Browsing by Issue Date, starting with "2007-08-02"

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Ultra broad-band low noise amplifier utilizing dual feedback technique
(2007-08-02)
Fu, Chang-Tsung
;
Kuo, Chien-Nan
This invention relates to a low noise amplifier, used in radio frequency integrated circuit design, especially low noise amplifiers for ultra broad-band wireless communication, comprising at least a transistor of the core circuit of a low noise amplifier structure, a transformer that is implemented on the chip, in order to form a dual feedback amplifier, that is, an amplifier structure comprising an inductive feedback and a capacitive feedback, wherein the capacitive feedback is used for the low and medium frequency range, while the inductive feedback is used for the high frequency range. By assembling an amplifier circuit with these two feedback paths, it is possible to provide a broadband and good impedance matching at the signal input end of the circuit. The low noise amplifier circuit structure of the present invention is able to provide optimal conditions for broadband input impedance matching and broadband noise optimum; besides significantly increasing the gain and gain flatness, there are also huge improvements to the noise performance and the cost-down on fabrication, and the energy consumption can also be maintained at a very low level.
Selective enrichment of ochratoxin A using human serum albumin bound magnetic beads as the concentrating probes for capillary electrophoresis/electrospray ionization-mass spectrometric analysis
(2007-08-03)
Hong, Chen-Yu
;
Chen, Yu-Chie
;
應用化學系
;
應用化學系分子科學碩博班
;
Department of Applied Chemistry
Ochratoxin A (OTA) is a toxicant commonly present in many food products. Conventionally, immuno-affinity analysis is applied to rapidly screen the presence of OTA in food. However, antibodies are expensive. In this study, we present a new approach for selectively enriching OTA from aqueous samples using human serum albumin (HSA) bound magnetic beads as the affinity probes, followed by the analysis of CE/ESI-MS. In addition to demonstrating the feasibility of using the affinity probes to concentrate OTA, we also propose a rapid concentration and elution method for extraction, that is, OTA are extracted from aqueous samples by pipetting the samples in and out of a sample vial for 1 min followed by elution with pipetting for another minute. On the basis of the magnetic property, the affinity magnetic probe-target species could be rapidly isolated from the solution during the process of extraction and elution by magnetic separation. CE/ESI-MS, coupled by the electrodeless/sheathless interface, is used for the analysis of the samples. As this method features speed and cost-effectiveness, it is suitable for the purpose of rapid screening. In fact, the lowest detection limit for OTA is similar to 4 x 10(-3) mg/L. (c) 2007 Elsevier B.V. All rights reserved.
On the enhancement of field emission performance of ultrananocrystalline diamond coated nanoemitters
(2007-08-06)
Tzeng, Yu-Fen
;
Lee, Yen-Chih
;
Lee, Chi-Young
;
Lin, I.-Nan
;
Chiu, Hsin-Tien
Ultrananocrystalline diamond (UNCD) nanoemitters were synthesized by a microwave plasma enhanced chemical vapor deposition process using silicon nanowires (SiNWs) as the template. Preseeding markedly enhances the nucleation of diamond on the SiNW templates, resulting in UNCD grains of smaller size and uniform distribution, which leads to significantly improved electron field emission (EFE) properties. The EFE for UNCD nanoemitters can be turned on at (E(0))(UNCD-NE)=4.4 V/mu m, achieving large EFE current density, (J(e))(UNCD-NE)=13.9 mA/cm(2) at an applied field of 12 V/mu m, which is comparable with that of carbon nanotubes, but with much better processing reliability. (c) 2007 American Institute of Physics.
交大e-News第007期
(2007-08-06)
Secretariat
;
國立交通大學秘書室
Suppression of Schottky leakage current in island-in amorphous silicon thin film transistors with the Cu/CuMg as source/drain metal
(2007-08-06)
Wang, M. C.
;
Chang, T. C.
;
Liu, Po-Tsun
;
Xiao, R. W.
;
Lin, L. F.
