Browsing by Issue Date, starting with "2009-08-10"

Now showing 1 - 20 of 50110

FORMATION AND IDENTIFICATION OF INTERSTELLAR MOLECULE LINEAR C(5)H FROM PHOTOLYSIS OF METHANE DISPERSED IN SOLID NEON
(2009-08-10)
Wu, Yu-Jong
;
Chen, Hui-Fen
;
Camacho, Cristopher
;
Witek, Henryk A.
;
Hsu, Sheng-Chuan
Photolysis of methane dispersed (1/1000) in solid Ne at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of several products, including new lines at 3319.3 and 1955.5 cm(-1). Based on experiments with isotopic labeling and results of quantum-chemical calculations, these lines are assigned to the C-H stretching and C=C stretching modes, respectively, of interstellar molecule linear C(5)H radicals.
Photovoltaic effects in BiFeO(3)
(2009-08-10)
Yang, S. Y.
;
Martin, L. W.
;
Byrnes, S. J.
;
Conry, T. E.
;
Basu, S. R.
We report a photovoltaic effect in ferroelectric BiFeO(3) thin films. The all-oxide heterostructures with SrRuO(3) bottom and tin doped indium oxide top electrodes are characterized by open-circuit voltages similar to 0.8-0.9 V and external quantum efficiencies up to similar to 10% when illuminated with the appropriate light. Efficiencies are at least an order of magnitude larger than the maximum efficiency under sunlight (AM 1.5) thus far reported for ferroelectric-based devices. The dependence of the measured open-circuit voltage on film thickness suggests contributions to the large open-circuit voltage from both the ferroelectric polarization and band offsets at the BiFeO(3)/tin doped indium oxide interface.
FORMATION AND IDENTIFICATION OF INTERSTELLAR MOLECULE LINEAR C5H FROM PHOTOLYSIS OF METHANE DISPERSED IN SOLID NEON
(2009-08-10)
Wu, Yu-Jong
;
Chen, Hui-Fen
;
Camacho, Cristopher
;
Witek, Henryk A.
;
Hsu, Sheng-Chuan
Photolysis of methane dispersed (1/1000) in solid Ne at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of several products, including new lines at 3319.3 and 1955.5 cm(-1). Based on experiments with isotopic labeling and results of quantum-chemical calculations, these lines are assigned to the C-H stretching and C=C stretching modes, respectively, of interstellar molecule linear C5H radicals.
Photovoltaic effects in BiFeO3
(2009-08-10)
Yang, S. Y.
;
Martin, L. W.
;
Byrnes, S. J.
;
Conry, T. E.
;
Basu, S. R.
We report a photovoltaic effect in ferroelectric BiFeO3 thin films. The all-oxide heterostructures with SrRuO3 bottom and tin doped indium oxide top electrodes are characterized by open-circuit voltages similar to 0.8-0.9 V and external quantum efficiencies up to similar to 10% when illuminated with the appropriate light. Efficiencies are at least an order of magnitude larger than the maximum efficiency under sunlight (AM 1.5) thus far reported for ferroelectric-based devices. The dependence of the measured open-circuit voltage on film thickness suggests contributions to the large open-circuit voltage from both the ferroelectric polarization and band offsets at the BiFeO3/tin doped indium oxide interface.
