Search Results - (Author, Cooperation:K. H. Chang)

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  1. 1
    Staff View
    Publication Date:
    2014-11-21
    Publisher:
    American Association for the Advancement of Science (AAAS)
    Print ISSN:
    0036-8075
    Electronic ISSN:
    1095-9203
    Topics:
    Biology
    Chemistry and Pharmacology
    Computer Science
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Animals ; Base Sequence ; *Conserved Sequence ; DNA/*genetics ; Deoxyribonuclease I ; *Evolution, Molecular ; Genome, Human ; Humans ; Mice ; Regulatory Sequences, Nucleic Acid/*genetics ; Restriction Mapping ; Transcription Factors/*metabolism
    Published by:
    http://www.aaas.org/

    Latest Papers from Table of Contents or Articles in Press
  2. 2
    F. Yue ; Y. Cheng ; A. Breschi ; J. Vierstra ; W. Wu ; T. Ryba ; R. Sandstrom ; Z. Ma ; C. Davis ; B. D. Pope ; Y. Shen ; D. D. Pervouchine ; S. Djebali ; R. E. Thurman ; R. Kaul ; E. Rynes ; A. Kirilusha ; G. K. Marinov ; B. A. Williams ; D. Trout ; H. Amrhein ; K. Fisher-Aylor ; I. Antoshechkin ; G. DeSalvo ; L. H. See ; M. Fastuca ; J. Drenkow ; C. Zaleski ; A. Dobin ; P. Prieto ; J. Lagarde ; G. Bussotti ; A. Tanzer ; O. Denas ; K. Li ; M. A. Bender ; M. Zhang ; R. Byron ; M. T. Groudine ; D. McCleary ; L. Pham ; Z. Ye ; S. Kuan ; L. Edsall ; Y. C. Wu ; M. D. Rasmussen ; M. S. Bansal ; M. Kellis ; C. A. Keller ; C. S. Morrissey ; T. Mishra ; D. Jain ; N. Dogan ; R. S. Harris ; P. Cayting ; T. Kawli ; A. P. Boyle ; G. Euskirchen ; A. Kundaje ; S. Lin ; Y. Lin ; C. Jansen ; V. S. Malladi ; M. S. Cline ; D. T. Erickson ; V. M. Kirkup ; K. Learned ; C. A. Sloan ; K. R. Rosenbloom ; B. Lacerda de Sousa ; K. Beal ; M. Pignatelli ; P. Flicek ; J. Lian ; T. Kahveci ; D. Lee ; W. J. Kent ; M. Ramalho Santos ; J. Herrero ; C. Notredame ; A. Johnson ; S. Vong ; K. Lee ; D. Bates ; F. Neri ; M. Diegel ; T. Canfield ; P. J. Sabo ; M. S. Wilken ; T. A. Reh ; E. Giste ; A. Shafer ; T. Kutyavin ; E. Haugen ; D. Dunn ; A. P. Reynolds ; S. Neph ; R. Humbert ; R. S. Hansen ; M. De Bruijn ; L. Selleri ; A. Rudensky ; S. Josefowicz ; R. Samstein ; E. E. Eichler ; S. H. Orkin ; D. Levasseur ; T. Papayannopoulou ; K. H. Chang ; A. Skoultchi ; S. Gosh ; C. Disteche ; P. Treuting ; Y. Wang ; M. J. Weiss ; G. A. Blobel ; X. Cao ; S. Zhong ; T. Wang ; P. J. Good ; R. F. Lowdon ; L. B. Adams ; X. Q. Zhou ; M. J. Pazin ; E. A. Feingold ; B. Wold ; J. Taylor ; A. Mortazavi ; S. M. Weissman ; J. A. Stamatoyannopoulos ; M. P. Snyder ; R. Guigo ; T. R. Gingeras ; D. M. Gilbert ; R. C. Hardison ; M. A. Beer ; B. Ren
    Nature Publishing Group (NPG)
    Published 2014
    Staff View
    Publication Date:
    2014-11-21
    Publisher:
    Nature Publishing Group (NPG)
    Print ISSN:
    0028-0836
    Electronic ISSN:
    1476-4687
    Topics:
    Biology
    Chemistry and Pharmacology
    Medicine
    Natural Sciences in General
    Physics
    Keywords:
    Animals ; Cell Lineage/genetics ; Chromatin/genetics/metabolism ; Conserved Sequence/genetics ; DNA Replication/genetics ; Deoxyribonuclease I/metabolism ; Gene Expression Regulation/genetics ; Gene Regulatory Networks/genetics ; Genome/*genetics ; Genome-Wide Association Study ; *Genomics ; Humans ; Mice/*genetics ; *Molecular Sequence Annotation ; RNA/genetics ; Regulatory Sequences, Nucleic Acid/genetics ; Species Specificity ; Transcription Factors/metabolism ; Transcriptome/genetics
    Published by:
    http://www.nature.com/

