Browsing by Issue Date, starting with "2006-02-07"

Now showing 1 - 20 of 63701

Manufacturing method and apparatus of fiber coupler
(2006-02-07)
Chi
;
Sien
;
Tseng
;
Shiao-Min
;
Chen
A manufacturing apparatus and method of a fiber coupler is provided. A movable electric arc is employed to fuse more than two stacked fibers for manufacturing a fiber coupler having a small size and good environment stability. It is advantageous that the fiber coupler can be used in a SDH (Synchronous Digital Hierarchy) communication system, and the method also be used to manufacture the all-fiber CWDM (Coarse Wavelength Division Multiplexing) multiplexer which covers the E-band wavelengths and the sub-components of the OADM (Optical Add/Drop Multiplexer). And, all these functions are difficult to be achieved by the conventional techniques.
Transitions of domain ordering and domain size in a spherical-forming polystyrene-block-poly(ethylene oxide) copolymer and its composites with colloidal cadmium sulfide quantum dots
(2006-02-08)
Sun, YS
;
Jeng, US
;
Liang, KS
;
Yeh, SW
;
Wei, KH
With specific annealing schemes applied to a neat polystyrene-block-poly(ethylene oxide) (SE) and its composites with cadmium sulfide quantum dots (CdS QD), we have observed microdomain structures and phase transitions in the system using temperature-resolved small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Both TEM images and SAXS results show clearly that incorporation of surfactant-tethered US QD preferentially into PEO blocks leads to increases in thermal stabilities of both bcc-packed lattice (referred as long-range order) and microdomains themselves in the sphere-forming SE/CdS composites. The bcc-packed lattice in the SE/CdS composites sustains better than that in the neat SE, during a temperature elevation to similar to 160 degrees C, at which the bcc-packed SE/CdS spheres start to transform into micelles with a short-range liquid-like order. Quantitative model analysis shows that the PEO/CdS micelles can retain their size in the SE/CdS composites up to 200 degrees C, whereas the PEO micelles shrink after the softening of the PS matrix around 100 degrees C and disassociate largely into the PS matrix of the neat SE at 160 degrees C. (c) 2005 Elsevier Ltd. All rights reserved.
Process for protecting solder joints and structure for alleviating electromigration and joule heating in solder joints
(2006-02-09)
Chen, Chih
;
Yeh, Everett Chang-Ching
;
Tu, King-Ning
This invention provides a process for protecting solder joints, comprising forming an UBM or pad metallurgy in solder joints and then further forming a small solder bump on UBM or pad metallurgy between substrate and chip. Wherein a material of high electric resistance is coated at the ends of UBM or pad metallurgy where substrate is connected to chip, as to equalize the current distribution of solder bump, therefore the electromigration resistance of solder joints is improved by suppressing the current crowding and joule heating phenomenon.
Process for manufacturing self-assembled nanoparticles
(2006-02-09)
Chen, Wei-Kuo
;
Lee, Ming-Chih
;
Chou, Wu-Ching
;
Chen, Wen-Hsiung
;
Ke, Wen-Cheng
Process for fabricating self-assembled nanoparticles on buffer layers without mask making and allowing for any degree of lattice mismatch; that is, binary, ternary or quaternary nanoparticles comprising Groups III-V, II-VI or IV-VI. The process includes a first step of applying a buffer layer, a second step of turning on the purge gas to modulate the first reactant to the lower first flow rate, then the second reactant is supplied to the buffer layer to form a metal-rich island on the buffer layer, and a third step of turning on purge gas again to modulate the first reactant to the higher second flow rate onto the buffer layer. On the metal-rich island is formed the nanoparticles of the binary, ternary or quaternary III-V, II-VI and IV-IV semiconductor material. This is then recrystallized under the first reactant flow at high temperature forming high quality nanoparticles.
