Browsing by Author "Wang, Yu"

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Bis(diphenylamino)-9,9 '-spirobifluorene functionalized Ir(III) complex: a conceptual design en route to a three-in-one system possessing emitting core and electron and hole transport peripherals
(2011)
Chen, Hsiao-Fan
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Wong, Ken-Tsung
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Liu, Yi-Hung
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Wang, Yu
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Cheng, Yi-Ming
Conceptual design of a three-in-one (luminescence chromophore with electron and hole transports) system was demonstrated by a functionalized Ir(III) complex 3, in which 4,5-diazafluorene and bis(diphenylamino) serve as electron and hole transporting sites, respectively. The poor emission quantum yield of 3 was systematically examined via a series of photophysical studies in combination with theoretical approaches. The far lifting of the pi-electron from -NPh(2) renders virtually no (3)MLCT contribution to the lowest transition in the triplet manifold as compared with that of the parent model 2 without amino substituents. With an empirical approach, we conclude that an energy gap law may account for the major deactivation process. A light-emitting electrochemical cell (LEC) device based on 3 shows peak EQE, peak current efficiency and peak power efficiency at 2.4 V of 0.020%, 0.013 cd A(-1) and 0.017 lm/W, respectively. The low device efficiencies are in accordance with the low PL quantum yield, stemming from the ligand-centered radiationless deactivation. The conceptual design presented here should provide valuable information for future progress en route to an ideal three-in-one system suited for OLEDs.
Delivery Guarantee of Greedy Routing in Three Dimensional Wireless Networks
(2008)
Wang, Yu
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Yi, Chih-Wei
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Li, Fan
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交大名義發表
;
National Chiao Tung University
In this paper, we investigate how to design greedy routing to guarantee packet delivery in a three-dimensional (313) network. In 2D networks, many position-based routing protocols apply face routing on planar routing structure as a backup method to guarantee packet delivery when greedy routing fails at local minimum. However, in 3D networks, no planar topology can be constructed anymore. Even worse, a recent result [6] showed that there is no deterministic localized routing algorithm that guarantees the delivery of packets in 3D networks. Therefore, we propose to set up the transmission radius large enough to eliminate local minimum in the 3D network. In particular, we study the asymptotic critical transmission radius for greedy routing to ensure the packet delivery in randomly deployed 3D networks. Using similar techniques in [12], we theoretically prove that for a 3D network, formed by nodes that are produced by a Poisson point is process of density n over a convex compact region of unit volume, 3 root 3 beta(0)1n n/4 pi n is asymptotically almost surely (abbreviated by a.a.s.) the threshold of the critical transmission radius for 3D greedy routing, where beta(0) = 3.2. We also conduct extensive simulations to confirm our theoretical results.
Journey from Mo-Mo Quadruple Bonds to Quintuple Bonds
(2009-09-09)
Tsai, Yi-Chou
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Chen, Hong-Zhang
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Chang, Chie-Chieh
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Yu, Jen-Shiang K.
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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.
Quintuply-Bonded Dichromium(I) Complexes Featuring Metal-Metal Bond Lengths of 1.74 angstrom
(2008)
Hsu, Chia-Wei
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Yu, Jen-Shiang K.
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Yen, Chun-Hsu
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Lee, Gene-Hsiang
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Wang, Yu
Remarkably short metal-metal bonds: A lantern-type quintuply bonded Dichromium(I) complex
(2008)
Tsai, Yi-Chou
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Hsu, Chia-Wei
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Yu, Jen-Shiang K.
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Lee, Gene-Hsiang
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Wang, Yu
Resonant X-Ray Scattering and Absorption for the Global and Local Structures of Cu-modified Metallothioneins in Solution
(2009-07-22)
Li, Meiyi
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Huang, Yu-Shan
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Jeng, U-Ser
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Hsu, I-Jui
;
Wu, YewChung Sermon
With Cd and Zn metal ions removed from the native rabbit-liver metallothionein upon unfolding, Cu-modified metallothioneins (Cu-MTs) were obtained during refolding in solutions containing Cu(I) or Cu(II) ions. X-ray absorption near-edge spectroscopic results confirm the respectively assigned oxidation states of the copper ions in Cu(I)-MT and Cu(II)-MT. Global and local structures of the Cu-MTs were subsequently characterized by anomalous small-angle x-ray scattering (ASAXS) and extended x-ray absorption fine structure. Energy-dependent ASAXS results indicate that the morphology of Cu(II)-MT resembles that of the native MT, whereas Cu(I)-MT forms oligomers with a higher copper content. Both dummy-residue simulation and model-shape fitting of the ASAXS data reveal consistently rodlike morphology for Cu(II)-MT. Clearly identified Cu-S, Cu-O, and Cu-Cu contributions in the extended x-ray absorption fine structure analysis indicate that both Cu(I) and Cu(II) ions are bonded with O and S atoms of nearby amino acids in a four-coordination environment, forming metal clusters smaller than metal thiolate clusters in the native MT. It is demonstrated that a combination of resonant x-ray scattering and x-ray absorption can be particularly useful in revealing complementary global and local structures of metalloproteins due to the atom specific characteristics of the two techniques.
Stepwise Construction of the Cr-Cr Quintuple Bond and Its Destruction upon Axial Coordination
(2012)
Huang, Yu-Lun
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Lu, Duan-Yen
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Yu, Hsien-Cheng
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Yu, Jen-Shiang K.
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Hsu, Chia-Wei
Theory-Guided Experiments on the Mechanistic Elucidation of the Reduction of Dinuclear Zinc, Manganese, and Cadmium Complexes
(2011)
Lu, Duan-Yen
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Yu, Jen-Shiang K.
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Kuo, Ting-Shen
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Lee, Gene-Hsiang
;
Wang, Yu
Three-dimensional greedy routing in large-scale random wireless sensor networks
(2013-06-01)
Wang, Yu
;
Yi, Chih-Wei
;
Huang, Minsu
;
Li, Fan
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資訊工程學系
In this paper, we investigate how to design greedy routing to achieve sustainable and scalable in a large-scale three-dimensional (3D) sensor network. Several 3D position-based routing protocols were proposed to seek either delivery guarantee or energy-efficiency in 3D wireless networks. However, recent results [1,2] showed that there is no deterministic localized routing algorithm that guarantees either delivery of packets or energy-efficiency of its routes in 3D networks. In this paper, we focus on design of 3D greedy routing protocols which can guarantee delivery of packets and/or energy-efficiency of their paths with high probability in a randomly deployed 3D sensor network. In particular, we first study the asymptotic critical transmission radius for 3D greedy routing to ensure the packet delivery in large-scale random 3D sensor networks, then propose a refined 3D greedy routing protocol to achieve energy-efficiency of its paths with high probability. We also conduct extensive simulations to confirm our theoretical results. (c) 2010 Elsevier B.V. All rights reserved.