Browsing by Issue Date, starting with "2008-06-15"

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Characterization and properties of infrared NLO crystals: AGeX(3) (A = Rb, Cs; X = Cl, Br)
(2008-06-15)
Lin, Zhi-Guang
;
Tang, Li-Chuan
;
Chou, Chang-Pin
;
機械工程學系
;
Department of Mechanical Engineering
innovative infrared nonlinear optical crystals AGeX(3) were synthesized. Their powder X-ray diffraction patterns demonstrated that they had rhombohedral structures with R3m (no. 160) space group symmetry (except RbGeBr3). Their structural distortion increased with Br content, but decreased with Rb content. The Kurtz powder methods revealed that the nonlinear optical efficiency of CsGeBr3 is 9.64 times that of rhombohedral CsGeCl3 and 28.29 times that of KDP; most importantly, AGeX(3) is phasematchable (except RbGeBr3). (C) 2008 Elsevier B.V. All rights reserved.
Mechanical properties of InGaN thin films deposited by metal-organic chemical vapor deposition
(2008-06-15)
Jian, Sheng-Rui
;
Jang, Jason Shian-Ching
;
Lai, Yi-Shao
;
Yang, Ping-Feng
;
Yang, Chu-Shou
We report in this study characteristics of InGaN thin films developed by metal-organic chemical vapor deposition (MOCVD) at various growth temperatures. The effect of deposition temperatures on microstructures and mechanical properties are examined using X-ray diffraction (XRD), scanning probe microscopy (SPM), and nanoindentation techniques. The XRD analysis shows no evidence of phase separation for InGaN thin films. The SPM micrographs indicate that the films have relatively smooth surfaces. Hardness and Young's modulus of InGaN thin films vary according to the deposition temperature. As the deposition temperature increases from 730 to 790 degrees C, the grain size increases from 28 to 52 nm. Hardness for InGaN thin films dropped from 13.8 to 17.6 GPa in accordance with the increase of the grain size. By fitting experimental data with the Hall-Petch equation, a probable lattice friction stress of 3.48 GPa and Hall-Petch constant of 73.15 GPa nm(1/2) are obtained. (C) 2007 Elsevier B.V. All rights reserved.
Design and analysis of an orientation estimation system using coplanar gyro-free inertial measurement unit and magnetic sensors
(2008-06-15)
Kao, C. F.
;
Chen, T. L.
;
機械工程學系
;
Department of Mechanical Engineering
Conventionally, there are two ways to determine the orientation angles of an object. One uses 3-axis accelerometers and 3-axis magnetic sensors, while the other one uses additional 3-axis gyroscopes to achieve a higher sensing accuracy than the first one. This paper presents a novel orientation estimation system that uses seven single-axis linear accelerometers and 3-axis magnetic sensors. These seven linear accelerometers are deployed in a way to form a "coplanar" gyro-free inertial measurement unit (IMU). As such, they can perform the integrated measurements of gravity force and angular velocity for the subsequent sensor fusion algorithms. With the information of the angular velocity, this novel design achieves a comparable performance with the one that includes 3-axis gyroscopes. The analysis of the system observability indicates that the angular velocity measurements can improve the observability of the angle estimation under certain circumstances. This result suggests the possibility of using fewer sensors in an orientation estimation system. Simulation results indicate that the proposed design achieve a sensing accuracy of 0.11 degrees, 0.09 degrees, and 0.2 degrees for the roll, pitch, and yaw angle; this leads to the improvement of 540%, 632%, and 754% over the one that does not include the measurement of the angular velocity. (C) 2008 Elsevier B.V. All rights reserved.
