Browsing by Issue Date, starting with "2015-06-18"

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Intersystem Crossing Pathway in Quinoline-Pyrazole Isomerism: A Time-Dependent Density Functional Theory Study on Excited-State Intramolecular Proton Transfer
(2015-06-18)
Liu, Yu-Hui
;
Lan, Sheng-Cheng
;
Zhu, Chaoyuan
;
Lin, Sheng-Hsien
;
應用化學系分子科學碩博班
The dynamics of the excited-state intramolecular proton-transfer (ESIPT) reaction of quinoline pyrazole (QP) isomers, designated as QP-I and QP-II, has been investigated by means of time-dependent density functional theory (TDDFT). A lower barrier has been found in the potential energy curve for the lowest singlet excited state (S-1) along the proton-transfer coordinate of QP-II compared with that of QP-I; however, this is at variance with a recent experimental report [J. Phys. Chem. A 2010, 114, 7886-7891], in which the authors proposed that the ESIPT reaction would only proceed in QP-I due to the absence of a PT emission for QP-II. Therefore, several deactivating pathways have been investigated to determine whether fluorescence quenching occurs in the PT form of QP-II (PT-II). The Si state of PT-II has n pi* character, which is a well-known dark state. Moreover, the energy gap between the S-1 and T-2 states is only 0.29 eV, implying that an intersystem crossing (ISC) process would occur rapidly following the ESIPT reaction. Therefore, it is demonstrated that the ESIPT could successfully proceed in QP-II and that the PT emission would be quenched by the ISC process.
MULTI-PORT SRAM WITH SHARED WRITE BIT-LINE ARCHITECTURE AND SELECTIVE READ PATH FOR LOW POWER OPERATION
(2015-06-18)
HWANG Wei
;
WANG Dao-Ping
A multi-port SRAM with shared write bit-line architecture and selective read path for low power operation includes a first memory cell, a second memory cell, and a common switch set. The second memory cell makes use of the common switch set to share the A-port write bit-line and the B-port write bit-line with the first memory cell so as to reduce half write bit-line number and reduce the write current consumption caused by pre-charging the bit-line to VDD. It also provides a selective read path structure for read operation. Replacing the ground connection in the read port with a virtual VSS controlled by a Y-select signal reduces read-port current consumption.
Effect of phosphate surface pretreatment on corrosion resistance and adhesion of PI coating on Mg-5 wt.% Sn alloy
(2015-06-18)
Lee, Hsiao-Chien
;
Huang, Yi-Chia
;
Liu, Tzeng-Feng
;
Whang, Wha-Tzong
;
Chao, Chuen-Guang
In this study, phosphate surface pretreatment (PSPT) and poly[pyromellitic dianhydride-co-4,4MODIFIER LETTER PRIME-oxydianiline] polyimide (PMDA-ODA PI) coating were used to provide corrosion protection for Mg-5 wt.% Sn alloy. PSPT enhanced the adhesion of PI coating by mechanical interlocking and chemical anchoring. Surface roughness was increased and provided stronger mechanical interlocking. Phosphates were formed on the alloy surface to act as anchor groups. Energy dispersive X-rayspectrometer and X-ray photoelectron spectroscopy results indicated that bonds formed between anchor groups and PI coating. The bonds provided chemical anchoring and enhanced the adhesion of PI coating. The increase of corrosion resistance of PI coating on Mg-5 wt.% Sn alloy (E-corr = -0.86V/SCE, [GRAPHICS] mu A cm(-2) and corrosion rate far less than [GRAPHICS] showed the bonds were stable enough to stand the attack of electrolyte and inhibit the electrochemical reaction at the interface.
Highly Selective Dissociation of a Peptide Bond Following Excitation of Core Electrons
(2015-06-18)
Lin, Yi-Shiue
;
Tsai, Cheng-Cheng
;
Lin, Huei-Ru
;
Hsieh, Tsung-Lin
;
Chen, Jien-Lian
The controlled breaking of a specific chemical bond with photons in complex molecules remains a major challenge in chemistry. In principle, using the K-edge absorption of a particular atomic element, one might excite selectively a specific atomic entity in a molecule. We report here highly selective dissociation of the peptide bonds in N-methylformamide and N-methylacetamide on tuning the X-ray wavelength to the K-edge absorption of the atoms connected to (or near) the peptide bond. The high selectivity (56-71%) of this cleavage arises from the large energy shift of X-ray absorption, a large overlap of the Is orbital and the valence pi* orbital that is highly localized on a peptide bond with antibonding character, and the relatively low bond energy of the peptide bonds. These characteristics indicate that the high selectivity on bond dissociation following core excitation could be a general feature for molecules containing peptide bonds.