The feasibility of using Cu/CuMg as a source/drain metal for the island-in amorphous silicon thin film transistors (a-Si:H TFTs) has been investigated. The issue of adhesion between the Cu film and n(+)-a-Si layer has been overcome by introducing the Cu/CuMg alloy. Furthermore, the suppression of Schottky leakage current in metal/a-Si:H structure was also observed in the island-in a-Si:H TFT. The island-in a-Si:H TFT exhibited the mobility of 0.52 cm(2)/V s, the subthreshold slope of 0.78 V/decade, and the V-th of 3.02 V. The experimental result also showed superior performance of the a-Si:H TFT with minimal loss of critical dimension and good thermal stability.
Growth of polycrystalline tubular silicon carbide Yajima-type reaction at the vapor-solid interface
(2007-08-07)
Wang, Chia-Hsin
;
Lin, Huang-Kai
;
Ke, Tsung-Ying
;
Palathinkal, Thomas-Joseph
;
Tai, Nyan-Hwa
Polycrystalline tubular SiC on Si is prepared by reacting MeSiHCl2 vapor and Ca thin film on Si at 773-923 K followed by heat treatment at 1273 K. The reaction is a solvent-free Yajima-type process taking place at the vapor-solid interface. The products phase-segregate into a cable-like radial heterostructure composed of a core of CaCl2 and a shell of SiCxHy. After removal of the CaCl2 core, the layer of polycrystalline SiC tubes on Si can emit electrons at a low applied field of 2.5 V/mu m with a current of 10 mu A/cm(2).
真空紫外線を励起光とする赤色蛍光材料およびその製造方法
(2007-08-09)
陳登銘
;
呉佳蓁
【課題】高い発光輝度、および色飽和度を備える赤色蛍光材料を提供する。【解決手段】真空紫外線を励起光とする赤色蛍光材料であって、その化学式は（Ｙ１－ｒ－ｓＧｄｓ）（Ｖ１－ｔＰｔ）Ｏ４：ｒＥｕで表わされる。式中において、０≦ｒ≦０．５、０＜ｓ＜１、０＜ｔ＜１である。本発明による赤色蛍光材料は、プラズマテレビ、バックライトまたは照明灯具などに使用することができ、さらに高い発光輝度および色飽和度を備える。【選択図】図１
Syntheses and characterizations of the multiple morphologies formed by the self-assembly of the sernicrystalline P4VP-b-PCL diblock copolymers
(2007-08-10)
Chan, Shih-Chi
;
Kuo, Shiao-Wei
;
Lu, Chu-Hua
;
Lee, Hsin-Fang
;
Chang, Feng-Chih
A series of semicrystalline diblock copolymers of poly(4-vinylpyridine-b-epsilon-caprolactone) (P4VP-b-PCL) have been synthesized by the living ROP of CL followed by the TEMPO polymerization of 4-VP. Depending on the relative block length and different solvent compositions, these copolymers self-assemble into different supramolecular structures in toluene/dichloromethane (DCM) solution, including spherical micelles, bowl-shaped vesicles, multilayer vesicles, porous spheres, and large compound micelles. In methanol/DCM solution system, the crystalline PCL core disturbs the balance of free energy, thus results in a series of morphological changes including spherical micelles, worm-like rods, vesicles, coexisted vesicles and lamella, and finally platelet lamella. (c) 2007 Elsevier Ltd. All rights reserved.
