Browsing by Issue Date, starting with "2007-08-20"

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Nonvolatile memory characteristics of nickel-silicon-nitride nanocrystal
(2007-08-20)
Chen, Wei-Ren
;
Chang, Ting-Chang
;
Liu, Po-Tsun
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Yeh, Jui-Lung
;
Tu, Chun-Hao
The formation of nickel-silicon-nitride nanocrystals by sputtering a comixed target in the argon and nitrogen environment is proposed in this letter. High resolution transmission electron microscope analysis clearly shows the nanocrystals embedded in the silicon nitride and x-ray photoelectron spectroscopy also shows the chemical material analysis of nanocrystals. The memory window of nickel-silicon-nitride nanocrystals enough to define 1 and 0 states is obviously observed, and a good data retention characteristic to get up to 10 years is exhibited for the nonvolatile memory application.
Sr3B2O6 : Ce3+,Eu2+: A potential single-phased white-emitting borate phosphor for ultraviolet light-emitting diodes
(2007-08-20)
Chang, Chun-Kuei
;
Chen, Teng-Ming
;
應用化學系
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Department of Applied Chemistry
The Ce3+/Eu2+ coactivated Sr3B2O6 phosphors exhibit varied hues from blue through white and eventually to yellow-orange by resonance-type energy transfer from Ce3+ to Eu2+ and tuning the relative proportion of Ce3+/Eu2+ properly. The authors have demonstrated that electric dipole-dipole interaction dominates the energy transfer mechanism in Sr3B2O6:Ce3+,Eu2+ phosphor, and the critical distance of energy transfer has been estimated to be about 30 A by both spectral overlap and concentration quenching methods. They have also shown that under the excitation of UV radiation, white light is generated by coupling 434 and 574 nm emission bands attributed to Ce3+ and Eu2+ radiations, respectively.
月亮洗頭
(2007-08-20)
管管
Micellization and the surface hydrophobicity of amphiphilic poly(vinylphenol)-block-polystyrene block copolymers
(2007-08-20)
Tung, Pao-Hsaing
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Kuo, Shiao-Wei
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Chan, Shih-Chien
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Hsu, Chih-Hao
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Wang, Chih-Feng
The self-assembly of PVPh-b-PS in different solvents was studied. Upon replacing toluene by THF as the solvent, the morphology of the resulting aggregates change from core-shell spheres, rod-like micelles and vesicles to onion-like aggregates. With increasing block copolymer concentration, morphologies such as honeycomb-like films, surfaces of aggregated large porous spheres, or pincushion-like spheres with protruding tubular vesicle aggregates are observed. These surface-patterned films show significantly enhanced hydrophobicity. The results suggest that a superhydrophobic . behavior can be achieved, with a maximum contact angle of 158 degrees, by using the pincushion-like micellar structure.
Pentacene-based thin-film transistors with multiwalled carbon nanotube source and drain electrodes
(2007-08-20)
Chang, Chia-Hao
;
Chien, Chao-Hsin
;
Yang, Jung-Yen
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
In this letter, the authors propose a practical and reliable approach-using deposited multiwalled carbon nanotubes (MWCNTs) as source and drain electrodes-for reducing the contact resistance (R-c) in pentacene-based bottom-contact thin-film transistors. The value of R-c of the devices was closely linked to the resultant length of the deposited MWCNTs; the lowest value was 3x10(8) Omega mu m. The largest saturation mobility was 0.14 cm(2)/V s; this value reached up to three times higher when the threshold voltage was determined using the maximum transconductance (G(m,max)) extrapolation method, rather than the constant current method. The on/off ratio was more than 10(6). (C) 2007 American Institute of Physics.
交大e-News第008期
(2007-08-20)
Secretariat
;
國立交通大學秘書室
Efficient deep blue emitters for organic electroluminescent devices
(2007-08-20)
Ho, Meng-Huan
;
Wu, Yao-Shan
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Wen, Shih-Wen
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Chen, Teng-Ming
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Chen, Chin H.
Highly efficient deep blue organic light emitting devices have been fabricated with a 4-(styryl)biphenyl-core based fluorescent dopant (SK-1) in the wide band gap 2-methyl-9,10-di(1-naphthyl)anthracene (alpha,alpha-MADN) host system which achieved an electroluminescence efficiency of 5.0 cd/A and an external quantum efficiency of 4.2% at 20 mA/cm(2) with a saturated blue Commission Internationale de l'Eclairage coordinates of (0.15, 0.14) and a half-decay lifetime of 8000 h at an initial brightness of 100 cd/m(2). The current efficiency and electroluminescent color of SK-1 doped devices have been shown to be essentially immune to drive current density. (C) 2007 American Institute of Physics.
