Browsing by Issue Date, starting with "2002-10-21"

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用於印刷微波積體電路之平面式模轉換器
(2002-10-21)
莊晴光
;
李振榮
一種用於印刷微波積體電路之平面式模轉換器，包含：一矩形波導，一微帶線饋入電路及一微帶線饋出電路。該矩形波導之內部填充複數個介質層，各該介質層上下彼此緊鄰相接，其中最上層介質層之頂面、最下層介質層之底面及各該介質層之左、右側面，有金屬材料覆蓋於其上，該最下層介質層其介質常數最大、厚度最厚，除了該最下層介質層以外之各該介質層之前端及後端各有一矩形孔徑，各該前端之矩形孔徑上下緊鄰，各該後端之矩形孔徑上下緊鄰。
詩歌節今夜畫下句點
(2002-10-26)
陳盈珊
詩歌節壓軸詩人化身煉金術士
(2002-10-26)
台北訊
On-off switching of edge direct tunneling currents in metal-oxide-semiconductor field-effect transistors
(2002-10-28)
Chen, MJ
;
Lu, MP
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
On-off switching behaviors or two-level random telegraph signals (RTS) are measured in the low voltage (-1.4 0V
A single mutation converts the nucleotide specificity of phenol sulfotransferase from PAP to AMP
(2002-10-29)
Hsiao, YS
;
Yang, YS
;
生物科技學系
;
Department of Biological Science and Technology
Sulfotransferases (STs) catalyze all the known biological sulfonations, in which a sulfuryl group from a common sulfonate donor such as 3'-phosphoadenosine 5-phosphosulfate (PAPS) is transferred to a nucleophilic acceptor. In addition to PAPS, phenol sulfotransferase (PST), a member of the ST family, utilizes other nucleotides as substrates with much less catalytic efficiency [Lin, E. S., and Yang, Y. S. (2000) Biochem. Biophys. Res. Commun. 271, 818-822]. Six amino acid residues of PST have been chosen for mutagenesis studies on the basis of a model of PST and its sequence alignment with those of available cytosolic and membrane-anchored STs. Systematic analyses of the mutants reveal that Ser134 is important for the regulation of nucleotide specificity between 3'-phosphoadenosine 5'-phosphate (PAP) and adenosine 5'-monophosphate (AMP). Kinetic studies also indicate that Ser134 plays a key role in nucleotide binding (K-m) but not in catalysis (k(cat)). Consequently, the catalytic efficiency (k(cat)/K-m) of PST can be altered by 5 orders of magnitude with a mutation of Ser134. Moreover, the change in nucleotide specificity from PAP to AMP can be achieved by mutation of Ser134 to any of the following residues: Glu, Gln, Arg, and His. Roles of Lys44, Arg126, and Arg253, which interact directly with the 5'- and 3'-phosphate of PAP, were also investigated by mutagenesis and kinetic experiments. On the basis of these findings, we suggest that Ser134 is the key residue that enables PST to discriminate PAP from AMP.
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
Experimental and theoretical studies of the rate coefficients of the reaction O(P-3)+HCl at high temperatures
(2002-10-31)
Hsiao, CC
;
Lee, YP
;
Wang, NS
;
Wang, JH
;
Lin, MC
Rate coefficients of the reaction O(P-3) + HCl in the temperature range 1093-3197 K were determined using a diaphragmless shock tube. O atoms in the ground electronic P-3 states were generated either by photolysis Of SO2 with a KrF excimer laser at 248 nm or by pyrolysis of N2O with the shock wave. Their concentrations were monitored via atomic resonance absorption excited by emission from a microwave-discharged mixture of O-2 and He. Rate coefficients determined in this work show non-Arrhenius behavior, with values consistent with previously reported. measurements for T < 1486 K; they fit well with the equation k(1)(T) = (9.27 +/- 0.03) X 10(-24) T3.67+/-0.18 exp[-(1030 +/- 160)/T] cm(3) molecule(-1) s(-1); listed errors represent one standard deviation in fitting. Theoretical calculations at the CCSD(T)/6-311 +G(d, p) level locate a bent (3)A" (TS1) and a linear (3)A' (TS3) transition state characterized previously. On the basis of the results computed by CCSD(T)/ 6-311 +G(3df,2p)//CCSD(T)/6-311 +G(d,p), the rate coefficients predicted with conventional transition-state theory, including Eckart-tunneling corrections and with variational transition-state theory including zero- and small-curvature tunneling corrections, all agree satisfactorily with experimental observations.
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
石頭臉上的苔蘚皺紋--管管答客問
(2002-10-31)
管管
Optimal 1-edge fault-tolerant designs for ladders
(2002-10-31)
Chuang, YC
;
Hsu, LH
;
Chang, CH
;
資訊工程學系
;
Department of Computer Science
A graph G* is 1-edge fault-tolerant with respect to a graph G, denoted by 1-EFT(G), if every graph obtained by removing any edge from G* contains G. A1-EFT(G) graph is optimal if it contains the minimum number of edges among all 1-EFT(G) graphs. The kth ladder graph, L-k, is defined to be the cartesian product of the P-k and P-2 where P-n is the n-vertex path graph. In this paper, we present several 1-edge fault-tolerant graphs with respect to ladders. Some of these graphs are proven to be optimal. (C) 2002 Elsevier Science B.V. All rights reserved.