    Latest Papers from Table of Contents or Articles in Press
  3. 3
    Rezaei, S. D., Lu, H. K., Chang, J. J., Rhodes, A., Lewin, S. R., Cameron, P. U.
    The American Society for Microbiology (ASM)
    Published 2018
    Staff View
    Publication Date:
    2018-06-14
    Publisher:
    The American Society for Microbiology (ASM)
    Print ISSN:
    0022-538X
    Electronic ISSN:
    1098-5514
    Topics:
    Medicine
    Published by:
    http://www.asm.org/

    Latest Papers from Table of Contents or Articles in Press
  4. 4
    Tsai, K. L. ; Chang, K. H. ; Lee, C. P. ; Huang, K. F. ; Chang, Y. ; Fan, J. C. ; Liu, D. G.

    [S.l.] : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Influence of a thin protective but subsequently evaporated InAs layer on the regrowth of AlGaAs has been studied. It was found that although most of the InAs could be evaporated by thermal desorption, some would react with Al0.36Ga0.64As to form InAlGaAs. These InAlGaAs islands act as potential wells for carrier recombination and dominate the photoluminescence spectrum. Transmission electron microscopy photographs show that dislocations are formed near the islands. These defects are caused by lattice mismatch between AlGaAs and InAlGaAs. These islands and defects strongly affect the optical quality of surrounding Al0.36Ga0.64As and quantum wells.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.351590

    Articles: DFG German National Licenses
  5. 5
    Liu, D. G. ; Chang, K. H. ; Lee, C. P. ; Hsu, T. M. ; Tien, Y. C.

    [S.l.] : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Photoreflectance spectroscopy has been used to study the surface electric-field strength and the surface potential of delta-doped GaAs. Franz–Keldysh oscillations in the reflectance spectra were clearly observed and the oscillation periods were used to calculate the internal electric fields of the delta-doped samples. Based on the measured results and the self-consistent calculation, a surface potential of 0.6 eV is obtained.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.351710

    Articles: DFG German National Licenses
  6. 6
    Wu, J. S. ; Lee, C. P. ; Chang, C. Y. ; Chang, K. H. ; Liu, D. G. ; Liou, D. C.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We report the enhancement of peak-to-valley current ratios (PVCRs) of double-barrier resonant tunneling structures (DBRTSs) based on the AlGaAs/GaAs material system. The PVCRs as high as 25.4 and 18 have been obtained at 77 K for superlattice and alloy barrier structures with 0.2-μm undoped electrodes, respectively. These are the largest PVCRs to date for AlGaAs/GaAs DBRTSs. The large band bending across the undoped electrodes causes size quantization of the accumulation layer, resulting in better resonant tunneling characteristics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.347385

    Articles: DFG German National Licenses
  7. 7
    Wu, J. S. ; Lee, C. P. ; Chang, C. Y ; Chang, K. H. ; Liu, D. G. ; Liou, D. C.