Correlation between a negative group velocity and a slanted stop band in two-dimensionally periodic structures
(2006-02-10)
Hwang, RB
;
電信工程研究所
;
Institute of Communications Engineering
[1] In this paper, we employed the rigorous mode-matching method to carry out the calculation for the scattering characteristics of a two-dimensionally periodic structure made up of metallic rectangular cylinders. From the scattering characteristics, the interesting phenomenon of an anomalous dispersion was observed to possess negative group velocities. In order to understand the underlying physics involved, we begin with the investigation of the band structure associated with the corresponding structure of infinite extent; thereby, the band structures are classified into two types: vertical stop band that is mainly due to the effect of periodicity in a single direction and slanted stop band that is due to the combined effects of periodicities in two directions. Notably, the negative group velocity ( delay) within the slanted stop band of a two-dimensional periodic structure was directly related to the experimentally measurable scattering characteristics of the finite structure.
Exploration of glycosyl hydrolase family 75, a chitosanase from Aspergillus fumigatus
(2006-02-10)
Cheng, CY
;
Chang, CH
;
Wu, YJ
;
Li, YK
;
交大名義發表
A powerful endo-chitosanase ( CSN) previously described for a large scale preparation of chito-oligosaccharides ( Cheng, C.-Y., and Li, Y.-K. ( 2000) Biotechnol. Appl. Biochem. 32, 197 - 203) was cloned from Aspergillus fumigatus and further identified as a member of glycosyl hydrolase family 75. We report here a study of gene expression, functional characterization, and mutation analysis of this enzyme. Gene cloning was accomplished by reverse transcription-PCR and inverse PCR. Within the 1382-bp Aspergillus gene ( Gen-Bank (TM) accession number AY190324), two introns ( 67 and 82 bp) and an open reading frame encoding a 238-residue protein containing a 17-residue signal peptide were characterized. The recombinant mature protein was overexpressed as an inclusion body in Escherichia coli, rescued by treatment with 5 M urea, and subsequently purified by cation exchange chromatography. A time course H-1 NMR study on the enzymatic formation of chito-oligosaccharides confirmed that this A. fumigatus CSN is an inverting enzyme. Tandem mass spectrum analysis of the enzymatic hydrolysate revealed that the recombinant CSN can cleave linkages of GlcNAc-GlcN and GlcN-GlcN in its substrate, suggesting that it is a subclass I chitosanase. In addition, an extensive site-directed mutagenesis study on 10 conserved carboxylic amino acids of glycosyl hydrolase family 75 was performed. This showed that among these various mutants, D160N and E169Q lost nearly all activity. Further investigation using circular dichroism measurements of D160N, E169Q, wild-type CSN, and other active mutants showed similar spectra, indicating that the loss of enzymatic activity in D160N and E169Q was not because of changes in protein structure but was caused by loss of the catalytic essential residue. We conclude that Asp(160) and Glu(169) are the essential residues for the action of A. fumigatus endo-chitosanase.
Exploration of glycosyl hydrolase family 75, a chitosanase from Aspergillus fumigatus
(2006-02-10)
Cheng, CY
;
Chang, CH
;
Wu, YJ
;
Li, YK
;
應用化學系
A powerful endo-chitosanase ( CSN) previously described for a large scale preparation of chito-oligosaccharides ( Cheng, C.-Y., and Li, Y.-K. ( 2000) Biotechnol. Appl. Biochem. 32, 197 - 203) was cloned from Aspergillus fumigatus and further identified as a member of glycosyl hydrolase family 75. We report here a study of gene expression, functional characterization, and mutation analysis of this enzyme. Gene cloning was accomplished by reverse transcription-PCR and inverse PCR. Within the 1382-bp Aspergillus gene ( Gen-Bank (TM) accession number AY190324), two introns ( 67 and 82 bp) and an open reading frame encoding a 238-residue protein containing a 17-residue signal peptide were characterized. The recombinant mature protein was overexpressed as an inclusion body in Escherichia coli, rescued by treatment with 5 M urea, and subsequently purified by cation exchange chromatography. A time course H-1 NMR study on the enzymatic formation of chito-oligosaccharides confirmed that this A. fumigatus CSN is an inverting enzyme. Tandem mass spectrum analysis of the enzymatic hydrolysate revealed that the recombinant CSN can cleave linkages of GlcNAc-GlcN and GlcN-GlcN in its substrate, suggesting that it is a subclass I chitosanase. In addition, an extensive site-directed mutagenesis study on 10 conserved carboxylic amino acids of glycosyl hydrolase family 75 was performed. This showed that among these various mutants, D160N and E169Q lost nearly all activity. Further investigation using circular dichroism measurements of D160N, E169Q, wild-type CSN, and other active mutants showed similar spectra, indicating that the loss of enzymatic activity in D160N and E169Q was not because of changes in protein structure but was caused by loss of the catalytic essential residue. We conclude that Asp(160) and Glu(169) are the essential residues for the action of A. fumigatus endo-chitosanase.
