Browsing by Issue Date, starting with "2009-09-05"

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Nanosecond laser preparation of C(60) aqueous nanocolloids
(2009-09-05)
Sugiyama, Teruki
;
Ryo, Sen-ichi
;
Oh, Isamu
;
Asahi, Tsuyoshi
;
Masuhara, Hiroshi
C(60) aqueous nanocolloids were prepared by irradiating a suspended aqueous solution of C(60) with intense nanosecond 532 and 355 nm laser pulses. The initial submicron crystal of C(60) was fragmented into nanoparticles, resulting in a transparent yellow solution which was followed by UV/vis absorption spectroscopy. The obtained absorption spectra were similar to those for C(60) bulk film and its nanoparticles, which have a size on the order of 10 nm, and their formation had thresholds with respect to laser fluence. The nanoparticles were confirmed by their SEM observation and by examining the centrifuging effect on the colloids, while possible photochemical decomposition was excluded by (13)C NMR analysis of 1,2-dichlorobenzene-d(4) solution, where the possible products can be dissolved in addition to C(60) nanoparticles. The present result is the first demonstration of the preparation of pure and very stable C(60) aqueous nanocolloids without any additives. The formation mechanism and potential application to biological testing and toxicity are discussed. (C) 2009 Elsevier B.V. All rights reserved.
Nanosecond laser preparation of C-60 aqueous nanocolloids
(2009-09-05)
Sugiyama, Teruki
;
Ryo, Sen-ichi
;
Oh, Isamu
;
Asahi, Tsuyoshi
;
Masuhara, Hiroshi
C-60 aqueous nanocolloids were prepared by irradiating a suspended aqueous solution of C-60 with intense nanosecond 532 and 355 nm laser pulses. The initial submicron crystal of C-60 was fragmented into nanoparticles, resulting in a transparent yellow solution which was followed by UV/vis absorption spectroscopy. The obtained absorption spectra were similar to those for C-60 bulk film and its nanoparticles, which have a size on the order of 10 nm, and their formation had thresholds with respect to laser fluence. The nanoparticles were confirmed by their SEM observation and by examining the centrifuging effect on the colloids, while possible photochemical decomposition was excluded by C-13 NMR analysis of 1,2-dichlorobenzene-d(4) solution, where the possible products can be dissolved in addition to C-60 nanoparticles. The present result is the first demonstration of the preparation of pure and very stable C-60 aqueous nanocolloids without any additives. The formation mechanism and potential application to biological testing and toxicity are discussed. (C) 2009 Elsevier B.V. All rights reserved.
Preface
(2009-09-05)
Misawa, Hiroaki
;
Tryk, Donald A.
;
Masuhara, Hiroshi
;
交大名義發表
;
National Chiao Tung University
Raman Spectra of Isotope-substituted Mitochondria of Living Budding Yeast Cells: Possible Origin of the "Raman Spectroscopic Signature of Life"
(2009-09-05)
Onogi, Chikao
;
Torii, Hajime
;
Hamaguchi, Hiro-o
;
應用化學系
;
應用化學系分子科學碩博班
The (13)C and (2)H isotope Substitution effects have been examined for the "Raman spectroscopic signature of life," a mitochondrial Raman band at 1602 cm(-1) that sharply reflects the metabolic activity of living yeast cells. The band shifts to 1542 cm(-1) with (13)C substitution and to 1599 cm(-1) with (2)H substitution. Normal mode analysis based oil a DFT calculation suggests that it originates from a C=C double bond having no hydrogen atoms attached to the carbon atoms. The in-phase C=C stretch mode of ubisemiquinone radicals (CoQ and/or CoQH*) emerges as a strong candidate for the origin of the 1602 cm(-1) band.
Mutually independent hamiltonian cycles for the pancake graphs and the star graphs
(2009-09-06)
Lin, Cheng-Kuan
;
Tan, Jimmy J. M.
