Browsing by Issue Date, starting with "2009-02-18"

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Primary Conformation Change in Bacteriorhodopsin on Photoexcitation
(2009-02-18)
Yabushita, Atsushi
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Kobayashi, Takayoshi
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電子物理學系
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Department of Electrophysics
Ultrafast dynamics of bacteriorhodopsin (bR) has been extensively studied experimentally and theoretically. However, there are several contradictory results reported, indicating that its detailed dynamics and initial process have not yet been fully clarified. In this work, changes in the amplitude and phase of molecular vibration in the isomerization process of bR were real-time probed simultaneously at 128 different wavelengths through intensity modulation of the electronic transition. Systematic information on the transient change in continuous spectrum extending from 505 nm (2.45 eV) to 675 nm (1.84 eV) showed different dynamics in each spectral region reflecting the difference in the excited states and intermediates dominating the dynamics during the photoisomerization. Careful analysis of the transient spectral changes and spectrograms calculated from the vibrational real-time traces elucidated that the primary event just after photoexcitation is the deformation of the retinal configuration, which decays within 30 fs near the C=N bond in the protonated Schiff base. The intensity of C=N stretching mode starts to decrease before the initiation of the frequency modulation of the C=C stretching mode. The C=C stretching mode frequency was modulated by a coupled torsion around the C(13)=C(14) bond, leading to the photoisomerization around the bond. This study clarified the dynamics of the C=N and C=C stretching modes working as key vibration modes in the photoisomerization of bR. Furthermore, we have elucidated the modulation and decay dynamics of the C=C stretching mode in the photoreaction starting from H (Franck-Condon excited state) followed by I (twisted excited), and J (first intermediate) states.
Ordered polythiophene/fullerene composite core-shell nanorod arrays for solar cell applications
(2009-02-18)
Wang, Hsu-Shen
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Lin, Li-Hua
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Chen, Shih-Yung
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Wang, Yuh-Lin
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Wei, Kung-Hwa
For the first time, we have used melt-assisted wetting of porous alumina templates to prepare ordered core-shell nanorod arrays of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C(61)-butyric acid methyl ester (PCBM) for use in polymer solar cells. We characterized these arrays using tunneling electron microscopy and conductance atomic force microscopy, which revealed the presence of phase-separated shell (p-type) and core (n-type) regions. Under illumination, we observed a variation of several picoamperes between the currents in the core and shell regions of the P3HT/PCBM nanorod arrays.
半导体发光元件及其制作方法
(2009-02-18)
邱清华
;
黄泓文
;
郭浩中
;
卢廷昌
;
王兴宗
本发明有关一种半导体发光元件及其制作方法。半导体发光元件，包含基板、形成基板上的p型半导体层、形成p型半导体层上的发光层，及形成发光层上的n型半导体层，n型半导体层表面形成多数垂直基板方向且深度不小于0.2微米奈米柱体。藉加深奈米柱体深度可改变半导体发光元件发光场型，提升正向出光强度及发光效率。半导体发光元件制作方法包含：在第一基板上磊晶形成n型半导体层、发光层及p型半导体层；提供导电性基板，反转第一基板上磊晶结构层于导电基板上，使n型半导体层表面裸露；将多数球状颗粒散布n型半导体层表面做蚀刻遮罩；及以垂直导电基板方向蚀刻n型半导体层，形成多数深度不小于0.2微米奈米柱体。该制作方法可形成较大深度的奈米柱体，提高正向出光强度。
交大e-News第042期
(2009-02-20)
Secretariat
;
國立交通大學秘書室
Thermodynamics of a conformational change using a random walk in energy-reaction coordinate space: Application to methane dimer hydrophobic interactions
(2009-02-21)
Morozov, A. N.
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Lin, S. H.
