Browsing by Issue Date, starting with "2013-04-12"

Now showing 1 - 20 of 31894

Infrared Absorption Spectrum of the Simplest Criegee Intermediate CH2OO
(2013-04-12)
Su, Yu-Te
;
Huang, Yu-Hsuan
;
Witek, Henryk A.
;
Lee, Yuan-Pern
;
應用化學系
The Criegee intermediates are carbonyl oxides postulated to play key roles in the reactions of ozone with unsaturated hydrocarbons; these reactions constitute an important mechanism for the removal of unsaturated hydrocarbons and for the production of OH in the atmosphere. Here, we report the transient infrared (IR) absorption spectrum of the simplest Criegee intermediate CH2OO, produced from CH2I + O-2 in a flow reactor, using a step-scan Fourier-transform spectrometer. The five observed bands provide definitive identification of this intermediate. The observed vibrational frequencies are more consistent with a zwitterion rather than a diradical structure of CH2OO. The direct IR detection of CH2OO should prove useful for kinetic and mechanistic investigations of the Criegee mechanism.
周波数逓倍器装置及びその動作方法
(2013-04-12)
郭建男
;
顏子超
Semi-analytical solution of groundwater flow in a leaky aquifer system subject to bending effect
(2013-04-12)
Yu, Chia-Chi
;
Yang, Shaw-Yang
;
Yeh, Hund-Der
;
環境工程研究所
;
Institute of Environmental Engineering
The bending of aquitard like a plate due to aquifer pumping and compression is often encountered in many practical problems of subsurface flow. This reaction will have large influence on the release of the volume of water from the aquifer, which is essential for the planning and management of groundwater resources in aquifers. However, the groundwater flow induced by pumping in a leaky aquifer system is often assumed that the total stress of aquifer maintains constant all the time and the mechanical behavior of the aquitard formation is negligible. Therefore, this paper devotes to the investigation of the effect of aquitard bending on the drawdown distribution in a leaky aquifer system, which is obviously of interest in groundwater hydrology. Based on the work of Wang et al. (2004) this study develops a mathematical model for investigating the impacts of aquitard bending and leakage rate on the drawdown of the confined aquifer due to a constant-rate pumping in the leaky aquifer system. This model contains three equations; two flow equations delineate the transient drawdown distributions in the aquitard and the confined aquifer, while the other describes the vertical displacement in response to the aquitard bending. For the case of no aquitard bending, this new solution can reduce to the Hantush Laplace-domain solution (Hantush, 1960). On the other hand, this solution without the leakage effect can reduce to the time domain solution of Wang et al. (2004). The results show that the aquifer drawdown is influenced by the bending effect at early time and by the leakage effect at late time. The results of sensitivity analysis indicate that the aquifer compaction is sensitive only at early time, causing less amount of water released from the pumped aquifer than that predicted by the traditional groundwater theory. The dimensionless drawdown is rather sensitive to aquitard's hydraulic conductivity at late time. Additionally, both the hydraulic conductivity and thickness of the aquifer are the most sensitive parameters in influencing the predicted dimensionless drawdown. (C) 2013 Elsevier B.V. All rights reserved.
Organic thin film transistors as selective sensing platforms for Hg2+ ions and the amino acid cysteine
(2013-04-15)
Ramesh, Mohan
;
Lin, Hong-Cheu
;
Chu, Chih-Wei
;
材料科學與工程學系
;
光電工程學系
In this short communication we report a sensor for divalent mercuric (Hg2+) ions that we constructed from a perylene bisimide (PBI)-based organic thin film transistor. We improved the performance of the n-channel device by positioning N,N'-dioctyl-3,4,9,10-perylenedicarboximide between the dielectric and the active layer (PSI), increasing the electron mobility (mu) from 0.002 to 0.25 +/- 0.04 cm(2) V-1 s(-1) and enhancing the on/off ratio (I-on/I-off) by two orders of magnitude (from 102 to 104). Based on a "thymine-Hg2+-thymine" mechanism and monitoring the shift in the threshold voltage (V-th), we used this transistor to discriminate Hg2+ ions from mixed ion solutions and it extended to different concentration Hg2+ solutions (from 50 to 350 mu M). By monitoring the shifts in drain current (I-DS) and V-th, we also used this bilayer device as a sensor for cysteine, a thiol-containing amino acid; the selective detection of cysteine was accompanied by a red shift in the fluorescence maximum of PBI, from 532 to 537 nm. (C) 2012 Elsevier B.V. All rights reserved.