Improving the electrical integrity of Cu-CoSi2 contacted n(+)p junction diodes using nitrogen-incorporated Ta films as a diffusion barrier
(2002-11-01)
Yang, WL
;
Wu, WF
;
You, HC
;
Ou, KL
;
Lei, TF
The study on improving the electrical integrity Of Cu-CoSi2 contacted-junction diodes by using the reactively sputtered TaNx as a diffusion barrier is presented in this paper. In this study, the Cu(300 nm)-CoSi2 (50 nm)/n(+)p junction diodes were intact with respect to metallurgical reaction up to a 350 degreesC thermal annealing while the electrical characteristics started to degrade after annealing at 300 degreesC in N-2 ambient for 30 min. With the addition of a 50-nm-thick TaNx diffusion barrier between Cu and CoSi2, the junction diodes were able to sustain annealing up to 600 degreesC without losing the basic integrity of the device characteristics, and no metallurgical reaction could be observed even after a 750 degreesC annealing in furnace. In addition, the structure of TaNx layers deposited on CoSi2 at various nitrogen flow rates has been investigated. The TaNx film with small grain sizes deposited at nitrogen flow ratios exceeding 10% shows better barrier capability against Cu diffusion than the others.
Role of positive trapped charge in stress-induced leakage current for flash EEPROM devices
(2002-11-01)
Wang, TH
;
Zous, NK
;
Yeh, CC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The transient behavior of hot hole (HH) stress-induced leakage current (SILC) in tunnel oxides is investigated. The dominant SILC mechanism is positive oxide charge-assisted tunneling (PCAT). The transient effect of SILC is attributed to positive oxide charge detrapping and thus the reduction of PCAT current. A correlation between SILC and stress-induced substrate current is observed. Our study shows that both SILC and stress-induced substrate current have power law time-dependence t(-n) with the power factor n about 0.7 and 1, respectively. Numerical analysis for PCAT current incorporating a trapped charge caused Coulombic potential in the tunneling barrier is performed to evaluate the time-and field-dependence of SILC and the substrate current. Based on our model, the evolution of threshold voltage shift with read-disturb time in a Flash EEPROM cell is derived. Finally, the dependence of SILC on oxide thickness is explored. As oxide thickness reduces from 100 Angstrom to 53 Angstrom, the dominant SILC mechanism is found to change from PCAT to neutral trap-assisted tunneling (TAT).
Evolutionary programming synthesis of optimal long-period fiber grating filters for EDFA gain flattening
(2002-11-01)
Lee, CL
;
Lai, Y
;
光電工程學系
;
Department of Photonics
An innovative long-period fiber grating (LPG) synthesis method based on the stochastic evolutionary programming (EP) algorithms is demonstrated to be effective for designing optimal LPG filters. Synthesis of a single-stage LPG filter for the entire C-band erbium-doped fiber amplifier (EDFA) gain flattening is used as an example to show the feasibility and the effectiveness of the proposed algorithm. To the best of our knowledge, this is the first demonstration that good EDFA gain flattening for the entire band can be achieved with a single-stage LPG filter that is properly designed.
An investigation of dust emissions from unpaved surfaces in Taiwan
(2002-11-01)
Tsai, CJ
;
Chang, CT
;
環境工程研究所
;
Institute of Environmental Engineering
One of the critical problems in making an effective strategy to control fugitive road dust is to estimate the emission factor accurately. The paper presents measured results of emission factor at field and in a wind tunnel. For the field study, three unpaved roads in Hsin Chu, Taiwan were tested. For the wind tunnel testing, the tested road dust was also collected from the field. Results of field study indicate that the emission factor of unpaved roads increases with the increasing wind speed, the number of vehicles and the speed of vehicles. It can be predicted as e (g/m(2)day) = 8.72 x 10(-3) x V-w(0.64) X s(0.19) x M-0.05 x V-v(1.32) x N-v(1.11) (V-w, m/s-wind speed, s, %-silt content of road dust; M, %-moisture content of road dust; N-v, #/h-number of vehicles: V-v, km/h-speed of vehicles) by the multi-variable regression technique. The fractions of PM10 and PM2.5, in the TSP reentrained from the unpaved roads are 20.6 +/- 12.9% and 2.3 +/- 1.2%, respectively. The wind tunnel test results show that air acceleration rate and edge effect of the dust surface increase the emission factors considerably. As air acceleration rate increases from 0.1 to 1.5 m/s(2), the emission factor increases linearly from 1.0 x 10(-4) to 7.0 x 10(-4) kg/m(2) s. However, test results show no significant effect of air acceleration and edge effect of dust surface on the threshold wind speed of reentrainment. (C) 2002 Elsevier Science B.V. All rights reserved.