Molecular Dynamics Simulation of Oxygen Ion Diffusion in Yttria Stabilized Zirconia Single Crystals and Bicrystals

Huang, H. C.,Su, P.‐,C.,Kwak, S. K.,Pornprasertsuk, R.,Yoon, Y.‐,J. WILEY‐VCH Verlag 2014 Fuel Cells Vol.14 No.4

<P><B>Abstract</B></P><P>Molecular dynamics simulation studies have been performed to study the oxygen ion diffusion in yttria stabilized zirconia single crystals and bicrystals separated by tilt grain boundaries (GBs). Two types of GBs which are Σ 5 (3 1 0) and Σ 13 (5 1 0) are studied at temperatures between 1,000 K and 2,000 K. The effect of grain size, which is the distance between two GBs, and the effect of GB orientations are systematically investigated in this study. The oxygen diffusion in the bicrystals is found to be blocked by the GB, and the blocking effect increases with decreasing grain size and is affected by different grain orientations. In addition, the oxygen diffusion along the GB plane is most hindered.</P>

IDENTIFICATION CAMPAIGN OF SUPERNOVA REMNANT CANDIDATES IN THE MILKY WAY. I.<i>CHANDRA</i>OBSERVATION OF G308.3-1.4

Hui, C. Y.,Seo, K. A.,Huang, R. H. H.,Trepl, L.,Woo, Y. J.,Lu, T.-N.,Kong, A. K. H.,Walter, F. M. IOP Publishing 2012 The Astrophysical journal Vol.750 No.1

<P>ROSAT all-sky survey data have provided another window in which to search for supernova remnants (SNRs). In re-examining this data archive, a list of unidentified extended X-ray objects have been suggested as promising SNR candidates. However, most of these targets have not yet been fully explored by state-of-the-art X-ray observatories. To select a pilot target for a long-term identification campaign, we observed the brightest candidate, G308.3-1.4, with the Chandra X-ray Observatory. An incomplete shell-like X-ray structure that is well correlated with the radio shell emission at 843 MHz has been revealed. The X-ray spectrum suggests the presence of a shock-heated plasma. All these evidences confirm G308.3-1.4 as an SNR. The brightest X-ray point source detected in this field of view is also the one located closest to the geometrical center of G308.3-1.4, which has a soft spectrum. The intriguing temporal variability and the identification of the optical/infrared counterpart rule out the possibility of an isolated neutron star. On the other hand, the spectral energy distribution from the K-s band to the R band suggests a late-type star. Together with a putative periodicity of similar to 1.4 hr, the interesting excesses in the V and B bands and in H alpha suggest that this source is a promising candidate for a compact binary that survived a supernova explosion.</P>

Photoluminescence and Electromodulation Spectroscopy Characterization of Zn0.93Mg0.07Se and Zn0.81Be0.04Mg0.15Se Mixed Crystals

H. P. Hsu,D. O. Dumcenco,C. T. Huang,Y. S. Huang,F. Firszt,S. Legowski,H. Meczynsk,K. Strza lkowski,A. Marasek,K. K. Tiong 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.1

A detailed optical characterization of zinc-blende-type Zn0.93Mg0.07Se and Zn0.81Be0.04Mg0.15Se mixed-crystal samples grown by using the modified high pressure Bridgman method has been carried out via photoluminescence (PL), contactless electrore ectance (CER) and photore ectance (PR) in the temperature range of 15 to 400 K. PL spectra at low temperatures consist of an exciton line, a broader emission band due to recombination of donor-acceptor pairs and a broad band related to recombination through deep-level defects. Interband transitions, originating from the band edge and spin-orbit splitting critical points, have been observed in the CER/PR spectra. The optical properties of these two mixed crystals are compared and the results indicate the superior quality of the Be-incorporated mixed quaternary crystals. The peak positions of the excitonic emission lines in the PL spectra correspond quite well to the energies of the fundamental transitions obtained by means of electromodulation data. The parameters that describe the temperature dependence of the fundamental and spin split-off band gaps and the broadening function of the band-edge excitons are evaluated and discussed. A detailed optical characterization of zinc-blende-type Zn0.93Mg0.07Se and Zn0.81Be0.04Mg0.15Se mixed-crystal samples grown by using the modified high pressure Bridgman method has been carried out via photoluminescence (PL), contactless electrore ectance (CER) and photore ectance (PR) in the temperature range of 15 to 400 K. PL spectra at low temperatures consist of an exciton line, a broader emission band due to recombination of donor-acceptor pairs and a broad band related to recombination through deep-level defects. Interband transitions, originating from the band edge and spin-orbit splitting critical points, have been observed in the CER/PR spectra. The optical properties of these two mixed crystals are compared and the results indicate the superior quality of the Be-incorporated mixed quaternary crystals. The peak positions of the excitonic emission lines in the PL spectra correspond quite well to the energies of the fundamental transitions obtained by means of electromodulation data. The parameters that describe the temperature dependence of the fundamental and spin split-off band gaps and the broadening function of the band-edge excitons are evaluated and discussed.