Association of poly(N-isopropylacrylamide) containing nucleobase multiple hydrogen bonding of adenine for DNA recognition
(2013-04-15)
Yang, Hsiu-Wen
;
Chen, Jem-Kun
;
Cheng, Chih-Chia
;
Kuo, Shiao-Wei
;
應用化學系
In this study we used the poly(N-isopropylacrylamide) (PNIPAAm) as a medium to generate PNIPAAm-adenine supramolecular complexes. A nucleobase-like hydrogen bonding (NLHB) between PNIPAAm and adenine was found that changed the morphology, crystalline structure, and temperature responsiveness of PNIPAAm microgels relatively to the adenine concentrations. With increasing the adenine concentration, the PNIPAAm-adenine supramolecular complexes gradually altered their morphologies from microgel particles to thin film structures and suppressed the thermodynamical coil-to-globule transition of PNIPAAm because of the NLHB existed between the PNIPAAm amide and ester groups and the adenine amide groups (C=O center dot center dot center dot H-N and N-H center dot center dot center dot N-R), verified by FTIR spectral analysis. NLHB was also diverse and extensive upon increasing the temperature; therefore, the thermoresponsive behavior of the complexes was altered with the NLBH intensity, evaluated by the inter-association equilibrium constant (K-a) above and below their LCST. Therefore, PNIPAAm can be as a medium to recognize adenine in various concentrations, which could potentially be applied in DNA recognition. (C) 2013 Elsevier B.V. All rights reserved.
A proteomic approach to study molecular mechanisms of andrographolide-mediated degradation of Src oncoproteins.
(2013-04-15)
Liu, Sheng-Hung
;
Chen, Pei-Fen
;
Lin, Chao-Hsiung
;
Sun, Chung-Ming
;
Chi, Chin-Wen
Wireless near-infrared spectroscopy system for determining brain hemoglobin levels in laboratory animals
(2013-04-15)
Kuo, Jinn-Rung
;
Chang, Ming-Hsien
;
Wang, Che-Chuan
;
Chio, Chung-Ching
;
Wang, Jhi-Joung
Traumatic brain injury (TBI) is usually caused by brain shaking or impact. It can affect normal brain function and may even lead to disability or death. However, there are very few studies on the associated physiologic changes in humans or animals. In this study, a non-invasive, wireless multi-channel near-infrared spectroscopy (NIRS) was developed to continuously monitor the concentration change of oxyhemoglobin (HbO(2)), deoxyhemoglobin (HbR), and total hemoglobin (HbT) to elucidate changes in the physiological state of the brain during and after different strength impaction. The triphenyltetrazolium chloride (TTC) staining was also used to monitor changes of infarction volume after different strength impaction. The results indicated that the concentration changes of HbO(2) and HbT, and the changes of infarction volumes were significantly related to the impact strength. In conclusion, the status of TBI can be clinically evaluated by detecting HbO(2) and HbT changes. The system proposed here is stable, accurate, non-invasive, and mostly important wireless which can easily be used for TBI study. (C) 2013 Elsevier B.V. All rights reserved.
Spectral radius and degree sequence of a graph
(2013-04-15)
Liu, Chia-an
;
Weng, Chih-wen
;
應用數學系
;
Department of Applied Mathematics
Let G be a simple connected graph of order n with degree sequence d(1), d(2), ... , dr, in non-increasing, order. The spectral radius rho(G) of G is the largest eigenvalue of its adjacency matrix. For each positive integer l at most n, we give a sharp upper bound for rho(G) by a function of d(1), d(2), ... ,d(l), which generalizes a series of previous results. (C) 2013 Elsevier Inc. All rights reserved.