尖端增強之微電漿元件
(2009-08-11)
吳正宇
;
金星吾
一種尖端增強之微電漿元件,主要是利用微尖端結構具有很強的電場集中效應,乃於陰極板上設置有微尖端電極,可將電場局部集中於微尖端電極上,而易於在陰極板與陽極板間的放電空間中誘發出電漿現象,藉此達到降低電漿崩解電壓的效果。
相依排程之派工方法
(2009-08-11)
巫木誠
;
吳政翰
本發明係揭露一種相依排程之派工方法,包含提供部份或全部具有相依性的複數個任務排程及複數個處理設備,經由任務排程及處理設備的配對產生一處理時間矩陣及一傳輸時間,再由處理時間矩陣及傳輸時間產生任務排程之各別優先値,並據以排列任務排程之排程序列,且重複產生多個該排程序列,以形成母體,接續,由共識因子將抽樣自母體之排程序列進行演化,以產生新世代母體,重複的對新產生的新世代母體抽樣進行演化,直到新產生的新世代母體達到演化門檻或演化代數,即停止演化,最後,求解出演化後之排程序列,以縮短任務排程完成的時程。
CAPIH: A Web interface for comparative analyses and visualization of host-HIV protein-protein interactions
(2009-08-12)
Lin, Fan-Kai
;
Pan, Chia-Lin
;
Yang, Jinn-Moon
;
Chuang, Trees-Juen
;
Chen, Feng-Chi
Background: The Human Immunodeficiency Virus type one (HIV-1) is the major causing pathogen of the Acquired Immune Deficiency Syndrome (AIDS). A large number of HIV-1-related studies are based on three non-human model animals: chimpanzee, rhesus macaque, and mouse. However, the differences in host-HIV-1 interactions between human and these model organisms have remained unexplored. Description: Here we present CAPIH (Comparative Analysis of Protein Interactions for HIV-1), the first web-based interface to provide comparative information between human and the three model organisms in the context of host-HIV-1 protein interactions. CAPIH identifies genetic changes that occur in HIV-1-interacting host proteins. In a total of 1,370 orthologous protein sets, CAPIH identifies similar to 86,000 amino acid substitutions, similar to 21,000 insertions/deletions, and similar to 33,000 potential post-translational modifications that occur only in one of the four compared species. CAPIH also provides an interactive interface to display the host-HIV-1 protein interaction networks, the presence/absence of orthologous proteins in the model organisms in the networks, the genetic changes that occur in the protein nodes, and the functional domains and potential protein interaction hot sites that may be affected by the genetic changes. The CAPIH interface is freely accessible at http://bioinfo-dbb.nhri.org.tw/capih. Conclusion: CAPIH exemplifies that large divergences exist in disease-associated proteins between human and the model animals. Since all of the newly developed medications must be tested in model animals before entering clinical trials, it is advisable that comparative analyses be performed to ensure proper translations of animal-based studies. In the case of AIDS, the host-IV-1 protein interactions apparently have differed to a great extent among the compared species. An integrated protein network comparison among the four species will probably shed new lights on AIDS studies.
Enhanced light output power of GaN-based vertical-injection light-emitting diodes with a 12-fold photonic quasi-crystal by nano-imprint lithography
(2009-08-12)
Huang, H. W.
;
Lin, C. H.
;
Lee, K. Y.
;
Yu, C. C.
;
Huang, J. K.
GaN-based thin-film vertical-injection light-emitting diodes (VLEDs) with a 12-fold photonic quasi-crystal (PQC) by nano-imprint lithography (NIL) are fabricated and presented. At a driving current of 20 mA and with a chip size of 350 mu m x 350 mu m, the light output power of our thin-film LED with a 12-fold PQC structure reaches 41 mW. This result is an enhancement of 78% when compared with the output power of a VLED without a PQC structure. In addition, the corresponding light radiation pattern shows a narrower beam shape due to the strong guided light extraction effect by the formed PQC structure in the vertical direction.
Efficiency improvement of single-junction InGaP solar cells fabricated by a novel micro-hole array surface texture process
(2009-08-12)
Chang, Yi-An
;
Li, Zhen-Yu
;
Kuo, Hao-Chung
;
Lu, Tien-Chang
;
Yang, Su-Fan
In this study, single-junction InGaP solar cells fabricated by a novel micro-hole array surface texture process are presented. The characteristics of the single-junction InGaP solar cells with and without the micro-hole array surface texture are studied. An increase of 10.4% in short-circuit current is found when a single-junction InGaP solar cell is fabricated by the micro-hole array surface texture process. The conversion efficiency measured under one-sun air mass 1.5 global illumination at room temperature can also be improved from 13.8% to 15.9% when the size of the micro-holes is 5.3 mu m and the period of micro-hole array is designed to 5 mu m.
Signal remodulation high split-ratio hybrid WDM-TDM PONs using RSOA-based ONUs
(2009-08-13)
Chow, C. W.
;
Yeh, C. H.
;
Wang, C. H.
;
Shih, F. Y.
;
Chi, S.