;
交大名義發表
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National Chiao Tung University
A random walk sampling algorithm allows the extraction of the density of states distribution in energy-reaction coordinate space. As a result, the temperature dependences of thermodynamic quantities such as relative energy, entropy, and heat capacity can be calculated using first-principles statistical mechanics. The strategies for optimal convergence of the algorithm and control of its accuracy are proposed. We show that the saturation of the error [Q. Yan and J. J. de Pablo, Phys. Rev. Lett. 90, 035701 (2003); E. Belardinelli and V. D. Pereyra, J. Chem. Phys. 127, 184105 (2007)] is due to the use of histogram flatness as a criterion of convergence. An application of the algorithm to methane dimer hydrophobic interactions is presented. We obtained a quantitatively accurate energy-entropy decomposition of the methane dimer cavity potential. The presented results confirm the previous results, and they provide new information regarding the thermodynamics of hydrophobic interactions. We show that the finite-difference approximation, which is widely used in molecular dynamic simulations for the energy-entropy decomposition of a free energy potential, can lead to a significant error.
利用雙重負迴授之超寬頻低雜訊放大器
(2009-02-21)
傅昶綜
;
郭建男
本發明關於一種低雜訊之放大器,應用於射頻積體電路設計領域中,特別是超寬頻無線通訊系統之低雜訊放大器,至少包括具有該放大器之架構的核心電路之電晶體,與利用在其晶片上實現的變壓器,而組合成一雙重之負迴授,即“電感性負迴授"與“電容性負迴授"之放大器架構,其中,該電容性負迴授主要作用在中頻及低頻頻段,該電感性負迴授則作用在高頻頻段;結合此具有雙重負迴授路徑之放大電路,因而可在電路之信號輸入端提供非常寬頻且良好的阻抗匹配;本發明之低雜訊之放大器電路架構,可提供寬頻輸入阻抗匹配(broadband impedance match)及寬頻雜訊最佳化(broadband noise optimum)的最佳狀況,除了大幅提昇增益(gain)及增益平坦度(gain flatness)外,在雜訊性能上更有非常大的改善,且其耗電量仍可維持在非常小的程度。
高紅色光飽和度Mn（IV）摻雜之螢光材料及其製法
(2009-02-21)
陳登銘
;
羅巨澤
本發明係提供一種發光裝置,其係包含一半導體光源,該半導體光源之發光波長係介於250nm~500nm;以及一系列螢光材料組成物,該螢光材料組成物會受該半導體光源所發出的光而激發;其中該螢光組成物係可選自於Mg14(Ge(5-a)Mna)O24、Sr(Ge(4-b)Mnb)O9、Mg2(Ti(1-c)Mn c)O4、Zn2(Ti(1-d)Mn d)O4、SrMg(Al(10-e)Mne)O17、Y3(Ga(5-f)Mn f)O12等化學式所組成之群組中其中之一。
Preparation of the stimuli-responsive ZnS/PNIPAM hollow spheres
(2009-02-23)
Fu, Huei-Kuan
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Kuo, Shiao-Wei
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Huang, Chih-Feng
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Chang, Feng-Chih
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Lin, Han-Ching
Novel quantum dots ZnS/poly(N-isopropylacrylamide) (PNIPAM) hybrid hollow spheres were obtained by localizing free radical polymerization of NIPAM and crosslinker (MBA) at the peripheral of PCL nanoparticles, followed by biodegradation of PCL with an enzyme of the Lipase PS. The formation of ZnS/PNIPAM hollow spherical structures and the thermo-sensitive reversible properties was systematically investigated by transmission electron microscopy (TEM) and dynamic light scattering (DLS), respectively. The ZnS/PNIPAM hollow spheres possess the photoluminescence properties and a swelling and deswelling at about 32 degrees C, which agrees well with the slight red shift in photoluminescence spectra. (c) 2009 Elsevier Ltd. All rights reserved.