Enhanced ductility of the ZA85 magnesium alloy fabricated by equal-channel angular pressing
(2013-04-15)
Lin, Che-Yi
;
Bor, Hui-Yum
;
Chao, Chuen-Guang
;
Liu, Tzeng-Feng
;
材料科學與工程學系
Equal-channel angular pressing (ECAP) was applied to the as-cast Mg-8 wt.% Zn-5 wt.% Al (ZA85) alloy to produce a fine-grained structure with fine and uniformly distributed Mg-32 (Al, Zn)(49) (tau-phase) particles. Experiments showed that the ZA85 alloy had an initial grain size of similar to 150 mu m after casting and was significantly reduced to 4 mu m after six ECAP passes at 180 degrees C. After annealing at 300 degrees C for 1 h, the average grain size merely increased to 7.1 mu m. This thermal stability of the fine-grained structure at temperatures at or below 325 degrees C is attributed to the presence of the fine and well distributed tau-phase. It was demonstrated that ECAP processing greatly enhances ductility of the experimental alloy. By testing over a range of temperatures and strain rates, a maximum elongation to failure of 400% was obtained in the ECAP ZA85 alloy tested at 300 degrees C (0.53 T-m) with the initial strain rate of 1.0 x 10 (4) s (1). The dominant deformation mechanism for the specimens tested at 300 and 350 degrees C with the initial strain rates ranging from 1.0 x 10 (4) s (1) to 1.0 x 10 (3) s (1) is GBS controlled by grain boundary diffusion. At the higher testing temperature of 400 degrees C, the deformation mechanism for the experimental alloy is dislocation creep. (C) 2012 Elsevier B. V. All rights reserved.
Noninvasive current sensor for household appliances and compensation for installation variation
(2013-04-15)
Cheng, S. H.
;
Lin, S. F.
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The lack of natural resources requires a more efficient use of energy. This study proposes a noninvasive coil current sensor for energy efficiency in the home. The proposed sensor is used to detect current in two-wire power cords used by household appliances. Moreover, the proposed sensor has no contact with the conductors in the power cords, ensuring a safe measurement process. Mathematical models and experiments are conducted to verify the characteristics and performance of the proposed device. In addition, this study develops relevant algorithms and the method for reducing installation variation. Using the developed algorithms, the measurement errors caused by an installation gap were reduced to less than 3%. The information provided by the current sensor supports home energy management systems and encourages energy-saving behaviors for every household member, resulting in an increasingly efficient energy usage. (C) 2013 Elsevier B.V. All rights reserved.
延遲線裝置與延遲訊號方法
(2013-04-16)
許騰尹
;
賴煒棋
;
廖原德
一種延遲線裝置與延遲訊號方法在此揭露。延遲線裝置包含差動電路、延遲電路與除頻器。差動電路用以將輸入訊號的上升緣以及下降緣分別轉成脈衝而產生脈衝訊號。延遲電路包含內迴路與計數模組。脈衝訊號會驅動內迴路開始運作，當內迴路訊號繞內迴路一次時，代表內迴路延遲一預設時段並將內迴路中的內迴路訊號反相。計數模組用以控制內迴路訊號重複迴圈的次數，在脈衝訊號驅動內迴路時，計數模組開始計算，直到內迴路的重複迴圈次數至預設次數時，計數模組輸出一個延遲訊號並將所算之次數歸零且停止內迴路的運作。
多孔奈米結構之製作方法
(2013-04-16)
張原銘
;
莊振益
一種多孔奈米結構之製作方法，係藉由在一半導體基材上進行一濺鍍製程，以形成一金屬奈米網格陣列。之後，再對上述之半導體基材與金屬奈米網格陣列進行一乾蝕刻製程，以在半導體基材上形成一多孔奈米結構。利用此種製作方法，僅需兩道製程步驟，即可完成高性能之抗反射多孔矽奈米仿生結構的製作，相較於習知，可有效兼具減少繁瑣製程步驟以及具備高抗反射性之優點。
Fully-on-chip temperature, process, and voltage sensor system
(2013-04-16)
Chen Shi-Wen
;
Chang Ming-Hung
;
Hsieh Wei-Chih
;
Hwang Wei
A fully on-chip temperature, process, and voltage sensor includes a voltage sensor, a process sensor and a temperature sensor. The temperature sensor includes a bias current generator, a ring oscillator, a fixed pulse generator, an AND gate, and a first counter. The bias current generator generates an output current related to temperature according to the operating voltage of chip. The ring oscillator generates an oscillation signal according to the output current. The fixed pulse generator generates a fixed pulse signal. The AND gate is connected to the ring oscillator and the fixed pulse generator for performing a logic AND operation on the oscillation signal and the fixed pulse signal, and generating a temperature sensor signal.