處理含氮有機廢水之方法
(2007-08-11)
林志高
;
鄭宏邦
本發明係提供一種封閉式硫循環系統，其係結合自營性與異營性脫硝處理程序、回收硫酸根並予以再利用之封閉式硫循環廢水處理系統。具體而言，本發明提供一種處理含氮有機廢水之方法，其係用於處理含有硝酸鹽或氨氮之氮污染源、與有機碳之碳污染源的含氮有機廢水，藉由(A)廢水導入步驟、(B)同步脫硝程序處理步驟、(G)廢氣再循環利用步驟及(D)處理水排除步驟，經由使含氮有機廢水接觸與硫顆粒、活性碳顆粒來提供自營性與異營性微生物成長所需之碳、氮來源，並藉由前述成長並附著於硫顆粒與活性碳顆粒上之自營性與異營性微生物進行同步脫硝程序，來處理廢水中所含的硝酸鹽或氨氮之氮污染源、與碳污染源。
具陣列式奈米孔洞之氧化鋁薄膜的製造方法
(2007-08-11)
朝春光
;
陳建仲
;
陳蓉萱
;
郭金國
本發明提出一種具陣列式奈米孔洞之氧化鋁薄膜的製造方法，首先提供一商用鋁基材，將商用鋁基材經過退火處理，再經過電解拋光處理，以使鋁基材表面呈現鏡面效果，並接著進行陽極處理，使鋁基材表面上形成一含有奈米級之數孔洞的氧化鋁薄膜，且孔洞呈現陣列式排列，再來進行熱處理，使鋁基材產生氧化反應，而使部分較小孔洞被產生氧化反應之氧化物因自我擴散效應填滿，使得孔洞均一化，最後再進行擴孔處理，以使孔洞擴張。本發明可簡化製程、便於控制製造過程之操作，並可在同時降低成本下，在氧化鋁薄膜上得出均一孔徑且具陣列式排列之奈米孔洞分佈。
Highly efficient and stable white light organic light-emitting devices
(2007-08-13)
Lin, Mei-Fang
;
Wang, Lei
;
Wong, Wai-Kwok
;
Cheah, Kok-Wai
;
Tam, Hoi-Lam
A highly efficient two-element white light organic light-emitting device with a sky blue dopant BUBD-1 and a yellow dopant TBRb was fabricated. The device achieved an electroluminescence efficiency of 17.1 cd/A and 7.9 lm/W at 20 mA/cm(2). From 112 to 32 010 nits, the CIEx,y coordinates variation was Delta(x,y)<+/-(0.01,0.01), which is superior to common white light organic light-emitting devices (OLEDs) that tend to change color with drive conditions. Moreover, the device reached a half-decay t(1/2) lifetime over 40 000 h at an initial luminance of 300 cd/m(2). This result is among the best records of fluorescent white light OLEDs. (C) 2007 American Institute of Physics.
Liquid crystal surface alignments by using ion beam sputtered magnetic thin films
(2007-08-13)
Wu, Hsin-Ying
;
Pan, Ru-Pin
;
電子物理學系
;
Department of Electrophysics
A method for liquid crystal surface alignment by using a one-step, ion beam bombardment of the glass substrates is demonstrated. Precoating by polyimide is not necessary. The authors show that the homeotropic alignment is achieved due to orientation of the diamagnetic nematogenic molecules by the magnetic field from the gamma-Fe2O3 ferrimagnetic thin films created on the substrates by ion beam bombardment. The film exhibits a high Curie temperature well above 300 K and a compensation temperature which is the typical feature of ferrimagnetism. This is a simple, noncontact, and reliable alignment method for liquid crystal devices. (C) 2007 American Institute of Physics.
Investigation of the transient symmetric H state in a pi cell
(2007-08-13)
Yang, Bo-Ru
;
Elston, Steve J.
;
Raynes, Peter
;
Shieh, Han-Ping D.
;
光電工程學系
The so-called symmetric H (H-s) state has been reported to have submillisecond response times, which results from the symmetric profile of the liquid crystal director; however, no direct evidence has been obtained to show the profile symmetry. The difficulty in proving this symmetric structure by direct observation results from the short lifetime of H-s state (typically around a few tens of milliseconds). In the work reported here, the authors utilize a burst driving method along with stroboscopic illumination from blue and red light emitting diodes to capture conoscopic images for the H-s director profile; these showed good agreement with their modeling. (c) 2007 American Institute of Physics.
Transparent photo-curable co-polyacrylate/silica nanocomposites prepared by sol-gel process
(2007-08-15)
Chou, Yen-Chun
;
Wang, Yu-Young
;
Hsieh, T.-E.
