GLORIA

GEOMAR Library Ocean Research Information Access

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
    Keywords: Forschungsbericht ; Manöver ; Schiffsnavigation ; Radarortung ; Computerunterstütztes Verfahren ; Benutzeroberfläche
    Type of Medium: Online Resource
    Pages: 96 p. = 1,7 Mb., text and images , Ill
    Edition: [Electronic ed.]
    Language: German
    Note: Differences between the printed and electronic version of the document are possible
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 86 (1999), S. 1196-1201 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Packaging-induced strain is studied in high-power semiconductor lasers by a noninvasive optical technique. Fourier-transform photocurrent measurements with intentionally strained laser array devices for 808 nm emission reveal spectral shifts of optical transitions within the active region. These shifts by up to 10 meV serve as a measure for the strain status within the active layer of the devices and are compared with model calculations. For different packaging architectures we quantify the strain portion which is transmitted to the optically active region of the semiconductor device. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: We have investigated the relationship between energy metabolism, NMDA-receptor antagonism, and anoxic damage in vitro. Anoxic damage was assessed by measuring protein synthesis, defined as the incorporation of [14C]lysine into perchloric acid-insoluble tissue extracts. The concentrations of energy metabolites were measured by ion-exchange HPLC. Anoxia caused an inhibition of protein synthesis, a reduction in phosphocreatine and adenosine triphosphate, and extensive neuronal damage. The reduction of protein synthesis depended on the duration of anoxia and the time allowed for recovery. Preincubation with the creatine dose-dependently (0.03–3 mmol/L) increased baseline levels of phosphocreatine, reduced the anoxia-induced decline in phosphocreatine and adenosine triphosphate, prevented the impairment of protein synthesis, and reduced neuronal death. Incubation with (R,S)-3-guanidinobutyric acid, a synthetic analogue of creatine that cannot be phosphorylated, did not prevent the anoxia-induced impairment of protein synthesis and did not enhance the levels of phosphocreatine and adenosine triphosphate. Incubation with a combination of both creatine and the noncompetitive NMDA antagonist MK-801 provided complete protection. These results indicate that energy status is a major factor controlling anoxic damage in the rat hippocampal slice.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 6135-6144 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: New experimental and theoretical results on TE/TM bistability in 1.3 μm ridge-waveguide InGaAsP/InP bulk lasers at room temperature are presented. Measured polarization resolved light power–current (P–I) characteristics as well as lateral near- and far-field patterns are compared with results from a theoretical model based on the paraxial wave equations for TE- and TM-polarized modes and the diffusion equation for the carrier distribution. The model was numerically evaluated by use of the beam propagation method. The observed TE/TM bistability is explained by the interplay of three different effects: (i) Tensile stress of about 109 dyn/cm2 promotes the TM gain strongly enough to compete with the TE mode. (ii) Improved TM waveguiding due to an enhancement of the effective refractive index near the beam axis caused by carrier depletion with increasing current leads to the onset of TM lasing and TE/TM switching. (iii) The TE/TM transition is accompanied by an abrupt increase of spatial hole burning in the lateral carrier distribution. Because of this nonlinear effect, a lower current is needed to switch the laser back to TE, giving rise to a hysteresis loop in the P–I characteristics and to TE/TM polarization bistability. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 2064-2069 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Light emission from a ridge waveguide 1.3 μm InGaAsP/InP semiconductor laser pumped both electrically and optically was analyzed by polarization- and time-resolved measurements. The electric and the optical excitation was realized with a dc-bias current and with 150 ps pulses from a Q-switched Nd-YAG laser at 1.064 μm wavelength, respectively. The pump light was introduced into the InGaAsP/InP laser through a window opened in the substrate gold contact. The steady-state P–I characteristics of the semiconductor laser exhibited a transition from TM- to TE-polarized light emission if the injection current surpasses a certain value that depends on the heatsink temperature. Depending on the dc-bias current and the optical pulse power, a variety of different emission characteristics of the semiconductor laser were observed: pure TE or TM pulsations, in combination with a background cw emission in some cases; simultaneous emission of TE and TM pulses and switching between TM and TE emission states with switching times as short as 30 ps. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 308-312 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Decays of the diffraction efficiency of gratings written in Fe:LiNbO3 have been studied in connection with photorefractive fixing. Measurements have been carried at five different temperatures within the range of interest in photorefractive fixing, 144–168 °C. The decay curves are nonexponential and can be fitted to a sum of three simple exponential components, whose effective activation energies and preexponential factors have been determined. The dependence of the last exponential component on the grating period Λ has been measured and a 1/Λ2 law has been found. The decay constants have also been found to depend on the time the crystal is kept at the setting temperature before writing the grating. The difficulties for establishing a model taking into account the occurrence of several sites for protons in LiNbO3 are discussed. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Objective To identify counselling requirements, we reviewed the frequency and type of non-trisomy 21 chromosome abnormalities found at amniocentesis after maternal serum screening for Down's syndrome.Design The study involved a review of the cytogenetic results of amniocenteses performed because of a raised maternal serum screening risk.Setting The maternal serum screening and amniocenteses were performed at hospitals in the Yorkshire region.Sample 1715 amniocenteses were performed as a result of a raised maternal serum screening risk for the period 1990 to 1993.Methods The cytogenetic results were classified into the main categories of numerical and structural chromosomal abnormalities.Main outcome measures The nature and frequency of abnormal cytogenetic results were identified in which parental samples were required in order to determine if the abnormal finding was de novo or familial and/or for which specialist genetic counselling was required.Results Sixty-nine pregnancies of 1715 amniocenteses were identified with a chromosomal abnormality (4.0%): 35 (2.0%) with trisomy 21 and 34 (2.0%) with another chromosomal abnormality. For 20 of these 34 abnormalities, parental karyotypes were required and in 29 of the 34 specialist genetic counselling was required.Conclusions Women undergoing maternal serum screening and, in particular, those proceeding to amniocentesis, should be informed that there is an equal chance that a chromosomal abnormality other than trisomy 21 will be found at amniocentesis, the nature of which usually requires parental samples and specialist counselling.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 3908-3910 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thermally induced strain caused by device packaging is studied in high-power semiconductor lasers by a noninvasive technique. Fourier-transform photocurrent measurements with intentionally strained laser array devices for 808 nm emission reveal spectral shifts of quantum-confined optical transitions in the optical active region. These shifts by up to 7 meV serve as a measure for strain and are compared with model calculations. For a given packaging architecture, about one quarter of the mounting-induced strain is transferred to the quantum-well region of the device. Spatially resolved measurements demonstrate a lateral strain gradient in the devices. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 391-393 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The critical current of a Nb–InGaAs/InP Josephson junction is increased stepwise by light exposure. Shubnikov–de Haas effect measurements under illumination show that the increase of the critical current originates from photogenerated electrons in the quantum well. A further enhancement of the critical current is gained under continuous illumination. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1520-5827
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...