Browsing by Issue Date, starting with "2012-08-19"

Now showing 1 - 20 of 35738

Excited state dynamics of green fluorescence protein chromophore derivatives investigated with time-resolved fluorescence and transient infrared absorption
(2012-08-19)
Cheng, Chi-Wen
;
Hsu, Hung-Yu
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Huang, Guan-Jhih
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Diau, Eric Wei-Guang
;
Yang, Jye-Shane
Effects of surface doped metal ions on the photocatalytic activity of titanium dioxide
(2012-08-19)
Liu, Wei S.
;
Chang, Sue-min
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環境工程研究所
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Institute of Environmental Engineering
Effects of counter-rotating interaction on driven tunneling dynamics: Coherent destruction of tunneling and Bloch-Siegert shift
(2012-08-20)
Lu, Zhiguo
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Zheng, Hang
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電子物理學系
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物理研究所
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Department of Electrophysics
We investigate the dynamics of a driven two-level system (classical Rabi model) using the counter-rotating-hybridized rotating-wave method (CHRW), which is a simple method based on a unitary transformation with a parameter.. This approach is beyond the traditional rotating-wave approximation (Rabi-RWA) and more importantly, remains the RWA form with a renormalized tunneling strength and a modified driving strength. The reformulated rotating-wave method not only possesses the same mathematical simplicity as the Rabi-RWA but also allows us to explore the effects of counter-rotating (CR) components. We focus on the properties of off-resonance cases for which the Rabi-RWA method breaks down. After comparing the results of different RWA schemes and those of the numerically exact method in a wide range of parameter regime, we show that the CHRW method gives the accurate driven dynamics which is in good agreement with the numerical method. Moreover, the other RWA methods appear as various limiting cases of the CHRW method. The CHRW method reveals the effects of the CR terms clearly by means of coherent destruction of tunneling and Bloch-Siegert shift. Our main results are as follows: (i) the dynamics of the coherent destruction of tunneling is explicitly given and its dependence on Delta is clarified, which is quantitatively in good agreement with the exact results; (ii) the CR modulated Rabi frequency and the Bloch-Siegert shift are analytically calculated, which is the same as the exact results up to fourth order; (iii) the validity of parameter regions of different RWA methods are given and the comparison of dynamics of these methods are shown. Since the CHRW approach is mathematically simple as well as tractable and physically clear, it may be extended to some complicated problems where it is difficult to do a numerical study.
Prism-type holographic optical element design and verification for the blue-light small-form-factor optical pickup head
(2012-08-20)
Shih, Hsi-Fu
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Chiu, Yi
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Cheng, Stone
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Lee, Yuan-Chin
;
Lu, Chun-Shin
This paper presents the prism-type holographic optical element (PT-HOE) design for a small-form-factor (SFF) optical pickup head (OPH). The surface of the PT-HOE was simulated by three steps of optimization and generated by binary optics. Its grating pattern was fabricated on the inclined plane of a microprism by using the standard photolithography and specific dicing procedures. The optical characteristics of the device were verified. Based on the virtual image method, the SFF-OPH with the device was assembled and realized. (c) 2012 Optical Society of America
Design, fabrication, and characterization of Si-based ARROW photonic crystal bend waveguides and power splitters
(2012-08-20)
Chen, Jian-Hua
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Huang, Yang-Tung
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Yang, Yu-Lin
;
Lu, Ming-Feng
;
Shieh, Jia-Min
