Browsing by Author "Lo, SH"

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Behavior of steel beam to circular CFT column connections
(2003)
Chen, CC
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Lo, SH
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交大名義發表
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National Chiao Tung University
This paper describes the structural behavior of connections between concrete-filled tubular (CFT) steel column and steel beam. The connections are characterized with the flange plates penetrated through the column. Four beam-to-column subassemblage specimens were tested under reversal loading. Specimens with strong shear capacity in the panel zone demonstrated stable hysteresis behavior by forming the plastic hinge in the beam. Specimen having panel zone shear yielding resulted in pinching hysteresis curve, which was caused by the diagonal shear cracking of the concrete inside the steel tube. The shear capacity of the CFT column in the panel zone is contributed from the steel tube and concrete core and can be estimated by superposition of the strengths of the steel tube and the concrete.
Numerical analysis of frequency dispersion of transconductance in GaAs MESFET's
(1996-02-01)
Lo, SH
;
Lee, CP
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電控工程研究所
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Institute of Electrical and Control Engineering
A fully two-dimensional numerical model for the transconductance dispersion in GaAs MESFET's is presented, According to simulated results, the dominating surface traps belong to the hole trap type in order to obtain consistent results with reported measurements, The AC frequency-dependent modulation of negative surface charge can explain this anomalous phenomenon. The holes injecting from and emitting out of the gate metal electrode interact with the surface hole traps, and result in the change of the gate-to-source and the gate-to-drain resistances, which in turn cause the change in transconductance. The gate voltage and the gate length effects on the dispersion are also considered, Good agreement with reported results is obtained.
Sintering BaTi4O9/Ba2Ti9O20-based ceramics by glass addition
(2000-07-01)
Cheng, CM
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Yang, CF
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Lo, SH
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Tseng, TY
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電子工程學系及電子研究所
After calcining BaCO3 + 4TiO(2) mixed powder at 1150 degrees C for 2 h, BaTi4O9 is the major phase, Ba4Ti13O30 and BaTi5O11 are minor phases. After calcining 2BaCO(3) + 9TiO(2) mixed powder at 1200 degrees C for 10 h, Ba2Ti9O20 is the major phase, BaTi4O9 and BaTi5O11 are the minor phases. The calcining powders are used as the BaTi4O9 and Ba2Ti9O20 precursors. MgO-CaO-SiO2-Al2O3 (MCAS) composite glass powder, fabricated by sol-gel method, is used as the low melting addition to lower the sintering temperatures of BaTi4O9 and Ba2Ti9O20 dielectric. The addition of MCAS glass does not inhibit the residual satellite phases to transform into BaTi4O9 and Ba2Ti9O20. For MCAS-doped BaTi4O9 and Ba2Ti9O20 ceramics the major phases are BaTi4O9 and Ba2Ti9O20, cordierite is observed as minor phase. The temperatures needed to densify the BaTi4O9 and Ba2Ti9O20 ceramics are lowered down with the increase amount of MCAS glass addition. For BaTi4O9 and Ba2Ti9O20 ceramics, both the densities and the dielectric constants (at 1 MHz) increase with the sintering temperature and decrease with the amount of MCAS glass addition. (C) 2000 Elsevier Science Ltd. All rights reserved.