    [S.l.] : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We propose and demonstrate a novel operation in the vertical integration of double-barrier resonant tunneling structures (DBRTS's) in which the negative differential resistance (NDR) region can be repeated. When two DBRTS's are combined in series, one of which has a higher peak current, a lower valley current, and a larger operation range of voltage in the NDR region than those of the other, the current-voltage (I-V) characteristic shows three current peaks instead of the conventional two. This phenomenon is based on the fundamental requirement of current continuity in serially combined devices. This operation provides a method to obtain a large number of current peaks by using less DBRTS's.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.344910

    Articles: DFG German National Licenses
  8. 8
    Liou, D. C. ; Chiang, W. H. ; Lee, C. P. ; Chang, K. H. ; Liu, D. G. ; Wu, J. S. ; Tu, Y. K.

    [S.l.] : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    A novel fabrication technique has been developed for InGaAs/GaAs strained-layer buried heterostructure lasers. Dielectric masks and Zn diffusion are not required in this technique. This novel fabrication process is much easier than the conventional approach and yields excellent laser results. A low threshold of 3 mA and high-power operation for lasing wavelength of 9800±20 A(ring) have been achieved with graded index separate confinement heterostructure devices using this novel technique.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.351398

    Articles: DFG German National Licenses
  9. 9
    Liu, D. G. ; Fan, J. C. ; Lee, C. P. ; Chang, K. H. ; Liou, D. C.

    [S.l.] : American Institute of Physics (AIP)
    Published 1993
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    N-type and p-type delta-doped GaAs grown by molecular beam epitaxy with rather significantly high doses of Si and Be have been investigated by transmission electron microscopy (TEM). The amount of doses ranged from half a monolayer to two monolayers. The microscopic structures of the delta-doped regions and the adjacent epilayers were directly observed by TEM. The effect of impurity spreading on the heterointerfaces and superlattices was also studied. Si atoms present in Si delta-doped samples were confined to within a few atomic layers. The Be atoms present in Be delta-doped samples, however, spread over a quite wide region and caused rough heterointerfaces and wavy superlattices to form. Spreading of Be was attributed to segregation and diffusion which occurred during growth. Stacking faults were found in the delta-doped samples when they were grown at low temperatures. They could be attributed to local strain caused by heavy doping.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.353370

    Articles: DFG German National Licenses
  10. 10
    Chang, K. H. ; Lee, C. P. ; Wu, J. S. ; Liu, D. G. ; Liou, D. C. ; Wang, M. H. ; Chen, L. J. ; Marais, Mario A.

    [S.l.] : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The Al composition of AlGaAs has been determined by four methods: high-resolution transmission electron microscopy (HRTEM), reflection high-energy electron diffraction (RHEED), photoluminescence (PL), and double-crystal x-ray diffraction (DCXRD). HRTEM is direct and the most accurate method because it does not involve any formula or extrapolation. Using the result obtained from HRTEM as a standard, we have calibrated the results from other methods. RHEED intensity oscillation is found to be accurate and reliable, if the growth conditions are correctly chosen. Comparing the PL results with those determined from HRTEM and RHEED, we suggest three formulas to determine the Al contents at different temperatures. We also proposed a polynomial to determine the Al concentration using the DCXRD measurement.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.349030

    Articles: DFG German National Licenses
  11. 11
    Jiang, G. C. ; Chang, Y. ; Chang, L. B. ; Juang, Y. D. ; Lu, W. L. ; Lu, Luke S. ; Chang, K. H.

