Browsing by Issue Date, starting with "2009-08-05"

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Comparison of Geometric, Electronic, and Vibrational Properties for All Pentagon/Hexagon-Bearing Isomers of Fullerenes C(38), C(40), and C(42)
(2009-08-05)
Malolepsza, Edyta
;
Lee, Yuan-Pern
;
Witek, Henryk A.
;
Irle, Stephan
;
Lin, Chun-Fu
The self-consistent-charge density-functional tight-binding (SCC-DFTB) method is employed for computing geometric, electronic, and vibrational properties for various topological isomers of small fullerenes. We consider all pentagon/hexagon-bearing isomers of C(38), C(40), and C(42) as the second part of a larger effort to catalogue the CC distance distributions, valence CCC angle distributions, electronic densities of states (DOSs), vibrational densities of states (VDOSs), and infrared (IR) and Raman spectra for fullerenes C(20)-C(180) [analogous data for C(20)-C(36) were published previously in Malolepsza et al., J Phys Chem A, 2007, 111, 6649]. Common features among the fullerenes are identified and properties characteristic for each specific fullerene cage size are discussed. (c) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 1999-2011, 2009
Solution-processable phosphorescent to organic light-emitting diodes based on chromophoric amphiphile/silica nanocomposite
(2009-08-05)
Yang, Chung-He
;
Yang, Sheng-Hsiung
;
Hsu, Chain-Shu
;
應用化學系
;
Department of Applied Chemistry
We report the synthesis of a tris-cyclometalated iridium complex which emits sky-blue light and its potential use in phosphorescent light-emitting devices. The hybrid meso-structured nanocomposites by sol-gel co-assembly with tetraethyl ortho-silicate and corresponding molecular interactions within mesopores were also demonstrated. Electroluminescent devices were fabricated using carbazole-based monomers and iridium complex as the active layer, acting as a host/guest system through a co-assembled sol-gel process. Devices based on this nanocomposite showed improved luminescent efficiencies several times higher than that of similar chromophores elaborated in the literature. A triple-layer electroluminescence device with the configuration of ITO/PEDOT/Ir(F2OC11ppy)(3):CA-C11:PBD nanocomposite/TPBI/Ca/Al showed a maximum brightness of 1389 cd m(-2) at 12 V and a maximum efficiency of 3.29 cd A(-1).
A mild and general method for preparation of alpha-glycosyl chlorides
(2009-08-05)
Chang, Chih-Wei
;
Chang, Shih-Sheng
;
Chao, Chin-Sheng
;
Mong, Kwok-Kong T.
;
應用化學系
A mild and efficient chlorination method for production of glycosyl chlorides is first described which employs inexpensive trichlorotriazine (TCT) and DMF as a chlorination reagent and is compatible with typical acid-labile hydroxyl protecting functions. The scope and limitations, reaction mechanism and its application in the sequential glycosylations are discussed. (C) 2009 Elsevier Ltd. All rights reserved.
Comparison of Geometric, Electronic, and Vibrational Properties for All Pentagon/Hexagon-Bearing Isomers of Fullerenes C-38, C-40, and C-42
(2009-08-05)
Malolepsza, Edyta
;
Lee, Yuan-Pern
;
Witek, Henryk A.
;
Irle, Stephan
;
Lin, Chun-Fu
The self-consistent-charge density-functional tight-binding (SCC-DFTB) method is employed for computing geometric, electronic, and vibrational properties for various topological isomers of small fullerenes. We consider all pentagon/hexagon-bearing isomers of C-38, C-40, and C-42 as the second part of a larger effort to catalogue the CC distance distributions, valence CCC angle distributions, electronic densities of states (DOSs), vibrational densities of states (VDOSs), and infrared (IR) and Raman spectra for fullerenes C-20-C-180 [analogous data for C-20-C-36 were published previously in Malolepsza et al., J Phys Chem A, 2007, 111, 6649]. Common features among the fullerenes are identified and properties characteristic for each specific fullerene cage size are discussed. (c) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 109: 1999-2011, 2009
交大e-News第053期
(2009-08-05)
Secretariat
;
國立交通大學秘書室
NURSING SYSTEM
(2009-08-06)
Tsai, Chi-Yi
;
Huang, Fu-Sheng
;
Lin, Chen-Yang
;
Lin, Zhi-Sheng
;
Chen, Chun-Wei
A nursing system of the present invention can position where a person to be nursed through a sensor network widely deployed in an environment, instantaneously detect if the person to be nursed has an accident, and forward a message to inform a relative or medical staff. An autonomous robot will actively move beside the person to be nursed and transmit real-time images to a remote computer or PDA so that the relative or medical staff can swiftly ascertain the situation of the person to be nursed and the person to be nursed in case of emergency can be rescued as soon as possible.
