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
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Using the stable, dc current-voltage (I-V) curve measured from a double-barrier resonant tunneling structure, we have studied the effects of external circuit elements on device oscillations. A simulation, using the experimental I-V and a simple circuit model for the biasing arrangement, showed that hysteresis and vertical jumps appear in the current-voltage curve when the circuit oscillates. This observation is supported by experimental results obtained on the same device with external circuit elements intentionally added to the biasing configuration.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 56 (1990), S. 1772-1774 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report a study of transport in crossed electric and magnetic (B) fields in a double-barrier tunneling structure with a wide (600 A(ring)) well at T=1.5 K and 0〈B〈23 T. At B=0 we observe 21 resonances, 11 of which correspond to extended-state resonances for biases 〉0.85 V. Under a transverse magnetic field, the bound resonances evolve into magnetoelectric states and are shifted to higher biases. In the low bias range, for high magnetic fields, additional resonances from barrier-bound skipping states are observed. A semiclassical model for ballistic motion in crossed fields is used to determine boundaries between the different trajectory regimes (i.e., traversing, skipping, bulk-like) in the magnetic field-bias voltage space of the resonances. The model shows excellent quantitative agreement with experiment when nonparabolic corrections to the effective mass are included. In addition, the B-induced shift in the transition from bound to extended-state tunneling resonances is explained with this simple description.
    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 54 (1989), S. 1908-1910 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report a study of the current-voltage characteristics of a double barrier, lattice matched, quantum well tunneling structure in a quantizing magnetic field (B(parallel)J). Experiments were conducted at fields up to 23 T at 1.5 K. The heterostructure investigated had 400 A(ring) spacer layers in the emitter and collector, a barrier width of 72 A(ring), and a 43-A(ring)-wide quantum well. This structure showed one negative differential resistance region with a peak-to-valley ratio of 23 at 4.2 K. We observed magnetoquantum oscillations, periodic in 1/B, associated with tunneling from a quantized state in the emitter. The overall magnetoconductance dramatically changed with applied bias. We associated these variations with a field-induced increase of the impedance of the undoped spacer layers. The frequency of these oscillations increased linearly with applied bias. A discontinuity in this dependence is observed around the peak bias voltage which is the direct result of the dynamical storage and release of charge in the well.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 109 (1987), S. 1600-1601 
    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 ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of low temperature physics 52 (1983), S. 115-135 
    ISSN: 1573-7357
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The low-temperature dielectric dispersions of LiF, NaCl, KCl, and KBr have been measured for different concentrations of OH−. With decreasing tunnel splitting of the OH− levels, and with increasing dipolar interaction, a behavior is observed below ∼1 K similar to that found in amorphous materials and attributed to two-level states (TLS). Differences between OH− and TLS are noted, the main difference being that the broad spectrum of energy levels associated with the OH− in alkali halides arises from dipolar interactions rather than an atomically disordered environment. It is argued that an electric dipole analog of the magnetic spin-glass state does not occur in the OH− systems.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Chemie International Edition in English 7 (1968), S. 845-856 
    ISSN: 0570-0833
    Keywords: Polymerization ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Previously it was generally assumed that high energy radiation could only initiate radical polymerization in solutions of monomers. However, examples of radiation-induced polymerization have recently become known that proceed via an ionic mechanism. Thus, solutions of a monomer can be polymerized ionically, preferably in the presence of a solid, at low temperatures. Suprisingly, this may also be accomplished with ultra-pure, mainly anhydrous systems, even at room temperature. The nature of the ions has not yet been fully elucidated.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für die chemische Industrie 80 (1968), S. 921-932 
    ISSN: 0044-8249
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Früher wurde allgemein angenommen, daß energiereiche Strahlung in Lösungen von Monomeren nur eine radikalische Polymerisation auszulösen vermag. Seit einiger Zeit sind jedoch strahleninduzierte Polymerisationen bekannt geworden, die über Ionen verlaufen. So kann man z. B. Lösungen eines Monomeren bei tiefer Temperatur, vorzugsweise in Gegenwart einer festen Substanz, ionisch polymerisieren. Überraschenderweise gelingt dies in ultrareinen, vor allem wasserfreien Systemen sogar bei Raumtemperatur. Die Natur der Ionen ist noch nicht völlig geklärt.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 877-890 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: We have applied the pulse radiolysis technique of studying short-lived, radiation-produced intermediates to a study of pure, dry liquid styrene. We have observed at least three distinct species. The most rapidly decaying species (τ1/2 = 4 μsec., λmax ≈ 370 mμ) exhibits an apparent first-order decay which is slowed down in the presence of dry oxygen, occurs too rapidly to be measured in the presence of water, and has a temperature coefficient of approximately 1 kcal./mole between 25 and 45°C. We have tentatively identified the species as the styryl anion with a G value for formation of approximately 0.15. A second species (τ1/2 = 220 μsec. λmax ≈ 320-330 mμ) exhibits a first-order decay which appears to be independent of oxygen and water. From its spectrum, we have tentatively identified it as the styryl radical. The third species (λmax ≈ 310 and 320 mμ) is relatively stable in the dark, but is radily photolyzed by the analyzing light of the usual experimental set-up for pulse radiolysis studies. The formation of this species appears to be independent of the water and oxygen content of the styrene.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 419-430 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pure liquid styrene, carefully purified and exhaustively dried, exhibits kinetic behavior under γ-irradiation that can best be described in terms of an ionic mechanism. This is based on the observed linear dependence of the rate of polymerization on the dose rate, the independence of molecular weight on the same parameter, and comparison with the thermal and ultraviolet initiated polymerization of monomer prepared under the same stringent conditions. The highest rate of conversion to polymer is 400%/hr. at a dose rate of 106 rads/hr., corresponding to a G(-monomer) ≈ 40,000.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 2295-2306 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this second paper of the series we present additional evidence that the γ-radiation-induced polymerization of very pure, ultradry styrene exhibits kinetics that can best be explained as due to one or more ionic processes, depending on the dryness of the sample. We have shown the effect of the various steps in the drying procedure on the observed kinetics, and we have described a preparative procedure which yields good reproducibility among independently prepared samples. Under these conditions, the rate of polymerization is proportional to the 0.70 power of the dose rate at 0°C.; there appears to be no wall effect; and the temperature coefficient for the process appears to be a complicated function, most probably a small negative value over the range of temperature (0-50°C.) and dose rates (∼103-105 rad/hr.) covered in this study. The maximum G value for disappearance of monomer which we have observed is of the order of 6 × 105 molecules of monomer/100 e.v. at 0°C. and a dose rate of 2 × 103 rad/hr.
    Additional Material: 5 Ill.
    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...