Library

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
    Nuclear spin dependence of polarization enhancement by multi-tilted foils studied by short-lived beta-emitters8B and12B (1993)
    Springer
    Hyperfine interactions 80 (1993), S. 1281-1286 
    Details
    ISSN: 1572-9540
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract In order to study the basic mechanism of polarization enhancement realized by the multitilted foil technique, nuclear polarization of short-lived beta-emitter8B(T1/2=769 ms,I π=2+) was induced. Utilizing up to ten tilted foils, the polarization enhancement was measured as a function of the foil numbers. The observed enhancement for8B was combined with the previous results for12B(I π=1+,T 1/2=20 ms) which has the same atomic configurations but different nuclear spin. Analyzing these results in the framework of the classical vector model, the essential features of the enhancement depending on the nuclear spin was disclosed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00567492
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Detection of Superoxide Production by Activated Microglia Using a Sensitive and Specific Chemiluminescence Assay and Microglia-Mediated PC12h Cell Death (1994)
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 63 (1994), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: Superoxide production by cultured microglia derived from neonatal rat brains and the cytotoxicity of these cells were evaluated. The chemiluminescence (photon counts) detected in the presence of MCLA, a new chemiluminescence probe, was strongly correlated with the microglial cell count. Chemiluminescence observed in this system was confirmed to originate specifically from superoxide produced by activated microglia. Phorbol myristate acetate-stimulated microglia caused a pronounced reduction of PC12h cell numbers in coculture. The addition of superoxide dismutase with catalase or the addition of deferoxamine mesylate inhibited PC12h cell death, suggesting that active oxygen species derived from superoxide generated by the microglia or iron-oxygen complex formation were responsible for the cytotoxicity. These results imply that activated microglia may participate in the progression of the pathologic process in some neurodegenerative disorders.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1471-4159.1994.63010266.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Epitaxial CoAl/AlAs/GaAs metal semiconductor heterostructures: Growth, structure, and electrical properties (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 885-896 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Molecular beam epitaxial (MBE) growth, structural, and electrical properties of novel epitaxial metal/semiconductor heterostructures (MSHs), consisting of monocrystalline CoAl, an intermetallic compound, and AlAs/GaAs III-V semiconductors have been studied. The CoAl with stoichiometric composition has a CsCl-type crystal structure whose lattice constant is very close to half the lattice constant of GaAs and AlAs, hence, it is a good candidate as a constituent metal in epitaxial monocrystalline metal/semiconductor heterostructures. MBE growth of CoAl thin films on AlAs/GaAs, and also semiconductor overgrowth on ultrathin CoAl films, together with structural characterizations by in situ reflection high energy electron diffractions, ex situ x-ray diffractions and cross sectional transmission electron microscopy have been explored. By optimizing the growth parameters and procedures, high quality monocrystalline CoAl/AlAs/GaAs heterostructures with atomically abrupt interfaces have been successfully grown. Furthermore, the electrical properties of such novel heterostructures as Schottky barrier heights of CoAl/AlAs/GaAs MSHs and transport properties in ultrathin buried CoAl films are described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356443
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Epitaxial ferromagnetic MnAs thin films grown by molecular-beam epitaxy on GaAs: Structure and magnetic properties : The 6th joint magnetism and magnetic materials (MMM)-intermag conference (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 6278-6280 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have studied structural and magnetic properties of epitaxial MnAs thin films with various thicknesses (L=1.0–200 nm) on GaAs substrates. The MnAs thin films were grown at 200–250 °C on an As-rich disordered c(4×4) (001) GaAs surface by molecular-beam epitaxy (MBE). The growth direction of the MnAs was found to be along the [1¯100] axis of the hexagonal unit cell. X-ray spectra of the MnAs at room temperature have two peaks, indicating that the present MBE-grown MnAs films consist of the hexagonal ferromagnetic phase and orthorhombic paramagnetic phase. Magnetization measurements revealed that the MnAs thin films have perfectly square hysteresis characteristics with relatively high remnant magnetization Mr=300–567 emu/cm3 and low coercive field Hc=65–926 Oe, compared with those of epitaxial MnGa and MnAl thin films reported previously.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.358304
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Development of high power negative-ion sources for fusion research at JAERI : Proceedings of the 5th international conference on ion sources (1994)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 65 (1994), S. 1159-1161 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Recent progress regarding high power negative-ion source development for fusion research at JAERI is described. Using the cesium-seeded volume production-type negative-ion sources with an electrostatic acceleration system, a stable production of multiampere negative hydrogen/deuterium ion beams and a high energy acceleration of negative hydrogen ions of 0.2 A up to 350 keV have been demonstrated. On the basis of this recent progress, the construction of a 500 keV, 22 A, deuterium negative-ion source for a neutral beam injection system for the JT-60 tokamak was initiated. Additionally, a 1 MeV, 1 A Cockcroft–Walton-type test facility has been prepared in order to demonstrate high current negative ion acceleration up to 1 MeV. Through these research and development activities, the high power negative-ion source technology sufficient for the realization of a neutral beam injection system for a fusion experimental reactor such as the International Thermonuclear Experimental Reactor, is in the planning stages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145044