Photobleaching of the "Raman Spectroscopic Signature of Life" and Mitochondrial Activity in Rho(-) Budding Yeast Cells
(2009-08-06)
Onogi, Chikao
;
Hamaguchi, Hiro-O
;
應用化學系
;
應用化學系分子科學碩博班
;
Department of Applied Chemistry
Raman spectra of mitochondria in single living budding yeast (zygote of Saccharomyces cerevisiae and Saccharomyces bayanus) cells have been measured and compared for two types of tetraploid strains, the wild-type strain and the rho(-) strain. The "Raman spectroscopic signature of life", a strong Raman band at 1602 cm(-1) that sharply reflects the mitochondrial activity, has been found in both of the two strains with similar intensities. This signature showed photobleaching under irradiation of the 632.8 nm line of a He-Ne laser, only for the rho(-) strain. The photobleaching recovered by keeping the cell in the dark for two hours without laser irradiation. These findings indicate that the molecular species that gives rise to the 1602 cm(-1) band is an intermediate formed and accumulated during the metabolic cycle and that it absorbs at 632.8 nm to undergo photodecomposition. We also found a number of weak Raman bands in the 400-1200 cm(-1) region that show the same temporal behaviors as that of the 1602 cm(-1) band by an SVD analysis of time-resolved Raman spectra, Several new pieces of information oil the origin of the "Raman spectroscopic signature of life" have thus been obtained.
Fully Cu-metallized III-V group compound semiconductor device with palladium/germanium/copper ohmic contact system
(2009-08-06)
CHANG, Edward Yi
;
Chen, Ke-Shian
The present invention discloses a fully Cu-metallized III-V group compound semiconductor device, wherein the fully Cu-metallized of a III-V group compound semiconductor device is realized via using an N-type gallium arsenide ohmic contact metal layer formed of a palladium/germanium/copper composite metal layer, a P-type gallium arsenide ohmic contact metal layer formed of a platinum/titanium/platinum/copper composite metal layer, and interconnect metals formed of a titanium/platinum/copper composite metal layer. Thereby, the fabrication cost of III-V group compound semiconductor devices can be greatly reduced, and the performance of III-V group compound semiconductor devices can be greatly promoted. Besides, the heat-dissipation effect can also be increased, and the electric impedance can also be reduced.
Puzzling spectral structures of molecular vibration observed in ultrafast pump-probe experiment of transparent material
(2009-08-06)
Ozawa, A.
;
Kobayashi, T.
;
交大名義發表
;
National Chiao Tung University
A sub-5-fs ultrafast pump-probe experiment was applied to neat liquid tetrahydrofuran (THF). The observed periodic modulation of transmittance change (Delta T), similar to 5 x 10(-3), is assigned to the ground-state vibrational mode of C-H stretching. Although the sample has no stationary absorption in the wavelength region under study, the modulation amplitude shows strong dependence on the probe photon energy. A model is proposed to explain this feature based on the coherent Raman coupling between the fundamental and Stokes-shifted spectral components. The results demonstrate that a special attention is required in distinguishing the ground-and excited-state vibrational signals in ultrafast transient absorption spectroscopy. (C) 2009 Elsevier B. V. All rights reserved.
Size-fractionation of silver nanoparticles using ion-pair extraction in a counter-current chromatograph
(2009-08-07)
Shen, Ching-Wei
;
Yu, Tiing
;
應用化學系
;
Department of Applied Chemistry
Size separation of silver nanoparticles was investigated in counter-current chromatography (CCC) based on a unique step-gradient extraction process. Carboxylate anions were modified on silver nanoparticles to produce water-dispersible nanoparticles. The aqueous nanoparticles were readily transferred to the organic phase (toluene/hexane = 1: 1, v/v) together with the phase transfer catalyst, tetraoctylammonium bromide (TOAB), owing to the ion-pair adduct formation between silver nanoparticle anions and tetraoctylammonium cations. Smaller nanoparticles were found to be more readily transferred to the organic phase compared to larger nanoparticles. Various concentrations of TOAB in the organic elution phase were used in the CCC extraction experiments. it appeared that a concentration of 0.02 mM of TOAB was adequate to achieve optimum separation and recovery for the aqueous Ag nanoparticle sample (1.5 mg) in the CCC extraction experiments. Samples of 15.8 +/- 5.3 nm were separated; the distributions of four fractions collected were 13.7 +/- 1.9, 14.1 +/- 3.5, 19.2 +/- 4.3, and 22.2 +/- 4.9 turn. Compared with the step-wise extraction performed in this study, the step-gradient extractions using CCC provided much better size discrimination. (C) 2009 Elsevier B.V. All rights reserved.
