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
    Magnetic field effects on triplet exciton fission and fusion in a polydiacetylene (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 6642-6646 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We have studied the origin and decay dynamics of triplet excitons in the conjugated polymer poly(4BCMU) in its sol(yellow) and gel(red) phases. Wavelength and intensity dependencies of the triplet yield show that the triplet exciton cannot be produced by excitation into the singlet exciton edge but only from higher lying states. The observed lifetime of the triplet state, coupled with the magnetic field dependence of the triplet state production and decay, indicate that the triplet state is created by a fission process from the excited singlet. The time and magnetic field dependence of the triplet exciton decay indicate that the triplet exciton decay in the red phase occurs by diffusive bimolecular fusion, but in the yellow phase the triplet exciton decay is nondiffusive. We postulate that the unimolecular decay of the triplet exciton in the yellow phase results from exciton pinning by conformational disorder.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.456281
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    An investigation of the annihilated unrestricted Hartree–Fock wave function and its use in second-order Møller–Plesset perturbation theory (1989)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 1789-1795 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The recently introduced annihilated unrestricted Hartree–Fock (AUHF) wave function—in which the first spin contaminant in an unrestricted Hartree–Fock (UHF) wave function has been annihilated self-consistently—is discussed in some detail with particular attention to its use as a basis for a perturbation expansion. A series of calculations are presented highlighting the advantages and disadvantages of a second-order Møller–Plesset (AUMP2) perturbation treatment.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.457084
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Measurement and interpretation of electron cyclotron emission on JET (abstract) (1985)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 56 (1985), S. 940-940 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The first two channels of the JET electron cyclotron emission diagnostic have been in regular use for several months. A Michelson interferometer provides several hundred broadband spectral measurements (with time resolution 15 ms) on every plasma pulse. The second cyclotron harmonic in these spectra is used to deduce absolutely calibrated electron temperature profiles in the outer half of the plasma. Current measurements and their interpretation will be discussed, and the full diagnostic system, for the determination of two-dimensional profiles, will be described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1138055
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    High-power soliton generation at microwave frequencies (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 3277-3281 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We point out that the creation of a soliton pulse train in a nonlinear-dispersive system can be used for the generation of high-power microwave bursts. A modulated transmission line with an appropriate nonlinear dielectric is proposed. The nonlinear wave evolution is analyzed and requirements for the dielectric material are found. Problems associated with the material are discussed. Low-power experimental demonstrations of these concepts are presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.341517
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Impurity diffusion and layer interdiffusion in AlxGa1−xAs-GaAs heterostructures (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 1838-1844 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Data are presented and a model describing the diffusion of the donor Si in GaAs from grown-in dopant sources. In addition, the effects of background impurities on Si diffusion and layer interdiffusion in AlxGa1−xAs-GaAs superlattices are described. These results are obtained on epitaxial GaAs samples with alternating doped and undoped layers and on AlxGa1−xAs-GaAs superlattices with doped (Si or Mg) layers. The layer-doped GaAs and the AlxGa1−xAs-GaAs superlattices have been grown using metalorganic chemical vapor deposition and are characterized using secondary ion mass spectroscopy and transmission electron microscopy. Different annealing conditions are used to study the interaction between the grown-in impurities and the native defects of the crystal controlling the diffusion processes. The model describing the impurity diffusion and layer (Al-Ga) interdiffusion is based on the behavior of column III vacancies, VIII, and column III interstitials, IIII, and the control of their concentration by the position of the crystal Fermi level and the crystal stoichiometry. Experimental data show that n-type AlxGa1−xAs-GaAs superlattices undergo enhanced layer interdiffusion because of increased solubility of the VIII defect, while enhanced layer interdiffusion in p-type superlattices is caused by an enhanced solubility of IIII. The model employed is consistent with the experimental data and with the data of previous work.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.341759
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    An electron channeling study of polycrystalline YBa2Cu3Ox (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 761-765 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An electron channeling study has been done on large grained YBa2Cu3Ox samples. Selected area channeling patterns (SACP) were used to examine several dozen grains on electropolished surfaces and it was demonstrated that (a) the twin planes observed in polarized optical light microscopy lie parallel to {110} crystal planes, and (b) the long flat sides of high aspect ratio grains are formed by basal planes, and the shorter sides are formed by either (010), (100), or {110} planes. A majority of the large grains examined were found to contain subgrains, misaligned by 0.5°–1° and ranging in size from less than 3 to 20 μm. The origin of the subgrains is not understood.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.341921
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    A corona discharge probe system for measuring phase velocities in a dense suspension (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 3475-3477 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Measurement of distribution of velocities of phases in pipe flow of a dense gas-solid suspension was facilitated by the use of an ion source in the form of a localized corona discharge and a downstream traversing electrostatic probe. The system utilizes the transient behavior of a corona discharge which provides a distinction of times of arrival of ions and solid particles of modified charges at a downstream probe. This probe system does not suffer the handicap of other available probe systems in a dense solid phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1140495
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    CO2 large-area discharge laser using an unstable-waveguide hybrid resonator (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 1950-1952 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A one-dimensional unstable resonator combining free-space and waveguide propagation is used to efficiently extract power from a large-area gain medium in a slab waveguide CO2 laser. A power of 240 W in a near-diffraction-limited beam has been attained at 12% conversion efficiency from a 38 cm gain length in a compact sealed-off laser head, corresponding to a specific power extraction of 14 kW m−2 of discharge area.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101203
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Disorder-defined buried-heterostructure AlxGa1−xAs-GaAs quantum well lasers by diffusion of silicon and oxygen from Al-reduced SiO2 (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 1265-1267 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We describe a convenient method utilizing chemical reduction of SiO2 by Al (from AlxGa1−xAs) to generate Si and O for impurity-induced layer disordering (IILD) of AlxGa1−xAs-GaAs quantum well heterostructures (QWHs). Experimental data show that Si-O diffusion (from SiO2) is an effective source of Si for Si-IILD and of O that compensates the Si donor, thus resulting in higher resistivity layer-disordered crystal. The usefulness of the Si-O IILD source for fabricating low-threshold disorder-defined buried-heterostructure AlxGa1−xAs-GaAs QWH lasers is demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.100734
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Oriented high Tc superconductive layers on silver by devitrification of glasses formed in the Bi-Sr-Ca-Cu oxide system (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 371-373 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Highly oriented crystalline layers of Bi4(Sr,Ca)3Cu4O16+x high Tc superconductors were produced by the devitrification of aerosol suspensions of glasses prepared from the mixed oxides when the suspensions were brought into rapid contact with heated silver substrates. The best magnetic susceptibility signals, produced by superconductivity at 77 K, were obtained when the glass was rapidly heated to about 850 °C from room temperature. The deposited layers are composed of a nearly pure superconductive phase in the form of flat platelets up to several hundred microns in diameter that are oriented with the c axis normal to the substrate. The addition of a small amount of Pb to the glass lowers the optimum deposition temperature and improves the crystal morphology.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.101453
    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...