Browsing by Issue Date, starting with "2014-11-17"

Now showing 1 - 20 of 24953

Collective flow dynamics across a bacterial carpet: Understanding the forces generated
(2014-11-17)
Hsiao, Yi-Teng
;
Wang, Jing-Hui
;
Wu, Kuan-Ting
;
Tsai, Jengjan
;
Chang, Cheng-Hung
Bacterial carpets consist of randomly anchored uni-polar-flagellated sodium-motive bacterial matrix are prepared by flow deposition. Collective flow dynamics across the bacterial carpets are probed with optical tweezers-microsphere assay. Around the center of a uniform bacterial cluster, collective forces that pull microsphere towards carpet surface are detected at a distance of 10 mu m away from carpets. At sodium-motive driving over a critical value, the force magnitudes increase abruptly, suggesting a threshold-like transition of hydrodynamic synchronization across bacterial carpet. The abrupt force increase is explained in term of bifurcation to phase synchronization in a noisy non-linearly coupled rotor array mediated by hydrodynamic interactions. (C) 2014 AIP Publishing LLC.
Design of metal-dielectric grating lasers only supporting surface-wave-like modes
(2014-11-17)
Chiang, Po-Jui
;
Chang, Shu-Wei
;
光電工程學系
;
Department of Photonics
We present a prototype of semiconductor lasers with plasmonic periodic structures that only support transverse-magnetic modes at telecommunication wavelengths. The structure does not sustain transverse-electric guided modes which are irrelevant to surface-wave-enhanced applications, and lasing modes must be surface-wave-like. With thin low-index dielectric buffers near the metal surface, the threshold gain is kept at a decent level around the photonic band edge. Thin windows are then opened on the metal surface to let out significant surface fields. This facilitates usages of surface waves for the spectroscopy and sensing. (C) 2014 Optical Society of America
Pattern formation of second harmonic conical waves in a nonlinear medium with extended defect structure
(2014-11-17)
Lin, Y. C.
;
Su, K. W.
;
Huang, K. F.
;
Chen, Y. F.
;
電子物理學系
We experimentally demonstrate the propagation of the conical second harmonic fields generated from a nonlinear crystal with extended defects to investigate their pattern formation. The generated second harmonic waves are found to be the interference of multiple Bessel-like beams that originate from distinct longitudinal layers inside the crystal. To reconstruct the experimental results, we model the individual Bessel-like beam to be the superposition of an ensemble of identical decentered Gaussian waves with random phases. We present that the randomness of the phases leads the Bessel-like beams to show wave profiles with different extent of localization. Moreover, we use the coherent superposition of the developed wave functions with a phase factor to manifest the interference of multiple Bessel-like beams. The relative phases among the Bessel-like beams are shown to be closely related to the near and far-field patterns. With the experimental observations and the theoretical model, the relative phases are decided to successfully reconstruct the propagation characteristics of the multiple Bessel-like beams. (C) 2014 Optical Society of America
Numerical study of the subtraction threshold for fluorescence difference microscopy
(2014-11-17)
Wang, Nan
;
Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
Subtraction microscopy has recently been promoted for its compactness and simplicity of enhancing spatial resolution. However, until now, the subtraction factors used in such microscopes to process raw images have been chosen experientially, and it has been impossible to determine whether the resolved structures after subtraction are appropriate or over-processed. Based on vector diffraction theory and two-dimensional convolution, this paper presents numerical investigations of the parameters that may offer the selection criterion of subtraction factors used in subtraction microscopy. It proposes two essential parameters for appropriately evaluating the subtraction factor: the fluorescence peak intensity after subtraction and resolution derivative. (C) 2014 Optical Society of America
Current stimulator
(2014-11-18)
Lin Chun-Yu
;
Li Yi-Ju
;
Ker Ming-Dou
The disclosure relates to a current stimulator, which comprises a high voltage output module, a voltage control module and a charge pump module. The high voltage output module includes a plurality of stacked transistors, and receives an input control signal able to turn on/off the current stimulator and a first voltage. A second voltage is generated by adding the voltages output by all the transistors to the first voltage and then output to the voltage control module. The voltage control module outputs a voltage control signal able to stabilize the stimulus current for the load according to the second voltage and the load impedance variation. The charge pump regulates the first voltage according to the voltage control signal, and outputs the regulated first voltage to the high voltage output module. Thereby, the current stimulator can adaptively stabilize the stimulus current, responding to load impedance variation.
