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  • 1
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Magnetic aftereffect and irreversible flux loss at elevated temperatures were studied for fully dense isotropic and anisotropic Nd-Fe-Co−B magnets consolidated from rapidly quenched powder by direct joule heating. The consolidation process and the subsequent alignment of c axis do not affect the aftereffect constant Sv and the prepared magnets have roughly the same Sv as a bonded magnet, independent of coercivity at room temperature (650–1200 kA/m), exposure temperature (60–120 °C), and anisotropy of the magnets. Thus the magnitude of the aftereffect is determined mainly by the magnitude of the irreversible susceptibility χirr. It was also clarified empirically that the irreversible flux loss FL is proportional in magnitude to χirr. However, the slopes of the FL vs χirr line for isotropic magnets are much larger than those for the anisotropic ones. Thus FL can be reduced by decreasing χirr and/or making magnets anisotropic.
    Materialart: Digitale Medien
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  • 2
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 67 (1990), S. 6334-6339 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The photoelectric work function of a cesiated molybdenum converter surface in a cesiated hydrogen discharge and the negative-hydrogen-ion (H−) current produced at the surface were simultaneously measured. With the negative bias potential of the converter constant, the H− yield increased exponentially as the work function was decreased by introducing Cs into the discharge. The yield of H− current was always higher for a higher bias potential on the surface, provided the measured surface work function was nearly the same. When the concentration of Cs in a discharge was nearly constant, the bias potential of the surface at which the H− production became maximum was observed. At this bias potential, the surface work function was close to the work-function minimum.
    Materialart: Digitale Medien
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  • 3
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 2729-2731 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A beam of negative lithium ions (Li−) with a current density as high as 3×10−5 A/cm2 was extracted from a 5 cm diam, 7 cm long multicusp ion source. The extracted Li− current was correlated to the plasma temperature and density measured with Langmuir probes heated to avoid Li condensation. The neutral lithium flux from the ion source was measured with a Langmuir–Taylor detector, and it showed a linear correlation with the extracted Li− current. Further increase in efficiency to produce Li− current is expected by improving the plasma confinement of the ion source.
    Materialart: Digitale Medien
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  • 4
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 2726-2728 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A plasma sputter negative ion source was evaluated for its applicability for measuring the plasma potentials in fusion devices. Both the beam current density and the beam energy spread are key issues for this application. The energy spectra of self-extracted Au− beams from the source were measured under the condition of a constant work function of the production surface. The FWHM increases from 3 to 9 eV monotonically as the target voltage increases from 50 to 300 V, independently from the target surface work function of 2.2–3 eV.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 63 (1992), S. 2447-2449 
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Negative sodium ions and negative dimer ions of sodium are extracted from a sodium plasma. The extraction characteristics of Na− and Na2− from a low power discharge (about 1 W) through a single aperture (φ1.5 mm) are described. Both extracted currents of Na− and Na2− increase with the temperature of the heat shield inside the discharge chamber. The current ratio of Na− to Na2− is almost constant independent of discharge voltage. By increasing the discharge power, the value of the bias voltage of the plasma electrode that gives the optimum extraction currents of Na− and Na2− increases. The extracted current of Na2− is lower than that of Na− by two orders of magnitude.