OPTIMAL DYNAMIC SEAM ADJUSTMENT SYSTEM AND METHOD FOR IMAGE STITCHING
(2015-06-18)
GUO Jiun-In
;
CHANG Hsiu-Cheng
;
CHIEN Cheng-An
;
HUANG Kai-Chen
An optimal dynamic seam adjustment system for image stitching includes an image obtaining module, a feature difference calculation module and a dynamic seam module. The image obtaining module obtains at least two images to be stitched, which have at least one overlapping area divided into a plurality of pixels arranged in a plurality of pixel columns and a plurality of pixel rows. The feature difference calculation module calculates a feature difference value for each pixel within the overlapping area. The dynamic seam module establishes a plurality of dynamic seam routes started from a top end of the overlapping area, so as to find an optimal dynamic seam route based on the feature difference value, wherein each dynamic seam route is composed of a plurality of pixels.
可適性計算方法與架構
(2015-06-21)
張良正
;
陳宇文
;
蔡瑞彬
1.一種用於獲得地下水流之一性質的方法，包括以下步驟：(a)用一方程式集合來描述該地下水流的一守恆量，該方程式集合具有與該守恆量相關的至少一方程式與代表該性質的至少一變數；(b)對該方程式集合進行一一致性分析，以檢驗該至少一方程式與該至少一變數之一致性，並得一求解順序，且定義多個空間網格與多個節點，並依該等節點將該方程式集合與該至少一變數，離散化成為一離散方程組；以及(c)依據該求解順序，求解該離散方程組。
利用下壓方式組裝之三維斜面微結構
(2015-06-21)
邱一
;
施錫富
;
林健安
一種利用下壓方式組裝之三維斜面微結構，其包括：一基底層；一斜面主體，其設置於該基底層上，該斜面主體兩側相對應各設有一第一凸出部，該斜面主體底部設有一第一推墊，該第一推墊下方處前述基底層設有一第一容置空間用以容納該第一推墊，且該斜面主體底部設有向兩側水平延伸之第一扭轉樑；以及一U型支撐架，其設置於該基底層上，該U型支撐架之兩支架部內側相對應各設有一第二凸出部，該U型支撐架底部設有一第二推墊，該第二推墊下方處前述基底層設有一第二容置空間用以容納該第二推墊，且該U型支撐架底部設有向兩側水平延伸之第二扭轉樑；俾藉，下壓推動該第一推墊及第二推墊，使該斜面主體經由第一扭轉樑為軸心轉動，該U型支撐架經由第二扭轉樑為軸心轉動，並藉由該些第一凸出部與第二凸出部互相卡扣固定形成一三維斜面微結構。
石墨氧化物製備方法
(2015-06-21)
韋光華
;
鄧文成
一種石墨氧化物之製備方法，包含下列步驟：提供一電漿電解裝置，其中該電漿電解裝置具有一電解液，該電解液之pH為介於11與17之間，以及該電漿電解裝置之一陰極為一石墨電極；以及提供一陰極電流於該石墨電極，使該石墨電極進行一電漿電解反應以得到石墨氧化物。
使用車用電源線傳輸控制信號之設備
(2015-06-21)
曾煜輝
;
蘇朝琴
;
何盈杰
一種使用車用電源線傳輸控制信號之設備，包含：一發送端信號收發實體連接介面，係電性連接一車用電源線；一控制信號發送器，係電性連接該發送端信號收發實體連接介面，藉以電性連接該車用電源線；複數個接收端信號收發實體連接介面，係電性連接該車用電源線；複數個控制信號接收器，各控制信號接收器係與該複數個接收端信號收發實體連接介面對應電性連接，藉以電性連接該車用電源線，且各控制信號接收器係分別電性連接一車用電子設備；其中，該控制信號發送器係經由該車用電源線以一寬頻數位通信傳輸技術將一組二進位數位信號傳送至該複數個控制信號接收器其中之一，藉以控制電性連接該控制信號接收器之車用電子設備。
基於語音情感辨識之音樂播放系統及其方法
(2015-06-21)
宋開泰
;
史威德
一種音樂播放系統，適用在基於語音情感辨識以選擇曲目播放，包括：一第一資料庫，儲存多首歌曲及該些歌曲映射在一情緒座標圖上的歌曲情緒座標；一第二資料庫，儲存情緒辨識參數；一收音裝置，接收一語音資料；一控制裝置，連接至該第一資料庫、該第二資料庫及該收音裝置，分析該語音資料的頻率，透過該第二資料庫進行比對，獲取該語音資料映射在該情緒座標圖之上的一當前情緒座標，接著接收一目標情緒座標之設定，在該當前情緒座標及該目標情緒座標相連的一喚醒直線上，找尋該第一資料庫中最接近該喚醒直線的至少一特定歌曲情緒座標。
交大e-News第188期-立足交大點亮世界
(2015-06-22)
國立交通大學秘書室
;
Secretariat
Phosphorus-Doped p-n Homojunction ZnO Nanowires: Growth Kinetics in Liquid and Their Optoelectronic Properties
(2015-06-23)
Lee, Wei-Che
;
Chen, Jul-Yuan
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Huang, Chun-Wei
;
Chiu, Chung-Hua
;
Lin, Ting-Yi