    [S.l.] : American Institute of Physics (AIP)
    Published 1995
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Photoluminescence and Raman spectroscopies are employed to study undoped InGaP layers grown on GaAs (100) substrates at 750 °C by liquid phase epitaxy. There are four peaks in the photoluminescence spectrum in the energy range between 1.55 and 2.25 eV. Besides a bound exciton recombination, three longitudinal optical phonon replicas with one superimposed donor-acceptor emission are identified based upon their dependences of emission energies on temperature and excitation intensity. © 1995 American Institute of Physics.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.360031

    Articles: DFG German National Licenses
  12. 12
    Tsai, K. L. ; Lee, C. P. ; Chang, K. H. ; Chen, H. R. ; Tsang, J. S.

    [S.l.] : American Institute of Physics (AIP)
    Published 1994
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The influence of oxygen on the performance of GaAs/AlGaAs quantum well infrared photodetectors (QWIP) has been studied. Photoluminescence and secondary ion mass spectroscopy were used to examine the relationship between the quality of AlGaAs and the oxygen content that were then correlated to the performance of QWIPs. It was found that oxygen is the dominant impurity in the GaAs/AlGaAs superlattice. Because oxygen atoms behave likes electron traps, which effectively reduce the carrier concentration in the material, both of the responsivity and the dark current of QWIP are reduced. The detectivities of QWIPs with lower oxygen concentrations are better than those with higher oxygen concentrations.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.358439

    Articles: DFG German National Licenses
  13. 13
    Liu, D. G. ; Lee, C. P. ; Chang, K. H. ; Wu, J. S. ; Liou, D. C.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Delta doping in quantum well structures has been studied. The quantum wells consist of a strained InGaAs layer sandwiched between two GaAs layers. The layers were undoped except for a sheet of Si dopants deposited in the middle of the quantum well. Structures with various doses and quantum well thicknesses were studied and compared. Capacitance voltage measurements were carried out to determine the carrier distribution. A very narrow carrier profile with a full width at half maximum of only 12 A(ring) has been achieved. This is the narrowest carrier profile ever reported for any growth technique.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.104001

    Articles: DFG German National Licenses
  14. 14
    Wu, J. S. ; Chang, K. H. ; Lee, C. P. ; Chang, C. Y. ; Liu, D. G. ; Liou, D. C.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1991
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The photoluminescence (PL) of double-barrier resonant tunneling structures (DBRTSs) with undoped electrodes under bias has been studied. The strong band bending across the cathode causes the quantum size effect in the accumulation layer. The resonant tunneling of electrons from the first excited quantum level in the accumulation layer produces a kink in the current-voltage characteristic. It is found that the PL intensity from the quantum well (QW) as a function of bias sharply peaks at the voltage corresponding to the kink. This provides evidence of the interaction between the first excited quantum state in the accumulation layer and the resonant state in the QW.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.105532

    Articles: DFG German National Licenses
  15. 15
    Chang, K. H. ; Lee, C. P. ; Wu, J. S. ; Liu, D. G. ; Liou, D. C.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Influence of indium doping on the qualities of AlGaAs layers grown by molecular beam epitaxy has been studied. It was found that a proper amount of In doping can increase the photoluminescence intensity drastically by a factor greater than 10 indicating an improvement in the optical quality of AlGaAs epilayers. The improvement in the material quality is attributed to a higher surface migration rate of In atoms than those of Ga and Al atoms leading to a reduction of group III vacancies. However, too great a concentration of In atoms leads to effects that may degrade the film quality.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.104073

    Articles: DFG German National Licenses
  16. 16
    Liu, D. G. ; Lee, C. P. ; Chang, K. H. ; Wu, J. S. ; Liou, D. C.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    The first layer growth in GaAs molecular beam epitaxy has been studied by reflection high-energy electron diffraction (RHEED). The time between the growth start and the first RHEED intensity peak is found to be dependent on the starting surface condition and is different from the time needed for a single layer growth. Periodic flux interruption has been used to study the surface recovery behavior as a function of growth time. When the growth time is the same as the time for a single layer growth, sustained two-dimensional growth can be obtained.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.103445