多聲道之交越失真消除系統
(2006-02-11)
白明憲
;
董志偉
;
李志中
本發明係有關於一種多聲道交越失真消除系統，可提供範圍較廣大之愉悅點，此多聲道交越失真消除系統包括：中央處理器或數位訊號處理器，可輸入音訊輸入訊號並輸出立體聲訊號；濾波器，可輸入立體聲訊號並進行濾波處理，以輸出聲音訊號；陣列揚聲器，可輸入並傳送聲音訊號以在陣列揚聲器之前方形成愉悅點，其中濾波處理係依據多聲道交越失真消除系統及與立體聲訊號之頻率相關之正規化參數，音源訊號處理器可為中央處理器或數位訊號處理器。
晶片挾持器之改良結構
(2006-02-11)
劉安誠
;
陳仁浩
;
陳悅婷
本發明係一種晶片挾持器之改良結構，其係由下而上依序在旋轉主軸上套設錐軸襯套、錐孔襯套及晶片挾持平台，旋轉主軸藉由錐軸襯套與錐孔襯套傳遞扭矩給晶片挾持平台，由於錐軸襯套與錐孔襯套之間的配合方式，係藉由二者間相對應之錐面密合，利用斜面縮短間隙距離和圓形半徑方向對稱觀念來校正中心和密閉效果，可大幅降低一般晶片塗佈製程在高轉速的平面跳動，對於製程設計彈性有很大的助益，品質良率亦可信賴，並且提高可分離式晶片挾持器內部改良結構的壽命。
Nanoimprinting-lithography-induced self-aligned liquid crystals for novel multifunctional optical films
(2006-02-13)
Chiu, CH
;
Kuo, HL
;
Chen, PC
;
Wen, CH
;
Liu, YC
Polymerizable nematic liquid crystal (LC) was adopted as a resist for our newly developed nanoimprinting lithography process. Liquid crystal molecules were self-aligned during imprinting process without precoated alignment layer. The large patterned area was able to achieve 4x4 cm(2) at very low impriting pressure, 1.5 bar. The optical anisotropic was verified through polarized optical microscopy and the retardation was measured by polarized ultraviolet/visible spectrometer. The micrograted LC films prepared by this novel method offer the potential applications for a LC alignment layer within LC cells, as well as preparation of optical anisotropic films. (c) 2006 American Institute of Physics.
Orbital susceptibilities of PbSe quantum dots
(2006-02-14)
Jian, WB
;
Lu, WG
;
Fang, JY
;
Chiang, SJ
;
Lan, MD
Different sizes of three-dimensional PbSe quantum dots have been synthesized for the study of orbital magnetic susceptibilities. Two types of orbital susceptibilities have been found, including the Curie susceptibility and finite-size corrections to the Landau susceptibility. The Curie term of a quantum dot manifests itself in the temperature dependence of magnetic susceptibility at low temperatures, while the field dependence of differential susceptibility at high temperatures shows finite-size corrections to the Landau susceptibility. Both of the two kinds of orbital susceptibility, estimated per quantum dot, show linear dependence on the size. (c) 2006 American Institute of Physics.
