2O4 powder was synthesized via an exothermic reaction between nitrates [Ni(NO3)(2).6H(2)O, Zn(NO3)(2).6H(2)O, Fe(NO3)(3).9H(2)O, and NH4NO3] and glycine [NH2CH2COOH]. By adjusting the glycine-to-nitrates ratio, the oxygen balance (OB) values of the reactant mixtures can be varied in which the combustion phenomena is altered and thereby the as-synthesized products with different characteristics are obtained. An interpretation based on the measurement of maximum combustion temperature (T-c) and the amounts of gas evolved during reaction for various OB values has been proposed regarding the nature of combustion and its correlation with the characteristics of as-synthesized products. After instrumental analyses, it is shown that the as-synthesized powders are nanoscale crystallites with a large specific surface area and they inherit a superparamagnetic behavior. (C) 2004 Elsevier Inc. All rights reserved.
Fluctuating characteristics and rotation induced stabilization of thermal buoyancy driven water flow in a vertical rotating cylinder
(2001-03-01)
Yin, CP
;
Ker, YT
;
Huang, TH
;
Lin, TF
;
機械工程學系
An experimental study was carried out here to investigate the fluctuating characteristics and stabilization of the thermal buoyancy driven unstable water flow in vertical closed circular cylinders heated from below by rotating the cylinder about its vertical axis. Results for the time variations of the water temperature at selected locations were obtained for the imposed temperature difference DeltaT ranging from 5 degreesC to 15 degreesC and the cavity rotation rate Ohm from 0 to 300 rpm for a cylinder with diameter D = 5 cm, height H = 10 cm and Ohm varying from 0 to 210 rpm for another cylinder with D = 2.5 cm and H = 5 cm. Based on the data for the time records of the water temperature, the flow suppression by the cylinder rotation causes the time-average temperature distributions along the cylinder axis for high rotation rates to become linear. Besides, the flow can be stabilized by the cylinder rotation when the rotation rate is in certain ranges. Significant dependence of the oscillation amplitude with the space is revealed. But the entire how oscillates at nearly the same frequency when the flow is time periodic. Moreover, non-monotonic variations of the oscillation frequency with the rotation rate are clearly shown. Based on the present data, a flow regime map and correlations delineating the stable and unstable states in the vertical rotating cylinders containing water are also provided. (C) 2001 Elsevier Science Ltd. All rights reserved.
High gain p-n-p gated lateral bipolar action in a fully depleted counter-type: Channel p-MOSFET structure
(1996-02-01)
Ho, JS
;
Huang, TH
;
Chen, MJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A three-terminal p-n-p gated lateral bipolar transistor in a counter-type channel p-MOSFET structure has exhibited experimentally ideal I-V characteristics in low-level injection, with a peak current gain exceeding 1000. Two-dimensional device simulation and additional experiments have revealed that high current gains with ideal bipolar I-V characteristics can be obtained only if the counter-type channel is fully depleted. Under this condition, not only the surface emitter-base junction barrier beneath the gate is lowered, but also the holes injected from the emitter almost go through the potential valley in the channel. An analytical model and its validity range have both been established to provide understanding of such behavior, and have been supported experimentally by two-dimensional device simulation. The measured I-V characteristics, including high-level injection, have also been appropriately reproduced.
Hyper-Rayleigh scattering of thiophene-incorporated polyene chromophores with pi-configuration locking
(1997-08-15)
Hsu, CC
;
Shu, CF
;
Huang, TH
;
Wang, CH
;
Lin, JL
The hyper-Rayleigh scattering (HRS) technique is used to determine and compare the first hyperpolarizabilities (beta) of thiophene-incorporated polyene chromophores with and without a configuration locked trans-triene bridge, To ensure the purity of the HRS signal, special attention is paid to its dependence on the fundamental intensity and the spectral content of the scattered radiation including the two-photon absorption induced fluorescence. From the HRS results, it is found that the configuration-locked trans-triene bridge enhances the beta values of the chromophores studied, The beta-enhancement is more pronounced when the electron acceptor CHC(CN)(2) in the chromophores is replaced with C-2(CN)(3). (C) 1997 Elsevier Science B.V.
Isolation on Si wafers by MeV proton bombardment for RF integrated circuits
(2001-05-01)
Lee, LS
;
Liao, CP
;
Lee, CL
;
Huang, TH
;
Tang, DDL
This paper studies issues related with using high energy protons to create local semi-insulating silicon regions on IC wafers for device isolation and realization of high-Q IC inductors, Topics on two approaches, i.e., one using Al as the radiation mask and the other using proton direct-write on wafers were studied, It was shown that Al can effectively mask the proton bombardment of 15 MeV up to the fluence of 10(17) cm(-2). For the unmasking direct write of the proton bombardment, isolation in the silicon wafer can be achieved without damaging active devices if the proton fluence is kept below 1 x 10(14) cm-2 with the substrate resistivity level chosen at 140 Omega -cm, or kept at 1 x 10(15) cm(-2) with the substrate resistivity level chosen at 15 Omega -cm. Under the above approaches, the 1 h-200 degreesC thermal treatment, which is necessary for device final packaging, still gives enough high resistivity for the semi-insulating regions while recovers somewhat the active device characteristics, For the integrated passive inductor fabricated on the surface of the silicon wafer, the proton radiation improves its Q value.
