Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 809-812 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In high-power AlGaAs window structure lasers with a window grown on facets (WGF) structure, dependence of window effects on Al content of the window layer is examined. When the Al content of the window layer is more than that of the cladding layer, the window effects are found. But, in other cases, the window effects do not occur. A calculation of a carrier leakage from the active layer to the window layer is performed. From the result, we deduce that the reduction of the window effects is caused by the carrier leakage. In the WGF laser with the confirmed window effects, a maximum output power of 350 mW is achieved and highly reliable operation under 100 mW at 50 °C beyond 10000 h is attained.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 5000-5003 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A thermally stimulated current (TSC) has been applied to estimate the trap properties on a thin film of β-form oxotitanium phthalocyanine (β-TiOPc) dispersed in polyester. The hole trapping levels derived from the activation energies (Eas) were obtained by an initial rising method and heating rate dependence on TSC peaks. The Eas for an electric field of 2.5×103 V/cm were distributed from 0.033 eV for shallow traps to 0.42 eV for deep traps.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 4583-4585 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The Faraday rotation constants in a magneto-optic channel waveguide whose magnetization aligns along the direction of propagation are measured by a novel method developed by the authors. The tested sample is a lanthanum and gallium substituted yttrium iron garnet optical channel waveguide prepared by the liquid phase epitaxial and the ion milling techniques. The proposed method is more practical than the previously reported one because of determination of the parameters with one time measurement. In the previous method we needed to know the phase constant difference between the orthogonally polarized waves to determine the Faraday coefficient. Using the presented technique we successfully measure the magneto-optic coefficients in the iron garnet waveguide at the near infrared wavelengths: 1.15, 1.3, and 1.55 μm. We confirm the validity of the proposed method by comparing with other methods: the previously reported method and the Faraday modulation method conventionally used for measuring the Faraday rotation. We also demonstrate the waveguide isolator operation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 3 (1991), S. 1468-1468 
    ISSN: 1089-7666
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In binary fluid mixtures with negative separation ratio, the conduction state has a vertical concentration gradient, due to the Soret effect, which opposes the destabilizing effect of the vertical temperature gradient. The first convective states are traveling waves (TW) with a phase velocity which is much lower than that of the linear instability. Recent perturbation theory calculations and numerical simulations of this nonlinear, traveling-wave state predict that the linear concentration gradient in the conduction state is eliminated in the interior of the fluid by convective mixing, and the concentration gradient remains only in the boundary layers. It is the persistence of the concentration gradient in these boundary layers which leads to the small but nonzero wave speed. As the Rayleigh number R is increased, convective stirring of the mixture decreases the concentration boundary layers, and the TW phase speed goes continuously to zero. We report experimental studies of these nonlinear, traveling-wave states in ethanol/water mixtures in an annular geometry. The measured TW phase speed as a function of R is in excellent agreement with the theoretical predictions over the entire TW branch. The experiments also confirm that this transition to stationary convection is not hysteretic. The role of mixing and the transport of concentration in the dynamics of nonlinear fronts and pulses observed in this system will also be discussed. [Work supported by DARPA URI Contract No. N00014-86-K-0758.]
