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Your search keyword '"Chang, H. H."' showing total 602 results
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602 results on '"Chang, H. H."'

1. Gap opening and orbital modification of superconducting FeSe above the structural distortion

Author

Wen, Y. -C., Wang, K. -J., Chang, H. -H., Luo, J. -Y., Shen, C. -C., Liu, H. -L., Sun, C. -K., Wang, M. -J., and Wu, M. -K.

Subjects
Condensed Matter - Superconductivity, Physics - Optics
Abstract

We utilize steady-state and transient optical spectroscopies to examine the responses of nonthermal quasiparticles with respect to orbital modifications in normal-state iron-chalcogenide superconductors. The dynamics shows the emergence of gap-like quasiparticles (associated to a ~36 meV energy gap) with a coincident transfer of the optical spectral weight in the visible range, at temperatures above the structural distortion. Our observations suggest that opening of the high-temperature gap and the lattice symmetry breaking are possibly driven by short-range orbital and/or charge orders, implicating a close correlation between electronic nematicity and precursor order in iron-based superconductors.

Published
2012
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2. Crystal orientation and thickness dependence of superconductivity on tetragonal FeSe1-x thin films

Author

Wang, M. J., Luo, J. Y., Huang, T. W., Chang, H. H., Chen, T. K., Hsu, F. C., Wu, C. T, Wu, P. M., Chang, A. M., and Wu, M. K.

Subjects
Condensed Matter - Superconductivity
Abstract

Superconductivity was recently found in the simple tetragonal FeSe structure. Recent studies suggest that FeSe is unconventional, with the symmetry of the superconducting pairing state still under debate. To tackle these problems, clean single crystals and thin films are required. Here we report the fabrication of superconducting beta-phase FeSe1-x thin films on different substrates using a pulsed laser deposition (PLD) technique. Quite interestingly, the crystal orientation, and thus, superconductivity in these thin films is sensitive to the growth temperature. At 320C, films grow preferably along c-axis, but the onset of superconductivity depends on film thickness. At 500C, films grow along (101), with little thickness dependence. These results suggest that the low temperature structural deformation previously found is crucial to the superconductivity of this material.

Published
2009
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3. Image segmentation using a charged fluid method

Author

Chang, H H and Valentino, Daniel J

Abstract

A new image segmentation algorithm that uses the simulation of a charged fluid is developed. Conceptually, a charged fluid consists of charged elements, each of which exerts a repelling electric force on the others. The charged fluid behaves like a liquid such that it flows through and around different obstacles. The boundary of the segmented object is determined by the image gradient, which is modeled as potential wells that stop the propagating front. The simulation is evolved in two steps that are governed by Poisson's equation. The first step distributes the elements of the charged fluid along the propagating interface until an electrostatic equilibrium is achieved. The second step advances the propagating front of the charged fluid such that it deforms into a new shape in response to the equilibrium electric potential and the image potential. The procedure is repeated until the propagating front resides on the boundary of objects being segmented. The electric potential of the simulated system is rapidly calculated using the finite-size particle (FSP) method implemented via the fast Fourier transform (FFT) algorithm. Experimental results using phantom images, photographic pictures, and medical images demonstrate the utility of this new algorithm in a wide variety of image processing applications. (C) 2006 SPIE and IS&T.

Published
2006

4. Traveling-wave photodetectors with high power-bandwidth and gain-bandwidth product performance

Author

Lasaosa, D, Shi, J W, Pasquariello, D, Gan, K G, Tien, M C, Chang, H H, Chu, S W, Sun, C K, Chiu, Y J, and Bowers, J E

Subjects
amplifier, GaAs, high speed, InGaAsP, photodetector, traveling wave
Abstract

Traveling-wave photodetectors (TWPDs) are an attractive way to simultaneously maximize external quantum efficiency, electrical bandwidth, and maximum unsaturated output power. We review recent advances in TWPDs. Record high-peak output voltage together with ultrahigh-speed performance has been observed in low-temperature-grown GaAs (LTG-GaAs)-based metal-semiconductor-metal TWPDs at the wavelengths of 800 and 1300 nm. An approach to simultaneously obtain high bandwidth and high external efficiency is a traveling-wave amplifier-photodetector (TAP detector) that combines gain and absorption in either a sequential or simultaneous traveling-wave structure.

