Browsing by Issue Date, starting with "2013-08-26"

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Periodic elastic nanodomains in ultrathin tetragonal-like BiFeO3 films
(2013-08-26)
Luo, Zhenlin
;
Chen, Zuhuang
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Yang, Yuanjun
;
Liu, Heng-Jui
;
Huang, Chuanwei
We present a synchrotron grazing incidence x-ray diffraction analysis of the domain structure and polar symmetry of highly strained BiFeO3 (BFO) thin films grown on LaAlO3 substrate. We reveal the existence of periodic elastic nanodomains in the pure tetragonal-like BFO ultrathin films down to a thickness of 6 nm. A unique shear strain-accommodation mechanism is disclosed. We further demonstrate that the periodicity of the nanodomains increases with film thickness but deviates from the classical square root law in the ultrathin thickness regime (6-30 nm). Temperature-dependent experiments further reveal the disappearance of periodic modulation above similar to 90 degrees C due to a M-C-M-A structural phase transition.
Universal scaling of nonlinear conductance in the two-channel pseudogap Anderson model: Application for gate-tuned Kondo effect in magnetically doped graphene
(2013-08-26)
Lee, Tsung-Han
;
Zhang, Kenneth Yi-Jie
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Chung, Chung-Hou
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Kirchner, Stefan
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電子物理學系
Based on the noncrossing approximation, we calculate both the linear and nonlinear conductance within the two-lead two-channel single-impurity Anderson model where the conduction electron density of states vanishes in a power-law fashion proportional to vertical bar omega - mu(F)vertical bar(r) with r = 1 near the Fermi energy, appropriate for a hexagonal system. For given gate voltage, we address the universal crossover from a two-channel Kondo phase, argued to occur in doped graphene, to an unscreened local moment phase. We extract universal scaling functions in conductance governing charge transfer through the two-channel pseudogap Kondo impurity and discuss our results in the context of a recent scanning tunneling spectroscopy experiment on Co-doped graphene.
Synthesis of Neisseria meningitidis Serogroup W135 Capsular Oligosaccharides for Immunogenicity Comparison and Vaccine Development
(2013-08-26)
Wang, Chia-Hung
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Li, Shiou-Ting
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Lin, Tzu-Lung
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Cheng, Yang-Yu
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Sun, Tsung-Hsien
Ultra-thin titanium nanolayers for plasmon-assisted enhancement of bioluminescence of chloroplast in biological light emitting devices (vol 103, 063703, 2013)
(2013-08-26)
Su, Yen Hsun
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Hsu, Chia-Yun
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Chang, Chung-Chien
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Tu, Sheng-Lung
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Shen, Yun-Hwei
The metal grating design of plasmonic hybrid III-V/Si evanescent lasers
(2013-08-26)
Hsu, Min-Hsiang
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Lin, Chien-Chung
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Kuo, Hao-Chung
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光電系統研究所
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Institute of Photonic System
A hybrid III-V/silicon laser design with a metal grating layer inserted in between is proposed and numerically studied. The metal grating layer is buried in a silicon ridge waveguide surrounded by silicon dioxide, and its structural parameters such as periodicity, width and depth can be varied for optimization purpose. The plasmonic effect originated from the grating layer can manage optical fields between III-V and silicon layers in hopes of dimension reduction. The substrate is planarized to minimize the bonding failure. A numerical algorithm with various combinations of metal grating and waveguide structural parameters was created and the optimal design with 730 nm grating period and 600 nm of buried waveguide ridge height was obtained by minimizing the corresponding laser threshold. With top AlInGaAs quantum wells and optimized design of hybrid metal/silicon waveguide, a 0.6 mu m(-1) threshold gain can be achieved. (C)2013 Optical Society of America
Electrical stimulation method and apparatus to stimulate nerve fibers
(2013-08-27)
Choi Charles Tak-Ming
;
Lee Yi-Hsuan
The present invention provides an electrical stimulation method and apparatus to stimulate nerve fibers, turning on suitable combination of adjacent electrodes simultaneously to form virtual channels based on predetermined rules, so that the stimulation signal will generate or evoke a nerve response spectrum that matches the original signal spectrum presented as the input sound. The method includes the steps of receiving a sound signal by a receiving unit; dividing the received sound signal into a plurality of frequency bands by a processing unit; extracting a spectral peak from each of the frequency bands and determining a stimulation sequence of frequency bands by the processing unit; and selectively driving a plurality of electrode groups in a plurality of cycles based on the stimulation sequence of frequency bands and a determination rule by the processing unit, so that the nerve response that matches the original signal will be generated.
