ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 809-812 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: 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.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 4946-4949 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We studied nonradiative recombination centers in undoped (AlxGa1−x)0.5In0.5Pgrown by metalorganic vapor phase epitaxy using transient capacitance spectroscopy. We found three deep energy levels, including a mid-gap level. We drew an equation to get a capture cross section for minority carriers, and obtained it using isothermal capacitance transient spectroscopy measurement. The mid-gap level had an electron capture cross section of 2 × 10−10 cm2 and a hole capture cross section of 1 × 10−15 cm2. The time constant of nonradiative recombination through the mid-gap level was found to be comparable to that of radiative recombination. We concluded that the mid-gap level is an effective nonradiative recombination center that reduces photoluminescence intensity.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 64 (1994), S. 3629-3630 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using time-resolved photoluminescence, we examined the carrier-recombination process in strained AlGaInP/GaInP double heterostructures grown by metal-organic vapor phase epitaxy. We found that interfacial recombination dominates the process at room temperature, and that the interfacial recombination is enhanced by tensile strain and reduced by compressive strain.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 1736-1738 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We fabricated a GaInP/AlGaInP visible laser with a real-index guide structure by one-step metalorganic vapor phase epitaxy using simultaneous impurity doping. We achieved an effective self-aligned current-confinement structure in the AlGaInP cladding layer and a threshold current of only 18 mA. The laser had stable transverse-mode oscillation with a beam astigmatism less than 1 μm.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 86 (1964), S. 1297-1300 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1432-0649
    Keywords: 42.60.Kg ; 87.60 Gp
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This paper describes a new application of optical heterodyne detection using a laser beam for two-dimensional imaging of the internal structure of strongly scattering media in which the structure is completely obstructed from normal visual observation. The directional resolution capability for image formation due to the excellent antenna properties of the heterodyne technique is verified experimentally using a ground glass to cause strong scattering of the signal beam. Successful image detection of a test target placed in a highly scattering absorptive medium, with spatial resolution better than 400 μm in the case of our experiments, demonstrates that this Coherent Detection Imaging (CDI) method can overcome the diffuse nature of images in media such as those of biomedical interest and others to achieve scanning and tomographic imaging.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1432-0800
    Source: Springer Online Journal Archives 1860-2000
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Medicine
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 97 (1992), S. 141-145 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A microcytofluorometrical DNA measurement was basically studied and was applied to single megakaryocytes previously identified on a Wright-Giemsa stained smear. The smear was first photographed and the location of each megakaryocyte was recorded on a cell map. The smear was then bleached with 50% acid ethanol and absolute methanol, and re-stained with 4′,6-diamidino-2-phenylindole (DAPI) reagent (pH 7.4) at 4° C. Nuclear blue fluorescence was observed and the intensity of this fluorescence was proportional to the amount of DNA with the coefficient of variation (CV) of 3.6% when stained for 30 min. After 30 min DAPI staining, the DNA measurement was microcytofluorometrically performed in single megakaryocytes which had been morphologically classified into 4 groups on the basis of cytoplasmic maturation, Bessis' classification, assessed on Wright-Giemsa-stained bone-marrow smears from normal human beings. The histograms of the cells did not show any difference in DNA ploidy distribution among the classes: that is, the DNA histograms disclosed ploidy distribution from 4 N to 64 N with the largest population of 16 N. These findings suggest that nuclear DNA synthesis is completed before platelet production starts. This method is useful for comparing the morphological features and DNA content of single megakaryocytes.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Histochemistry and cell biology 94 (1990), S. 257-262 
    ISSN: 1432-119X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A new method has been developed for the precise identification of human bone marrow colony forming unit erythroid (CFU-E) and burst forming unit erythroid (BFU-E) colonies, and for determination of the hemoglobin contents using microcytofluorometry. The method relies on a photochemical reaction in which intracellular hemoglobin is converted into fluorescent porphyrin under violet light (λ=405 nm) in the presence of an SH-donor (mercaptoethylamine hydrochloride). The CFU-E and BFU-E colonies showed red fluorescence with two spectrum peaks at 600 and 650 nm when illuminated by violet light. These two peaks are consistent with those of porphyrin fluorescence. The porphyrin fluorescence was not inducible in colony forming unit granulocyte-macrophage (CFU-GM) colonies, while 20% of the CFU-GM colonies were false positive with respect to the conventional benzidine reaction. The photochemically inducible fluorescence began to appear in BFU-E colonies on the 4th day of culture, while the same colonies started to be positive for the benzidine reaction on the 9th day. Therefore, the photochemical reaction was more specific and sensitive than the benzidine reaction for the identification of CFU-E and BFU-E colonies. In addition, this method enabled us to measure the hemoglobin level in the cells forming the colonies because the intensity of the fluorescence was proportional to the amount of hemoglobin when the photochemical reaction was carried out for 50 min. As a result of qualitative and quantitative analysis of CFU-E colonies by this method, it was possible to detect the hemoglobin levels in the colonies from 1 of 4 cases of untreated acute nonlymphocytic leukemia and from 2 of 4 cases of myelodysplastic syndrome in which the hemoglobin levels were too low to be detected by the benzidine reaction. These cases, where the CFU-E colonies showed very low levels of hemoglobin, were associated with poor prognosis. Thus, our method is useful for identifying CFU-E colonies, determining their hemoglobin synthesis, and as a cue to predict the clinical course of the patients.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Hyperfine interactions 78 (1993), S. 251-257 
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Nuclear polarization was measured by means of beam foil spectroscopy for a3He+ ion produced by an electron capture process of a3He2+ from a polarized sodium atom in an incident energy range from 20 to 28 keV. Assuming that a polarized electron of a sodium atom is predominantly captured to the 3d orbital of a3He+ ion andcascades down to the 1s ground state via the 2p orbital, an alignment factorA 0 col (L=2) for the 3d orbital of a3He+ ion was extracted by comparing the observed initial sodium polarization andfinal nuclear polarization. The observedA 0 col (L=2) showed a less pronounced energy dependence andwere qualitatively reproduced by the theoretical calculation.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...