Silicon-based (Si-based) photonic crystal waveguide based on antiresonant reflecting optical waveguide (ARROW PCW) structures consisting of 60 degrees bends and Y-branch power splitters were designed and first efficiently fabricated and characterized. The ARROW structure has a relatively large core size suitable for efficient coupling with a single-mode fiber. Simple capsule-shaped topography defects at 60 degrees photonic crystal (PC) bend corners and Y-branch PC power splitters were used for increasing the broadband light transmission. In the preliminary measurements, the propagation losses of the ARROW PC straight waveguides lower than 2 dB/mm with a long length of 1500 mu m were achieved. The average bend loss of 60 degrees PC bend waveguides was lower than 3 dB/bend. For the Y-branch PC power splitters, the average power imbalance was lower than 0.6 dB. The results show that our fabricated Si-based ARROW PCWs with 60 degrees bends and Y-branch structures can provide good light transmission and power-splitting ability. (c) 2012 Optical Society of America
Effect of Ti doping concentration on resistive switching behaviors of Yb2O3 memory cell
(2012-08-20)
Mondal, Somnath
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Chen, Hung-Yu
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Her, Jim-Long
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Ko, Fu-Hsiang
;
Pan, Tung-Ming
We investigate the resistive memory switching behaviors of Yb2O3 thin films for different Ti-dopant concentrations. A higher doping concentration of 9.4% of Ti atom into Yb2O3 thin film causes the switching mechanism to change from bipolar to unipolar behavior. This is ascribed to different chemical compositions of the filament through the oxide film. The reset mechanism is associated with the annihilation of oxygen vacancies and other ionic and electronic defects within or near the interface area of oxide film for bipolar switching, while it is believed to be due to rupture of the conducting filament by local Joule heating effect for unipolar resistive switching. Furthermore, the incorporation of Ti atom into the Yb2O3 memory device exhibits improved electrical performances including low set/reset voltages and good endurance and retention characteristics. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4747695]
Characterization and modeling of trap number and creation time distributions under negative-bias-temperature stress
(2012-08-20)
Chiu, Jung-Piao
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Li, Chi-Wei
;
Wang, Tahui
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Individual trapped charge creations and a trap number in p-type metal-oxide-semiconductor field effect transistors (pMOSFETs) under negative bias temperature instability (NBTI) stress are investigated. We find that the characteristic times of a trapped charge creation scatter over several decades of time in small area pMOSFETs, which is attributed to an activation energy distribution in the reaction-diffusion (RD) model of NBTI. We develop a statistical model by combining the RD model with an extracted activation energy distribution to calculate a threshold voltage shift distribution at different NBTI stress times. Our model agrees with measured results very well. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4748108]
交大e-News第124期
(2012-08-20)
Secretariat
;
國立交通大學秘書室
一種噻吩衍生物高分子與其製備方法
(2012-08-21)
韋光華
;
張耀德
本發明係提供一種噻吩衍生物高分子與其製備方法，其特徵在於該噻吩衍生物高分子的至少一側鏈含有己基－菲基－1,3－二氮雜茂基團，其末端則具有至少一己基官能基。此噻吩衍生物高分子在太陽能電池的應用上與[6,6]－苯基－C61－丁酸甲酯([6,6]－phenyl－C61－butyric acid methyl ester,PCBM)掺混，可提升高分子的溶解度及高分子之電荷快速分離，有效提高光電轉換效率。
Document processing system and method thereof
(2012-08-21)
Lee Chia-Hoang
;
Liao Zan-Wei
In a document processing system and a document processing method, the document processing method includes the steps of: obtaining a document and dividing the document into a plurality of terms and giving a syntactic index to each of the terms; dividing the document into a plurality of sentences; selecting a key syntactic index from the syntactic indexes, and transforming each of the sentences into a preliminary key terms sequence which includes a preliminary key term corresponding to the key syntactic indexes according to the key syntactic indexes; selectively expanding the preliminary key term of a representative sentence of the document into an advanced key term; and determining at least one core candidate sentence among the sentences to generate a core abstract of the document according to the preliminary key terms and the advanced key term.
基於位置影像資料與位置資訊之查詢系統、查詢方法及建立方法
(2012-08-21)
曹孝櫟
;
林政龍
;
林冠儒
;
陳薪中
本發明係揭露一種基於位置影像資料與位置資訊之資料查詢系統及查詢方法，其係包括一行動擷取裝置與一遠端伺服裝置。其中，行動擷取裝置透過一傳輸模組以提供一空間參數及一鏡頭參數予遠端伺服裝置。遠端伺服裝置以此空間參數及鏡頭參數決定出一查詢空間範圍，並查詢出物件空間位置參數位於該查詢空間範圍之物件資料，於該行動擷取裝置顯示的影像資料上標記物件資料，以便利使用者選取決定欲觀看之物件，進一步查詢物件資料及相關影像資料。同時，本發明再提供一種基於位置影像資料及位置資訊的資料建立方法，本方法利用至少一第一建立資料與一第二建立資料。根據該些建立資料所提供之空間參數及鏡頭參數之交集，建立一對應之物件資料。
Probing the bulk electronic states of Bi2Se3 using nuclear magnetic resonance
(2012-08-21)
Young, Ben-Li
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Lai, Zong-Yo
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Xu, Zhijun
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Yang, Alina
;
Gu, G. D.