A signal remodulation scheme using DPSK downstream and OOK upstream signals for high split-ratio hybrid WDM-TDM PONs is proposed and demonstrated. Colourless and polarisation insensitive operations are implemented using RSOA at the customer side. By comparing with previous similar remodulation schemes, the proposed scheme can mitigate the phase-to-intensity and polarisation tracking issues. The driving current and launched power of the RSOA are also studied, showing that it could be a promising candidate for the next generation of high split-ratio hybrid WDM-TDM PONs.
Role and channel assignments for wireless mesh networks using hybrid approach
(2009-08-13)
Jeng, Andy An-Kai
;
Jan, Rong-Hong
;
資訊工程學系
;
Department of Computer Science
The wireless mesh network has been considered one of the most promising techniques to extend the broadband access to the last mile. To utilize multiple channels on more than one interface, a number of approaches have been proposed. In particular, the hybrid strategy that combines the benefits of high channel diversity and low coordination cost has seen growing interest in recent studies. In this paper, we define two optimization problems, named the role assignment and the semi-fixed channel assignment, to characterize the unique feature in the hybrid strategy. We proved that the two problems are NP-hard even if the transmission ranges of interfaces are equal. In order to solve our problems in reasonable time, we design efficient algorithms. For the role assignment problem, we give an 1/2-approximate algorithm to find a nearly optimal solution. For the semi-fixed channel assignment problem, a heuristic algorithm, based on transferring from a coloring-based problem, is proposed. Experimental results show that optimizing the defined problems is indeed beneficial to improve the network throughput, and the proposed algorithms are significantly superior to existing methods. (C) 2009 Elsevier B.V. All rights reserved.
Gate controlled field emission triode and process for fabricating the same
(2009-08-13)
Tseng, Tseung-Yuan
;
Lee, Chia-Ying
;
Li, Seu-Yi
;
Lin, Pang
;
Tseng, Tseung-Yuen
This invention relates to a process for fabricating ZnO nanowires with high aspect ratio at low temperature, which is associated with semiconductor manufacturing process and a gate controlled field emission triode is obtained. The process comprises providing a semiconductor substrate, depositing a dielectric layer and a conducting layer, respectively, on the semiconductor substrate, defining the positions of emitter arrays on the dielectric layer and conducting layer, depositing an ultra thin ZnO film as a seeding layer on the substrate, growing the ZnO nanowires as the emitter arrays by using hydrothermal process, and etching the areas excluding the emitter arrays, then obtaining the gate controlled field emission triode.
Short-time power-law blinking statistics of single quantum dots and a test of the diffusion-controlled electron transfer model
(2009-08-14)
Tang, Jau
;
Lee, Der-Hau
;
Yeh, Yi-Cheun
;
Yuan, Chi-Tsu
;
光電工程學系
In this work we analyzed the blinking statistics data of single CdSe/ZnS quantum dots at vey short times to test some predictions of the diffusion-controlled electron transfer (DCET) model. Using autocorrelation function (ACF) approach we could extract the exponent of the inverse power-law blinking statistics down to 1 mu s. Such an approach also minimizes human subjectivity in choosing a bin time and an on-off threshold. We showed that the observed stretched exponential decay in the ACF and its relationship to the blinking statistics are consistent with the DCET model, and we set an upper bound for the characteristic time constant t(c).
Characteristics of a-Plane Green Light-Emitting Diode Grown on r-Plane Sapphire
(2009-08-15)
Ling, Shih-Chun
;
Wang, Te-Chung
;
Chen, Jun-Rong
;
Liu, Po-Chun
;
Ko, Tsung-Shine
In this work, we have successfully grown a-plane green light-emitting diodes (LEDs) on r-plane sapphire and investigated the device characteristics of a-plane green LEDs. The apparent emission polarization anisotropy was observed and the polarization degree was as high as 67.4%. In addition, the electroluminescence (EL) spectra first revealed a wavelength blue-shift with increasing drive current to 20 mA, which could be attributed to the band-filling effect, and then the EL peak become constant. The current-voltage curve showed the forward voltage of a-plane LED grown on r-plane sapphire substrate was 3.43 V and the differential series resistance was measured to be about 24 Omega as 20-mA injected current. Furthermore, the output power was 240 mu W at 100-mA drive current.