OGLE-2016-BLG-1190Lb: The First<i>Spitzer</i>Bulge Planet Lies Near the Planet/Brown-dwarf Boundary

Ryu, Y.-H.,Yee, J. C.,Udalski, A.,Bond, I. A.,Shvartzvald, Y.,Zang, W.,Jaimes, R. Figuera,Jørgensen, U. G.,Zhu, W.,Huang, C. X.,Jung, Y. K.,Albrow, M. D.,Chung, S.-J.,Gould, A.,Han, C.,Hwang, K.-H.,Sh American Astronomical Society 2018 The Astronomical journal Vol.155 No.1

<P>We report the discovery of OGLE-2016-BLG-1190Lb, which is likely to be the first Spitzer microlensing planet in the Galactic bulge/ bar, an assignation that can be confirmed by two epochs of high-resolution imaging of the combined source-lens baseline object. The planet's mass, M-p = 13.4 +/- 0.9 M-J, places it right at the deuteriumburning limit, i. e., the conventional boundary between 'planets' and 'brown dwarfs.' Its existence raises the question of whether such objects are really ' planets' (formed within the disks of their hosts) or 'failed stars' (lowmass objects formed by gas fragmentation). This question may ultimately be addressed by comparing disk and bulge/bar planets, which is a goal of the Spitzer microlens program. The host is a G dwarf, M-host = 0.89. +/- 0.07 M-circle dot, and the planet has a semimajor axis a similar to 2.0 au. We use Kepler K2 Campaign 9 microlensing data to break the lens-mass degeneracy that generically impacts parallax solutions from Earth-Spitzer observations alone, which is the first successful application of this approach. The microlensing data, derived primarily from near-continuous, ultradense survey observations from OGLE, MOA, and three KMTNet telescopes, contain more orbital information than for any previous microlensing planet, but not quite enough to accurately specify the full orbit. However, these data do permit the first rigorous test of microlensing orbital-motion measurements, which are typically derived from data taken over < 1% of an orbital period.</P>

Nonlinear Characteristics of Fuzzy Scatter Partition-Based Fuzzy Inference System

Park, Keon-Jun,Huang, Wei,Yu, C.,Kim, Yong K. The Institute of Internet 2013 International journal of advanced smart convergenc Vol.2 No.1

This paper introduces the fuzzy scatter partition-based fuzzy inference system to construct the model for nonlinear process to analyze nonlinear characteristics. The fuzzy rules of fuzzy inference systems are generated by partitioning the input space in the scatter form using Fuzzy C-Means (FCM) clustering algorithm. The premise parameters of the rules are determined by membership matrix by means of FCM clustering algorithm. The consequence part of the rules is represented in the form of polynomial functions and the parameters of the consequence part are estimated by least square errors. The proposed model is evaluated with the performance using the data widely used in nonlinear process. Finally, this paper shows that the proposed model has the good result for high-dimension nonlinear process.