    Articles: DFG German National Licenses
  17. 17
    Wu, J. S. ; Chang, C. Y. ; Lee, C. P. ; Chang, K. H. ; Liu, D. G. ; Liou, D. C.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1990
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We report the first observation of the resonant tunneling features associated with the quantized levels in the accumulation layer of the double-barrier resonant tunneling structure (DBRTS) with undoped electrodes. This quantum effect causes additional kinks in the current-voltage (I-V) characteristic and an increasingly enhanced oscillation behavior in the differential conductance-voltage (G-V) curve. Three discrete quantum levels have been observed based on the room-temperature G-V curve. Our measurements are made without the presence of magnetic field and thus the experimental results are totally different from the magneto-oscillation.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.103879

    Articles: DFG German National Licenses
  18. 18
    Chang, K. H. ; Bhattacharya, P. K. ; Gibala, R.

    [S.l.] : American Institute of Physics (AIP)
    Published 1989
    Staff View
    ISSN:
    1089-7550
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    We have investigated the generation and propagation of misfit dislocations in strained InyGa1−yAs/GaAs multiquantum wells grown by molecular-beam epitaxy, with cross-sectional transmission electron microscopy. The samples are of excellent optical quality, with multiquantum wells having well widths of 100 A(ring), being characterized by excitonic linewidths and Stokes shifts of 1.5–2.5 and 1–2 meV, respectively. We have examined the growth of 2-μm-thick multiquantum-well samples grown either directly on GaAs, or with an intermediate composition buffer layer, and for the cases of small (y=0.07) and large (y=0.16) misfits. It is seen that for the case of quantum wells with small misfit, grown directly on GaAs, metastable growth can be achieved. This is confirmed by low-temperature absorption measurements and from transmission electron microscopy experiments performed both before and after post-growth thermal annealing. In the case of quantum wells with large misfits directly grown on GaAs, dislocations are generated within the first few periods, and high optical quality is retained in the subsequent free-standing quantum wells. In the case of quantum wells grown with an intermediate composition InxGa1−xAs buffer layer, dislocations are generated at the buffer-GaAs interface, and the freestanding multiquantum well is again of very high quality.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.342654

    Articles: DFG German National Licenses
  19. 19
    Lee, C. P. ; Chang, K. H. ; Tsai, K. L.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Multiple quantum well infrared photodetectors (QWIPs) with bi-periodic grating couplers have been demonstrated. The bi-periodic grating consists of two gratings with different periods. The response linewidths of such QWIPs are found to be much wider than those of conventional grating coupled QWIPs. By using bi-periodic gratings for coupling the radiation into QWIPs, the influence of variation of material and grating quality on the performance of QWIP can be largely eliminated.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.108189

    Articles: DFG German National Licenses
  20. 20
    Liu, D. G. ; Fan, J. C. ; Lee, C. P. ; Tsai, C. M. ; Chang, K. H. ; Liou, D. C. ; Lee, T. L. ; Chen, L. J.

    Woodbury, NY : American Institute of Physics (AIP)
    Published 1992
    Staff View
    ISSN:
    1077-3118
    Source:
    AIP Digital Archive
    Topics:
    Physics
    Notes:
    Direct observation of the Si delta-doped layer in GaAs has been achieved by high resolution transmission electron microscopy. Samples with different Si doses, from half a monolayer to two monolayers, were studied. The observed spreading of the delta-doped layer showed that Si atoms are largely confined in five monolayers at most (in the highest dose case), indicating excellent confinements of dopants in GaAs. From the images, the Si atoms were uniformly distributed in the doped layer, no cluster formation was observed. For delta-doped GaAs grown at low temperature (480 °C), stacking faults originated from the doped layers were observed. These faults were thought to be caused by the large unrelaxed strain in the low-temperature grown GaAs.
    Type of Medium:
    Electronic Resource
    URL:
    http://dx.doi.org/10.1063/1.106902

    Articles: DFG German National Licenses