Synthesis and Characterization of Poly (epsilon-caprol actone-b-4-vinylpyridine): Initiation, Polymerization, Solution Morphology, and Gold Metalation
(2009-02-24)
Lu, Chu-Hua
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Huang, Chih-Feng
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Kuo, Shiao-Wei
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Chang, Feng-Chih
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應用化學系
We have synthesized a difunctional initiator-the hydroxyl-4-oxo-N-alkoxyamine (HOA)-by first mixing benzoyl peroxide (BPO) and 4-hydroxyl-2,2,6,6-tetramethylpiperdinooxy (4-OH-TEMPO) in styrene at temperatures below 25 degrees C to give the 4-oxo-N-alkoxyamine (OA) and then hydrolyzing the benzoate ester on OA with NaOH. This low-temperature preparation of OA reveals that benzyloxyl radicals can be generated from the BPO through redox reaction with 4-OH-TEMPO its well as through thermal decomposition. The N-oxoammonium cation (i.e., the oxidative state of 4-OH-TEMPO), which formed as a side product, mediated the alcohol oxidation to give OA. We prepared three PCL-b-P4VP diblock copolymers (BCI-3) from HOA through two-step polymerizations: (i) diethylaluminum alkoxide-induced ring-opening polymerization of epsilon-caprolactone at 25 degrees C followed by (ii) nitroxide-mediated radical polymerization of 4-vinylpyridine Lit 125 degrees C. With the combination of biodegradable hydrophobic PCL blocks and polymeric blocks of P4VP ligands, we used the immiscible PCL-b-P4VP copolymers to transport AuCl(4) anions from aqueous phases to organic phases and to stabilize Au nanoparticles in the PCL-b-P4VP micelles Au-BC1-3 after reduction with NaBH(4).
Temperature-Sensitive Nanocapsules for Controlled Drug Release Caused by Magnetically Triggered Structural Disruption
(2009-02-24)
Liu, Ting-Yu
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Liu, Kun-Ho
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Liu, Dean-Mo
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Chen, San-Yuan
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Chen, I-Wei
Self-assembled nanocapsules containing a hydrophilic core and a crosslinked yet thermosensitive shell are successfully prepared using poly(ethylene-oxide) poly(propylene-oxide)-poly(ethylene-oxide) block copolymers, 4-nitrophenyl chloroformate, gelatin, and 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The core is further rendered magnetic by incorporating iron oxide nanoparticles via internal precipitation to enable externally controlled actuation under magnetic induction. The spherical nanocapsules exhibit a hydrophilic-to-hydrophobic transition at a characteristic but tunable temperature reaching 40 degrees C, triggering a size contraction and shrinkage of the core. The core content experiences very little leakage at 25 degrees C, has a half life about 5 h at 45 degrees C, but bursts out within a few minutes under magnetic heating due to iron oxide coarsening and core/shell disruption. Such burst-like response may be utilized for controlled drug release as illustrated here using a model drug Vitamin B12.
CONTROL APPARATUS AND METHOD
(2009-02-26)
Lee, Chia Hoang
;
Lin, Jian Liang
The invention discloses a control apparatus capable of providing a user with a control over an object displayed on a display apparatus by a pointing device. The control apparatus includes an image capturing module, a separating module, a positioning module, a constructing module, and a processing module. The image capturing module is used to record an image sequence included N images. The separating module is applied to capture the pointing device image related to the pointing device from each image. The positioning module is used for calculating a specific point of the pointing device image of each image to generate a first set of specific point information. The constructing module is applied to generate a trajectory in accordance with a pre-defined criterion and the first set of specific point information. Additionally, the processing module is used to analyze the trajectory and generate a control signal to control the object.
GROUP AUTHENTICATION METHOD
(2009-02-26)
Chen, Yu-Wen
;
Wang, Jui-Tang
;
Tseng, Chien-Chao
A group authentication method adaptable to a communication system is disclosed. The communication system includes a user group, a serving network, and a home network. The user group includes at least one mobile station. The home network pre-distributes a group authentication key to itself and all the mobile stations in the same user group and generates a mobile station authentication key for each mobile station. The home network generates a group list for recording related information of the user group. The home network has a database for recording the group list. The serving network has a database for recording the group list and a group authentication data received from the home network. The group authentication method includes following steps. The serving network performs an identification action to a mobile station. The communication system performs a full authentication action or a local authentication action according to the result of the identification action.
METAL OXIDE NANO-COMPOSITE MAGNETIC MATERIAL, FABRICATION METHOD, AND METHOD FOR LINKAGE, ENRICHMENT, AND ISOLATION OF PHOSPHORYLATED SPECIES
(2009-02-26)
CHEN, YU-CHIE
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CHEN, CHENG-TAI
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CHEN, WEI-YU
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LO, CHUN-YUEN
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LIN, HONG-YI
The present invention relates to a metal oxide nano-composite magnetic material, fabrication method, and method for linkage, enrichment, and isolation of phosphorylated species. The metal oxide nano-composite magnetic material comprises the magnetic iron oxide nanoparticle, a silica layer immobilized onto the magnetic iron oxide nanoparticle and a metal oxide layer coated onto the silica layer. The magnetic iron oxide nanoparticles can be used for absorbing microwave radiation to accelerate the enrichment and linkage for phosphorylated species onto the metal oxide nano-composite magnetic material. Furthermore, the magnetic property of magnetic iron oxide nanoparticles leads to isolation of the metal oxide nano-composite magnetic material-target species conjugates by simply employing an external magnetic field. The specificity of the metal oxide on the surface of the metal oxide nano-composite magnetic material for phosphorylated species also leads to the linkage/enrichment of phosphorylated species with high selectivity in a short time (extracting time is 30˜90 seconds).