For wide-ranging applications in nanoscale electronic devices, durable and reproducible p-type nanostructures are essential. In this work, simple ZnO nano-wire (NW) p-n homojunctions were grown using a two-step hydrothermal synthesis method. P2O5 served as a doping source to obtain p-type ZnO NW\'s. The morphology of the ZnO NW arrays was examined using field emission scanning electron microscopy. The high-resolution transmission electron microscopy (HRTEM) image indicated that the ZnO NW p-n homojunction is single-crystalline with a < 0001 > growth direction. The distribution of P element was analyzed using energy-dispersive spectroscopy. The dynamic growth observation was conducted using liquid in situ TEM to investigate the ZnO nucleation and growth mechanism. We divided the ZnO nanocrystal precipitation into three processes. Whether two adjacent particles grow stably or not was found to be related to the distance. Moreover, the temperature-dependent photoluminescence spectra revealed that two extra emission peaks located at 416 and 435 nm were emitted from the ZnO NW p-n homojunction, which resulted from donor-acceptor recombination. In addition, the electron transport properties confirmed the rectification behavior of the multi ZnO NW p-n homojunctions. The turn-on voltage and the current were approximately 2.8 V and 10(-4) to 10(-5) A, respectively, under forward bias. The results indicate the potential application of ZnO NW p-n homojunctions as nanoscale light-emitting diodes.
Tailoring low-dimensional structures of bismuth on monolayer epitaxial graphene
(2015-06-23)
Chen, H. -H.
;
Su, S. H.
;
Chang, S. -L.
;
Cheng, B. -Y.
;
Chen, S. W.
To improve graphene-based multifunctional devices at nanoscale, a stepwise and controllable fabrication procedure must be elucidated. Here, a series of structural transition of bismuth (Bi) adatoms, adsorbed on monolayer epitaxial graphene (MEG), is explored at room temperature. Bi adatoms undergo a structural transition from one-dimensional (1D) linear structures to two-dimensional (2D) triangular islands and such 2D growth mode is affected by the corrugated substrate. Upon Bi deposition, a little charge transfer occurs and a characteristic peak can be observed in the tunneling spectrum, reflecting the distinctive electronic structure of the Bi adatoms. When annealed to similar to 500 K, 2D triangular Bi islands aggregate into Bi nanoclusters (NCs) of uniform size. A well-controlled fabrication method is thus demonstrated. The approaches adopted herein provide perspectives for fabricating and characterizing periodic networks on MEG and related systems, which are useful in realizing graphene-based electronic, energy, sensor and spintronic devices.
