ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
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
    A microcomputer-based solid-state nuclear track image analyzer (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 771-778 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A microcomputer-based image processing system has been developed to use with solid-state nuclear track detectors for number counting, area measurement, and location identification. The image digitizer is designed to interface with a microcomputer and a standard black and white TV camera for data acquisition. A spatial dependent segmentation algorithm is proposed for track identification under nonuniform illumination and the low track-pixel population conditions. The system has been tested using Lexan samples irradiated by a Cf-252 spontaneous fission source. The counting accuracy is approximately 3% with a long term stability of 5%. Efficiency calibration was performed using samples with track densities up to 104/mm2. Results indicate that the proposed track identification scheme tends to reduce the track overlap effect and the system behaves as a nonparalyzable counting system. For track densities below 3000/mm2, either a paralyzable or a nonparalyzable counter model can be established with an accuracy better than 0.5%. For track densities below 1500/mm2, the track registration efficiency is in good agreement with manual counting results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1141017
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Spin fluctuations of La2−xSrxCu1−yZnyO4−δ (x=0.14, y=0.012) (abstract) : 37th annual conference on magnetism and magnetic materials (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 6333-6333 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetism of high-Tc superconductors is still the subject of intensive investigation. Zn substitution for Cu together with removal of oxygen suppresses the superconductivity quickly. We prepared two crystals to perform a neutron scattering study of the spin fluctuations of La2−xSrxCu1−yZnyO4−δ. One is a Zn-doped and deoxygenated crystal La1.86Sr0.14Cu0.988Zn0.012O4−δ (#1) which does not show superconductivity above 1.5 K. The other is a Zn-doped crystal La1.86Sr0.14Cu0.988Zn0.012O4 (#2) which shows superconductivity below 16 K. The incommensurate spin excitations observed previously in superconducting samples1,2 containing no Zn remain in both samples. However, there is significant difference in the spectral weight χ‘(q,ω) at low temperatures between the non-superconducting and superconducting Zn-doped crystals. In crystal #1 the spectral weight at low temperatures is qualitatively similar to that of Zn-undoped non-superconducting samples.3 In crystal #2 the spectral weight at low temperatures is qualitatively similar to that of Zn-undoped superconducting samples.1,2 These results demonstrate that there is an intimate relationship between the magnetism and the superconductivity. We are in the process of further measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352638
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Correlations between CdTe/CdS/SnO2/glass solar cell performance and the interface/surface properties (1996)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 79 (1996), S. 2151-2153 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Surface and interface properties of CdTe/CdS/SnO2/glass heterojunction solar cells are studied by means of x-ray photoelectron spectroscopy (XPS), secondary ion mass spectroscopy (SIMS), and optical reflectance (OR) techniques. First, n-type CdS layer was grown by solution growth technique on the SnO2 coated glass substrate and then the p-type CdTe was deposited on CdS by metal-organic chemical-vapor deposition. Despite many other efficiency limiting mechanisms in CdTe solar cells, this article shows that surfaces and interfaces play an important role in determining the cell efficiency. In an attempt to correlate the surface and interface properties to the cell performance, a series of CdTe/CdS solar cells with different conversion efficiencies were fabricated and analyzed. It was found that high efficiency cells possess Te-rich CdTe surface along with smooth interfaces, as revealed by XPS, SIMS, and OR measurements, while low efficiency cells display near stoichiometric or Cd-rich CdTe surface and abrupt interfaces. The impact and role of interface/surface properties on CdTe solar cell performance are discussed. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.361041
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Concentration-dependent oxygen diffusion in Tl1Ba2Ca2Cu3 and Ag1Tl2Ba2Ca2Cu3 superconductor precursor alloys (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 3511-3513 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: To study the growth mechanism in growing superconducting thin films by the liquid-gas-solidification process, oxygen diffusivities in liquid Tl1Ba2Ca2Cu3 and Ag1Tl1Ba2Ca2Cu3 precursor alloys were measured by a modified coulometric titration method. The diffusivities of oxygen are very high of the order of 10−4 to 10−3 cm2/s. The logarithm of oxygen diffusivities is found to be reciprocally proportional to the logarithm of oxygen concentrations. This concentration-dependent oxygen diffusivity phenomenon has not been observed in many metallic liquids investigated previously. An interstitial diffusion mechanism may contribute to the fast oxygen diffusion. The strong bonds between Ba and O atoms are proposed to enhance the configurational structural order and hence to quicken the oxygen diffusion that varies the oxygen concentration in Tl1Ba2Ca2Cu3 and Ag1Tl1Ba2Ca2Cu3 superconductor precursor liquids. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359985