Growth of GaAs epitaxial layers on Si substrate by using a novel GeSi buffer layer
(2007-08-21)
Chang
;
Edward Y.
;
Luo
;
Guangli
;
Yang
This invention provides a process for growing Ge epitaxial layers on Si substrate by using ultra-high vacuum chemical vapor deposition (UHVCVD), and subsequently growing a GaAs layer on Ge film of the surface of said Ge epitaxial layers by using metal organic chemical vapor deposition (MOCVD).The process comprises steps of, firstly, pre-cleaning a silicon wafer in a standard cleaning procedure, dipping it with HF solution and prebaking to remove its native oxide layer. Then, growing a high Ge-composition epitaxial layer, such as Si0.1Ge0.9in a thickness of 0.8 μm on said Si substrate by using ultra-high vacuum chemical vapor deposition under certain conditions. Thus, many dislocations are generated and located near the interface and in the low of part of Si01.Ge0.9due to the large mismatch between this layer and Si substrate.Furthermore, a subsequent 0.8 μm Si0.05Ge0.95layer, and/or optionally a further 0.8 μm Si0.02Ge0.98layer, are grown. They form strained interfaces of said layers can bend and terminate the propagated upward dislocation very effectively. Therefore, a film of pure Ge is grown on the surface of said epitaxial layers.Finally, a GaAs epitaxial layer is grown on said Ge film by using MOCVD.
Asynchronous first-in-first-out cell
(2007-08-21)
Chu
;
Yeh-Lin
;
Hwang
;
Wei
The present invention discloses an asynchronous first-in-first-out cell, wherein modified Muller C elements are used to reduce the complexity of the circuit of the asynchronous first-in-first-out cell; the asynchronous first-in-first-out cell of the present invention not only can be reusable, but also can apply to a single-supply-voltage system with a single clock frequency or multiple clock frequencies and a multiple-supply-voltage system with a single clock frequency or multiple clock frequencies. Further, when the asynchronous first-in-first-out cell of the present invention is applied to the interface circuit of a dual-supply-voltage 16-point radix-22GALS-based FFT architecture, considerable power saving and latency reduction can be achieved.
Self-alignment manufacturing method of the microlens and the aperture using in optical devices
(2007-08-21)
Chiu
;
Yi
;
Hsu
;
Wen Syang
;
Chang
The present invention discloses a self-alignment manufacturing method of a microlens and an aperture using in an optical device. The method manufactures the aperture and the circular opening in the opaque film on a transparent substrate, and utilizes the self-alignment backside exposure technology to precisely integrate the aperture and the microlens made by macromolecule material without any combination step. The claimed method is simpler than conventional technology and can precisely align and integrate the microlens and the aperture with a continuous batch manufacture. Since the aperture and the circular opening are concentric circles and formed in same step, the microlens and the aperture can be precisely aligned with the backside exposure. The claimed invention can effectively improve the optical resolution and efficiency of the optical access and measurement devices.
可自動作曲的方法及系統
(2007-08-21)
陳穎平
;
吳鎧竹
;
吳祖佑
;
傅道揚
;
陳錦德
習知之所謂「音樂創作」係由受過專業音樂訓練者，在熟悉樂理、各種樂器特性與各種音樂風格情況下的一種心智活動，而一般未受過音樂訓練者，無法輕易自行創作屬於個人的音樂。本專利揭示了一種利用內建有人工智慧專家系統軟體系統的方法與系統，可自動學習使用者對各種音樂旋律、節奏、風格之偏好，並依據使用者個人喜好回饋資訊，自動調整音樂之旋律、節奏、風格，以產生屬於使用者個人的音樂。
Clock switching circuit
(2007-08-21)
Wu
;
Jian-Hua
;
Hwang
;
Wei
The present invention discloses a clock switching circuit, which comprises: a clock generator, receiving two different clock signals; a logic gate, coupled to an enable-signal generator and an output-clock generator, wherein during clock switching, the logic gate turns off output clock according to the signal edges of those two clock signals to avoid the problems of clock glitch and timing insufficiency, and the logic gate will not restore clock output until an appropriate timing occurs.