Photon doughnut-shaped pair for easy production of entangled photon pairs
(2015-06-29)
Lo, Hsin-Pin
;
Yabushita, Atsushi
;
Kobayashi, Takayoshi
;
電子物理學系
;
Department of Electrophysics
Parametric down-conversion in a nonlinear crystal-generated photon pair in which photons have orthogonal polarization. The pair was emitted in a cone shape for each polarization and collimated by a lens to be doughnut shaped. The doughnutlike photon pair runs collinear to the pump laser. The group delay and walk-off between the orthogonal polarization photons in the pair were compensated passing through a half-wave plate and a nonlinear crystal. Then, the photon doughnut pair was coupled into a 1 x 2 fiber together with a pump laser, i.e., the intense pump laser was used as a guide for alignment. After the alignment was finished, a cut filter was inserted in the optical path to cut the pump laser transmitting the photon doughnut pair. The coincidence measurement of the output of the 1 x 2 fiber showed that the photon pairs are entangled in polarization.
Electrically tunable microlens arrays based on polarization-independent optical phase of nano liquid crystal droplets dispersed in polymer matrix
(2015-06-29)
Yu, Ji Hoon
;
Chen, Hung-Shan
;
Chen, Po-Ju
;
Song, Ki Hoon
;
Noh, Seong Cheol
Electrically tunable focusing microlens arrays based on polarization independent optical phase of nano liquid crystal droplets dispersed in polymer matrix are demonstrated. Such an optical medium is optically isotropic which is so-called an optically isotropic liquid crystals (OILC). We not only discuss the optical theory of OILC, but also demonstrate polarization independent optical phase modulation based on the OILC. The experimental results and analytical discussion show that the optical phase of OILC microlens arrays results from mainly orientational birefringence which is much larger than the electric-field-induced birefringence (or Kerr effect). The response time of OILC microlens arrays is fast similar to 5.3ms and the tunable focal length ranges from 3.4 mm to 3.8 mm. The potential applications are light field imaging systems, 3D integrating imaging systems and devices for augment reality. (C) 2015 Optical Society of America
On-line monitoring of Soxhlet extraction by chromatography and mass spectrometry to reveal temporal extract profiles
(2015-06-30)
Chen, Ssu-Ying
;
Urban, Pawel L.
;
應用化學系
;
應用化學系分子科學碩博班
;
Department of Applied Chemistry
Soxhlet extraction is a popular sample preparation technique used in chemical analysis. It enables liberation of molecules embedded in complex matrices (for example, plant tissues, foodstuffs). In most protocols, samples are analyzed after the extraction process is complete. However, in order to optimize extraction conditions and enable comparisons between different types of extraction, it would be desirable to monitor it in real time. The main development of this work is the design and construction of the interface between Soxhlet extractor and GC-MS as well as ESI-MS system. The temporal extract profiles, obtained in the course of real-time GC-MS monitoring, have been fitted with mathematical functions to analyze extraction kinetics of different analytes. For example, the mass transfer coefficients of pinene, limonene and terpinene in lemon sample, estimated using the first-order kinetic model, are 0.540 h(-1), 0.507 h(-1) and 0.722 h(-1), respectively. On the other hand, the Peleg model provides the following extraction rates of pinene, limonene and terpinene: 0.370 nM h(-1), 0.216 nM h(-1) and 0.596 nM h(-1), respectively. The results suggest that both first-order kinetic and Peleg equations can be used to describe the progress of Soxhlet extraction. On-line monitoring of Soxhlet extraction reveals extractability of various analytes present in natural samples (plant tissue), and can potentially facilitate optimization of the extraction process. (C) 2015 Elsevier B.V. All rights reserved.