Generation of sub-20-fs multicolor laser pulses using cascaded four-wave mixing with chirped incident pulses
(2009-08-15)
Liu, Jun
;
Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
Negatively chirped or nearly transform-limited output pulses can be obtained in a four-wave mixing process when one of the pump beams is negatively chirped and the other is positively chirped. Nearly transform-limited 16 fs multicolor laser pulses are obtained in a fused-silica glass plate using this method. The resulting frequency shifts and compressed multicolor sidebands are continuously tunable in wavelength by varying the crossing angle between the two input beams. Sub-10-fs multicolor pulses should be possible obtained using this method in the future. (C) 2009 Optical Society of America
Thermal analysis on the degradation of poly-silicon TFTs under AC stress
(2009-08-15)
Weng, C. F.
;
Chang, T. C.
;
Tai, Y. H.
;
Huang, S. T.
;
Wu, K. T.
In this work, the degradation mechanism of N-channel poly-silicon thin-film transistor (poly-Si TFT) has been investigated under dynamic voltage stress at room temperature. The ON-current of TFT is degraded to as low as 0.3 times of the initial value after 1000 s stress. On the other hand, both the sub-threshold swing and threshold voltage kept well during the AC stress. The current crowding effect was rapidly increased with increasing of stress duration. However, comparing the initial and degraded characteristics at rising temperature, namely, 150 degrees C, the ON-current of TFT only decrease to 75% of the initial value after 1000 s AC stress. It depicts that creation of effective trap density in tail-states of poly-Si film is responsible for the electrical degradation of poly-Si TFT. At high temperature, electron has enough energy to pass the energy barrier created by ac stress and the degradation is less obvious. (C) 2009 Published by Elsevier B.V.
Diversity of traveling wave solutions in FitzHugh-Nagumo type equations
(2009-08-15)
Hsu, Cheng-Hsiung
;
Yang, Ting-Hui
;
Yang, Chi-Ru
;
應用數學系
;
Department of Applied Mathematics
In this work we consider the diversity of traveling wave solutions of the FitzHugh-Nagumo type equations u(t) = u(xx) + f (u, w), w(t) = epsilon g(u, w), where f(u, w) = u(u - a(w))(1 - u) for some smooth function a(w) and g(u, w) = u - w. When a(w) crosses zero and one, the corresponding profile equation possesses special turning points which result in very rich dynamics. In [W. Liu, E. Van Vleck, Turning points and traveling waves in FitzHugh-Nagumo type equations. J. Differential Equations 225 (2006) 381-410], Liu and Van Vleck examined traveling waves whose slow orbits lie only on two portions of the slow manifold, and obtained the existence results by using the geometric singular perturbation theory. Based on the ideas of their work, we study the co-existence of different traveling waves whose slow orbits could involve all portions of the slow manifold. There are more complicated and richer dynamics of traveling waves than those of [W. Liu, E. Van Vleck, Turning points and traveling waves in FitzHugh-Nagumo type equations, J. Differential Equations 225 (2006) 381-410]. We give a complete classification of all different fronts of traveling waves, and provide an example to support our theoretical analysis. (C) 2009 Elsevier Inc. All rights reserved.
Theory of ZEKE spectroscopy and molecular Rydberg dynamics
(2009-08-16)
Chao, Sheng Der
;
Wang, Yi Hsieh
;
Lin, Sheng Hsien
;
Selzle, Heinrich L.
;
Neusser, Hans J.
Molecular insight into catalytic mechanism of spinosyn rhamnosyltransferase by in vitro combinatorial reactions with NDP-sugar-modifying enzymes
(2009-08-16)
Chiu, Hsien-Tai
;
Chen, Yi-Lin
;
Lin, Yu-Chin
;
Chen, Yi-Hsine
;
生物科技學系
COLL 327-Sol-gel synthesis and surface reaction of oxygen plasma for flexible metal-insulator-metal devices
(2009-08-16)
Chu, Min-Ching
;
Lin, Ching-Chang
;
You, Hsin-Chiang
;
Ko, Fu-Hsiang
;
材料科學與工程學系奈米科技碩博班