Browsing by Issue Date, starting with "2007-09-13"

Now showing 1 - 20 of 59123

Wide-ratio broadband SiGe HBT regenerative frequency divider enhanced by differential TIA load
(2007-09-13)
Wei, H.-J.
;
Meng, C.
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Chang, Y.-W.
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電信工程研究所
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Institute of Communications Engineering
Well-aligned ternary Cd1-xZnxS nanowire Arrays and their composition-dependent field emission properties
(2007-09-13)
Lin, Yi-Feng
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Hsu, Yung-Jung
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Lu, Shih-Yuan
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Chen, Kuan-Tsung
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Tseng, Tseung-Yuen
Well-aligned plain CdS and ternary Cd1-xZnxS nanowire arrays were successfully fabricated via a noncatalytic and template-free metal-organic chemical vapor deposition process. The nanowires were grown on a 1 mu m thick buffer layer formed in situ on the surface of silicon substrates. These nanowires were 20-40 nm in diameter and 500-900 nm in length. High-resolution transmission electron microscopy analyses revealed that the nanowires were single-cry stalline and grew along the [0001] direction of the hexagonal crystalline phase. The photoluminescence characterizations showed near band edge emissions at 535, 498, and 473 nm for the US nanowire arrays and Cd1-xZnxS nanowire arrays with x values of 0.21 and 0.44, respectively, demonstrating clear color tunability achieved with the composition adjustment of the alloy nanowires. The same morphology. and single-crystallinity of these three nanowire arrays enabled investigation of the composition-dependent field emission characteristics of the nanowire arrays for the first time, excluding interferences originating from morphology and crystallinity related factors. The plain CdS nanowire arrays exhibited better field emission properties, a lower turn-on field, and a higher field enhancement factor than the ternary Cd1-xZnxS nanowire arrays, for which the lower resistivity of the CdS nanowires may have played an important role. An important parameter, the absolute field enhancement factor (beta(0)), to more intrinsically quantify the field emission performance of the plain US and ternary Cd1-xZnxS nanowires arrays was also studied. The values of beta(0) decreased with increasing Zn content in the ternary products. The high beta(0) values of the US based nanowire arrays, comparable to that of carbon nanotubes grown on silicon wafers, made these nanowire arrays a promising candidate material for high-performance field emitting devices.
A Method For Predicting Inductance And Self-Resonant Frequency Of A Spiral Inductor
(2007-09-13)
Chen, Chien-Chang
;
Cheng, Yu-Ting
In this invention, a closed-form integral model for on-chip freely suspended rectangular spiral inductor is presented. The model of this invention bases on the Kramers-Kronig relations, field theory, and solid state physics to characterize a spiral inductor which RFIC designers could easily have the optimal design utilizing this analytical method. Meanwhile, this model can provide satisfactory prediction to the inductance and self-resonant frequency of the spiral inductor without complicated geometry analysis. Furthermore, unlike conventional formulations only based on circuit parameters, this model could safely predict the inductance and the self-resonant frequency when altering the material (excluding ferromagnetic materials) of a spiral inductor.
High strength and high toughness alloy with low density and the method of making
(2007-09-13)
Liu, Tzeng-Feng
;
Lee, Jian-Wei
The present invention relates to a high strength and high toughness alloy with a low density and the method of making thereof. The alloy essentially comprises 15 to 33 wt % of manganese, 6 to 10 wt % of aluminum, 0.6 to 1.2 wt % of carbon, 0.1 to 1.0 wt % of silicon, and the balance of iron. The alloy has excellent properties of a density of 6.6 to 6.9 g/cm3, an elongation of 25 to 70%, and a tensile strength of 100 to 190 ksi. In particularly, and the alloy is useful for golf club heads with excellent properties. Further, the use of the alloy reduces pits and defects generated during the electroplating process of the heads. Therefore, the defect rate of the product is remarkably decreased so that the cost is reduced.
Dynamics of the F-2+CH3SCH3 reaction: A molecule-molecule reaction without entrance barrier
(2007-09-14)
Lu, Yu-Ju
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Lee, Lance
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Pan, Jun-Wei
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Witek, Henryk A.
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Lin, Jim J.