;
材料科學與工程學系
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Department of Materials Science and Engineering
This work prepared the highly transparent photo-curable co-polyacrylate /silica nanocomposites by using sol-gel process. The FTIR and C-13 NMR analyses indicated that during the sol-gel process, the hybrid precursors transform into composites containing nanometer-scale silica particles and crosslinked esters/ anhydrides. Transmission electron microscopy (TEM) revealed that the silica particles within the average size of 11.5 nm uniformly distributed in the nanocomposite specimen containing about 10 wt% of Si. The nanocomposite specimens exhibited satisfactory thermal stability that they had 5% weight loss decomposition temperatures higher than 150 degrees C and coefficient of thermal expansion (CTE) less than 35 ppm/degrees C. Analysis via derivative thermogravimetry (DTG) indicated that the crosslinked esters /anhydrides might influence the thermal stability of nanocomposite samples. The UV-visible spectroscopy indicated that the nanocomposite resins possess transmittance higher than 80% in visible light region. Permeability test revealed a higher moisture permeation resistance for nanocomposite samples, which indicated that the implantation of nano-scale silica particles in polymer matrix forms effective barrier to moisture penetration. Adhesion test of nanocomposite samples on glass substrate showed at least twofold improvement of adhesion strength compared with oligomer. This evidenced that the silica and the hydrophilic segments in nanocomposite resins might form interchains hydrogen bonds with the -OH groups on the surface of glass so the substantial enhancement of adhesion strength could be achieved. (c) 2007 Wiley Periodicals, fnc.
Electron emission properties of relaxation-induced traps in InAs/GaAs quantum dots and the effect of electronic band structure
(2007-08-15)
Chen, J. F.
;
Wang, J. S.
;
電子物理學系
;
Department of Electrophysics
The electron-emission properties of relaxation-induced traps in InAs/GaAs quantum dots (QDs) are studied in detail using capacitance-voltage (C-V) profiling and bias-dependent deep-level transient spectroscopy. Strain relaxation is shown to induce a threading-dislocation-related trap in the top GaAs layer and a misfit-dislocation-related trap near the QD. The threading trap decreases its electron-emission energy from 0.63 to 0.36 eV from sample surface toward the QD, whereas the misfit trap gradually increases its electron-emission energy from 0.28 to 0.42 eV from near the QD toward the GaAs bottom layer, indicating that both traps near the QD have lower electron-emission energies. Hence, the emission-energy change is attributed to the related traps across the QD interface where a band offset exists. The C-V profiling at 300 K shows extended carrier depletion near the QD. As temperature is increased, an electron-emission peak emerges at the QD followed by a prominent peak, suggesting that the trap responsible for the prominent peak lies in energy below the QD electron ground state. From a simulation, this trap is identified to be the misfit trap located at the QD and at the observed emission energy below the GaAs conduction band. Based on the energy location of this trap, we deduce a possible mode of strain relaxation. (C) 2007 American Institute of Physics.
Relieving Sn whisker growth driven by oxidation on Cu leadframe by annealing and reflowing treatments
(2007-08-15)
Wei, C. C.
;
Liu, P. C.
;
Chen, Chih
;
Lee, Jeffrey C. B.
;
Wang, I. Ping
Owing to environmental concern, Pb-free solders are replacing eutectic tin lead in electronic packaging industry. Thus, whisker growth becomes a serious reliability issue for Sn finishes. In this study, the mechanism of whisker growth from Sn finish on Cu leadframe was investigated under the temperature/humidity storage test. It is found that oxidation of the Sn finish was the driving force behind the whisker growth. Thermal treatments including annealing at 220 degrees C and reflowing at 260 degrees C were employed to mitigate the whisker growth. It is found that both heat treatments can significantly reduce the whisker growth rate. It is speculated that the heat treatments can relieve the residual stress in the Sn finishes and can modify their grain structure, resulting in a slower oxidation rate. Thus, they can slow down the grow rate of Sn whiskers. In addition, reflowing treatment can change the columnar grain structure of the Sn film to the equiaxed grain structure in some of its regions, resulting in a lower grain boundary diffusion rate of Sn. Therefore, the reflowed sample had the lowest growth rate of Sn whiskers. (c) 2007 American Institute of Physics.