Nonlinear generalized synchronization of chaotic systems by pure error dynamics and elaborate nondiagonal Lyapunov function
(2009-02-28)
Ge, Zheng-Ming
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Chang, Ching-Ming
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機械工程學系
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Department of Mechanical Engineering
By applying pure error dynamics and elaborate nondiagonal Lyapunov function, the nonlinear generalized synchronization is studied in this paper. Instead of current mixed error dynamics in which master state variables and slave state variables are presented, the nonlinear generalized synchronization can be obtained by pure error dynamics without auxiliary numerical simulation. The elaborate nondiagonal Lyapunov function is applied rather than current monotonous square sum Lyapunov function deeply weakening the powerfulness of Lyapunov direct method. Both autonomous and nonautonomous double Mathieu systems are used as examples with numerical simulations. (C) 2007 Elsevier Ltd. All rights reserved.
Material functions of liquid n-hexadecane under steady shear via nonequilibrium molecular dynamics simulations: Temperature, pressure, and density effects
(2009-02-28)
Tseng, Huan-Chang
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Wu, Jiann-Shing
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Chang, Rong-Yeu
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應用化學系
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Department of Applied Chemistry
Computer experiments of rheology regarding the effects of temperature (T), pressure (P), and density (rho) on steady shear flow material functions, which include viscosity (eta) and first and second normal stress coefficients (psi(1) and psi(2)) depending on shear rate (gamma), have been conducted via nonequilibrium molecular dynamics simulations for liquid n-hexadecane. Straightforwardly, using both characteristic values of a zero-shear-rate viscosity and critical shear rate, eta-gamma flow curves are well normalized to achieve the temperature-, pressure-, and density-invariant master curves, which can be formulary described by the Carreau-Yasuda rheological constitutive equation. Variations in the rate of shear thinning, obviously exhibiting in eta-gamma, psi(1)-gamma, and -psi(2)-gamma relationships, under different T, P, and rho values, are concretely revealed through the power-law model's exponent. More importantly, at low shear rates, the fluid explicitly possesses Newtonian fluidic characteristics according to both manifestations; first and second normal stress differences decay to near zero, while nonequilibrium states are close to equilibrium ones. Significantly, the tendency to vary of the degree of shear thinning in rheology is qualitatively contrary to that of shear dilatancy in thermodynamics. In addition, a convergent transition point is evidently observed in the -psi(2)/psi(1)-gamma curves undergoing dramatic variations, which should be associated with shear dilatancy, as addressed analytically.
Mining decision rules on data streams in the presence of concept drifts
(2009-03-01)
Tsai, Cheng-Jung
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Lee, Chien-I.
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Yang, Wei-Pang
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資訊工程學系
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Department of Computer Science
In a database, the concept of all example might change along with time, which is known as concept drift. When the concept drift occurs, the classification model built by using the old dataset is not suitable for predicting a new dataset. Therefore, the problem of concept drift has attracted a lot of attention in recent years. Although many algorithms have been proposed to solve this problem, they have not been able to provide users with a satisfactory solution to concept drift. That is, the current research about concept drift focuses only on updating the classification model. However, real life decision makers might be very interested in the rules of concept drift. For example, doctors desire to know the root causes behind variation in the causes and development of disease. In this paper, we propose a concept drift rule mining tree, called CDR-Tree, to accurately discover the underlying rule governing concept drift. The main contributions of this paper are: (a) we address the problem of mining concept-drifting rules which has not been considered in previously developed classification schemes; (b) we develop a method that call accurately mine rules governing concept drift: (c) we develop a method that should classification models be required, call efficiently and accurately generate such models via a simple extraction procedure rather than constructing them anew; and (d) we propose two strategies to reduce the complexity of concept-drifting, rules mined by our CDR-Tree. (C) 2007 Elsevier Ltd. All rights reserved.