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 1653-1655 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Time-dependent change in the visible luminescence of porous Si immersed in HF aqueous solution was measured in a short acquisition time (5 s) with a charge coupled device detector. Under Ar+ laser light (514.5 nm) irradiation, the photoluminescence band of the porous Si shifted to shorter wavelength accompanying a reduction of the peak intensity. The result suggests that the size of the Si nanostructure is closely related to the gap energy of the porous Si.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 2967-2969 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: In situ angle resolved x-ray photoemission spectroscopy has been performed on superconducting a,b-axis oriented YBa2Cu3O7−δ epitaxial films. The relative intensities of the Cu 2p Ba 3d, and Y 3d core emissions have shown the diffraction-like dependence on the electron escape angle due to the spatial distribution of elements in the surface layer. The calculated results by the single scattering cluster model on the surface with the Cu-O outermost layer show a better agreement with the experiment than the (Y, Ba)-O in the outermost layer.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    International journal of immunogenetics 8 (1981), S. 0 
    ISSN: 1744-313X
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie , Medizin
    Notizen: Five major glycoproteins with anti-B agglutinin activity were isolated from seeds of Euonymus Sieboldiana by a procedure based on precipitation with ammonium sulphate, Sepharose 4B gel filtration, CM- and DEAE-Sepharose chromatography and Sephacryl S-200 gel filtration. The purified glycoproteins each gave a single symmetrical peak on Sephacryl S-200 gel filtration with elution volumes corresponding to molecular weights of approximately 15,000 to 130,000, each forming a single precipitin line on gel diffusion plates with anti-E. Sieboldiana antibody. These anti-B glycoproteins were rich in acidic amino acids without cysteine and methionine and contained about 8-36% carbohydrate, of which galactose, arabinose and glucose were the predominant sugars, with small amounts of glucosamine, rhamnose, fucose, xylose, mannose and ribose. The most anti-B active lectin agglutinated human B red blood cells at a concentration of 2 μg/ml and was strongly inhibited by melibiose. The three other lectins with anti-B agglutinin activity, however, were not inhibited by any galactose-containing glycosides.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: An 800-MeV compact storage ring is under construction for development of the technology of a compact ring and for research of x-ray lithography and material analysis. Synchrotron radiation with a critical wavelength of 0.65 nm is emitted from a pair of superconducting bending magnets. A straight section of the ring has only one quadrupole magnet to make the smaller ring. An injection efficiency with a single kicker magnet is optimized by computer simulation. The kicker field strength and an injection angle are determined. A beam tracking with a numerical integration method shows this ring has a sufficiently wide dynamic aperture of ||x||(approximately-equal-to)30 mm and ||y||(approximately-equal-to)50 mm at the center of the bending magnet, which has βxmin and βymax. A 1-GeV synchrotron is used as an injector, which has accelerated a beam up to 1 GeV.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 1365-2826
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: It is not entirely clear whether or not atrial natriuretic peptide (ANP) directly inhibits vasopressin neurons in the supraoptic nucleus (SON) and paraventricular nucleus. Recently, a novel peptide, brain natriuretic peptide (BMP), which has been isolated from the brain, has been shown to have a similar action to ANP on the regulation of vasopressin release. Intracerebroventricular injection of both BNP and ANP inhibits stimulus-evoked increases of plasma vasopressin level. The present study was undertaken: 1) to investigate whether BNP affects the activity of neurons in the region of the anteroventral third ventricle (AV3V) and SON which are involved in the control of body fluid homeostasis and blood pressure regulation, 2) to reassess effects of ANP on SON neurons, and 3) to test whether BNP exerts its effects by mechanisms which are different from those of ANP. Extracellular recordings were made from 213 AV3V and 110 SON spontaneously firing neurons in the rat coronal hypothalamic slice preparation. Of the AV3V neurons tested, BNP inhibited 86 (40%) and excited 2 (1%) while 125 neurons remained unaffected. A dose-response relationship was obtained for 7 AV3V neurons at different BNP concentrations ranging from 10−11 M to 10−6 M; the firing rates of all 7 neurons decreased. The threshold concentration to evoke inhibitory responses was approximately 10−10M in the AV3V. When BNP and ANP were applied to the same neuron, most AV3V neurons which were inhibited by BNP were also inhibited by ANP and the neurons which were unaffected by BNP were also unaffected by ANP. Thus, these two peptides probably have a similar action on AV3V neurons. When BNP and angiotensin II were applied to a group of 60 neurons in the AV3V, most of the responsive neurons showed either inhibitory responses to BNP or excitatory responses to angiotensin II. Both BNP and ANP were applied to a group of 110 SON neurons: BNP (10 −7 M) inhibited 52 (75%) of 69 phasic (putative vasopressin) neurons, while BNP affected none of the 41 non-phasic (putative oxytocin) neurons. By contrast, ANP inhibited only 20 (29%) of 69 phasic neurons tested but it also had no effect on 41 non-phasic neurons tested. Our results are consistent with the suggestion that BNP is involved in the regulation of vasopressin release by acting on SON neurons and AV3V neurons.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental dermatology 1 (1976), S. 0 
    ISSN: 1365-2230
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...