Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    Localization and hopping of magnetoelastic waves in highly magnetostrictive strings with random chain structures (abstract) : The 41st annual conference on magnetism and magnetic materials (1997)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 5692-5692 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Analogous to the localization of the wave function of an electron in a random potential (Anderson localization), in the macroscopic system of magnetoelastic waves (MEWs) propagating in a highly magnetostrictive string exhibiting the giant ΔE effect, the piling-up of MEWs into a wave-packet in a restricted small region of the string is expected. This wave-packet is subject to hopping in a discontinuous wave by applying a magnetic field due to the change in the local elastic states caused by the ΔE effect. From this expectation, a theoretical analysis was performed focusing on the derivation of localization conditions of MEWs. The analysis was carried out using a one-dimensional string model having high magnetostriction. The string is assumed to be composed of random chains with (1) alloy-type disorder (random weights of masses with equal spacings) and (2) liquid-type disorder (random spacings of masses with equal weights). For the elastic and magnetoelastic constants of the string, the value of Fe78Si10B12 amorphous wire (Unitika) were used in the calculations. No substantial changes in the localization states were not recognized in both modes. The analysis revealed that, when the change of the apparent Young's modulus with magnetic field ΔE is 28%, the localized MEWs are subject to hopping conserving their wave identities (eigenfrequencies and eigenstates). This result in considered to originate from the changes in the disorder conditions to support the localization of MEWs. To confirm the above theoretical prediction experimentally, MEW properties have been measured by using Fe78Si10B12 amorphous wires connecting weights made of leads to form the random chain structure. The localized MEWs are, indeed, observed by detecting the local vibrations of the wires. Theoretical and experimental results will be presented in detail at the conference. © 1997 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.364639
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Effects of D-serine on bacterial D-amino acid transaminase: accumulation of an intermediate and inactivation of the enzyme (1989)
    s.l. : American Chemical Society
    Biochemistry 28 (1989), S. 8798-8803 
    Details
    ISSN: 1520-4995
    Quelle: ACS Legacy Archives
    Thema: Biologie , Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1021/bi00448a018
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Magnetoresistance in magnetite films prepared from aqueous solution at room temperature (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 87 (2000), S. 7127-7129 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Polycrystalline iron oxide films, 0.1–1.1 μm in thickness, are synthesized on glass substrates at room temperature directly from an aqueous solution of FeCl2 by ferrite plating. The films have a single phase spinel structure of mixed solution (Fe3O4)1−x–(γ-Fe2O3)x, as revealed by x-ray diffractometer and conversion electron 57Fe Mössbauer spectroscopy. At room temperature the films exhibit negative magnetoresistance (MR) of ratio ΔR/R=−3.3% to −7.4%, which is ascribed to intergranular tunneling of spin polarized electrons of Fe3O4. The resistivity R of the films is 2.2×100–1.3×103 Ω cm, much higher than that (∼10−2 Ω cm) reported for bulk samples of Fe3O4; R and ΔR/R depend on the plating conditions and, therefore, the composition x in (Fe3O4)1−x–(γ-Fe2O3)x of the samples. © 2000 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.372952
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Development of a fluorescent x-ray source for medical imaging : Proceedings of the 5th international conference on synchrotron radiation instrumentation (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 1981-1983 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A fluorescent x-ray source for medical imaging, such as K-edge subtraction angiography and monochromatic x-ray CT, has been developed. Using a 6.5 GeV accumulation ring in Tsukuba, fluorescent x rays, which range from about 30 to 70 keV are generated by irradiating several target materials. Measurements have been made of output intensities and energy spectra for different target angles and extraction angles. The intensities of fluorescent x rays at a 30 mA beam current are on the order of 1–3×106 photons/mm2/s at 30 cm from the local spot where the incident beam is collimated to 1 mm2. A phantom which contains three different contrast media (iodine, barium, gadolinium) was used for the K-edge energy subtraction, and element selective CT images were obtained. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1145776
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Ultrathin Si buffer layers to improve the exchange bias between Ni–Fe and FeMn layers (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 4934-4936 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Ni–Fe/FeMn bilayers were deposited by using dual ion beam sputtering apparatus. In order to promote (111) orientation in γ-FeMn layers and to exhibit exchange bias field Hex, Si and/or silicon nitride (Si3N4) layers were deposited as buffer layers. Although silicon nitride (Si3N4) buffer layers did not improve (111) orientation in FeMn layers, as well as in Ni–Fe layers, an amorphous Si buffer layer only 1 nm thick improved (111) orientation in FeMn layers and increased Hex to above 100 Oe. FeMn/Ni–Fe bilayers deposited on Si(0.5 nm)/Si3N4(1 nm) bilayered buffer layer also exhibited high Hex of about 130 Oe. This result implies that the ultrathin a-Si buffer layer was effective in improving (111) orientation in Ni–Fe layers. Very thin Si/Si3N4 bilayers may be applicable as dielectric layers in tunneling magnetoresistive spin valve devices. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.370050