Full-field measurement of the phase retardation for birefringent elements by using common path heterodyne interferometry
(2009-03-01)
Chen, Yen-Liang
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Su, Der-Chin
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光電工程學系
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Department of Photonics
A collimated heterodyne light passes through the tested material and an analyzer, full-field interference signals are taken by a fast CMOS camera. The series of interference intensities recorded at any pixel are the sampling points of a sinusoidal signal. From those points, the associated argument of that pixel can be derived by a least-square sine fitting algorithm on IEEE 1241 Standards. Subtracting the average argument of the reference signal, the phase retardation of that pixel can be obtained. The phase retardations of other pixels can be obtained similarly. Its validity is demonstrated. (C) 2008 Elsevier Ltd. All rights reserved
A FAST MULTISPRITE GENERATOR WITH NEAR-OPTIMUM CODING BIT-RATE
(2009-03-01)
Kuo, I-Sheng
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Chen, Ling-Hwei
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資訊工程學系
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Department of Computer Science
Sprite coding, which can increase the coding efficiency of backgrounds greatly, is a novel technology adopted in MPEG-4 object-based coding. Due to the geometric transformation applied to each nonreference frame in the procedure of sprite coding, the generated sprite is distorted and the available view angles relative to the reference frame are restricted. These problems can be resolved by using multiple sprites. An optimal multisprite generator has been proposed by Farin et al., but the optimal method requires high computation in the sprite coding cost. To treat this disadvantage, a fast multisprite partition algorithm is proposed in this paper based on frame translations and scalings. The proposed algorithm divides a video sequence into several subsequences, and a sprite is generated from each subsequence. The experimental results show that the executing speed of the proposed method is increased by 10 to 190 times than the optimal method, with the total size of generated sprites is slightly higher and the qualities of generated sprites are preserved.
Threshold-Voltage Fluctuation of Double-Gated Poly-Si Nanowire Field-Effect Transistor
(2009-03-01)
Hsu, Hsing-Hui
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Lin, Horng-Chih
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Chan, Leng
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Huang, Tiao-Yuan
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電子工程學系及電子研究所
In this letter, the fluctuation characteristics of polycrystalline silicon (poly-Si) nanowire (NW) thin-film transistors (TFTs) with independently controlled double-gate configuration were studied. The defects existing in the NW channels are identified as one of the major sources for the fluctuation. The passivation of these defects by plasma treatment is shown to be effective for reducing the fluctuation. We have also found that the fluctuation is closely related to the operation modes. When only one of the gates is employed as the driving gate to control the switching behavior of the device, an optimum bias for the other gate can be found for minimizing the fluctuation.
Variation Analysis of Sphygmogram to Assess Cardiovascular System under Meditation
(2009-03-01)
Liu, Chuan-Yi
;
Wei, Ching-Chuan
;
Lo, Pei-Chen
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電控工程研究所
;
電信工程研究所
In this article, we studied how meditation affects the characteristics of the cardiovascular system, mainly based on blood pressure waveforms (BPW). Four parameters derived from BPW include the rising slope (h(1)/t(1)), normalized height of T wave (h(3)/h(1)), normalized height of V(3) valley (h(4)/h(1)) and normalized height of D wave (h(5)/h(1)), where t(1) and h(i), i 1, ,5 are quantitative features of the BPW waveform pattern. A larger value of h(1)/t(1) reflects better heart ejection ability and aorta compliance. A larger value of h(3)/h(1) may infer an arterial system with good elasticity. The decrease (increase) of h(4)/h(1) parameter indicates the decrease (increase) of peripheral resistance of vessels. A larger value of h(5)/h(1) indicates better artery elasticity and aortic valve function. In comparison with the control group, Zen-meditation practitioners have more after-meditation h(1)/t(1), h(3)/h(1) and h(5)/h(1) increase, with more h(4)/h(1) decrease, with statistical significance (P 0.05). The observation allows us to infer that Zen meditation may effectively improve relevant characteristics of the cardiovascular system.