Degradation kinetics of di-(2-ethylhexyl) phthalate (DEHP) and organic matter of sewage sludge during composting
(2008-06-15)
Cheng, Hsiao-Fen
;
Kumar, Mathava
;
Lin, Jih-Gaw
;
環境工程研究所
;
Institute of Environmental Engineering
The potential degradation of di-(2-ethylhexyl) phthalate (DEHP) and organic matter of sewage sludge by composting was investigated using laboratory reactor at different operating conditions (E-1, E-2 and E-3). In all conditions, single stage thermophilic phase was observed within 2 days and almost, 60% of DEHP was degraded under this phase. At the end of composting, total DEHP degradation of more than 85% was observed in all conditions and total carbon reduction was 11.8% in E-1, 7.6% in E-2 and 10.8% in E-3. Similar trend was observed in the degradation of total nitrogen. The reduction of volatile solids (VS) in the composting reactors was 5.4% in E-1 (18 days), 5.5% in E-2 (12 days) and 4.3% in E-3 (18 days). The degradation kinetics of DEHP in thermophilic phase (including initial mesophilic phase) and the phase there after were determined by first order and fractional power kinetics, respectively. The significance of experimental parameters in DEHP degradation was assessed by Pearson correlation approach. Elevated temperature produced during composting was effective for the rapid degradation of DEHP from sewage sludge compared to mesophilic treatment. (c) 2007 Elsevier B.V. All rights reserved.
俺不說
(2008-06-15)
管管
Energy-dependent carrier relaxation in self-assembled InAs quantum dots
(2008-06-15)
Ling, H. S.
;
Lee, C. P.
;
Lo, M. C.
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Selective excitation photoluminescence spectroscopy was employed to study InAs/GaAs self-assembled quantum dots (QDs). Under different excitation energies, different groups of QDs are selected and then emit light. The excited carriers relax to the ground state through different mechanisms when excited at different energies. Three distinct regions with different mechanisms in carrier excitation and relaxation are identified in the emission spectra. These three regions can be categorized from high energy to low energy, as continuum absorption, electronic state excitation, and multiphonon resonance. The special joint density of state tail of the QD that extends from the wetting layer band edge facilitates carrier relaxation and is posited to explain these spectral results. (C) 2008 American Institute of Physics.
俺不說
(2008-06-15)
管管
俺不說
(2008-06-15)
管管
Conducting polymer blends prepared from polyaniline with n-dodecylbenzenesulfonic acid zinc salt as the secondary dopant
(2008-06-15)
Chao, Liang
;
Han, Yu-Kai
;
Hiseh, Bi-Zen
;
Huang, Ying-Jie
;
Hsieh, Tar-Hwa
A red-shift of the UV-vis spectra of n-dodecylbenzenesulfonic acid doped polyaniline (PANI (DBSA)(0.5)), resulting from the secondary doping of polyaniline backbones, was found in the presence of n-dodecylbenzenesulfonic acid zinc salt (Zn(DBS)(2)). It is proved to behave as steric hindrance spacers to induce the extension of the conjugation length through the straightening effect on the polyaniline backbones and the obtained mixtures (PANI(DBSA)(0.5) plus Zn(DBS)(2)) can be used as master batch materials (MB-13) for blending with regular polypropylene polymer (PP). The thermal degradation accompanied with loss of conductivity for MB-13 can be delayed to over 250 degrees C.when enough Zn(DBS)(2) was secondarily doped on PANI(DBSA)0.5., which allow the performance of its blending with other nonconducting/regular polymers possible. Below 80 rpm, increasing shear rates would induce higher viscosity difference between the MB-13 and PP matrix, resulting in elongation of MB-13 in the PP matrix and higher conductivities of the polyblends. The deviation from the Taylor equation, which is used to estimate the degree of elongation for a polyblend, started when shear rate is over 80 rpm. The leakage of Zn(DBS)(2) out of MB-13 can be confirmed by comparing the DSC thermograms and X-ray diffraction patterns with that of neat PP. Gradual deformation for the conductive fillers (MB-13) and a well-defined and expanded layered structure can be found when processing time is below 15 min with 60 rpm shear rate. The layers started to shrink back after 15 min of procession with the loss of the Zn(DBS)(2) from MB-13 in the PP matrix. (c) 2008 Wiley Periodicals, Inc.