Delirium, Subsyndromal Delirium, and Cognitive Changes in Individuals Undergoing Elective Coronary Artery Bypass Graft Surgery
(2015-07-01)
Li, Hsiu-Ching
;
Chen, Yih-Sharng
;
Chiu, Ming-Jang
;
Fu, Mei-Chiung
;
Huang, Guan-Hua
Background: The course of incident delirium and subsyndromal delirium (SSD) after cardiac surgery is not well studied. Objective: The aim of this study was to evaluate the course of incident delirium and SSD, their risk factors, and impact on patients\' cognitive function after elective coronary artery bypass graft (CABG) surgery. Methods: Consecutive patients scheduled for an isolated CABG at a tertiary medical center in Taiwan were enrolled if they had no preoperative delirium symptoms. Delirium was assessed daily for 1 week after surgery using the Confusion Assessment Method. Subsyndromal delirium was defined as presenting with any core symptom below the diagnostic threshold for delirium. Cognitive function was assessed by the Mini-mental State Examination. Results: Of 38 participants, 7 had incident (first-time) delirium (18.4% incidence) and 13 had incident SSD (34.2% incidence). Whereas SSD usually lasted 1 day, delirium changed gradually to SSD to recovery and its symptomatology lasted longer. We identified 6 delirium risk factors: older age, more comorbidities, cardiac pulmonary bypass, blood transfusion, larger transfusion volume, and longer duration of intraoperative blood pressure less than 60 mm Hg. The frequencies of these risk factors for SSD were often intermediate between those of risk factors in groups with and without delirium. By hospital discharge, participants with delirium had the longest hospital stays and lowest cognitive scores, those with SSD had intermediate stays and scores, and those without delirium had the lowest stays and scores. Conclusion: Delirium and SSD after CABG are common. Greater number and severity of risk factors for delirium may predict increasingly poor outcomes, with the dose-response relationship between risk factors and outcomes for SSD intermediate between that for no symptoms and full delirium. Intervention trials are indicated, particularly for patients with a greater number and severity of predisposing and precipitating risk factors.
Investigation of no analogue-equalization and blue filter for 185 Mbps phosphor-LED wireless communication
(2015-07-01)
Yeh, C. H.
;
Chow, C. W.
;
Liu, Y. L.
;
Chen, H. Y.
;
Liu, Y.
In this demonstration, we first propose an optimal analogue front end circuit without employing pre-equalization (series peaking) to increase the modulation bandwidth of phosphor-LED in visible light communication (VLC) transmission. And there is no blue filter and post-equalization in the client side. Here, only using optimal adjustment of resistance (R), inductance (L), and capacitance (C) in bias-tee to compensate the impedance matching of phosphor-LED, nearly 32 MHz modulation bandwidth can be accomplished. Therefore, utilizing orthogonal frequency division multiplexed modulation with bit-loading algorithm in VLC system, 185 Mbps data rate can be achieved under a transmission distance of 80 cm.
An investigation of unsteady flow reversal of natural convection in vertical parallel plates by the modified local one-dimensional inviscid relations method
(2015-07-01)
Fu, Wu-Shung
;
Huang, Shang-Hao
;
Li, Chung-Gang
;
機械工程學系
;
Department of Mechanical Engineering
An unsteady flow reversal of natural convection in vertical parallel plates with an asymmetrically heated wall is investigated numerically. For clarifying the occurrence of flow reversal, the width of the plates is regarded as a variable, and the non-reflecting boundary condition is adopted at apertures. The methods of the Roe scheme, preconditioning and dual time stepping matching LUSGS are siinultaneously used to solve governing equations which are available for a low speed compressible flow problem. The flow reversal is observed under broad width situations and absent under narrow width situations. Distributions of the pressure differences at the apertures are revealed to indicate the occurrence of flow reversal. The present Nusselt numbers, which mean time and area-averaged ones, display relatively good agreement with those of the existing works. (C) 2015 Elsevier Ltd. All rights reserved.
具容忍變異字元線驅動抑制機制之隨機存取記憶體
(2015-07-01)
莊景德
;
林宜緯
;
陳家政
;
石維強
一種隨機存取記憶體，包含：複數個列，每一該列包含複數個記憶單元及一對應的字元線；各該記憶單元包含一個用於儲存資料的閂鎖器以及至少一閘通電晶體，耦接於該閂鎖器、該對應字元線與一對應位元線之間；複數個字元線驅動器，每一該字元線驅動器包含一電源端、一驅動端、一輸入端及一驅動電晶體；該電源端接收一工作電壓，該驅動端耦接該些列的該些字元線的其中之一，該輸入端接收一解碼訊號，該驅動電晶體包含一控制端與兩通道端，分別耦接該輸入端、該驅動端與該電源端；至少一第一追隨電晶體，各該第一追隨電晶體對應該些字元線驅動器的其中之一，包含兩通道端；其中一通道端耦接該對應字元線驅動器的該電源端及該驅動端的其中之一；該第一追隨電晶體的電子特性追隨該對應字元線驅動器中該驅動電晶體的電子特性；以及至少一第二追隨電晶體，包含一通道端，耦接該第一追隨電晶體的該兩通道端的其中之一；該第二追隨電晶體的電子特性追隨該些記憶單元中該些閘通電晶體的電子特性。