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
Filter
  • American Chemical Society  (5,770)
  • American Institute of Physics (AIP)  (2,551)
  • 1990-1994  (4,966)
  • 1985-1989  (3,355)
  • 1980-1984
  • 1992  (4,966)
  • 1987  (3,355)
Collection
Publisher
Years
  • 1990-1994  (4,966)
  • 1985-1989  (3,355)
  • 1980-1984
Year
  • 1
    Electronic Resource
    Electronic Resource
    A fiber drop analyzer: A new analytical instrument for the individual, sequential, or collective measurement of the physical and chemical properties of liquids (1992)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 3431-3454 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new instrumental method has been devised for the individual, sequential, or collective measurement of the physical and chemical properties of liquids. The instrumental theory for the fiber drop analyzer (FDA) has been developed for the measurement of surface tension, viscosity, refractive index, and chemical composition of a liquid. An empirical theory is suggested for the measurement of pH in a limited range. The analytical theory for the fiber drop analyzer has been established, a prototype constructed and tested for measuring individually surface tension, viscosity, refractive index, and the chemical composition on a restricted set of test solution. The instrument is shown to have the capability to simultaneously measure the above measurands, but in addition can in individual measurement procedures, measure all these quantities. The instrument perhaps is also potentially capable of measuring specific gravity and pH in its existing form, and other optical properties of liquids with some basic modification. The laboratory FDA has been used to test a series of samples from a large cane sugar manufacturer's process and these measurements demonstrate that this technology has the potential to be used as a remote optrode industrial process monitor for sucrose manufacture and very possibly, elsewhere in other industrial applications.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143748
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Eight-shot pneumatic pellet injection system for the tokamak fusion test reactor (1987)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 58 (1987), S. 1195-1203 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: An eight-shot pneumatic pellet injection system has been developed for plasma fueling of the tokamak fusion test reactor (TFTR). The active cryogenic mechanisms consist of a solid hydrogen extruder and a rotating pellet wheel that are cooled by flowing liquid-helium refrigerant. The extruder provides solid hydrogen for stepwise loading of eight holes located circumferentially around the pellet wheel. This design allows for three different pellet diameters: 3.0 mm (three pellets), 3.5 mm (three pellets), and 4.0 mm (two pellets) in the present configuration. Each of the eight pellets can be shot independently. Deuterium pellets are accelerated in 1.0-m-long gun barrels with compressed hydrogen gas (at pressures from 70 to 105 bar) to velocities in the range 1.0–1.5 km/s. The pellets are transported to the plasma in an injection line that incorporates two stages of guide tubes with intermediate vacuum pumping stations. A remote, stand-alone control and data-acquisition system is used for injector and vacuum system operation. The eight-shot injection system has been installed and operated on TFTR. The design features, operation, and performance characteristics of the system are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1139439
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Investigation of global Alfvén instabilities in the Tokamak Fusion Test Reactor (1992)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 4 (1992), S. 2122-2126 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Toroidal Alfvén eigenmodes (TAE) were excited by the energetic neutral beam ions tangentially injected into plasmas at low magnetic field in the Tokamak Fusion Test Reactor (TFTR) [Proceedings of the 11th International Conference on Plasma Physics and Controlled Fusion Research (IAEA, Vienna, 1987), Vol. 1, p. 51]. The injection velocities were comparable to the Alfvén speed. The modes were identified by measurements from Mirnov coils and beam emission spectroscopy (BES). TAE modes appear in bursts whose repetition rate increases with beam power. The neutron emission rate exhibits sawtoothlike behavior and the crashes always coincide with TAE bursts. This indicates ejection of fast ions from the plasma until these modes are stabilized. The dynamics of growth and stabilization were investigated at various plasma currents and magnetic fields. The results indicate that the instability can effectively clamp the number of energetic ions in the plasmas. The observed instability threshold is discussed in light of recent theories. In addition to these TAE modes, intermittent oscillations at three times the fundamental TAE frequency were observed by Mirnov coils, but no corresponding signal was found in BES. It appears that these high-frequency oscillations do not have a direct effect on the plasma neutron source strength.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Arsenic cluster dynamics in doped GaAs (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3509-3513 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied the formation of As precipitates in doped GaAs structures that were grown by molecular beam epitaxy at low substrate temperatures and subsequently annealed. We find that the As precipitates form preferentially on the n side of such fabricated GaAs pn junctions. As the coarsening process proceeds, there is a gradual increase in the amount of As in precipitates in the n-GaAs region and a decrease in the p-GaAs region; the depletion region between the pn junction becomes free of As precipitates. These observations can be understood qualitatively based on the charge states of the As interstitial and using thermodynamic arguments in which the crystal attempts to minimize the chemical potential during the anneal. The presence of the excess As results in a stable Be profile even to anneals of 950 °C. Finally, a temperature cycling technique to grow arbitrarily thick GaAs epilayers containing As precipitates was demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352326