The F-2+CH3SCH3 reaction was studied with crossed molecular beam techniques and high level ab initio calculations. Significant reactivity was observed even at low collision energies, consistent with the negligible barrier height obtained from the ab initio calculations. All experimental findings are consistent with a weakly bound reaction intermediate of F-F-S(CH3)(2) structure, which possesses a special type of three-center four-electron bonding. Analogous intermediates can also explain the reactions of F-2 with CH3SH and CH3SSCH3.
Efficient algorithms for regular expression constrained sequence alignment
(2007-09-15)
Chung, Yun-Sheng
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Lu, Chin Lung
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Tang, Chuan Yi
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生物科技學系
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Department of Biological Science and Technology
Imposing constraints is an effective means to incorporate biological knowledge into alignment procedures. As in the PROSITE database, functional sites of proteins can be effectively described as regular expressions. In an alignment of protein sequences it is natural to expect that functional motifs should be aligned together. Due to this motivation, Arslan introduced the regular expression constrained sequence alignment problem and proposed an algorithm which, if implemented naively, can take time and space up to O(vertical bar Sigma vertical bar V-2 vertical bar vertical bar(4)n(2)) and O(vertical bar Sigma vertical bar(2)vertical bar V vertical bar(4)n), respectively, where Sigma is the alphabet, n is the sequence length, and V is the set of states in an automaton equivalent to the input regular expression. In this paper we propose a more efficient algorithm solving this problem which takes O(vertical bar V vertical bar(3)n(2)) time and O(vertical bar V vertical bar(2n)) space in the worst case. If vertical bar V vertical bar = O(log n) we propose another algorithm with time complexity O(vertical bar V vertical bar(2)log vertical bar V vertical bar n(2)). The time complexity of our algorithms is independent of Sigma, which is desirable in protein applications where the formulation of this problem originates; a factor of vertical bar Sigma vertical bar(2) = 400 in the time complexity of the previously proposed algorithm would significantly affect the efficiency in practice. (c) 2007 Elsevier B.V All rights reserved.
Optical method for measuring the azimuthal anchoring strength of liquid crystals using pitch values determined in imperfect samples
(2007-09-15)
Tang, Tsung-Ta
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Wu, Hsin-Ying
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Lin, Chia-Jen
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Pan, Ru-Pin
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電子物理學系
An improved Grandjean-Cano wedge method for measuring the pitch of a chiral nematic liquid crystal is demonstrated. This method is easy to implement and can yield results of high accuracy when it is used for measuring the liquid crystal surface anchoring strength.(C) 2007 American Institute of Physics.
Methods of achieving linear index-change response for narrow-band fiber Bragg grating sequential writing
(2007-09-15)
Hsu, Kuei-Chu
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Sheu, Lih-Gen
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Hsiang, Wei-Wei
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Lai, Yinchieh
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光電工程學系
This investigation elucidates the refractive index-change response of the photosensitive optical fiber to exposed UV flux. The nonlinear U-V photosensitivity deforms the index profile of FBGs on the tail edges where the writing UV flux is low. Pre-UV treatment eliminates the nonlinear index-change response and ensures the linearity of the response of subsequent grating writing. A new method that involves interference between two unequal beams in a single writing scan is proposed and demonstrated to be able to improve the index profile and the spectral response of fabricated FBGs. The procedure is stable for writing weak fiber Bragg gratings with pre-designed index profiles. (c) 2007 Elsevier B.V. All rights reserved.