;
Huang, Hua-Min
;
Hsu, D. Frank
;
Hsu, Lih-Hsing
A hamiltonian cycle C of a graph G is an ordered set < u(1), u(2,) ..., u(n(G)), u(1)> of vertices such that u(i) not equal u(j) for i not equal j and u(i) is adjacent to u(i+1) for every i is an element of {1, 2, ..., n(G) - 1} and u(n(G)) is adjacent to u(1), where n(G) is the order of G. The vertex u(1) is the starting vertex and u(i) is the ith vertex of C. Two hamiltonian cycles C(1) = < u(1), u(2), ..., u(n(G)), u(1)> and C(2) = < v(1), v(2), ..., v(n(G)), v(1)> of G are independent if u(1) = v(1) and u(i) not equal v(i) for every i is an element of {2, 3, ..., n(G)}. A set of hamiltonian cycles {C(1), C(2), ..., C(k)} of G is mutually independent if its elements are pairwise independent. The mutually independent hamiltonicity IHC(G) of a graph G is the maximum integer k such that for any vertex u of G there exist k mutually independent hamiltonian cycles of G starting at u. In this paper, the mutually independent hamiltonicity is considered for two families of Cayley graphs, the n-dimensional pancake graphs P(n) and the n-dimensional star graphs S(n). It is proven that IHC(P(3)) = 1, IHC(P(n)) = n - 1 if n >= 4, IHC(S(n)) = n - 2 if n is an element of {3, 4} and IHC(S(n)) = n - 1 if n >= 5. (C) 2009 Elsevier B.V. All rights reserved.
交大e-News第055期
(2009-09-07)
Secretariat
;
國立交通大學秘書室
A rapid and selective method for monitoring the growth of coliforms in milk using the combination of amperometric sensor and reducing of methylene blue
(2009-09-07)
Lee, Yuan-Geuy
;
Wu, Hung-Yi
;
Hsu, Chuan-Liang
;
Liang, Hong-Jen
;
Yuan, Chiun-Jye
A novel method for monitoring the growth of coliforms in milk was developed based on measuring the current change in an amperometric sensor. The sensor consists of a circuit with a homemade potentiostat and a pair of electrodes. The electrode was immersed in milk samples containing methylene blue with various concentrations of bacterial inoculums. The microbial metabolism led to the reduction of methylene blue resulting in a change of current. The time required to identify readily detectable change (detection time, DT) provided an approximate measurement of the amount of microorganisms in the initial inoculums. The sensor system used in this study has the selectivity towards coliform bacteria such as Escherichia coli and Enterobacter aerogenes. The calibration curve of DT against concentration of coliform showed a linear correlation coefficient (R(2) = 0.9192) over the range of 10(2)-10(8) CFU/mL. The sensor was able to detect the coliform bacteria at initial concentrations of 10(5) CFU/mL within 6 h, making it suitable for use in real-time monitoring of bacterial growth. This system has potential application in the detection of coliform concentration in milk at dairy farms when a proper selective media is designed. (C) 2009 Elsevier B.V. All rights reserved.