Architecture of an embedded internet robot system controlled by brain waves
(2007-08-21)
Wu
;
Li-Wei
;
Liao
;
Hsien-Cheng
The present invention discloses an architecture of an embedded internet robot system controlled by brain waves, wherein the brain-computer interface and the internet robot system cooperate with the alertness level detection technology and the instruction translation technology, and thereby, the user can control a distal-end robot purely via consciousness activities and can interact with the environment as if there were an entity representing the user's consciousness appearing in the distal end. The seriously disabled person can regain his expressive ability via the present invention. Further, the present invention can also be applied to a multi-player interactive game system.
On the spanning connectivity and spanning laceability of hypercube-like networks
(2007-08-22)
Lin, Cheng-Kuan
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Tan, Jimmy J. M.
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Hsu, D. Frank
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Hsu, Lih-Hsing
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資訊工程學系
Let u and v be any two distinct nodes of an undirected graph G, which is k-connected. For 1 <= w <= k, a w-container C(u, v) of a k-connected graph G is a set of w-disjoint paths joining u and v. A w-container C(u, v) of G is a w*-container if it contains all the nodes of G. A graph G is w*-connected if there exists a w*-container between any two distinct nodes. A bipartite graph G is w*-laceable if there exists a w*-container between any two nodes from different parts of G. Let G(0) = (V-0, E-0) and G(1) = (V-1, E-1) be two disjoint graphs with vertical bar V-0 vertical bar= vertical bar V-1 vertical bar. Let E = ((v, phi(v)) vertical bar v is an element of V0, phi(v) is an element of V-1, and phi : V-0 -> V-1 is a bijection}. Let G = G(0) circle plus G(1) = (V0 boolean OR V1, E-0 boolean OR E-1 boolean OR E). The set of n-dimensional hypercube-like graph H-n(') is defined recursively as (a) H-1(') = {K2}, K2 = complete graph with two nodes, and (b) if G(0) and G(1) are in H-n', then G = G(0) circle plus G(1) is in H-n+1('). Let B-n' = {G is an element of H-n' and G is bipartite} and N-n' = H-n' B-n'. In this paper, we show that every graph in B-n' is w*-laceable for every w, 1 <= w <= n. It is shown that a constructed N-n'-graph H can not be 4*-connected. In addition, we show that every graph in N-n' is w*-connected for every w, 1 <= w <= 3. (c) 2007 Published by Elsevier B.V.
Optical properties of In0.3Ga0.7N/GaN green emission nanorods fabricated by plasma etching
(2007-08-22)
Chiu, C. H.
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Lo, M. H.
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Lai, C. F.
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Lu, T. C.
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Huang, H. W.
In this study, we have fabricated In0.3Ga0.7N/GaN green emission nanorods and demonstrated optical enhancement by photoluminescence (PL) measurements. An enhancement factor of 3.5 and an emission peak blue-shift of 6.6 nm were observed at 300 K for the green emission nanorods structure in comparison to the as-grown flat surface structure. The blue-shift phenomenon from the nanorod structure could be caused by a partial reduction of the internal piezoelectric field. However, the similar carrier decay time for the green emission nanorod structure and the as-grown flat surface structure observed in low-temperature time-resolved PL measurements indicates that the dominant optical enhancement mechanism of the green emission nanorod structure could be mainly resulting from the large emission surface areas and the multiple scattering paths between the nanorods.
Calibration system for image capture apparatus and method thereof
(2007-08-23)
Chen, I-Hsien
;
Wang, Sheng-Jyh
A calibration system and a method to be used in an image capture apparatus are disclosed. The calibration system includes a calibration appliance, a feature extraction unit and a processor. The calibration appliance has a plurality of mark points. The plurality of mark points is on the same plane to form a line segment with a known length. The image capture apparatus captures an image. Then based on the captured image, the feature extraction unit extracts at least three image feature points corresponding to the mark points. The processor calculates the inclination angle of the image capture apparatus, and the height between the image capture apparatus and the plane. Besides a line segment with a known length, the mark points corresponding to the image feature points may form a corner with a known angle, two corners with unknown but equal angles, or two line segments with unknown but equal lengths. Convenience for the calibration system is therefore improved.