Selective real-time nitric oxide detection by functionalized zinc oxide
(2009-08-07)
Liu, Chien-Cheng
;
Li, Jan-Hao
;
Chang, Cheng-Chung
;
Chao, Yu-Chiang
;
Meng, Hsin-Fei
Ferriprotoporphyrin IX chloride (haemin)-functionalized Al-doped zinc oxide (ZnO) is used for nitric oxide (NO) sensing at room temperature. The devices show high selectivity to NO against CO(2) and O(2). There is no such selectivity without haemin. Porous ZnO film made by a polystyrene sphere template is used to provide a high surface area. In comparison with non-porous ZnO film with low surface area, both the sensitivity and the response speed of the sensor made by porous ZnO are clearly improved. NO concentration down to 1 ppm can be detected. The response time is 20 s. The sensor is reversible after purging with pure nitrogen for about 100 s. Such a device is able to detect real-time variation of NO which is a vital physiological signalling molecule.
Mechanism in determining pretilt angle of liquid crystals aligned on fluorinated copolymer films
(2009-08-07)
Wu, Hsin-Ying
;
Wang, Chih-Yu
;
Lin, Chia-Jen
;
Pan, Ru-Pin
;
Lin, Song-Shiang
This work explores the surface treatment of copolymer materials with fluorinated carbonyl groups in various mole fractions by ultraviolet irradiation and ion-beam (IB) bombardment and its effect on liquid crystal (LC) surface alignments. X-ray photoemission spectroscopic analysis confirms that the content of the grafted CF(2) side chains dominates the pretilt angle. A significant increase in oxygen content is responsible for the increase in the polar surface energy during IB treatment. Finally, the polar component of the surface energy dominates the pretilt angle of the LCs.
FORMATION AND IDENTIFICATION OF INTERSTELLAR MOLECULE LINEAR C(5)H FROM PHOTOLYSIS OF METHANE DISPERSED IN SOLID NEON
(2009-08-10)
Wu, Yu-Jong
;
Chen, Hui-Fen
;
Camacho, Cristopher
;
Witek, Henryk A.
;
Hsu, Sheng-Chuan
Photolysis of methane dispersed (1/1000) in solid Ne at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of several products, including new lines at 3319.3 and 1955.5 cm(-1). Based on experiments with isotopic labeling and results of quantum-chemical calculations, these lines are assigned to the C-H stretching and C=C stretching modes, respectively, of interstellar molecule linear C(5)H radicals.
Photovoltaic effects in BiFeO(3)
(2009-08-10)
Yang, S. Y.
;
Martin, L. W.
;
Byrnes, S. J.
;
Conry, T. E.
;
Basu, S. R.
We report a photovoltaic effect in ferroelectric BiFeO(3) thin films. The all-oxide heterostructures with SrRuO(3) bottom and tin doped indium oxide top electrodes are characterized by open-circuit voltages similar to 0.8-0.9 V and external quantum efficiencies up to similar to 10% when illuminated with the appropriate light. Efficiencies are at least an order of magnitude larger than the maximum efficiency under sunlight (AM 1.5) thus far reported for ferroelectric-based devices. The dependence of the measured open-circuit voltage on film thickness suggests contributions to the large open-circuit voltage from both the ferroelectric polarization and band offsets at the BiFeO(3)/tin doped indium oxide interface.
FORMATION AND IDENTIFICATION OF INTERSTELLAR MOLECULE LINEAR C5H FROM PHOTOLYSIS OF METHANE DISPERSED IN SOLID NEON
(2009-08-10)
Wu, Yu-Jong
;
Chen, Hui-Fen
;
Camacho, Cristopher
;
Witek, Henryk A.
;
Hsu, Sheng-Chuan
Photolysis of methane dispersed (1/1000) in solid Ne at 3 K with vacuum-ultraviolet light from a synchrotron produced infrared absorption lines of several products, including new lines at 3319.3 and 1955.5 cm(-1). Based on experiments with isotopic labeling and results of quantum-chemical calculations, these lines are assigned to the C-H stretching and C=C stretching modes, respectively, of interstellar molecule linear C5H radicals.
Photovoltaic effects in BiFeO3
(2009-08-10)
Yang, S. Y.
;
Martin, L. W.
;
Byrnes, S. J.
;
Conry, T. E.
;
Basu, S. R.