Excellence with a Soul：University of Science and Research Integrity
(2009-09-08)
曾志朗
;
開放教育推動中心
;
Open Education Office
課程日期： 2009年09月08日(二) 演講人：曾志朗政務委員內容摘要：在本次的演講，曾委員描述了許多經由現今科技快速進步，我們所能夠做到前人無法完成之創舉。藉由這些例子我們可以了解，如今先進的科技知識操縱了物理世界的生與死，人類幾乎能扮演神的角色，在這波衝擊帶來的巨大權力之下，我們又該如何自處？內容：影音實況影音(*.flv檔) 實況影音(*.wmv檔)
大學生的社會責任
(2009-09-08)
李家同
;
開放教育推動中心
;
Open Education Office
課程日期： 2009年09月08日(二) 演講人：李家同校長內容摘要：在本次的演講，李校長從人類是不斷進步中開始談起，如物質的進步、天花、小兒麻痺等傳染病的減少，而更重要的是，我們要關注社會的正義有沒有在進步。內容：影音實況影音(*.flv檔) 實況影音(*.wmv檔)
In-Situ Growing CdS Single-Crystal Nanorods via P3HT Polymer as a Soft Template, for Enhancing Photovoltaic Performance
(2009-09-08)
Liao, Hung-Chou
;
Chen, San-Yuan
;
Liu, Dean-Mo
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A novel method was used to synthesize CdS single-crystal nanorods directly in the presence of conjugated polymer poly(3-hexylthiophene-2,5-diyl) (P3FIT), where the P3HT is acting as a molecular template for geometrical manipulation of CdS nanocrystals and, in the meantime, as in efficient charge conductor in composite form. Such a templating process allows the CdS nanorods with various aspect ratios to be easily manufactured via a controlled solvency of a cosolvent Mixture, under which the conformational variation of the P3HT chain can be manipulated. The mechanism of in situ growth of high-aspect-ratio CdS nanorod is proposed based on spectroscopic analysis. A considerably improved PL quenching was detected for the nanorods and suggested a result of electronic coupling between the high-aspect-ratio CdS nanorods and the conducting polymer matrix. A photovoltaic device consisting of CdS nanorods with aspect ratio of ea. 16 and the conjugated polymer poly(3-hexylthiophene) was well assembled and showed a power conversion efficiency of as high as 2.9% under air mass (AM) 1.5 global solar conditions.
Journey from Mo-Mo Quadruple Bonds to Quintuple Bonds
(2009-09-09)
Tsai, Yi-Chou
;
Chen, Hong-Zhang
;
Chang, Chie-Chieh
;
Yu, Jen-Shiang K.
;
Lee, Gene-Hsiang
Heating K(4)Mo(2)Cl(8) and 2 equiv of Li[RC(NDipp)(2)] (R = H, Ph; Dipp = 2,6-i-Pr(2)C(6)H(3)) in tetrahydrofuran (THF) at 60 degrees C gives two paddlewheel type quadruply bonded dimolybdenum complexes, Mo(2)(mu-Cl)[Cl(2)Li(OEt(2))][mu-eta(2)-RC(N-2,6-i-Pr(2)C(6)H(3))(2)](2) (R = H (1), Ph (2)). The Mo-Mo bond lengths of 1 and 2 are 2.0875(4) and 2.0756(8) angstrom, respectively, indicating typical Mo-Mo quadruple bonds. Reduction of 1 and 2 by two electrons results in the isolation of their corresponding Mo-Mo quintuple bonded complexes, Mo(2)[mu-eta(2)-RC(N-2,6-i-Pr(2)C(6)H(3))(2)](2) (R = H (3), Ph (4)), and the Mo-Mo bond lengths dramatically decrease to 2.0187(9) angstrom (3) and 2.0157(4) angstrom (4), a consequence of the formation of the second delta bond and representing the shortest metal-metal bonds beyond the first row elements. The Mo-Mo quintuple bonding characters are corroborated by DFT calculations at the level of BP86/def2-TZVP and BP86/def2-TZVPP.
A Bipolar Host Material Containing Triphenylamine and Diphenylphosphoryl-Substituted Fluorene Units for Highly Efficient Blue Electrophosphorescence
(2009-09-09)
Hsu, Fang-Ming
;
Chien, Chen-Han
;
Shu, Ching-Fong
;
Lai, Chin-Hung
;
Hsieh, Cheng-Chih
Highly efficient blue electrophosphorescent organic light-emitting diodes incorporating a bipolar host, 2,7-bis(diphenylphosphoryl)-9-[4-(N,N-diphenylamino)phenyl]-9-phenylfluorene (POAPF), doped with a conventional blue triplet emitter, iridium(III) bis[(4,6-difluorophenyl)pyridinato-N,C(2)]picolinate (FIrpic) are fabricated. The molecular architecture of POAPF features an electron-donating (p-type) triphenylamine group and an electron-accepting (n-type) 2,7-bis(diphenylphosphoryl)fluorene segment linked through the sp(3)-hybridized C9 position of the fluorene unit. The lack of conjugation between these p- and n-type groups endows POAPF with a triplet energy gap (ET) of 2.75 eV, which is sufficiently high to confine the triplet excitons on the blue-emitting guest. In addition, the built-in bipolar functionality facilitates both electron and hole injection. As a result, a POAPF-based device doped with 7 wt% FIrpic exhibits a very low turn-on voltage (2.5 V) and high electroluminescence efficiencies (20.6% and 36.7 lm W(-1)). Even at the practical brightnesses of 100 and 1000cd m(-2), the efficiencies remain high (20.2%/33.8 lm W(-1) and 18.8%/24.3 lm W(-1), respectively), making POAPF a promising material for use in low-power-consumption devices for next-generation flat-panel displays and light sources.