III-V metal-oxide-semiconductor device
(2013-08-27)
Chang Edward Yi
;
Lin Yueh-Chin
A hafnium oxide layer, between a III-V semiconductor layer and a metal oxide layer is used to prevent interaction between the III-V semiconductor layer and the metal oxide layer.
Linking hydrophobicity and hydrodynamics by the hybrid fluctuating hydrodynamics and molecular dynamics methodologies
(2013-08-27)
Voulgarakis, Nikolaos K.
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Shang, Barry Z.
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Chu, Jhih-Wei
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生物科技學系
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生物資訊及系統生物研究所
The development of a hybrid fluctuating hydrodynamics (FHD) and molecular dynamics (MD) simulation method that combines the molecular dynamics of moving particles with the fluctuating hydrodynamics of solvent fields on Eulerian grid cells is presented. This method allows resolution of solute-solvent interfaces and realization of excluded volumes of particles in the presence of hydrodynamic coupling. With these capabilities, we show that the ubiquitous forces mediated by the solvent, hydrophobicity and hydrodynamics, can be linked in a mesoscopic simulation. The strategies we devise to overcome the numerical issues of mixing variables in the Eulerian and Lagrangian coordinate systems, i.e., using a pair of auxiliary fluids to realize the excluded volumes of particles and assigning collocating gridding systems on solutes to interface with solvent fields, are also presented. Simulation results show that the hybrid FHD and MD method can reproduce the solvation free energies and scaling laws of particles dynamics for hydrophobes of different sizes. The collapse of two hydrophobic particles was also simulated to illustrate that the hybrid FHD and MD method has the potential to be generally applied to study nanoscale self-assembly and dynamics-structure-function relationships of biomolecules.
Infrared absorption of 3-propenonyl (center dot CH2CHCO) radical generated upon photolysis of acryloyl chloride [CH2CHC(O)Cl] in solid para-H-2
(2013-08-28)
Das, Prasanta
;
Lee, Yuan-Pern
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應用化學系
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應用化學系分子科學碩博班
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Department of Applied Chemistry
Irradiation at 193 nm of a p-H-2 matrix containing acryloyl chloride CH2CHC(O)Cl at 3.2 K yielded infrared absorption lines at 3143.6 (nu(1)), 3057.0 (nu(2)), 3048.0 (nu(3)), 2103.1 (nu(4)), 1461.0 (nu(5)), 1349.8 (nu(6)), 1223.7 (nu(11)+nu(12) or 2 nu(12)), 1092.8 (nu(8)), 918.1 (nu(9)), 691.0 (nu(10)), 624.3 (nu(11)), and 597.1 (nu(12)) cm (1) that are assigned to the 3-propenonyl (center dot CH2CHCO) radical. The assignments are based on the photolytic behavior and a comparison of observed vibrational wavenumbers and infrared intensities with those predicted with the B3PW91/aug-cc-pVDZ method. The observation is consistent with a major radical formation channel CH2CHCO + Cl followed by escape of the Cl atom from the original p-H-2 cage. The observation of 3-propenonyl (center dot CH2CHCO) radical but not 3-propenalyl (s-cis- or s-trans-CH2CH(C) over dotO) radical indicates that the former is the most stable isomer and that the barrier heights for conversion from s-cis- or s-trans-CH2CH(C) over dotO to center dot CH2CHCO are small. (C) 2013 AIP Publishing LLC.
Electronic contribution to the enhancement of the ferromagnetic ordering temperature by Si substitution in Gd-5(SixGe1-x)(4)
(2013-08-29)
Tseng, Y. C.
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Paudyal, D.
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Mudryk, Ya
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Pecharsky, V. K.
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Gschneidner, K. A., Jr.
By using a combination of x-ray spectroscopic and diffraction measurements at high pressures together with density functional theory (DFT) calculations, we show that the increase in Curie temperature T-C, induced by Si substitutions in Gd-5(SixGe1-x)(4) giant magnetocaloric materials is predominately electronically driven as opposed to lattice driven. Whereas, a lattice contraction with applied pressure increases the strength of exchange (magnetic) interactions between Gd spins, leading to a modest increase in T-C at a rate of 1.2 K/angstrom(3), much larger enhancements in T-C are obtained with Si doping for the same volume reduction (13.5 K/angstrom(3)), indicating that volume (lattice) effects are secondary. Similarly, an orthorhombic [O(II)] to monoclinic (M) structural phase transition is observed to take place with applied pressure in the paramagnetic state of a Gd-5(Si0.125Ge0.875)(4) sample at room temperature at a much smaller volume than needed to drive the same structural transition with Si doping, indicating that, even in the absence of magnetic order, electronic effects with Si doping dominate the energetics of structural transformations over lattice (volume) effects. DFT calculations show that the electronic mechanism behind this effect is a stronger Si 3p-Gd 5d than Ge 4p-Gd 5d hybridization, a critical ingredient in mediating indirect exchange interactions between localized Gd 4f spins. The results highlight the strong sensitivity of the magnetic ordering temperature to the nature of p-d hybridization, opening opportunities for tailoring the magnetocaloric properties of these compounds by substituting other p and rare-earth elements at the Si/Ge and Gd sites, respectively.