We report a photovoltaic effect in ferroelectric BiFeO3 thin films. The all-oxide heterostructures with SrRuO3 bottom and tin doped indium oxide top electrodes are characterized by open-circuit voltages similar to 0.8-0.9 V and external quantum efficiencies up to similar to 10% when illuminated with the appropriate light. Efficiencies are at least an order of magnitude larger than the maximum efficiency under sunlight (AM 1.5) thus far reported for ferroelectric-based devices. The dependence of the measured open-circuit voltage on film thickness suggests contributions to the large open-circuit voltage from both the ferroelectric polarization and band offsets at the BiFeO3/tin doped indium oxide interface.
尖端增強之微電漿元件
(2009-08-11)
吳正宇
;
金星吾
一種尖端增強之微電漿元件,主要是利用微尖端結構具有很強的電場集中效應,乃於陰極板上設置有微尖端電極,可將電場局部集中於微尖端電極上,而易於在陰極板與陽極板間的放電空間中誘發出電漿現象,藉此達到降低電漿崩解電壓的效果。
相依排程之派工方法
(2009-08-11)
巫木誠
;
吳政翰
本發明係揭露一種相依排程之派工方法,包含提供部份或全部具有相依性的複數個任務排程及複數個處理設備,經由任務排程及處理設備的配對產生一處理時間矩陣及一傳輸時間,再由處理時間矩陣及傳輸時間產生任務排程之各別優先値,並據以排列任務排程之排程序列,且重複產生多個該排程序列,以形成母體,接續,由共識因子將抽樣自母體之排程序列進行演化,以產生新世代母體,重複的對新產生的新世代母體抽樣進行演化,直到新產生的新世代母體達到演化門檻或演化代數,即停止演化,最後,求解出演化後之排程序列,以縮短任務排程完成的時程。
CAPIH: A Web interface for comparative analyses and visualization of host-HIV protein-protein interactions
(2009-08-12)
Lin, Fan-Kai
;
Pan, Chia-Lin
;
Yang, Jinn-Moon
;
Chuang, Trees-Juen
;
Chen, Feng-Chi
Background: The Human Immunodeficiency Virus type one (HIV-1) is the major causing pathogen of the Acquired Immune Deficiency Syndrome (AIDS). A large number of HIV-1-related studies are based on three non-human model animals: chimpanzee, rhesus macaque, and mouse. However, the differences in host-HIV-1 interactions between human and these model organisms have remained unexplored. Description: Here we present CAPIH (Comparative Analysis of Protein Interactions for HIV-1), the first web-based interface to provide comparative information between human and the three model organisms in the context of host-HIV-1 protein interactions. CAPIH identifies genetic changes that occur in HIV-1-interacting host proteins. In a total of 1,370 orthologous protein sets, CAPIH identifies similar to 86,000 amino acid substitutions, similar to 21,000 insertions/deletions, and similar to 33,000 potential post-translational modifications that occur only in one of the four compared species. CAPIH also provides an interactive interface to display the host-HIV-1 protein interaction networks, the presence/absence of orthologous proteins in the model organisms in the networks, the genetic changes that occur in the protein nodes, and the functional domains and potential protein interaction hot sites that may be affected by the genetic changes. The CAPIH interface is freely accessible at http://bioinfo-dbb.nhri.org.tw/capih. Conclusion: CAPIH exemplifies that large divergences exist in disease-associated proteins between human and the model animals. Since all of the newly developed medications must be tested in model animals before entering clinical trials, it is advisable that comparative analyses be performed to ensure proper translations of animal-based studies. In the case of AIDS, the host-IV-1 protein interactions apparently have differed to a great extent among the compared species. An integrated protein network comparison among the four species will probably shed new lights on AIDS studies.
Enhanced light output power of GaN-based vertical-injection light-emitting diodes with a 12-fold photonic quasi-crystal by nano-imprint lithography
(2009-08-12)
Huang, H. W.
;
Lin, C. H.
;
Lee, K. Y.
;
Yu, C. C.
;
Huang, J. K.
GaN-based thin-film vertical-injection light-emitting diodes (VLEDs) with a 12-fold photonic quasi-crystal (PQC) by nano-imprint lithography (NIL) are fabricated and presented. At a driving current of 20 mA and with a chip size of 350 mu m x 350 mu m, the light output power of our thin-film LED with a 12-fold PQC structure reaches 41 mW. This result is an enhancement of 78% when compared with the output power of a VLED without a PQC structure. In addition, the corresponding light radiation pattern shows a narrower beam shape due to the strong guided light extraction effect by the formed PQC structure in the vertical direction.