Note on soft graviton theorem by KLT relation
(2014-11-18)
Du, Yi-Jian
;
Feng, Bo
;
Fu, Chih-Hao
;
Wang, Yihong
;
電子物理學系
Recently, new soft graviton theorem proposed by Cachazo and Strominger has inspired a lot of works. In this note, we use the KLT-formula to investigate the theorem. We have shown how the soft behavior of color ordered Yang-Mills amplitudes can be combined with KLT relation to give the soft behavior of gravity amplitudes. As a byproduct, we find two nontrivial identities of the KLT momentum kernel must hold.
Ten-transistor dual-port SRAM with shared bit-line architecture
(2014-11-18)
Hwang Wei
;
Wang Dao-Ping
A 10-transistor dual-port SRAM with shared bit-line architecture includes a first memory cell and a second memory cell. The first memory cell has a first storage unit, a first switch set, and a second switch set. The second memory cell has a second storage unit, a third switch set, and a fourth switch set. The second switch set is coupled to a complement first A-port bit line and a complement first B-port bit line, and connected to the first storage unit. The third switch set is connected to a complement second A-port bit line, a complement second B-port bit line, and the second storage unit. Thus, the second memory cell can make use of the third switch set to share the complement first A-port bit line and the complement first B-port bit line with the first memory cell.
Three-dimensional integrated circuit
(2014-11-18)
Tan An-Nan
;
Chen Hung-Ming
A three-dimensional integrated circuit, including a first adhesive bonding layer, a first chip, a second chip, and an inter-stratum thermal pad, is provided. The first adhesive bonding layer has a first surface and a second surface opposite to each other. The first chip is disposed on the first surface of the first adhesive bonding layer. The first chip includes a hot zone. The second chip is disposed on the second surface of the first adhesive bonding layer. The inter-stratum thermal pad is embedded in the first adhesive bonding layer and faces to the hot zone.
A meta-learning approach for B-cell conformational epitope prediction
(2014-11-18)
Hu, Yuh-Jyh
;
Lin, Shun-Chien
;
Lin, Yu-Lung
;
Lin, Kuan-Hui
;
You, Shun-Ning
Background: One of the major challenges in the field of vaccine design is identifying B-cell epitopes in continuously evolving viruses. Various tools have been developed to predict linear or conformational epitopes, each relying on different physicochemical properties and adopting distinct search strategies. We propose a meta-learning approach for epitope prediction based on stacked and cascade generalizations. Through meta learning, we expect a meta learner to be able integrate multiple prediction models, and outperform the single best-performing model. The objective of this study is twofold: (1) to analyze the complementary predictive strengths in different prediction tools, and (2) to introduce a generic computational model to exploit the synergy among various prediction tools. Our primary goal is not to develop any particular classifier for B-cell epitope prediction, but to advocate the feasibility of meta learning to epitope prediction. With the flexibility of meta learning, the researcher can construct various meta classification hierarchies that are applicable to epitope prediction in different protein domains. Results: We developed the hierarchical meta-learning architectures based on stacked and cascade generalizations. The bottom level of the hierarchy consisted of four conformational and four linear epitope prediction tools that served as the base learners. To perform consistent and unbiased comparisons, we tested the meta-learning method on an independent set of antigen proteins that were not used previously to train the base epitope prediction tools. In addition, we conducted correlation and ablation studies of the base learners in the meta-learning model. Low correlation among the predictions of the base learners suggested that the eight base learners had complementary predictive capabilities. The ablation analysis indicated that the eight base learners differentially interacted and contributed to the final meta model. The results of the independent test demonstrated that the meta-learning approach markedly outperformed the single best-performing epitope predictor. Conclusions: Computational B-cell epitope prediction tools exhibit several differences that affect their performances when predicting epitopic regions in protein antigens. The proposed meta-learning approach for epitope prediction combines multiple prediction tools by integrating their complementary predictive strengths. Our experimental results demonstrate the superior performance of the combined approach in comparison with single epitope predictors.
