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  • 1
    Electronic Resource
    Electronic Resource
    The role of sex steroid in two avian song behaviours differing in ontogenetic process (1994)
    Springer
    Cellular and molecular life sciences 50 (1994), S. 972-974 
    Details
    ISSN: 1420-9071
    Keywords: Bengalese finch ; birdsong ; directed song ; undirected song ; maturational process ; fecal steroid hormone ; testosterone dependency
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The male Bengalese finch,Lonchura striata, has two types of song behaviour (directed song, DS and undirected song, US). DS and US share a basically identical syllable repertoire, sequence pattern and tempo, but differ in the time course of appearance during the maturational process. In order to examine whether this results from a difference in testosterone (T) dependency, we studied developmental changes in the fecal T level and the amounts of DS and US during the 2–4 month period (N=7). DS appeared between 83 and 94 days of age, 4–16 days after a rise in the fecal T level. In contrast, US appeared earlier and at high frequency even when T was still at a very low level. These results suggest that DS is more dependent on the T level than US, and is not activated until the T level rises during the maturational process.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01923490
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  • 2
    Electronic Resource
    Electronic Resource
    Chromosomal complements of two forms ofNeanthes japonica (Polychaeta, Nereididae) with evidence of male-heterogametic sex chromosomes (1992)
    Springer
    Marine biology 112 (1992), S. 299-307 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Karyotypes of the brackish-water polychaeteNeanthes japonica (Izuka) collected from five rivers in Japan from 1984 to 1988 were examined with air-drying and flame-drying methods using materials consisting of regenerating tails, clumps of spermatogonia and youngN. japonica specimens (embryos, larvae or juveniles). A diploid number of 28 was determined in well-spread metaphase chromosomes of mitotic cells. The presence of an XX-XY (male heterogametic) sex chromosome system was established for the first time in polychaetes. The Y chromosome was larger than the X chromosome. Slight differences in karyotype were found between two forms (the small- and large-egg forms), which are very similar in adult morphology but can be distinguished by reproductive and developmental characteristics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00702475
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  • 3
    Electronic Resource
    Electronic Resource
    The Regulation of Cholesteryl Ester Metabolism by 17β-Estradiol in Macrophages (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 748 (1994), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1994.tb17379.x
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  • 4
    Electronic Resource
    Electronic Resource
    Characterization of interfacial atomic steps in GaAs/AlAs superlattices by transmission electron microscopy (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 379-381 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied interfacial atomic steps in GaAs/AlAs superlattices using high-resolution transmission electron microscopy (HRTEM) and lattice image simulation. We find arrays of bright spots at the interface in the TEM image to be good indicators of the interface configuration. Doubling of the bright spot arrays and step-shaped arrays in TEM lattice images indicate a "type 1'' monolayer step whose front is perpendicular to the direction of the electron beam and a "type 2'' monolayer step whose front is parallel to the direction of the electron beam. Our HRTEM observations indicate that the atomic steps at GaAs and AlAs interfaces grown at 700 °C are denser than at interfaces grown at 500 °C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.99899
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  • 5
    Electronic Resource
    Electronic Resource
    Low resistivity quasi-epitaxial Mo-Ta alloy and high-quality anodic oxide for a-Si thin-film transistor liquid-crystal display (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 2052-2055 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Sputtered Mo-Ta alloy and its anodic oxide have been studied in a Mo composition range from 0 to 30 at. %. Resistivity abruptly changed as Mo composition increased above 10 at. % from 185 μΩ cm to about 35 μΩ cm. The crystal structure transformed from tetragonal to cubic at this Mo composition. For higher Ta compositions, the crystal structure varied according to the under-layer polycrystalline film crystal structure, which may be denoted as quasi-epitaxial deposition, and the resistivity decreased to as low as 22 μΩ cm. Anodic oxide films of Mo-Ta alloy were superior to conventional Ta anodic oxide films in regard to resistivity and breakdown field, and the best insulator was obtained at Ta 95 at. %. This quasi-epitaxial Mo-Ta alloy and anodic oxide were applied for thin-film transistor matrix substrates.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.344312
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  • 6
    Electronic Resource
    Electronic Resource