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Activity and diffusivity of oxygen in liquid Ag-Yb1Ba2Cu3 and Tl1Ba2Ca2Cu3 alloys (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 5635-5641 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have measured the activity and diffusivity of oxygen in liquid Ag-Yb1Ba2Cu3 and Tl1Ba2Ca2Cu3 at 930 and 900 °C, respectively, by a modified coulometric titration method on the galvanic cell: O(underbar) in liquid alloys/yttria stabilized zirconia/air, Pt. The standard Gibbs formation energy and the diffusivity of oxygen in liquid Ag-Yb1Ba2Cu3 alloy for 1/2O2(1 atm)→O(underbar)(1 at. %) are determined to be ΔG=−247.4 kJ/g atom, and D=1.52×10−4 cm2/s. The oxygen solubility Cs in the Ag-Yb1Ba2Cu3 alloy is 0.0913 at. %, a factor of 5.5 higher than that in Yb1Ba2Cu3 alloy. The addition of Ag does not alter the growth mechanism and the oxygen diffusion controls the film growth. The growth speed is enhanced as a result of the enhanced oxygen solubility. ΔG and the diffusion coefficient of oxygen in the Tl1Ba2Ca2Cu3 liquid alloy are −257 kJ/g atom and 1.2×10−4 cm2/s, respectively. The oxygen solubility of the Tl1Ba2Ca2Cu3 alloy at 900 °C is found to be very high at ∼5.74 at. %. All thermodynamic data for oxygen in the precursor alloys are consistent with each other but there is a deviation of activity coefficient with composition for the different alloys from the theoretical model.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.351963
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Spontaneous patterning in high temperature superconducting film by liquid-gas-solidification processing (1994)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 1045-1047 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Without any post physical or chemical patterning a Tl-base high temperature superconducting film has been observed to pattern spontaneously on SrTiO3 (100) by liquid-gas-solidification process. The film exhibits the morphology of a microelectric network in which the directions of growth of the crystal walls follow the directions of the SrTiO3 (100) substrate. The crystal walls consisting of Tl-1223 and Tl-1212 phases are 0.25–1 μm wide, 2 μm high, and a few millimeters long. These walls are proposed to grow from independent nucleation sites and coalescence to form semiconductive junctions. The network exhibits a superconducting transition onset at 113 K and approaches zero resistance at 95 K. Below 95 K, the resistance increases exponentially with decreasing temperature. This strongly suggests that the films form a natural superconductor/semiconductor/superconductor junction array.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.112147
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Observation of quantum confinement effects in strained Si0.84Ge0.16/Si quantum wells at room temperature (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 2713-2715 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report the first study of quantum confinement shifts of energy gap in strained Si0.84Ge0.16/Si quantum wells at room temperature by photothermal deflection spectroscopy (PDS) technique. The experimental results obtained from the amplitude and phase of the PDS signal are in good agreement with quantum well subband calculation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.109241
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Reactivity of C60 in pure oxygen (1991)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 59 (1991), S. 2956-2958 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In pure oxygen at moderate temperatures of 200 °C, an fcc C60 transforms into amorphous carbon-oxygen compounds and the icosahedral C60 molecular structure is destroyed. The maximum oxygen uptake of pure C60, O/C60, is 12. Isothermal TGA transformation curves are sigmoid-shaped with the kinetic exponent n∼5/2 which conforms with a two-dimensional nucleation and growth mode. The heat of formation for the carbon-oxygen compounds is 90 kcal/mol O, and the formation energy for the reaction: 60C (graphite)→C60 molecule is estimated to be ∼600 kcal/mol.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.105810
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Activity and diffusivity of oxygen in a liquid Yb1Ba2Cu3 high temperature superconducting precursor alloy (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 60 (1992), S. 760-762 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The activity and diffusivity of oxygen in a liquid Yb1Ba2Cu3 high temperature superconducting precursor alloy have been measured by modified coulometric titration method in a temperature range from 913 to 957 °C. The standard Gibbs formation energies and the diffusivity of oxygen in liquid Yb1Ba2Cu3 for 1/2O2 (1 atm)→O (1 at. %) are determined to be ΔG=−655.20+0.335T(K) (±1.5) kJ/mol and D=1.8×10−2 exp(−48 100/RT) (cm2/s) where R=8.314 J/deg×mol. Despite very strong bonding of oxygen to the liquid alloys, the diffusion coefficient of oxygen is relatively high in the order of 10−4 cm2/s. The solubility of oxygen in the liquid alloy is low, of about 0.0145 and 0.017 at. % at 913 and 935 °C, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.106561
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Effect of the vibration-translation transfer rate on laser-induced frequency chirp in a long-pulse CO2 laser (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 2086-2088 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A frequency sweeping (chirping) mechanism governed by the lasing gas pressure and composition has been observed in a long-pulse TE CO2 laser for the first time. The mechanism was detected in heterodyned data obtained from photomixing the pulsed laser output with a cw local oscillator. A theory has been developed which links this chirp-governing mechanism to the vibration-translation (V-T) transfer rate from the lower laser level to the ground state. This new theory extends the existing theories on chirp in pulsed CO2 lasers into the long-pulse regime.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.102980
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...