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Magnetic properties of epitaxial MnAl/NiAl magnetic multilayers grown on GaAs heterostructures (invited) : 38th Annual Conference on Magnetism and Magnetic Materials (1994)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 75 (1994), S. 6665-6669 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: New ultrathin epitaxial magnetic multilayers consisting of ferromagnetic τMnAl and nonmagnetic NiAl have been prepared on GaAs by molecular beam epitaxy. The magnetic and magneto-optic properties of these multilayers and the effect of incorporating nonmagnetic NiAl into the structure have been investigated. Perpendicular magnetization was confirmed and the remnant magnetization and coercivity were improved compared to τMnAl thin films. In addition, by systematically changing the thickness of the NiAl layer the magnetic properties could be controlled. We discuss these issues and compare the magnetic and magneto-optic properties of these structures with other epitaxial magnetic structures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.356889
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Epitaxial τ (Mn,Ni)Al/(Al,Ga)As heterostructures: Magnetic and magneto-optic properties : 37th Annual conference on magnetism and magnetic materials (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 73 (1993), S. 6121-6123 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ferromagnetic perpendicularly magnetized epitaxial thin films of τ (Mn,Ni)Al have been successfully grown on AlAs/GaAs heterostructures by molecular beam epitaxy. We have investigated the polar Kerr rotation and magnetization of τ MnAl and (Mn,Ni)Al as a function of Mn and Ni concentration. The largest polar Kerr rotation and remnant magnetization were obtained for Mn0.5Al0.5 thin films with values of 0.16° and 224 emu/cm3, respectively. We observed that the Kerr rotation and magnetization remained constant with Ni additions up to about 12 at. % and subsequently decreased with further Ni additions. We discuss these results and one possible method of enhancing the Kerr rotation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.352721
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Interferometric measurements of the diameters of a single-crystal silicon sphere (1992)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 5320-5325 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new interferometer has been developed for the accurate determination of the density of a silicon crystal, in which a single-crystal silicon sphere of nearly perfect geometry is placed in a Fabry–Perot etalon of accurately known plate distance, and the diameters are obtained by measuring the two gaps between the etalon and the adjacent surface of the sphere. A new method is used to measure the sum of the length of the two gaps by scanning the etalon against the sphere. Two wavelengths, 633 nm from a frequency-stabilized He–Ne laser and 441 nm from a free-running He–Cd laser, are used to determine the order of interference by applying the method of exact fractions. The diameter of about 94 mm has been measured with a resolution of 0.5 nm. Diameter measurements from uniformly distributed directions have shown that the mean diameter has been determined with a standard deviation of 8.6 nm, corresponding to 0.28 ppm in the volume determination. The total uncertainty of the volume is estimated to be 0.34 ppm. Effects of a thin oxide layer and impurities on the bulk density are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1143447
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    A molecular beam study of alkali promotion of NO sticking on Si(100): Local promotion in a single collision regime (1992)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 97 (1992), S. 3781-3793 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Alkali–metal (K and Cs) promotion for sticking of nitrogen oxide molecule (NO) on Si(100) has been studied using a molecular beam method combined with an Auger electron spectroscopy (AES) and a laser ionization spectroscopy [resonance enhanced multiphoton ionization (REMPI)]. The observed sticking probability S shows a good correlation with alkali coverage, indicating that the alkali promotion is local in nature. The decay of S as a function of NO dose as observed with AES shows an anticorrelation with the evolution of the direct-inelastic scattering intensity as obtained with REMPI. This fact is understood as follows: since the direct-inelastic scattering occurs mostly in a single collision process with the surface, local alkali promotion is realized in a single collision of the incident NO molecule with the alkali–metal adsorbates. The decay of S as a function of NO dose is then analyzed with a reaction cross section. The evaluated reaction cross sections are close to the area of the 2×1 unit cell, and thus the estimated reaction radii are almost equal to but somewhat larger than the covalent radius of a K atom, with a increasing trend with alkali coverage. The alkali promotion is explained in terms of local electron charge transfer from the nonionized alkali adatoms to the affinity level of NO molecules based on the adatom density of state around EF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.462959
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Role of compressibility on driven magnetic reconnection (1992)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 4 (1992), S. 450-457 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Whether it is induced by an ideal (current driven) instability or by an external force, plasma flow causes a change in the magnetic field configuration and often gives rise to a current intensification locally, thereby a fast driven reconnection being driven there. Many dramatic phenomena in magnetically confined plasmas such as magnetospheric substorms, solar flares, magnetohydrodynamic (MHD) self-organization, and tokamak sawtooth crash, may be attributed to this fast driven reconnection. Using a fourth-order MHD simulation code it is confirmed that compressibility of the plasma plays a crucial role in leading to a fast (MHD time scale) driven reconnection. This indicates that the incompressible representation is not always applicable to the study of a global dynamical behavior of a magnetically confined plasma.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860295
    Library Location Call Number Volume/Issue/Year 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...