Organic electroluminescent derivatives containing dibenzothiophene and diarylamine segments
(2005)
Huang, TH
;
Whang, WT
;
Shen, JY
;
Lin, JT
;
Zheng, HG
A new series of 2,8-disubstituted dibenzothiophenes have been successfully synthesized via palladium-catalyzed C-N or C-C bond formation using 2,8-dibromodibenzothiophene and diarylamines as starting materials. These new dibenzothiophene derivatives are amorphous with a glass transition temperature ranging from 86 to 190 degrees C. Furthermore, they are fluorescent in the blue to bluish green region. Two types of light-emitting diodes ( LED) were constructed from these compounds, ( I) ITO/Cpd/TPBI/LiF/Al and (II) ITO/Cpd/Alq3/LiF/Al, where TPBI and Alq(3) are 1,3,5-tris(N-phenylbenzimidazol-2-yl) benzene and tris(8-hydroxyquinolinato) aluminium, respectively. In type I devices, the compounds function as the hole-transporting and emitting material. In type II devices, emission from Alq3 is observed. Several type I devices emit pure blue light, and most of the devices II have very promising performance. The relation between the energy levels of the materials and the performance of the light-emitting diodes is discussed.
Quinoxalines incorporating triarylamines: Dipolar electroluminescent materials with tunable emission characteristics
(2006-02-01)
Huang, TH
;
Whang, WT
;
Zheng, HG
;
Lin, JTS
;
材料科學與工程學系
Dipolar compounds (abbreviated as QuPy) featuring quinoxaline acceptors and diarylamine or triarylamine donors were prepared via palladium-catalyzed C-N or C-C bond formation in good yields. They possess high thermal stability with a high decomposition temperature (T-d > 400 degrees C) and exhibit no crystalline character. The emission colors of the materials vary from green to orange red and are dependent on the nature of the electron-withdrawing segments and solvents. Two types of double-layer organic light-emitting diodes (OLEDs) were constructed using these dipolar compounds as hole-transporting/emitting layers and TPBI or Alq(3) as an electron-transporting layer: (I) ITO/QuPy/Alq(3)/Mg:Ag and (II) ITO/QuPy/TPBI/Mg:Ag (TPBI = 1,3,5-tris(N-phenylbenzimidazol-2-yl)-benzen; Alq(3) = 1,3,5-tris(N-phenyl-benzimidazol-2-yl)-benzene). The recombination zone in most of those devices were confined in the quinoxaline layers, The green to orange colors in these devices correspond well with the film PL of the material used. The relation between the energy levels of the compounds and the performance of the light-emitting diode are discussed.
Signs of nonlinear refraction in chloroaluminum phthalocyanine solution
(1998-05-18)
Wei, TH
;
Huang, TH
;
Lin, MS
;
應用化學系
;
Department of Applied Chemistry
Opposite signs of nonlinear refraction in chloroaluminum (ClAl) phthalocyanine (Pc) dissolved in methanol are observed using the Z-scan technique with two output modes of a frequency-doubled, Q-switched, mode-locked Nd:YAG laser operating at 10 Hz. Using the single picosecond (ps) pulses switched out of the pulse trains, positive nonlinear refraction is observed and attributed to population transitions among ClAlPc's singlet states. Using the full nanosecond pulse trains, a sign change of nonlinear refraction relative to that of single ps-pulse excitation is observed, and is attributed to the heat-induced temperature rise and the population relaxing to CLAlPc's triplet states. (C) 1998 American Institute of Physics. [S0003-6951(98)01720-3].
Studies of nonlinear absorption and refraction in C-60/toluene solution
(2000-02-18)
Wei, TH
;
Huang, TH
;
Wu, TT
;
Tsai, PC
;
Lin, MS
Nonlinear absorptive and refractive properties of C-60/toluene solution are studied using the Z-scan technique and a 532 nm laser delivering single picosecond (ps) pulses and trains of ps pulses separated by 7 nanoseconds (ns). With single ps pulses, reverse saturable absorption and positive nonlinear refraction are observed and attributed to population transitions among the singlet states. With ps pulse trains, a sign change of nonlinear refraction relative to that of single ps-pulse excitation is observed and is attributed to heat-induced temperature rise and population relaxing to triplet states. (C) 2000 Elsevier Science B.V. All rights reserved.