含壓電管致動器之讀寫頭
(2009-09-11)
呂宗熙
;
湯逸君
一種具壓電管致動器之讀寫頭,係包含有一懸臂單元;一與懸臂單元一端連接且為管狀壓電材料之壓電管,該壓電管係分成至少四等分之外部電極,亦即至少兩對電極;以及一與壓電管另一端連接之讀寫頭單元。藉此,可施加電壓於其中一對電極使其包覆的部分壓電材料伸長,而同一對的另一電極施加反向電壓使其縮短,使壓電管產生一維方向的撓曲位移,同理施加電壓於別對電極,也能產生別的方向的撓曲位移,如此利用壓電管進行小行程之多方向位移,以使壓電管達到同時快速、高準確性執行對焦與尋軌的動作,而作為讀寫頭單元之雙軸致動器。
Effects of Ti top electrode thickness on the resistive switching behaviors of rf-sputtered ZrO2 memory films
(2009-09-14)
Wang, Sheng-Yu
;
Lee, Dai-Ying
;
Tseng, Tseung-Yuen
;
Lin, Chih-Yang
;
電子工程學系及電子研究所
In this study, we propose a simple method to produce the various interface thicknesses within Ti/ZrO2 by changing the thickness of the Ti top electrode. As the Ti thickness increases, the induced interface thickness also increases to degrade the dielectric strength of the ZrO2, further lowering the forming voltage. However, when the interface layer is thick enough, it will trap sufficient charges to build up an opposite electric field to increase the forming voltage. The induced interface thickness is found to obviously affect the bias polarity of the resistive switching behavior and the device reliability. A fluctuant ON process is also demonstrated to be attributed to the competition between the formation and rupture of the conducting filaments. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3231872]
Effects of Ti top electrode thickness on the resistive switching behaviors of rf-sputtered ZrO(2) memory films
(2009-09-14)
Wang, Sheng-Yu
;
Lee, Dai-Ying
;
Tseng, Tseung-Yuen
;
Lin, Chih-Yang
;
電子工程學系及電子研究所
In this study, we propose a simple method to produce the various interface thicknesses within Ti/ZrO(2) by changing the thickness of the Ti top electrode. As the Ti thickness increases, the induced interface thickness also increases to degrade the dielectric strength of the ZrO(2), further lowering the forming voltage. However, when the interface layer is thick enough, it will trap sufficient charges to build up an opposite electric field to increase the forming voltage. The induced interface thickness is found to obviously affect the bias polarity of the resistive switching behavior and the device reliability. A fluctuant ON process is also demonstrated to be attributed to the competition between the formation and rupture of the conducting filaments. (C) 2009 American Institute of Physics. [doi: 10.1063/1.3231872]
Detecting HER2 on Cancer Cells by TiO2 Spheres Mile Scattering
(2009-09-15)
Tsai, Min-Chiao
;
Tsai, Tsung-Lin
;
Shieh, Dar-Bin
;
Chiu, Hsin-Tien
;
Lee, Chi-Young
This work is the first to describe a bioimaging method that uses highly uniformly sized TiO2 submicrometer and micrometer spheres based on Mie scattering. Transmembrane proteins (HER2) located on the surface of cancer cells were detected by bonded antibody-linked TiO2 spheres using optic microscopy and UV-vis spectroscopy. A particular HER2 bond on cancer cells, which has a weaker binding affinity than the biotin/avidin interaction, can be identified between TiO2 spheres that are linked to anti-HER2 antibodies and those that are linked to nonspecific mouse IgG antibodies by observing the cells under an optical microscope or by measuring absorbance from a UV-vis spectrum. The TiO2 spheres used in this work was prepared by reacting TTIP with carboxylic acid, as described elsewhere and the uniformity of the TiO2 sphere was further improved by adjusting the amount of water used. The water content was inversely related to particle size and the size distribution: as more water was used, smaller spheres with a narrower size distribution were obtained. The most uniform sphere obtained had a diameter of about 1 mu m with a size variation of 3%.