We report a nuclear magnetic resonance (NMR) study of Bi2Se3 single crystals grown by three different methods. All the crystals show nine well-resolved peaks in their Bi-209 NMR spectra of the nuclear quadrupolar splitting, albeit with an intensity anomaly. Spectra at different crystal orientations confirm that all the peaks are purely from the nuclear quadrupolar effect, with no other hidden peaks. We identify the short nuclear transverse relaxation time (T-2) effect as the main cause of the intensity anomaly. We also show that the Bi-209 signal originates exclusively from bulk, while the contribution from the topological surface states is too weak to be detected by NMR. However, the bulk electronic structure in these single crystals is not the same, as identified by the NMR frequency shift and nuclear spin-lattice relaxation rate (1/T-1). The difference is caused by the different structural defect levels. We find that the frequency shift and 1/T-1 are smaller in samples with fewer defects and a lower carrier concentration. Also, the low-temperature power law of the temperature-dependent 1/T-1 (proportional to T-alpha) changes from the Korringa behavior alpha = 1 in a highly degenerate semiconductor (where the electrons obey Fermi statistics) to alpha < 1 in a less degenerate semiconductor (where the electrons obey Boltzmann statistics).
Planar antenna and electromagnetic band gap structure thereof
(2012-08-21)
Chung Shyh-Jong
;
Ling Ching-Wei
;
Yang Tzu-Hsien
An electromagnetic band-gap structure includes a circuit board, a ground plane and a plurality of electromagnetic band-gap units. The circuit board includes a first side and a second surface, and the ground plane disposed on the first side. The plurality of electromagnetic band-gap units are located on both the first surface and the second surface and connected to each other along an edge of the ground plane. Every electromagnetic band-gap unit includes a first strip line, a second strip line and a via. The first strip line is located on the first side, including a first relative long strip line and a first relative short strip line connected to the ground. The second strip line is located on the second side. The second strip line is connected to the first strip line of the adjacent electromagnetic band-gap unit through the via.
Study of InN epitaxial films and nanorods grown on GaN template by RF-MOMBE
(2012-08-21)
Chen, Wei-Chun
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Kuo, Shou-Yi
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Wang, Wei-Lin
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Tian, Jr-Sheng
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Lin, Woei-Tyng
This paper reports on high-quality InN materials prepared on a GaN template using radio-frequency metalorganic molecular beam epitaxy. We also discuss the structural and electro-optical properties of InN nanorods/films. The X-ray diffraction peaks of InN(0002) and InN(0004) were identified from their spectra, indicating that the (0001)-oriented hexagonal InN was epitaxially grown on the GaN template. Scanning electron microscopic images of the surface morphology revealed a two-dimensional growth at a rate of approximately 0.85 mu m/h. Cross-sectional transmission electron microscopy images identified a sharp InN/GaN interface and a clear epitaxial orientation relationship of [0001](InN) // [0001](GaN) and ((2) over bar 110)(InN) // ((2) over bar 110)(GaN). The optical properties of wurtzite InN nanorods were determined according to the photoluminescence, revealing a band gap of 0.77 eV.
多載波系統之通道估計方法
(2012-08-21)
洪崑健
;
林大衛
本發明係提供一種多載波系統之通道估計方法，係利用有限領航訊號取得導引子載波之通道響應，接著利用內插法運算解出資料子載波通道，藉此，更快速地估算出資料子載波的通道響應。本發明係用少數領航訊號進行通道估計，以更低運算量之方法精確地估算出各種通道延遲參數(如：初始延遲、平均延遲及均方根延遲擴散)，且本方法適用性廣，不需要配合特定功率延遲輪廓(power delay profile，PDP)，亦適用導引子載波配置不規則之通道。
Method for manufacturing optoelectronic memory device
(2012-08-21)
Wei Kung-Hwa
;
Sheu Jeng-Tzong
;
Chen Chen-Chia
;
Chiu Mao-Yuan
The present invention provides an optoelectronic memory device, the method for manufacturing and evaluating the same. The optoelectronic memory device according to the present invention includes a substrate, an insulation layer, an active layer, source electrode and drain electrode. The substrate includes a gate, and the insulation layer is formed on the substrate. The active layer is formed on the insulation layer, and more particularly, the active layer is formed of a composite material comprising conjugated conductive polymers and quantum dots. Moreover, both of the source and the drain are formed on the insulation layer, and electrically connected to the active layer.