The Combination Effects of LiCl and the Active Leflunomide Metabolite, A771726, on Viral-Induced Interleukin 6 Production and EV-A71 Replication
(2014-11-20)
Hung, Hui-Chen
;
Shih, Shin-Ru
;
Chang, Teng-Yuan
;
Fang, Ming-Yu
;
Hsu, John T. -A.
Enterovirus 71 (EV-A71) is a neurotropic virus that can cause severe complications involving the central nervous system. No effective antiviral therapeutics are available for treating EV-A71 infection and drug discovery efforts are rarely focused to target this disease. Thus, the main goal of this study was to discover existing drugs with novel indications that may effectively inhibit EV-A71 replication and the inflammatory cytokines elevation. In this study, we showed that LiCl, a GSK3 beta inhibitor, effectively suppressed EV-A71 replication, apoptosis and inflammatory cytokines production (Interleukin 6, Interleukin-1 beta) in infected cells. Furthermore, LiCl and an immunomodular agent were shown to strongly synergize with each other in suppressing EV-A71 replication. The results highlighted potential new treatment regimens in suppressing sequelae caused by EV-A71 replication.
PLANAR SOLID OXIDE FUEL CELL STACK AND ITS INTERCONNECT THEREOF
(2014-11-20)
WEI SHIH-SIN
;
WU JONG-SHINN
A planar solid oxide fuel cell stack which can expand in both the vertical and horizontal directions is disclosed. The planar solid oxide fuel cell stack comprises an interconnect which consists of an interconnect body, a first flowing area and a second flowing area, wherein the first and the second flowing area are disposed on opposite side of the interconnect body, and have one gas inlet and two gas outlets, respectively. By employing multiple hexagonal interconnects for cell stack expanding in the horizontal direction, each three stacks can share the same pipeline of the flow channel, thereby reaching the goals of reducing the space and materials required and system complexity as well.
Density Functional Theory Study of Pt3M Alloy Surface Segregation with Adsorbed O/OH and Pt3Os as Catalysts for Oxygen Reduction Reaction
(2014-11-20)
Tsai, Ho-Cheng
;
Yu, Ted H.
;
Sha, Yao
;
Merinov, Boris V.
;
Wu, Pu-Wei
Using quantum mechanics calculations, we have studied the segregation energy with adsorbed O and OH for 28 Pt3M alloys, where M is a transition metal. The calculations found surface segregation to become energetically unfavorable for Pt3Co and Pt3Ni, as well as for the most other Pt binary alloys, in the presence of adsorbed O and OH. However, Pt3Os and Pt3Ir remain surface segregated and show the best energy preference among the alloys studied for both adsorbed species on the surface. Binding energies of various oxygen reduction reaction (ORR) intermediates on the Pt(111) and Pt3Os(111) surfaces were calculated and analyzed. Energy barriers for different ORR steps were computed for Pt and Pt3Os catalysts, and the rate-determining steps (RDS) were identified. It turns out that the RDS barrier for the Pt3Os alloy catalyst is lower than the corresponding barrier for pure Pt. This result allows us to predict a better ORR performance of Pt3Os compared to that of pure Pt.
LIGHT-GUIDING STRUCTURE AND LIGHT-EMITTING DEVICE
(2014-11-20)
HSU RAY-QUEN
;
WEI SHAO-HUA
A light-emitting device includes a base unit, a light-guiding structure and a cover unit. The light-guiding structure is disposed on the base unit, and the light-guiding structure includes a light-guiding unit and a light-emitting unit. The cover unit includes a light-transmitting cover body disposed on the base unit to cover the light-guiding structure. The light-guiding unit includes a single light-guiding element having a columnar body and an expansion body integrally and upwardly extended from the columnar body. The columnar body has a light input surface and a vertical surrounding peripheral surface. The expansion body has a surrounding bottom surface connected with the vertical surrounding peripheral surface, an inclined surrounding peripheral surface connected with the surrounding bottom surface, and a trumpet-shaped top surface connected with the inclined surrounding peripheral surface. The light-emitting unit includes at least one light-emitting module adjacent to the light input surface of the columnar body.