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Plasmon excitation and self-coupling in a bi-periodically modulated two-dimensional electron gas (1992)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 71 (1992), S. 6049-6061 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report far infrared (FIR) studies of plasmons in spatially modulated two-dimensional electron gases (2DEGs) in AlGaAs/GaAs heterostructures using biased overlaid metal gratings, including interdigitated gratings, both as optical couplers and as spatially modulating gates. Comparison of the experimental results with the predictions of scattering matrix calculations of the FIR response of a modulated 2DEG in the presence of a perfectly conducting lamellar grating allow us to deduce the spatial variation of the number density distribution in the 2DEG as a function of grating bias. For the interdigitated grating gates, the 2DEG can be modulated at a period of twice that of the grating fingers by differentially biasing alternate fingers; 2D plasmon resonances have been observed at half-integral values of the grating wave vector G, corresponding to the electrically induced periodicity of the 2DEG modulation itself acting as an optical coupler in addition to the metal grating. The observed G/2 plasmon frequencies decrease with increasing amplitude of the 2DEG number density modulation, in quantitative agreement with those obtained from scattering matrix calculations of the optical response of a modulated 2DEG under a perfectly conducting lamellar grating; calculations of the oscillating charge density profiles show that this occurs because, as the modulation amplitude increases, the oscillation becomes localized in regions of low 2DEG number density which are also under one of the sets of grating fingers, and is therefore better screened.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.350462
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Extending J walking to quantum systems: Applications to atomic clusters (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 5713-5731 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The J-walking (or jump-walking) method is extended to quantum systems by incorporating it into the Fourier path integral Monte Carlo methodology. J walking can greatly reduce systematic errors due to quasiergodicity, or the incomplete sampling of configuration space in Monte Carlo simulations. As in the classical case, quantum J walking uses a jumping scheme to overcome configurational barriers. It couples the usual Metropolis sampling to a distribution generated at a higher temperature where the sampling is sufficiently ergodic. The J-walker distributions used in quantum J walking can be either quantum or classical, with classical distributions having the advantage of lower storage requirements, but the disadvantage of being slightly more computationally intensive and having a more limited useful temperature range. The basic techniques are illustrated first on a simple one-dimensional double well potential based on a quartic polynomial. The suitability of J walking for typical multidimensional quantum Monte Carlo systems is then shown by applying the method to a multiparticle cluster system consisting of rare gas atoms bound by pairwise Lennard-Jones potentials. Different degrees of quantum behavior are considered by examining both argon and neon clusters. Remarkable improvements in the convergence rate for the cluster energy and heat capacity, analogous to those found in classical systems, are found for temperatures near the cluster transition regions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.463756
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Nanometer-scale columns in GaAs fabricated by angled chlorine ion-beam-assisted etching (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1726-1728 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Angled chlorine ion-beam-assisted etching has been used in combination with masked ion beam lithography to produce columns in GaAs with widths of less than 10 nm and height-to-width ratios greater than 25. This technique allows the highly controllable fabrication of structures with dimensions smaller than initially defined by the lithography. It can be applied to the fabrication of ultrasmall GaAs/AlGaAs quantum well structures having quantized energy states in two or three dimensions while at the same time being compatible with full-wafer processing.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.98557
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    High-speed and high-power 1.3-μm InGaAsP buried crescent injection lasers with semi-insulating current blocking layers (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 1783-1785 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The fabrication and performance of high-speed and high-power 1.3-μm InGaAsP buried crescent lasers with semi-insulating current blocking layers are reported. A modulation bandwidth of 11 GHz and acw output power of 42 mW/facet have been achieved. An approximate circuit model of the semi-insulating buried crescent laser, which describes the effect of dc bias on parasitic capacitance at high-speed operation, is also presented.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.98521
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Characterization of GaAs self-aligned refractory-gate metal-semiconductor field-effect transistor (MESFET) integrated circuits (1987)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 61 (1987), S. 3080-3092 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: GaAs metal-semiconductor field-effect transistors (MESFETs) and other integrated-circuit elements were characterized by including extensive process test sites on wafers with digital logic and memory circuits. A self-aligned, refractory-gate enhancement/depletion (E/D) process was employed which included 47SiF+ channel and source/drain implants, capless arsenic overpressure furnace annealing, WSi0.11 gate metal with in situ sputter cleaning, Ni-Au-Ge ohmic contacts, Si3N4 or SiO2 insulation, and Ni-Au wiring. On-water threshold voltage standard deviations as low as 31 mV for 1-μm E-FETs and 49 mV for 1-μm D-FETs were measured using 51-mm standard semi-insulating liquid-encapsulated Czochralski GaAs substrates. Threshold voltage control from wafer to wafer was of order 100 mV. Schottky diode barrier height was about 0.73 eV with an ideality of 1.2, although small self-aligned Schottky gates often showed excess conduction believed to occur at the gate edges. FET square-law coefficient, subthreshold leakage, gate capacitance, backgating, contact resistance, and wiring and insulation characteristics were also measured and found satisfactory. Fully functional 1-μm gate E/D MESFET circuits including a 4×4 bit multiplier, a 4×4 crosspoint switch, a 448-bit static RAM, and an integrated photodiode amplifier were demonstrated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.337808
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Observation of the focusing of x-ray transition radiation using cylindrical optics (1992)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 61 (1992), S. 1019-1021 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have measured the profile of x rays generated by a transition radiator and focused by simple cylindrical optics. Soft x rays with photon energies between 1 and 4 keV were generated by a 93-MeV electron beam striking a stack of eight foils of 3.5-μm-thick mylar. These x rays were emitted in an annular cone and were collected by a quartz cylinder which focused the x rays to a 0.5-mm-diam spot at a distance of 1.35 m from the transition radiator.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.107702
    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...