Published
2004

5. Development of a Novel Micro-motion Dental Implant System

Author

Chen, Y. Y., Chen, W. P., Chang, H. H., Huang, S. H., Lin, C. P., MAGJAREVIC, Ratko, Editor-in-chief, Ładyzynsk, Piotr, Series editor, Ibrahim, Fatimah, Series editor, Lacković, Igor, Series editor, Rock, Emilio Sacristan, Series editor, Su, Fong-Chin, editor, Wang, Shyh-Hau, editor, and Yeh, Ming-Long, editor

Published
2015
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13. List of Contributors

Author

Azmi, A.S., primary, Bai, W., additional, Bepler, G., additional, Bian, M., additional, Bruflat, J.K., additional, Chang, H.-H., additional, Chow, C.R., additional, Clark, G.J., additional, Ebine, K., additional, Eibl, G., additional, Eisner, J.L., additional, Gray, N.S., additional, Hattaway, H.Z., additional, Hunter, J.C., additional, Irving, J.A.E., additional, Isbell, A.J., additional, Kashatus, D.F., additional, Keeton, A.B., additional, Kumar, K., additional, McArthur, G.A., additional, Mezzanotte, J.N., additional, Munshi, H.G., additional, Njogu, M.M., additional, O’Neill, E., additional, Odanga, J.J., additional, Philip, P.A., additional, Piazza, G.A., additional, Rao, A.D., additional, Samatar, A.A., additional, Schmidt, A., additional, Schmidt, R.L., additional, Siewertsz van Reesema, L.L., additional, Stuart, D.D., additional, Svyatova, E., additional, Tang, A.H., additional, Tang-Tan, A.M., additional, Van Sciver, R.E., additional, Westover, K.D., additional, Xiang, S., additional, Zhang, X., additional, and Zheleva, V., additional

Published
2017
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30. Long-term results of Taiwan Pediatric Oncology Group studies 1997 and 2002 for childhood acute lymphoblastic leukemia

Author

Liang, D-C, Yang, C-P, Lin, D-T, Hung, I-J, Lin, K-H, Chen, J-S, Hsiao, C-C, Chang, T-T, Peng, C-T, Lin, M-T, Chang, T-K, Jaing, T-H, Liu, H-C, Wang, L-Y, Yeh, T-C, Jou, S-T, Lu, M-Y, Cheng, C-N, Sheen, J-M, Chiou, S-S, Wu, K-H, Hung, G-Y, Chen, R-L, Chen, S-H, Cheng, S-N, Chang, Y-H, Chen, B-W, Ho, W-L, Wang, J-L, Lin, S-T, Hsieh, Y-L, Wang, S-C, Chang, H-H, Yang, Y-L, Huang, F-L, Chang, C-Y, Chang, W-H, and Lin, K-S

Published
2010
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34. Photocatalytic Reduction of CO2 by TiO2 Nanotubes.

Author

Chang, H.-H., Wei, L.-W., Huang, H.-L., Chang, H.-Y., and Wang, H. Paul

Subjects
*NANOTUBES, *FOURIER transform infrared spectroscopy, *CHEMICAL reduction, *SURFACE reactions, *CHEMICAL energy, *PHOTOREDUCTION
Abstract

Continuously increasing atmospheric concentrations of CO2 have given rise to great concerns about climate change. Photocatalytic reduction of CO2 to chemicals by solar energy is considered a green and sustainable process. Interactions between CO2 molecules and photocatalysts surfaces are the key factors that affect photocatalytic reduction efficiency. Thus, a better understanding of their reactive species on the TiO2 nanotube (TNT) surfaces by in situ FTIR spectroscopy was studied in the present work. The FTIR absorbance features at 1303 cm − 1 and 1393 cm − 1 were associated with carbonate species, e.g., bidentate carbonate on the TNT. Complete desorption of CO2 from the TNT occurred at T > 4 1 8 K. The carboxylate species that were adsorbed on the TNT may conduct the surface reactions enhanced by UV–Vis light to yield low carbon chemicals. A better understanding of reactive species on the TiO2 nanotube (TNT) surfaces by in situ FTIR spectroscopy was studied. The FTIR absorbance features at 1303 and 1393 cm–1 were associated with carbonate species, e.g., bidentate carbonate on the TNT. Complete desorption of CO2 from the TNT occurred at T > 418 K. The carboxylate species that were adsorbed on the TNT may conduct the surface reactions enhanced by UV–Vis light to yield low carbon chemicals. [ABSTRACT FROM AUTHOR]

Published
2022
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