Nanomechanical characterizations of InGaN thin films
(2006-02-15)
Jian, SR
;
Fang, TH
;
Chuu, DS
;
電子物理學系
;
Department of Electrophysics
InxGa1-x thin films with In concentration ranging from 25 to 34 at.% were deposited on sapphire substrate by metal-organic chemical vapor deposition (MOCVD). Crystalline structure and surface morphology of the deposited films were studied by using X-ray diffraction (XRD) and atomic force microscopy (AFM). Hardness, Young's modulus and creep resistance were measured using a nanoindenter. Among the deposited films, In0.25Ga0.75N film exhibits a larger grain size and a higher surface roughness. Results indicate that hardness decreases slightly with increasing In concentration in the InxGa1-xN films ranged from 16.6 +/- 1.1 to 16.1 +/- 0.7 GPa and, Young's modulus for the In0.25Ga0.75N, In0.3Ga0.7N and In0.34Ga0.66N films are 375.8 +/- 23.1, 322.4 +/- 13.5 and 373.9 +/- 28.6 GPa, respectively. In addition, the time-dependent nanoindentation creep experiments are presented in this article. (c) 2005 Elsevier B.V. All rights reserved.
Impact of band gap shrinkage on simulated bifurcation routes in directly modulated semiconductor lasers
(2006-02-15)
Lim, CG
;
Iezekiel, S
;
Snowden, CM
;
光電工程學系
;
Department of Photonics
A carrier heating model is derived by taking into account the various temperature processes in the active layer of laser diodes. This model is then used to simulate the static and dynamic characteristics of a directly modulated 1.55 mu m distributed-feedback laser diode. The calculated results are compared with the measured results of this device as obtained in an earlier work [H. F. Liu and W. F. Ngal, IEEE J. Quantum Electron. 29, 1668 (1993)], and this reveals the significant impact of band gap shrinkage on simulated results. This study also shows that the carrier heating model is a self-consistent model that naturally describes the gain suppression phenomena in directly modulated laser diodes. (c) 2006 American Institute of Physics.
Short time deposition kinetics of diethyl phthalate and dibutyl phthalate on a silicon wafer surface
(2006-02-15)
Kang, YH
;
Den, W
;
Bai, HL
;
環境工程研究所
;
Institute of Environmental Engineering
Short time adsorption and desorption behaviors of two alkyl phthalate esters, namely diethyl phthalate (DEP) and dibutyl phthalate (DBP), on silicon wafers exposed under various ambient concentrations were experimentally and theoretically investigated. The results showed that the surface density of DBP was significantly affected by both the length of exposure time and its ambient concentration, whereas that of DEP was only affected by its ambient concentration within the tested periods between 60 and 240 min. The determination of rate parameters for adsorption and desorption showed that the rate constants of DEP were always larger than those of DBP. Also, the sticking coefficient of DEP was larger during the initial adsorption stage due to its relatively lower molecular weight as compared to DBP. The value of the sticking coefficient for DEP, however, decreased much faster such that the value eventually became smaller than that for DBP. Therefore, for silicon wafers experiencing a short exposure time, organic compounds with lower molecular weights may be a more important source of airborne molecular contamination than those with higher molecular weights.
Continuous time Markov chains observed on an alternating renewal process with exponentially distributed durations
(2006-02-15)
Chan, WY
;
Peng, NF
;
統計學研究所
;
Institute of Statistics
A continuous time Markov chain observed on a system following the dynamic behavior of an alternating renewal process is studied. This alternating renewal process is assumed to have exponentially distributed durations. The limiting behavior of the process is examined. Examples of applications are given. (c) 2005 Published by Elsevier B.V.
影子
(2006-02-15)
管管
Inelastic interactions of electrons with cylindrical interfaces
(2006-02-15)
Tu, YH
;
Kwei, CM
;
Tung, CJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A theory was developed to deal with inelastic interactions for an electron moving parallel to the axis of a cylindrical structure. Formulas for the differential inverse inelastic mean free path (DIIMFP) and the total inverse inelastic mean free path (IIMFP) were derived using dielectric response theory. A sum-rule-constrained extended Drude dielectric function with spatial dispersion was applied to calculate DIIMFPs and IIMFPs for a solid wire and a cavity in solid. The calculated results showed that surface excitations occurred as the electron moved near the boundary either inside or outside the solid, whereas volume excitations arose only for electron moving inside the solid. It was found that the probability for surface excitations increases and that for volume excitations decreases for an electron moving close to the surface. Near the surface, the decrease in volume excitations is compensated by the increase in surface excitations. For a cavity in solid, the IIMFP inside the solid can be approximated by a constant value equal to the IIMFP for the infinite solid, except in the immediate vicinity of the cavity boundary. (c) 2005 Elsevier B.V. All rights reserved.