Method for treating the dislocation in a GaN-containing semiconductor layer
(2013-04-16)
Lee Wei-I
;
Yeh Yen-Hsien
;
Wu Yin-Hao
;
Yu Tzu-Yi
A method for treating the threading dislocation within a GaN-containing semiconductor layer is provided. The method includes a substrate is provided. A GaN-containing semiconductor layer with the threading dislocation is formed on the substrate. An etching process with an etching gas is performed to remove the threading dislocation in the GaN-containing semiconductor layer so as to increase the efficiency for the light emitting device.
無接觸式共振器耦合之天線裝置及其方法
(2013-04-16)
鍾世忠
;
陳亞萍
提出一種整合型天線，該整合型天線包含一第一共振元件以及一第二共振元件，該第二共振元件為一輻射單元。該第一共振元件配置於一晶片上，並接收來自該晶片之一第一信號；該晶片配置於一基板上，而該第二共振元件係配置於該基板上。該第一信號具有一頻率，該第一信號因該頻率使該第一共振元件和該第二共振元件在其之間建立一非接觸式的耦合，使得該第二共振元件產生一第二信號，該第二信號藉由該第二共振元件之輻射單元輻射之。
In Situ TEM and Energy Dispersion Spectrometer Analysis of Chemical Composition Change in ZnO Nanowire Resistive Memories
(2013-04-16)
Huang, Yu-Ting
;
Yu, Shih-Ying
;
Hsin, Cheng-Lun
;
Huang, Chun-Wei
;
Kang, Chen-Fang
Resistive random-access memory (ReRAM) has been of wide interest for its potential to replace flash memory in the next-generation nonvolatile memory roadmap. In this study, we have fabricated the Au/ZnO-nanowire/Au nanomemory device by electron beam lithography and, subsequently, utilized in situ transmission electron microscopy (TEM) to observe the atomic structure evolution from the initial state to the low-resistance state (LRS) in the ZnO nanowire. The element mapping of LRS showing that the nanowire was zinc dominant indicating that the oxygen vacancies were introduced after resistance switching. The results provided direct evidence, suggesting that the resistance change resulted from oxygen migration.
自組式金屬奈米島陣列之製作方法
(2013-04-16)
張原銘
;
莊振益
;
戴鴻名
;
王浩偉
;
曾文綬
一種自組式金屬奈米島陣列之製作方法，係藉由在一半導體基材上進行一濺鍍製程，以形成一金屬奈米島陣列。利用此種製作方法，僅需單一濺鍍製程，即可完成金屬奈米島陣列的製作，相較於習知，不僅可有效減少繁瑣之製程步驟，更可進一步地節約能源、電力及製作成本。
Method for fabricating a GaN-based thin film transistor
(2013-04-16)
Chang Yi
;
Chang Chia-Hua
;
Lin Yueh-Chin
A method for fabricating a GaN-based thin film transistor includes: forming a semiconductor epitaxial layer on a substrate, the semiconductor epitaxial layer having a n-type GaN-based semiconductor material; forming an insulating layer on the semiconductor epitaxial layer; forming an ion implanting mask on the insulating layer, the ion implanting mask having an opening to partially expose the insulating layer; ion-implanting a p-type impurity through the opening and the insulating layer to form a p-doped region in the n-type GaN-based semiconductor material, followed by removing the insulating layer and the ion implanting mask; forming a dielectric layer on the semiconductor epitaxial layer; partially removing the dielectric layer; forming source and drain electrodes; and forming a gate electrode.
用於視訊監控以即時分辨前景區塊的裝置與其方法
(2013-04-16)
連振昌
;
蔡雅婷
一種即時分辨一前景區塊為移動物或陰影的方法，包含以下步驟：(a)提供時序相近且包含該前景區塊的多個訊框；(b)利用整數離散餘弦轉換來取得對應於該等訊框之該前景區塊的DC參數以及AC參數；以及(c)各別分析該DC參數與AC參數之變異情形，以分辨該此區塊代表移動物體或是陰影。
可電壓控制之光學元件及其製備方法
(2013-04-16)
劉立偉
;
陳致維
;
蘇雍仁
;
黃乙白
一種可電壓控制之光學元件，其包括：第一基板；第一導體層，設置在第一基板上；液晶層，設置在第一導體層之上；半導體層，設置在液晶層之上；第二導體層，設置在半導體層上；及第二基板，設置在第二導體層上。