Integrated cladding-pumped multicore few-mode erbium-doped fibre amplifier for space-division-multiplexed communications

Chen, H.,Jin, C.,Huang, B.,Fontaine, N. K.,Ryf, R.,Shang, K.,Gré,goire, N.,Morency, S.,Essiambre, R.-J.,Li, G.,Messaddeq, Y.,LaRochelle, S. Nature Publishing Group 2016 Nature photonics Vol.10 No.8

Space-division multiplexing (SDM), whereby multiple spatial channels in multimode and multicore optical fibres are used to increase the total transmission capacity per fibre, is being investigated to avert a data capacity crunch and reduce the cost per transmitted bit. With the number of channels employed in SDM transmission experiments continuing to rise, there is a requirement for integrated SDM components that are scalable. Here, we demonstrate a cladding-pumped SDM erbium-doped fibre amplifier (EDFA) that consists of six uncoupled multimode erbium-doped cores. Each core supports three spatial modes, which enables the EDFA to amplify a total of 18 spatial channels (six cores × three modes) simultaneously with a single pump diode and a complexity similar to a single-mode EDFA. The amplifier delivers >20 dBm total output power per core and <7 dB noise figure over the C-band. This cladding-pumped EDFA enables combined space-division and wavelength-division multiplexed transmission over multiple multimode fibre spans.

Inhomogeneous Level Splitting inPr2−xBixRu2O7

van Duijn, J.,Kim, K. H.,Hur, N.,Adroja, D.,Adams, M. A.,Huang, Q. Z.,Jaime, M.,Cheong, S.-W.,Broholm, C.,Perring, T. G. American Physical Society 2005 Physical review letters Vol.94 No.17

<P>We report that Bi doping drives Pr 2-x BixRu2O7 from an antiferromagnetic insulator (x = 0) to a metallic paramagnet (x approximately 1) with a broad low T maximum in C/T. Neutron scattering reveals local low energy spin excitations (variant Planck's omega approximately 1 meV) with a spectrum that is unaffected by heating to k(B)T >> variant Planck's omega. We show that a continuous distribution of splittings of the non-Kramers Pr3+ ground-state doublet such as might result from various types of lattice strain can account for all the data.</P>

Magnetic Properties and Microstructure of Cr₉₀Ru₁₀/Fe₅₅Pt₄₅ Bilayer Thin Film

K. T. Huang,H. W. Chang,An-Cheng Sun,P. C. Kuo,C. T. Lee,S. C. Chen,Jen-Hwa Hsu 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

X-RAY STUDIES OF THE BLACK WIDOW PULSAR PSR B1957+20

Huang, R. H. H.,Kong, A. K. H.,Takata, J.,Hui, C. Y.,Lin, L. C. C.,Cheng, K. S. IOP Publishing 2012 The Astrophysical journal Vol.760 No.1

<P>We report on Chandra observations of the black widow pulsar, PSR B1957+20. Evidence for a binary-phase dependence of the X-ray emission from the pulsar is found with a deep observation. The binary-phase-resolved spectral analysis reveals non-thermal X-ray emission of PSR B1957+20, confirming the results of previous studies. This suggests that the X-rays are mostly due to intra-binary shock emission, which is strongest when the pulsar wind interacts with the ablated material from the companion star. The geometry of the peak emission is determined in our study. The marginal softening of the spectrum of the non-thermal X-ray tail may indicate that particles injected at the termination shock are dominated by synchrotron cooling.</P>

Optimal wind-induced load combinations for structural design of tall buildings

C.M. Chan,F. Ding,K.T. Tse,M.F. Huang,K.M. Shum,K.C.S. Kwok 한국풍공학회 2019 Wind and Structures, An International Journal (WAS Vol.29 No.5

Wind tunnel testing technique has been established as a powerful experimental method for predicting wind-induced loads on high-rise buildings. Accurate assessment of the design wind load combinations for tall buildings on the basis of wind tunnel tests is an extremely important and complicated issue. The traditional design practice for determining wind load combinations relies partly on subjective judgments and lacks a systematic and reliable method of evaluating critical load cases. This paper presents a novel optimization-based framework for determining wind tunnel derived load cases for the structural design of wind sensitive tall buildings. The peak factor is used to predict the expected maximum resultant responses from the correlated three-dimensional wind loads measured at each wind angle. An optimized convex hull is further developed to serve as the design envelope in which the peak values of the resultant responses at any azimuth angle are enclosed to represent the critical wind load cases. Furthermore, the appropriate number of load cases used for design purposes can be predicted based on a set of Pareto solutions. One 30-story building example is used to illustrate the effectiveness and practical application of the proposed optimization-based technique for the evaluation of peak resultant wind-induced load cases.