聲源能量分佈可視化系統及其方法
(2007-09-16)
白明憲
;
林家鴻
;
甯攸威
本發明提供一種聲源能量分佈可視化系統及其方法,其係在求得波傳遞矩陣與窗口矩陣後,透過將波傳遞矩陣進行反逆運算,以及將反逆運算結果與窗口矩陣作相乘運算,把相乘運算結果由頻率域轉換成時間域後,建立起聲源能量分佈重建器,而在進一步利用陣列式麥克風接收聲源訊號,且使用多通道擷取裝置將聲源訊號轉換成數位聲源訊號後,讓數位聲源訊號與聲源能量分佈重建器作旋積運算,而得到一可視化之聲源能量分佈。因此,本發明提供一種聲源能量分佈可視化系統及其方法,其可獲得近場及遠場之穩態與非穩態聲源的能量分佈情形,或是任一頻帶內的聲源能量分佈情況。
低密度高強度高韌性合金材料及其製法
(2007-09-16)
劉增豐
;
李堅瑋
本發明係關於一種低密度、高强度、高韌性之合金材料及其製法。該合金材料其主要包含15~33重量百分比之錳、6~10重量百分比之鋁、0.6~1.2重量百分比之碳、0.1~1.0重量百分比之矽及其餘比例以鐵為基材之合金材料,其具有6.6~6.9g/cm^3的密度、25~70%的延伸率或100~190ksi的抗拉强度等極佳的性質,故使得該合金材料可達到高强度、低密度、高延展性及優異表面性質之高爾夫桿頭設計目的,且該合金材料更可降低高爾夫桿頭在電鍍過程中所產生的孔蝕孔洞及缺陷的發生,因此大幅降低產品的不良率及成本。
在矽（110）基板上設有壓縮應變矽鍺通道之N型金氧半電晶體架構
(2007-09-16)
羅廣禮
;
簡昭欣
;
楊宗
本發明係提供一種在矽(110)基板上設有壓縮應變矽鍺通道之N型金氧半電晶體架構,其係包括一P^-型矽(110)基板、二離子植入區用於源極與汲極、一壓縮應變矽鍺通道層與一閘極結構,其中,在P^-型矽(110)基板上成長應變矽鍺電子通道層,以使得電子在【1-10】晶格方向上的傳導有效質量降低,提高電子在【1-10】方向上的傳導速度。因此,本發明係在矽(110)基板上可製作出高電子遷移率的N型金氧半電晶體。本發明所提出的N型金氧半電晶體還可以配合矽(110)基板上之高速P型金氧半電晶體以形成高性能之互補式金氧半電晶體。
一種預測雙埠晶片懸浮螺旋式電感之感值與共振頻率的方法
(2007-09-16)
陳健章
;
鄭裕庭
本發明關於一種預測懸浮電感之共振頻率及其感値的方法。本發明係根據Kramers-Kronig relations、場論以及固態物理所推導而成之物理公式,因此RFIC的設計工程師可輕易地藉由適當的選擇與改變本方法當中之物理參數,以達到電感最佳化設計之目的。更進一步地,不同於其他方法缺乏材料之物理特性的缺點,若設計工程師必須更改電感之材料(鐵磁性材料除外)時,本發明方法亦可以成功預測其感値與共振頻率。
Anisotropy of light extraction from two-dimensional photonic crystal light-emitting diodes
(2007-09-17)
Lai, Chun-Feng
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Kuo, H. C.
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Chao, C. H.
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Hsueh, H. T.
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Wang, J.-F. T.
Anisotropic light extraction of photonic crystal (PhC) light-emitting diodes in the azimuthal direction has been investigated with an annular structure of triangular PhC lattice. The optical images of the photoluminescence light extraction are obtained with laser excitation. For increasing lattice constant, sixfold symmetric patterns with varying numbers of petals in multiples of six are observed and analyzed. A map of the anisotropy for various lattice constants and numerical apertures is constructed. Several features of light propagations associated with the PhC are observed including the focusing and collimating behaviors.(c) 2007 American Institute of Physics.
Interband transitions in sol-gel-derived ZrO2 films under different calcination conditions
(2007-09-18)
Chang, Sue-min
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Doong, Ruey-an
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環境工程研究所
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Institute of Environmental Engineering
Different types of interband transitions as well as the microstructures and O/Zr ratios in sol-gel-derived ZrO2 films calcined at elevated temperatures in air or N-2 were systematically examined to clarify the formation of different band structures in the structural ZrO2 films. Optical absorptions indicate that the structural ZrO2 films all contain direct-band transitions, while the occurrence of indirect-band and band-tail transitions, depends on O/Zr ratios. Band tails mainly result from imperfect structures in the grain boundaries and appear in the ZrO2 films with O/Zr >= 2. When the ZrO2 films are non-stoichiometric (O/Zr < 2), indirect-band transitions occur due to the folded bands caused by lattice oxygen vacancies. Monoclinic ZrO2 has two direct-band transitions with bandgaps of 5.02-5.08 and 5.83-6.01 eV. The valence-band XPS spectra indicate that an additional occupied sub-band is located above its valence band. Indirect bandgaps in the monoclinic ZrO2 films are in the range of 5.00-5.10 eV. Amorphous ZrO2 films exhibit indirect-band transitions with bandgaps of 5.01-5.47 eV followed by direct-band transitions with bandgaps of 5.90-6.12 eV. In addition, tetragonal ZrO2 contains direct bandgaps of 5.32-5.74 eV and indirect bandgaps of 4.72-5.40 eV. Size-dependent bandgaps are observed in the sol-gel-derived ZrO2 films calcined in air, while the exponential dependence of bandgaps on O/Zr ratios is obtained in the ZrO2 films calcined in N-2. The discrepancy is primarily due to different fates of oxygen vacancies resulting from different calcination atmospheres.