俺不說
(2008-06-15)
管管
用於太陽能電池轉換光電之可溶性phenanthrenyl-imidazle材料
(2008-06-16)
韋光華
;
張耀德
一種用於太陽能電池轉換光電之可溶性phenanthrenyl-imidazle材料,經由導入phenanthrenyl-imidazole基團後,使高分子之能帶降低,證明phenanthrenyl-imidazole基團聚有增加高分子主鏈共軛長度之功能,且發光效率也降低了,顯示高分子於經由光激發光後,電子電洞之分離遠快於電子電動之結合。而光電流密度由10.8 mA/cm2(P00)提升至17.7 mA/cm2(P82),且光電轉換效率也由1.52%提升至3.48%,顯示出這系列之菲基咪唑塞酚高分子非常適用於太陽能電池上,並可一併提升光電轉換效率。
一種形成半導體深次微米線寬結構的方法
(2008-06-16)
陳仕鴻
;
連亦中
;
張翼
本發明為一種僅利用光阻顯影及斜角度蝕刻,形成半導體深次微米線寬結構的方法。首先在半導體基材表面披覆兩層光阻,控制適當的曝光能量或顯影條件,以顯影第二層光阻,而第一層光阻不被顯開。而具有下切(Under-Cut)側壁的凹槽結構可形成於第二層光阻上。再以相對於半導體基材垂直方向的斜角度,對第一層光阻進行非等向性蝕刻製程。而第二層光阻凹槽的一邊側壁,可以保護部分第一層光阻免於受到蝕刻;且本發明亦可在半導體基材表面披覆三層光阻再以上述方式進行蝕刻。於進行金屬蒸鍍與浮離(Lift-Off)製程後,可定義出金屬電極的線寬,形成具有深次微米線寬之��型閘極。
應用於點對點閘道器上之辨別及管理系統及其方法
(2008-06-16)
林柏青
;
蔡孟甫
;
張朝江
;
林盈達
;
賴源正
本發明提供一種應用於點對點閘道器上之辨別及管理系統及其方法,其係設置於核心空間(kernel space)中,並於核心空間上外掛一核心模組,使封包的前置處理及應用程式處理皆可在核心空間上完成,不需將資料複製到使用者空間再做處理,另在核心空間中設置一連線快取(connection cache)用以處理所有封包的來源/目的IP位址及連接埠號,識別出相同的重新連線請求封包並將其擋下,因此應用本發明可加速內容過濾閘道器之通過量,並提升封包處理之效率。
垂直式有機電晶體及其製造方法
(2008-06-16)
孟心飛
;
洪勝富
;
趙宇強
本發明提出一種垂直式有機電晶體及其製造方法,此種垂直式有機電晶體乃是在基板上方垂直設有射極、柵極與集極,而射極與柵極之間、多孔洞之柵極與集極之間為有機半導體層,其載子通道的長度將可簡單的由有機半導體層之厚度所決定,並使得集極電流可以由射極與柵極孔洞間的電位差所貢獻出的空間電荷電流所決定,藉以達到利用柵極電壓來有效控制集極電流之目標,且本發明垂直式有機電晶體係具有簡單製程,並無須採用光微影蝕刻技術。
用於氣體吸收之平行平板分離器
(2008-06-16)
蔡春進
;
林冠宇
本發明為一種高效率的平板式濕式分離器,它的氣體吸收表面主要由兩片親水性多孔玻璃平板所組成,其表面塗敷TiO2微粒並照射UV光可進一步產生一個超親水性的表面,有利於平板表面之均勻水膜的形成及氣體吸收效率的提升。本發明可用於人工的酸鹼氣體採樣裝置,酸鹼氣體吸收控制設備,氣體-微粒分離採樣設備,並可結合離子層析儀作成半自動酸鹼氣體-微粒的分離採樣儀器。
Polarized light emission from photonic crystal light-emitting diodes
(2008-06-16)
Lai, Chun-Feng
;
Chi, Jim-Yong
;
Yen, Hsi-Hsuan
;
Kuo, Hao-Chung
;
Chao, Chia-Hsin
We have experimentally studied polarization characteristics of the two-dimensional photonic crystal (PhC) light-emitting diodes (LEDs) using an annular structure with square lattice and observed a strong polarization dependence of the lattice constant and orientation of the PhC. The extracted light from the GaN PhC LEDs has P/S ratios of 5.5 (similar to 85% polarization light) for light propagating in the Gamma X direction and 2.1 (similar to 68% polarization light) for the Gamma M direction, respectively. Based on the couple mode theory, the dependence of polarization behaviors on different lattice constant and orientation was found to be in good agreement with theoretical discussion.