    Selenium and zinc doping in Ga0.5In0.5P and (Al0.5Ga0.5)0.5In0.5P grown by metalorganic chemical vapor deposition (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 5285-5289 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Electrical properties of Se- and Zn-doped Ga0.5In0.5P and (Al0.5Ga0.5)0.5In0.5P grown by atmospheric pressure metalorganic chemical vapor deposition under a wide range of growth conditions were investigated using van der Pauw–Hall measurements at room temperature. The dopants were hydrogen selenide and dimethylzinc. The samples were prepared so that parasitic conduction in the GaAs substrate just adjacent to the ternary or quaternary layers could be eliminated from the Hall measurement. The carrier concentration of GaInP and AlGaInP increased as the 0.8±0.1th power of the feed amount of dopants for both conductivity types. At a growth temperature around 680 °C, the hole concentration tended to saturate near the 1018 cm−3 level as the amount of dimethylzinc being fed increased. The carrier concentration decreased with increasing growth temperature, with apparent activation energies of 0.95 eV for Se doping and 1.9 eV for Zn doping. The group-V to group-III feed ratio had a weak influence on the carrier concentration. On the other hand, the Hall mobility of the layers grown under the various growth conditions remained almost constant: the electron mobilities of Se-Ga0.5In0.5P and Se-(Al0.5Ga0.5)0.5In0.5P within the carrier concentration range of 1017 〈n〈1018 cm−3 were 950–700 and ∼100 cm2/V s, respectively. The hole mobilities of Zn-Ga0.5In0.5P and Zn-(Al0.5Ga0.5)0.5In0.5P within the carrier concentration range of 1017 〈p〈1018 cm−3 were ∼34 and ∼16 cm2/V s, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.343718
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  • 7
    Electronic Resource
    Electronic Resource
    Thermal strain-induced degradation mechanism in the visible AlGaAs/GaAs laser (1985)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 58 (1985), S. 2448-2452 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We fabricated and life-tested visible AlGaAs/GaAs channeled-substrate-planar-type lasers and found that some are degraded within 100 h of operation. We investigated these using photoluminescence and transmission electron microscopic images. The characteristic features in photoluminescence images are dark defects that run parallel to the channeled stripe. Using transmission electron microscopy, we found that these dark defects are composed of precipitates, dislocation loops, and dislocation dipoles. In order to know the relation between these degradation phenomena and the thermal strain induced by lattice mismatch, we calculated the stress distribution in the semiconductor laser using the finite element method. According to this simulation, a stress concentration in the active layer arises near the edges of the channeled stripe where the volume dilatation is maximal. Combining the results of experiments and simulation, we concluded that interstitial atoms created by nonradiative recombination migrate to the edges of the stripe, and that ultimately dark defects appear near the edges of the stripe.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.335919
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  • 8
    Electronic Resource
    Electronic Resource
    Anisotropic Nd–Fe–B thin-film magnets for milli-size motor : The 5th Joint MMM−Intermag Conference (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 6627-6629 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Efforts were made to obtain anisotropic thin-film magnets at low substrate temperature. This is an important criterion for practical applications such as to build motors. The influence of substrate materials as well as film thickness on the c-axis orientation were studied. It has been shown that thin-film magnets with the easy axis of magnetization normal to the film plane could be deposited at a substrate temperature of around 450 °C by choosing the composition near the line from Nd13Fe76B11 to Nd13Fe70B17 in the ternary phase diagram. It was found that the anisotropic film magnets could be also deposited on the metallic substrate. The c-axis orientation tended to be isotropic with an increase in film thickness. The obtained results were used to fabricate a milli-size motor by depositing 20-μm-thick Nd–Fe–B films on a silicon steel disk substrate of 5-mm diam. The milli-size motor exhibited a torque of 0.8 g mm at a rotational speed of 3000 rpm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349879
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  • 9
    Electronic Resource
    Electronic Resource
    Transmission electron microscopic study of the ordered structure in GaInP/GaAs epitaxially grown by metalorganic chemical vapor deposition (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 53 (1988), S. 2164-2166 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: GaInP epitaxial crystals grown on (001) GaAs at 660–700 °C by metalorganic chemical vapor deposition are examined by transmission electron microscopy. The computer-processed image of the high-resolution electron micrograph clearly reveals a lamellate-ordered domain structure of two variants of {111} superlattices, which is also investigated using cross-section and plan-view dark field electron micrographs. The spikes of well-defined superspots in the diffraction pattern were found to originate from the shape of the domains. The investigation of GaInP grown with different Zn concentrations showed that the disordering occurs as a result of a decrease in the density rather than the size of the domain.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.100287
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  • 10
    Electronic Resource
    Electronic Resource
    680-nm band GaInP/AlGaInP tapered stripe laser (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1572-1573 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A gain-guiding tapered stripe laser was fabricated using a Ga0.5In0.5P/(Al0.5Ga0.5)0.5In0.5P double heterostructure wafer grown by metalorganic chemical vapor deposition. The laser showed a continuous wave (cw) threshold current of 48 mA, a maximum temperature for cw operation of 81 °C, an aspect ratio of about 2, and an astigmatism near 25 μm. The emission wavelength was 684 nm. Thirty-two devices have been operating without significant degradation for more than 2000 h at 50 °C with a constant output power of 3 mW.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.98610
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