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    The pressure effect of the Curie temperature in TbAl2 (1990)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 5298-5299 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The pressure effect of the ferromagnetic Curie temperature in Tb(Al1−xCox)2, 0≤x≤0.1 was measured by the induction method under hydrostatic pressure. The Curie temperatures of these compounds increased with increasing pressure and the derivative dTc/dp as a function of cobalt concentration did not change so much compared with that of Gd(Al1−xCox)2 [Sato et al., J. Phys. (Paris) Colloq. 49, C8-453 (1988)]. These results are discussed on the basis of the RKKY model.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.344588
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Material and electrical characterization of polycrystalline boron-doped diamond films grown by microwave plasma chemical vapor deposition (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 3142-3148 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Crystal/material quality and electrical properties of B-doped diamond films synthesized by microwave plasma chemical vapor deposition were investigated. Raman spectroscopy verified the presence of diamond and indicated that the crystal quality increased with B doping. Secondary-ion mass spectroscopy showed that the B/C ratios in the films were larger than the B/C ratios in the gas phase, possibly due to differences in B and C sticking coefficients. Electrode patterns of Pt were fabricated on the films and electrical properties were investigated. On undoped diamond films with a residual B concentration of ∼5×1017 cm−3, these contacts were rectifying with small reverse leakage currents and on B-doped diamond films with a B concentration of 200 and 400 ppm, they yielded ohmic behavior. The temperature dependence of the resistivity showed that these doped films had activation energies, an order of magnitude smaller than that associated with the B impurity level in diamonds. The small activation energies associated with these heavily doped films suggest that an impurity band conduction plays an important role. Experimentally determined Hall mobility of the films was also interpreted qualitatively by an impurity band conduction mechanism and effects of grain boundaries and sp2 components on the transport properties are considered to be small for heavily doped films.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.348582
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Formation of positive radial electric field by electron cyclotron heating in compact helical system (1994)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 3400-3406 
    Details
    ISSN: 1089-7674
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The radial electric field is driven to positive value by off-axis second harmonic electron cyclotron heating (ECH) in the Compact Helical System [Plasma Physics and Controlled Nuclear Fusion Research 1988, Nice (International Atomic Energy Agency, Vienna, 1989), Vol. II, p. 411]. The observed positive electric field is associated with the outward particle flux enhanced with ECH. The enhanced particle flux triggered by the production of the electrons accelerated perpendicularly to the magnetic field with ECH results in the change of the electric field.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.870488
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Magnetic-field study in a compact helical system (1990)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 61 (1990), S. 686-692 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Implementation of the designed magnetic field in the compact helical system torsatron device has been verified both experimentally and numerically. A misalignment of the outer two sets of poloidal field coils has been identified both quantitatively and qualitatively. A magnetic-field-mapping experiment has indicated that closed magnetic surfaces have been successfully achieved up to 95% of the outermost surface and that islands exist on the m=2 and 3 major rational surfaces. The experimental results and the computational analysis consistently explain that these islands are mainly caused by the ambient field resulting from magnetization of the building structure. The m=2 island width is estimated to be several millimeters during regular plasma heating experiments when the toroidal field is more than 1 T.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1141479
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    High-speed image-acquisition system for energy subtraction angiography : International conference on synchrotron radiation instrumentation (1989)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 60 (1989), S. 2260-2263 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: The aim of this study is to visualize the coronary artery with the intravenus injection of contrast media. We propose a method of rapid and successive acquisition of two-dimensional images in a digital processing system which uses a pair of video cameras, a shutter operation, and a beam-splitting apparatus. A prototype of the high-speed acquisition system was constructed. The two-monochromatic video-camera method was very suitable for quick acquisition. Electro-optical shutters (PLZT) were found practical with respect to the dynamic range and response time. The field blanking method was essential for the data acquisition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1140788
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...