Fiber Bragg grating sensored segmented deflectometer for ground displacement monitoring
(2008-06-17)
Huang
;
An-Bin
;
Ho
;
Yen-Te
The invention provides a monitoring device mainly for sensing ground displacement, including the fiber Bragg grating sensored deflectometer and the signal interrogator/computer system. The device uses a segmented design that consists of a flexible tube (referred to as the flexible segment) and two rigid segments and thus referred to as the double hinged FBG segmented deflectometer (DH-FBG-SD). For field installation, multiple DH-FBG-SD units are connected together to form a string as it is inserted into a grouted-in-place inclinometer casing. The distortion of the inclinometer casing induced by ground movement causes relative rotation of the inserted DH-FBG-SD. All of the DH-FBG-SD units are connected to an FBG interrogator/computer system situated on ground surface. The FBG signals are recorded and analyzed by the interrogator/computer system.
Relational analysis between parameters and defects for electron beam welding of AZ-series magnesium alloys
(2008-06-19)
Chi, Chao-Ting
;
Chao, Chuen-Guang
;
Liu, Tzeng-Feng
;
Wang, Che-Chung
;
材料科學與工程學系
In the last half century, lightweight magnesium alloy has gradually shifted from military applications to civil applications. More noteworthy is that its low melting point, high thermal conductivity, and superior fluidity are good for weld pool flow and welding parameter research. This paper presents a novel approach to these characteristics, which analyzes the influences of electron beam welding parameters on weldment strength and defect formation by linking Taguchi's method with the grey relational analysis. Not only are the parameter contribution and the defect weight individually quantified, but also the relationship between welding parameters and defect dimensions can also be obtained this way. Crown Copyright (C) 2008 Published by Elsevier Ltd. All rights reserved.
Sodium niobate nanowire and its piezoelectricity
(2008-06-19)
Ke, Tsung-Ying
;
Chen, Hsiang-An
;
Sheu, Hwo-Shuenn
;
Yeh, Jien-Wei
;
Lin, Heh-Nan
Nanowires of crystalline orthorhombic sodium niobate (NaNbO3) with diameters of approximately 100 nm and lengths of several to hundreds of microns, as well as cubes with edges of lengths of hundreds of nanometers were obtained by reacting niobium oxide (Nb2O5) with 10 and 12.5 M NaOH solutions, respectively. The microstructures of the synthesized wiry and cubic piezoelectric materials were investigated, and the details of the reactions were elucidated as well. The piezoelectricity of individual NaNbO3 (Pbma) nanowires was confirmed by piezoresponse force microscopy, and an effective piezoelectric coefficient along the vertical direction of around a few pm/V was obtained. To our knowledge, the present work is the first report of the preparation of NaNbO3 nanowires as well as the determination of piezoelectricity.
Image Processing System For Integrating Multi-Resolution Images
(2008-06-19)
Hung, Yi-Ping
;
Yeh, Wei-Shian
The image processing system for integrating multi-resolution images mainly applies several different multi-resolution image capture devices to extract the images from the observed scene and using the multi-resolution imaging devices to present the scene images relative to the observed scenes, respectively, by means of integration. In order to present a seamless image according to two different-resolution image sources, the coordinate conversions among the image capture devices, and among the imaging devices are mainly applied to extract and present the entire image to be able to resemble of having a single image capturing source and a single imaging source.