Biocompatible and detectable carboxylated nanodiamond on human cell
(2007-08-15)
Liu, Kuang-Kai
;
Cheng, Chia-Liang
;
Chang, Chia-Ching
;
Chao, Jui-I
;
生物科技學系
Surface-modified carboxylated nanometre-sized diamond (cND) has been applied for the conjugation of biological molecules such as DNA and protein. In this study, we evaluated the biocompatibility and detection of cNDs and carbon nanotubes on human lung A549 epithelial cells and HFL-1 normal fibroblasts. Treatment with 5 or 100 nm cND particles, 0.1 - 100 mu g ml(-1), did not reduce the cell viability and alter the protein expression profile in lung cells; however, carbon nanotubes induced cytotoxicity in these cells. The cNDs particles were accumulated in A549 cells, which were observed by atomic force microscopy and laser scanning confocal microscopy. Both 5 and 100 nm cNDs particles exhibited the green fluorescence and were ingested into cells. Moreover, the fluorescence intensities were increased in cells via a concentration-dependent manner after treatment with 5 and 100 nm cNDs, which can be detected by flow cytometer analysis. The fluorescence intensities of 5 nm cNDs were relative higher than 100 nm cNDs in cells at equal concentration treatment. The observation demonstrated that cND-interacting with cell is detectable by a confocal microscope, flow cytometer and atomic force microscope. These nanoparticles may be useful for further biomedical applications based on the properties of uptake ability, detectability and little cytotoxicity in human cells.
Coaxial transitions for CPW-to-CPW flip chip interconnects
(2007-08-16)
Wu, W. C.
;
Chang, E. Y.
;
Huang, C. H.
;
Hsu, L. H.
;
Starski, J. P.
A novel coaxial transition for CPW-to-CPW flip chip interconnect is presented and experimentally demonstrated. To realise the coaxial transition on the CPW circuit, benzocyclobutene was used as the interlayer dielectric between the vertical coaxial transition and the CPW circuit. The coaxial interconnect structure was successfully fabricated and RF characterised to 67 GHz. The structure showed excellent interconnect performance from DC up to 55 GHz with low return loss below 20 dB and low insertion loss less than 0.5 dB even when the underfill was applied to the structure.
Triazole-modified calix[4]crown as a novel fluorescent on-off switchable chemosensor
(2007-08-16)
Chang, Kai-Chi
;
Su, In-Hao
;
Senthilvelan, Annamalai
;
Chung, Wen-Sheng
;
應用化學系
A novel fluorescent on-off switchable chemosensor 1 with two different types of cationic binding sites is synthesized, which is composed of a triazole-modified calix[4]crown in the 1,3-alternate conformation. Among 15 metal ions examined, the fluorescence of 1 was strongly quenched by Hg2+, Cu2+, Cr3+, and Pb2+; however, the revival of emission from the strongly quenched 1 center dot Pb2+ complex was achievable by the addition of K+, Ba2+, or Zn2+ ions. Thus, metal ion exchange can trigger an on-off switchable fluorescent chemosensor.
Solar-pumped active device
(2007-08-16)
Chi, Sien
;
Chen, Nan-Kuang
;
Shy, Jow-Tsong
The present invention provides a solar-pumped active device which utilizes a holographic antenna grating on a solar energy silicon substrate to select specific diffracted wavelength and couple pump wavelength in an approximately vertical way and converge the pump wavelength to excite an optical gain medium so that an optical amplifier or a laser can be obtained. The present invention requires no big size and is flexible over the surface shape and is suitable for free space optical communications on the ground and satellite optical communications. It means that the holographic antenna grating can be applied on the top floor of a building or on the glass surface of an outer wall. If it is applied to a satellite, the present invention can be deposited on a solar energy cell substrate to form a high optical amplification so that not only the electricity required in satellite optical communications can be reduced, but also a high-speed and large capacity of data can be transferred between satellites.