Series quartz crystal sensor for remote bacteria population monitoring in raw milk via the Internet
(2006-02-15)
Chang, KS
;
Jang, HD
;
Lee, CF
;
Lee, YG
;
Yuan, CJ
A remote monitoring system based on a piezoelectric quartz crystal (SPQC) sensor was developed for the determination of the bacteria population in raw milk. The system employs the Windows XP server operating system, and its programs for data acquisition, display and transmission were developed using the LabVIEW 7.1 programming language. The circuit design consists of a circuit with a piezoelectric quartz crystal (SPQC) and a pair of electrodes. This system can provide dynamic data monitoring on a web-page via the Internet. Immersion of the electrodes in a cell culture with bacteria inoculums resulted in a change of frequency caused by the impedance change due to microbial metabolism and the adherence of bacteria on the surface of the electrodes. The calibration curve of detection times against density of bacteria showed a linear correlation coefficient (R-2 = 0.9165) over the range of 70-10(6) CFU ml(-1). The sensor could acquire sufficient data rapidly (within 4 h) and thus enabled real-time monitoring of bacteria growth via the Internet. This system has potential application in the detection of bacteria concentration of milk at dairy farms. (c) 2005 Elsevier B.V. All rights reserved.
Hydrogen bonding interactions and miscibility between phenolic resin and octa(acetoxystyryl) polyhedral oligomeric silsesquioxane (AS-POSS) nanocomposites
(2006-02-15)
Kuo, SW
;
Lin, HC
;
Huang, WJ
;
Huang, CF
;
Chang, FC
We have synthesized a polyhedral oligomeric silisesquioxane (POSS) derivative containing eight acetoxystyryl functional groups [octa(acetoxystyryl)octasilsesquioxane (AS-POSS)] and then blended it with phenolic resin to form nanocomposites stabilized through hydrogen bonding interactions between the phenolic resin's hydroxyl group and the AS-POSS derivative's carbonyl and siloxane groups. One-and two-dimensional infrared spectroscopy analyses provided positive evidence for these types of hydrogen bonding interactions. In addition, we calculated the interassociation equilibrium constant, based on the Painter-Coleman association model (PCAM), between phenolic resin and POSS indirectly from the fraction of hydrogen-bonded carbonyl groups; quantitative analyses indicate that the hydroxyl-siloxane interassociation from the PCAM is entirely consistent with the classical Coggesthall and Saier (C and S) methodology. From a thermal analysis, we observed that the miscibility between phenolic and AS-POSS occurs at a relatively low AS-POSS content, which characterizes this mixture as a polymer nanocomposite system. (c) 2006 Wiley Periodicals, Inc.
製作自行聚合奈米粒之方法
(2006-02-16)
陳衛國
;
李明知
;
周武清
;
陳文雄
;
柯文政
一種用以成長奈米粒的方法，係可在任何晶格匹配度材料之緩衝層上，不需透過圖案遮罩(mask)之製作，即可自行聚合方式(self–assembled)成長包含III–V族、II–VI族或IV–IV族材料之二元、三元以上化合物之奈米粒為特徵。該方法係在基板上先成長任一種材料之緩衝層，然後於適當溫度範圍內完成週期性流量調制磊晶成長，包含：在通入第二反應物前，先通入清除氣體並調制第一反應物至較低第一莫耳流量範圍，致使通入之第二反應物得以在緩衝層上形成金屬或該高金屬含量化合物島狀物，再通入清除氣體以清除殘餘未形成金屬或高金屬含量化合物島狀物之第二反應物，再調制第一反應物至較高第二莫耳流量範圍使該金屬或該高金屬含量化合物島狀物可以形成奈米粒。最後在完成週期性流量調制磊晶成長後，於較高之成長溫度下進行再結晶化步驟，以形成結構性佳之高品質奈米粒。