Controlled pulsatile drug release from a ferrogel by a high-frequency magnetic field
(2007-09-18)
Hu, Shang-Hsiu
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Liu, Ting-Yu
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Liu, Dean-Mo
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Chen, San-Yuan
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材料科學與工程學系
Loudspeaker system having sensorless bass compensation
(2007-09-20)
Bai, Ming-Shian
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Lee, Chih-Chung
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Lin, Chien-Liang
The present invention compensates bass frequency for a loudspeaker without using any sensor. The strength and stability of the loudspeaker are enhanced and the working frequency is lowered too. Adaptive loudnesses for various spaces are set. And the parameter drift owing to long-term operation is restrained as well.
交大e-News第010期
(2007-09-20)
Secretariat
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國立交通大學秘書室
Theory of time-resolved sum-frequency generation and its applications to vibrational dynamics of water
(2007-09-20)
Hayashi, Michitoshi
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Shiu, Ying-Jen
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Liang, Kuo Kan
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Lin, Sheng Hsien
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Shen, Yuan Ron
A molecular theory of time-resolved sum-frequency generation (SFG) has been developed. The theoretical framework is constructed using the coupled-oscillator model in the adiabatic approximation. This theory can treat not only the vibrational spectroscopy but also vibrational dynamics. An application of this theory is also provided for estimation of the time constants of the intermolecular vibrational energy transfer between water molecules. This approach can be used for molecular analysis of the experimental results of Shen at al. on the SFG studies of vibrational dynamics of water.
GATE DIELECTRIC STRUCTURE AND AN ORGANIC THIN FILM TRANSISTOR BASED THEREON
(2007-09-20)
Chen, Fang-Chung
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Chuang, Chiao-Shun
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Lin, Yung-Sheng
A gate dielectric structure and an organic thin film transistor based thereon, wherein the gate dielectric structure comprises: an organic-inorganic composite layer and an organic insulation layer, and the gate dielectric structure is applied to an organic thin film transistor. As the organic-inorganic composite layer of the gate dielectric structure has an organic insulation matrix blended with inorganic surface-modified particles, it can achieve a high dielectric constant. Further, as the organic insulation layer can modify the surface of the organic-inorganic composite layer, not only the leakage current is reduced, but also the crystalline structure of the organic semiconductor layer becomes more orderly. Thus, the carrier mobility is raised, the current output of the element is increased, and the performance of the element is also greatly enhanced.
嵌入式網路操控之光流影像定位全方向運動系統
(2007-09-21)
吳立偉
;
鄭榮煌
;
張永融
;
胡竹生
本發明係為一種嵌入式網路操控之光流影像定位全方向運動系統，其係為以一本體上設置複數個運動單元以及至少一嵌入式網路操控系統，且在本體朝向地面的表面上設置有至少一光流感測器(Optical Flow Sensor)，其中，在運動單元中包含一全向輪(Omni-Directional Wheel)及一馬達裝置；本體的運動係藉由運動單元提供動力，以光流感測器偵測運動狀態且產生光流感測資料，而嵌入式網路操控系統透過通訊網路，可與外部的資訊處理運算端傳輸運動資料與光流感測資料，同時，此運動系統更可連接週邊控制裝置，增加整體系統操控的便利性。由於本發明係利用光流影像偵測的定位方法，即使有輪子滑動、週遭環境變化、誤差累積等等干擾計算的因素產生，仍可獲得精準的定位結果。