交大e-News第175期
(2014-11-20)
Secretariat
;
國立交通大學秘書室
控制微游泳器轉向之方法
(2014-11-21)
陳慶耀
;
李彥宏
Nodal adsorbate bound states in armchair graphene nanoribbons: Fano resonances and adsorbate recognition in weak disorder
(2014-11-21)
Chiu, C. H.
;
Chu, C. S.
;
電子物理學系
;
Department of Electrophysics
We consider adsorbates on metallic armchair-graphene nanoribbons (AGNRs). An adsorbed atom on a nodal site of the gapless subband in the AGNR is found to induce a bound state. The nodal-adsorbate bound state alone does not cause reflection in the AGNR quantum transport in the one propagating-channel regime. Yet its manifestation, as a Fano resonance in G, is brought forth by the presence of a non-nodal adsorbate (or a scatterer) located on a longitudinally separated site. Both the adsorbate-dependent nature and the significantly enhanced energy resolution of the Fano structure in G invite adsorbate recognition. The Fano peak is shown to be robust against weak disorder such as from edge vacancies, due to the localized nature of the Fano resonant state. Adsorbates F and OH, described within an extended Huckel model, are considered as examples.
薄膜電晶體之製造方法
(2014-11-21)
周政偉
;
陳蔚宗
;
冉曉雯
;
蔡娟娟
Synthesis and morphological studies of a poly(5,6-difluorobenzo-2,1,3-thiadiazole-4,7-diyl-alt-quaterchalcogenophene) copolymer with 7.3% polymer solar cell efficiency
(2014-11-21)
Wu, Jhong-Sian
;
Jheng, Jyun-Fong
;
Chang, Jen-Yun
;
Lai, Yu-Ying
;
Wu, Kuan-Yi
To obtain a poly(5,6-difluorobenzo-2,1,3-thiadiazole-4,7-diyl-alt-quaterchalcogenophene) (P(FBT-alt-CP4)) copolymer with a small optical band gap (E-g), and to achieve high short-circuit current (J(sc)) in the P(FBT-alt-CP4) : PC71BM polymer solar cells (PSCs), P(FBT-alt-Se2Th2), which contains selenophene-2,5-diyl (-Se-) pi-bridges, was synthesized. P(FBT-alt-Se2Th2) shows a Eg of 1.56 eV and is strongly aggregated in solution. Wide angle X-ray diffraction (WAXD) and grazing incidence X-ray diffraction (GI-XRD) results revealed the high solid-state order of P(FBT-alt-Se2Th2) and its edge-on orientation on the substrate. It delivered a high hole mobility (mu(h)) of 0.36 cm(2) V-1 s(-1) in organic field-effect transistors (OFETs). The strong aggregation tendency of P(FBT-alt-Se2Th2) caused large segregation domains in the P(FBT-alt-Se2Th2) : PC71BM thin film, as is seen in the high-resolution transmission electron microscopy (HR-TEM) images. The addition of 8 vol% of 1-chloronaphthalene (1-CN) effectively suppressed the aggregation and led to more homogeneous active layer morphology. The improved morphology enhanced the J(sc) of the PSCs. A superior PCE of 7.34% with a V-oc of 0.70 V, a J(sc) of 15.8 mA cm(-2), and a FF of 66.4% was achieved in the inverted P(FBT-alt-Se2Th2) : PC71BM PSCs. The strong aggregation of P(FBT-alt-Se2Th2) is likely related to its more straight conjugated backbone according to the theoretical calculation results of the FBT-alt-Se2Th2 repeat unit.
多軸慣性微動系統
(2014-11-21)
洪紹剛
;
鄭喬華
;
林建宇
一種高輸出增益電晶體元件
(2014-11-21)
劉柏村
;
鄒一德
;
鄧立峯
;
傅治翔
;
謝漢萍