SRAM based on 6 transistor structure including a first inverter, a second inverter, a first pass-gate transistor, and a second pass-gate transistor
(2013-08-29)
CHUANG Ching-Te
;
Jou Shyh-Jye
;
Hwang Wei
;
Lin Yi-Wei
;
Tsai Ming-Chien
The present invention provides a 6T SRAM including a first inverter, a second inverter, a first pass-gate transistor, and a second pass-gate transistor. The first inverter zs a first pull-up transistor and a first pull-down transistor. The second inverter includes a second pull-up transistor and a second pull-down transistor. The gate of the second pull-up transistor is coupled with the gate of the second pull-down transistor, and the drain of the second pull-up transistor is coupled with the drain of the second pull-down transistor. The SRAM can measure the trip voltage, the read disturb voltage, and the write margin by controlling the first bit line, the second bit line, the GND, the first word line, and the voltage source without changing of the physic parameter of the SRAM.
Oscillator based on a 6T SRAM for measuring the Bias Temperature Instability
(2013-08-29)
Chuang Ching-Te
;
Jou Shyh-Jye
;
Hwang Wei
;
Tsai Ming-Chien
;
Lin Yi-Wei
The present invention provides an oscillator which is based on a 6T SRAM for measuring the Bias Temperature Instability. The oscillator includes a first control unit, a first inverter, a second control unit, and a second inverter. The first control unit is coupled with the first inverter. The second control unit is coupled with the second inverter. The first control unit and the second control unit is used to control the first inverter and the second inverter being selected, biased, and connected respectively, so that the NBTI and the PBTI of the SRAM can be measured separately, and the real time stability of the SRAM can be monitored immediately.
CLOUD-BASED MULTIMEDIA TEACHING SYSTEM, DEVELOPMENT METHOD AND INTERACTION METHOD THEREOF
(2013-08-29)
SUN Jerry Chih-Yuan
;
Walsh John P.
;
Misiaszek Greg
The present invention discloses a cloud-based multimedia teaching system, a development method and an interaction method thereof. In the present invention, a teacher produces a course in the Abode Flash format and uploads it from a client computer to a multimedia teaching system via the cloud; the multimedia teaching system communicates with a back-end server via a server framework in the Flash Remoting technology and establishes the course in the back-end server; the user interface of the multimedia teaching system contains a plurality of buttons linked to the courses. When a user clicks on a button of the user interface to select a course, the multimedia teaching system retrieves related data of the course from the back-end server via the server framework in the Flash Remoting technology and presents the data on the user interface thereof.
Poly(ethylene glycol) modified activated carbon for high performance proton exchange membrane fuel cells
(2013-08-30)
Tsai, Li-Duan
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Chien, Hung-Chung
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Wang, Cheng-Hong
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Lai, Chien-Ming
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Lin, Jiunn-Nan
A high water retention membrane is developed by co-assembling poly(ethylene glycol) (PEG) grafted activated carbon (AC-PEG) with Nafion. The AC-PEG is prepared via a sol gel process. The use of PEG as a transporting medium in AC-PEG shows a largely improved water retention ability, a higher proton conductivity and a reduced swelling ratio, making it well suited for proton exchange membrane fuel cells (PEMFCs). Further, the composite membranes show improved mechanical properties at high temperature, thus ensuring the structural stability of membranes during the fuel cell operation. Compositional optimized AC-PEG/Nafion composite membrane (15 wt% compared to Nafion) demonstrates a better performance than the commercially available counterpart, Nafion 212, in fuel cell measurements. To identify the key factor of the improved performance, current interrupt technique is used to quantitatively verify the changes of resistance under different relative humidity environment. Copyright (C) 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Modeling contaminant transport in a two-aquifer system with an intervening aquitard
(2013-08-30)
Liu, Chih-Tien
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Yeh, Hund-Der
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Yeh, Li-Ming
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環境工程研究所
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應用數學系
This study deals with the issue of one-dimensional solute transport in a two-aquifer system, where an aquitard lies between two aquifers. Different from previous studies on analysis of the contaminant transport affected by the presence of an aquitard, we developed a mathematical transport model in an aquifer-aquitard-aquifer system with considering transport of solutes in the aquitard governed by both advection and diffusion. The Laplace-domain solution of the model for concentration distributions is obtained by the Laplace transform technique and its corresponding time-domain results are computed numerically by using Laplace numerical inversion. An explicit finite difference model is also developed to simulate two-dimensional contaminant transport process in the system. The simulated depth-averaged concentrations in the lower and upper aquifers slightly differ from those predicted by the present solution. The results show that the movement of contaminant in the upper aquifer is slowed down considerably due to the advective transport in aquitard. When neglecting the aquitard advection (a zero Pedet number), the concentration level in the lower aquifer will be underestimated, especially at late times. In addition, the contaminant concentration in the lower aquifer increases significantly with aquitard's Peclet number. (C) 2013 Elsevier B.V. All rights reserved.