Method for promoting light emission efficiency of LED using nanorods structure
(2009-09-15)
Huang
;
Hung-Wen
;
Lu
;
Tien-Chang
;
Chiu
Method for the light emitting diode (LED) having the nanorods-like structure is provided. The LED employs the nanorods are subsequently formed in a longitudinal direction by the etching method and the PEC method. In addition, the plurality of the nanorods is arranged in an array so that provide the LED having much greater brightness and higher light emission efficiency than the conventional LED.
A refined cellular automaton model to rectify impractical vehicular movement behavior
(2009-09-15)
Lan, Lawrence W.
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Chiou, Yu-Chiun
;
Lin, Zih-Shin
;
Hsu, Chih-Cheng
;
運輸與物流管理系註：原交通所+運管所
When implementing cellular automata (CA) into a traffic simulation, one common defect yet to be rectified is the abrupt deceleration when vehicles encounter stationary obstacles or traffic jams. To be more in line with real world vehicular movement, this paper proposes a piecewise-linear movement to replace the conventional particle-hopping movement adopted in most previous CA models. Upon this adjustment and coupled with refined cell system, a new CA model is developed using the rationale of Forbes' et al. car-following concept. The proposed CA model is validated on a two-lane freeway mainline context. It shows that this model can fix the unrealistic deceleration behaviors, and thus call reflect genuine driver behavior in the real world. The model is also capable of revealing Kerner's three-phase traffic patterns and phase transitions among them. Furthermore, the proposed CA model is applied to simulate a highway work zone wherein traffic efficiency (maximum flow rates) and safety (speed deviations) impacted by various control schemes are tested. (C) 2009 Elsevier B.V. All rights reserved.
Optimal control algorithm and neural network for dynamic groundwater management
(2009-09-15)
Chu, Hone-Jay
;
Chang, Liang-Cheng
;
土木工程學系
;
Department of Civil Engineering
Researchers have found that obtaining optimal solutions for groundwater resource-planning problems, while simultaneously considering time-varying pumping rates, is a challenging task. This study integrates any artificial neural network (ANN) and constrained differential dynamic programming (CDDP) as simulation-optimization model, called ANN-CDDP. Optimal solutions for a groundwater resource-planning problem are determined while simultaneously considering time-varying pumping rates. A trained ANN is used as the transition function to predict ground water table under variable pumping conditions. The results show that the ANN-CDDP reduces computational time by as much as 94.5% when compared to the time required by the conventional model. The proposed optimization model saves a considerable amount of computational time for solving large-scale problems. Copyright (c) 2009 John Wiley & Sons, Ltd.
Utilization of four WDM channels with signal rernodulation of OFDM-QAM for 10 Gb/s uplink passive optical networks
(2009-09-15)
Yeh, Chien Hung
;
Chow, Chi Wai
;
光電工程學系
;
Department of Photonics
In this investigation, we experimentally investigate an extended reach (ER) time-division-multiplexed passive optical network (TDM-PON) using four wavelength-multiplexed channels to achieve 16Gb/s downlink and 10 Gb/s uplink traffic. Each downlink signal uses the highly spectral efficient 4 Gb/s OFDM-QAM, and each uplink signal is generated by signal remodulating the downlink signal via a reflective semiconductor amplifier (RSOA) at 2.5 Gb/s non-return-to-zero (NRZ). In addition, the performance of the proposed ER TDM-PON has also been analyzed and discussed. (c) 2009 Elsevier B.V. All rights reserved.