Metallo-homopolymer and metallo-copolymers containing light-emitting poly (fluorene/ethynylene/(terpyridyl)zinc (II)) backbones and 1,3,4-oxadiazole (OXD) pendants
(2007-08-24)
Chen, Yi-Yu
;
Lin, Hong-Cheu
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材料科學與工程學系
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Department of Materials Science and Engineering
A series of novel metallo-polymers containing light-emitting poly(fluorene/ethynylene/(terpyridyl)zinc(II)) backbones and electrontransporting 1,3,4-oxadiazole (OXD) pendants (attached to the C-9 position of fluorene by long alkyl spacers) were synthesized by self-assembled reactions. The integrated ratios of H-1 NMR spectra reveal a facile result to distinguish the well-defined main-chain metallo-polymeric structures which were constructed by different monomer ligand systems (i.e. single, double, and triple monomer ligands with various pendants). Furthermore, UV-vis and photoluminescence (PL) spectral fitration experiments were carried out to verify the metallo-polymeric structures by varying the molar ratios of zinc(II) ions to monomers. As a result, the enhancement of thermal stability (T-d) and quantum yields were introduced by the metallo-polymerization, and their physical properties were mainly affected by the nature of the pendants. The photophysical properties of these metallo-polymers exhibited blue PL emissions (around 418 nm) with quantum yields of 34-53% (in DMF). In contrast to metallo-polymers containing alkyl pendants, the quantum yields were greatly enhanced by introducing 1,3,4-OXD pendants but reduced by carbazole (CAZ) pendants. Moreover, electrolumineseent (EL) devices with these light-emitting metallo-polymers as emitters showed green EL emissions (around 550 nm) with turn-on voltages of 6.0-6.5 V, maximum efficiencies of 1.05-1.35 cd A(-1) (at 100 mA/cm(-2)), and maximum luminances of 2313-3550 cd/m(2) (around 15 V), respectively. (c) 2007 Elsevier Ltd. All rights reserved.
Intramolecular Diels-Alder reaction of 2-diphenylphosphinyl-5-(propargyloxymethyl)furans followed by nucleophilic 1,2-rearrangement of the phosphinyl group
(2007-08-27)
Wu, Hsien-Jen
;
Liu, Chuan-Fang
;
Wang, Zhongyi
;
Lin, Hui-Chang
;
應用化學系
The base-catalyzed intramolecular Diels-Alder reactions of 2-diphenylphosphinyl-5-(propargyloxymethyl)furans 2a-e gave the tetrahydrofuran ring annulated o-diphenylphosphinophenols 3a-e in 70-80% yields, a novel reaction involving an intramolecular Diels-Alder reaction of furan diene with allenyl ether dienophile followed by a nucleophilic 1,2-rearrangement of the diphenylphosphinyl group. (C) 2007 Elsevier Ltd. All rights reserved.
Current injection and transport in polyfluorene
(2007-08-27)
Yang, Chieh-Kai
;
Yang, Chia-Ming
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Liao, Hua-Hsien
;
Horng, Sheng-Fu
;
Meng, Hsin-Fei
A comprehensive numerical model is established for the electrical processes in a sandwich organic semiconductor device with high carrier injection barrier. The charge injection at the anode interface with 0.8 eV energy barrier is dominated by the hopping among the gap states of the semiconductor caused by disorders. The Ohmic behavior at low voltage is demonstrated to be not due to the background doping but the filaments formed by conductive clusters. In bipolar devices with low work function cathode it is shown that near the anode the electron traps significantly enhance hole injection through Fowler-Nordheim tunneling, resulting in rapid increases of the hole carrier and current in comparison with the hole-only devices. (c) 2007 American Institute of Physics.
Nano-ferrosponges for controlled drug release
(2007-08-28)
Hu, Shang-Hsiu
;
Liu, Ting-Yu
;
Liu, Dean-Mo
;
Chen, San-Yuan
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材料科學與工程學系
Magnetic sponge-like hydrogels (ferrosponges) were fabricated by using an in-situ synthesis of magnetic nanoparticles (MNPs) in the presence of various concentrations of gelatin. The resulting ferrosponges show an interconnected nanopore structure which serves as a reservoir to accommodate therapeutic drugs and the nanoporous networks demonstrate magnetic sensitive behavior under the application of magnetic field. The ferrosponges showed high swelling ratios, together with excellent elasticity and hydrophilicity, allow them to response rapidly to an external magnetic stimulation for fast and repeatable swelling-deswelling (or expansion-contractile) operations. The ferrosponges with lower gelatin concentration exhibited good performance on magnetification. Furthermore, drug release from the ferrosponges is relatively magnetic-sensitive and is dominated by its magnetism and associated interaction between the magnetic nanoparticle and the gelatin matrix under an external magnetic field. Higher MNPs concentration in the ferrosponges exhibited higher degree of magnetic sensitive which is due to stronger interparticle forces. By taking these peculiar magnetic sensitive behaviors of the ferrosponges, a novel drug delivery system can be designed for medical uses. (C) 2007 Elsevier B.V. All rights reserved.