Enhanced particle destabilization and aggregation by flash-mixing coagulation for drinking water treatment
(2013-08-30)
Lin, Jr-Lin
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Pan, Jill R.
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Huang, Chihpin
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環境工程研究所
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生物科技學系
In water treatment plants (WTPs), the operation of rapid mixing in coagulation units dominates particle destabilization and the formation of flocs. The goal of this study was to investigate the effect of enhanced rapid-mixing intensity (velocity gradient [G]) on the performance of coagulation for natural turbid water treatment. Two surface-water samples of low and high turbidity were coagulated by using polyaluminum chloride (PACl), with G values ranging from 200 to 800 s(-1),and the destabilization of particles and dissolved organic matter (DOM) was determined, followed by measurement of filterability of the supernatant. Furthermore, the effect of high rapid mixing on the coagulation efficiency was studied by using a pilot-scale, in-line instantaneous flash mixer (IFM) which could generate much higher G than a conventional mechanical mixing of WTP. The results of Jar test showed that the enhanced reduction in turbidity was accompanied by the improved filterability of the supernatant, which was due to the formation of larger flocs with strong structure in response to higher rapid-mixing intensity, especially for low-turbidity water. It was found that the fractal dimension (D-f) of coagulated flocs is inversely proportional to the recovery factor of broken flocs. The in-line IFM with intensive mixing (G > 5000 s(-1)) substantially improved the removal of particles and DOM, as a result of the formation of large flocs. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved.
Growth of lattice-matched InAlN/GaN on Si (111) substrate for ultraviolet photodiode application
(2013-09-01)
Binh Tinh Tran
;
Chang, Edward Yi
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材料科學與工程學系
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Department of Materials Science and Engineering
In this paper, we report on the growth of high quality In (x) Al1-x N/GaN hetero-structures on Si substrate by metal organic chemical vapor deposition with various indium compositions (x = 10.2, 16.2 and 17.6%). The lattice-matched In0.176Al0.838N/GaN structure shows a smooth surface with good crystalline quality. In addition, the ultraviolet photodiode device shows excellent device characteristics with a low leakage current of 0.12 A mu A, and a high spectral response. It has good quantum efficiency of 94 mA/W and 44% at 265 nm which is comparable to that of the InAlN photodiode grown on sapphire substrate.
Deriving the Vehicle Speeds from a Mobile Telecommunications Network
(2013-09-01)
Liou, Ren-Huang
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Lin, Yi-Bing
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Chang, Yu-Long
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Hung, Hui-Nien
;
Peng, Nan-Fu
Vehicle speeds are often measured by intelligent transportation systems (ITSs) by utilizing sensors or software solutions. Our previous work proposed the Lin-Chang-Huangfu (LCH) scheme to compute the cell residence times by the standard counter values in mobile telecommunications switches. In this paper, we use mathematical and statistical developments to investigate the accuracy of the LCH scheme by deriving the bias of the cell residence times computed in this scheme. Then, we extend the LCH scheme with some filtering and compensation techniques for vehicle speed estimation and validate our approach with vehicle detector (VD) measurements at National Highway 3, Longtan Township, Taoyuan County, Taiwan. Our study indicates that the LCH scheme is an effective approach to vehicle speed estimation.
「溫度」
(深河出版有限公司, 2013-09-01)
晨野
Critical point defect detection for small-pixel thin-film transistor array applied to medical display
(2013-09-01)
Wang, Yao-Chin
;
Lin, Bor-Shyh
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光電系統研究所
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影像與生醫光電研究所
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生醫電子轉譯研究中心