THREE-DIMENSIONAL OBLIQUE MICROSTRUCTURE WITH PRESS DOWN AND ENGAGEMENT MECHANISMS
(2012-08-23)
Chiu Yi
;
Shih Hsi-Fu
;
Lin Chen-An
A three-dimensional oblique microstructure with press down and engagement mechanisms. A pair of corresponding first lugs is disposed on the both sides of the oblique body, and the bottom part of the oblique body has a first push pad. A pair of corresponding second lugs respectively disposed on the inner sides of the two supports of the α-shaped supporting rack, a second push pad is disposed on the bottom part of the U-shaped supporting rack. Thus, by pressing down the first and the second push pad, the oblique body rotates through the first twist bar and the U-shaped supporting rack rotates through the second twist bar so as to engage the first lugs with the second lugs, such that the three-dimensional microstructures with different angles can be packed to satisfy the needs of varied optical platform applications, and simplify semiconductor fabrication for higher production efficiency and product yield.
OPTICAL PICKUP HEAD
(2012-08-23)
CHIU Yi
;
Shih Hsi-Fu
;
Lin Chen-An
An optical pickup head is provided, which includes a silicon substrate, in which an aperture and an objective lens are disposed on the silicon substrate; and a laser diode (LD), a 135-degree tilted reflector, and a 135-degree tilted holographic reflector are disposed on the silicon substrate. The two 135-degree tilted reflectors and a holographic optical element (HOE) are fabricated on a slant face structure of an optical platform using a semiconductor process, so all the elements are disposed at a straight zone, and then in combination with bonding of the LD and an optical sensor element, an miniaturization objective is achieved and an optical path is shortened.
Observation of Raman Optical Activity by Heterodyne-Detected Polarization-Resolved Coherent Anti-Stokes Raman Scattering
(2012-08-24)
Hiramatsu, Kotaro
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Okuno, Masanari
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Kano, Hideaki
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Leproux, Philippe
;
Couderc, Vincent
We report the first observation of Raman optical activity (ROA) by coherent anti-Stokes Raman scattering. Thanks to the more freedom of polarization configurations in coherent anti-Stokes Raman scattering than in spontaneous Raman spectroscopy, the contrast ratio of the chiral signal to the achiral background has been improved markedly. For (-)-beta-pinene, it is 2 orders of magnitude better than that in the reported spontaneous ROA measurement. This is also the first measurement of ROA signal using a pulsed laser source.
Circular Permutation Prediction Reveals a Viable Backbone Disconnection for Split Proteins: An Approach in Identifying a New Functional Split Intein
(2012-08-24)
Lee, Yun-Tzai
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Su, Tz-Hsiang
;
Lo, Wei-Cheng
;
Lyu, Ping-Chiang
;
Sue, Shih-Che
Split-protein systems have emerged as a powerful tool for detecting biomolecular interactions and reporting biological reactions. However, reliable methods for identifying viable split sites are still unavailable. In this study, we demonstrated the feasibility that valid circular permutation (CP) sites in proteins have the potential to act as split sites and that CP prediction can be used to search for internal permissive sites for creating new split proteins. Using a protein ligase, intein, as a model, CP predictor facilitated the creation of circular permutants in which backbone opening imposes the least detrimental effects on intein folding. We screened a series of predicted intein CPs and identified stable and native-fold CPs. When the valid CP sites were introduced as split sites, there was a reduction in folding enthalpy caused by the new backbone opening; however, the coincident loss in entropy was sufficient to be compensated, yielding a favorable free energy for self-association. Since split intein is exploited in protein semi-synthesis, we tested the related protein trans-splicing (PTS) activities of the corresponding split inteins. Notably, a novel functional split intein composed of the N-terminal 36 residues combined with the remaining C-terminal fragment was identified. Its PTS activity was shown to be better than current reported two-piece intein with a short N-terminal segment. Thus, the incorporation of in silico CP prediction facilitated the design of split intein as well as circular permutants.