    Materialart: Digitale Medien
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  • 6
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish diseases 6 (1983), S. 0 
    ISSN: 1365-2761
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Biologie , Medizin
    Notizen: Abstract. The in vitro bacteriostatic activity of a combination of sulphadiazine (SDZ) and trimethoprim (TMP) against representative bacterial fish pathogens was studied. In general, the minimum inhibitory concentrations (MIC) of TMP were much smaller than comparable values for SDZ. When SDZ and TMP were combined, the bacteriostatic effect was enhanced in a synergistic manner for all bacteria tested except Pseudomonas fluorescens. The synergism was most remarkable in the case of bacterial strains that were sensitive to the action of SDZ alone. This degree of synergism was observed when the ratios of SDZ and TMP in combination were in the range of 1:1 io 5:1. The MIC of SDZ plus TMP combined was less than 3.13 μg/ml for SDZ resistant strains and as low as 0.2 to 0.78 μ/ml for SDZ sensitive strains. The possible usefulness of a combination of these two compounds for therapy or control of bacterial fish disease is discussed.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-5195
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Beschreibung / Inhaltsverzeichnis: Résumé Les auteurs ont revu 85 patients qui ont bénéficié d'une décompression antérieure et d'une arthrodèse cervicale pour myéloradiculopathie consécutive à une ossification du ligament longitudinal postérieur et ils ont étudié les facteurs en relation avec la récupération neurologique. Il s'agissait de 72 hommes et de 13 femmes qui ont été suivis pendant 8.3 ans en moyenne. Seize patients (Groupe I) ont subi une spondylectomie subtotale d'une vertèbre avec arthrodèse, 58 (Groupe II) une spondylectomie subtotale de deux vertèbres et 11 (Groupe III) de trois vertèbres. La récupération neurologique a été évaluée selon la cotation en 17 points du Comité standard de l'Association orthopédique japonaise. Les patients du Groupe I ont obtenu un taux d'amélioration de 75%, ceux du Groupe II de 72% et ceux du Groupe III de 23%, ce qui est significativement moins bon. La sévérité de l'atteinte du canal vertébral par l'ossification n'a pas affecté directement le taux d'amélioration postopératoire. La durée de la maladie, un traumatisme cervical préalable, des symptômes neurologiques marqués ont influencé défavorablement le résultat neurologique. Le type d'intervention recommandé en cas d'ossification du ligament longitudinal postérieur est une spondylectomie portant sur deux vertèbres au plus, chez des patients n'ayant pas de symptômes importants. Lorsque plus de trois vertèbres sont impliquées, une autre opération telle qu'une laminoplastie peut être envisagée.
    Notizen: Summary The authors reviewed 85 patients who had undergone anterior decompression and cervical fusion for myeloradiculopathy due to ossification of the posterior longitudinal ligament. There were 72 males and 13 females; the average follow up was for 8.3 years. Sixteen patients (group I) underwent one vertebra subtotal spondylectomy with fusion, 58 (group II) two vertebra subtotal spondylectomy, and 11 (group III) three vertebra subtotal spondylectomy. Neurological recovery was assessed on the grading system of the Japanese Orthopaedic Association. The patients in group I had an average improvement of 75%, in group II 72% and in group III 23%. The severity of compromise of the spinal cord did not affect the post-operative improvement. Duration of disease, previous injury and advanced neurological symptoms all affected neurological recovery. Spondylectomy of at most two vertebrae, with fusion, is recommended for ossification of the posterior longitudinal ligament. If there is more extensive involvement laminoplasty may be indicated.
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Oxford [u.a.] : International Union of Crystallography (IUCr)
    Acta crystallographica 50 (1994), S. 1276-1279 
    ISSN: 1600-5759
    Quelle: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    [S.l.] : International Union of Crystallography (IUCr)
    Acta crystallographica 49 (1993), S. 198-202 
    ISSN: 1600-5724
    Quelle: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Mössbauer diffraction experiments were performed on a single crystal of lithium heptagermanate in the temperature range 250–350 K. The high energy resolution of resonant γ radiation was used to separate elastically and inelastically scattered components. A lattice expansion along c and a decrease of the intensity of the elastically scattered radiation (IBragg) connected with an increase of the intensity of the inelastically scattered radiation (ITDS) are observed at the transition from the para- to the ferroelectric phase at 283.5 K. The experimentally determined maximum of ITDS/lBragg appearing at the phase transition is much more pronounced in comparison with that predicted from TDS-correction programs, which are based on the lattice dynamical theory restricted to acoustic phonons only.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Springer
    The European physical journal 347 (1993), S. 53-62 
    ISSN: 1434-601X
    Schlagwort(e): 25.85.Ge
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Isomeric yield ratios of 30 fission products in 24 MeV proton-induced fission of238U were measured by the use of the ion-guide isotope separator on-line. The obtained isomeric yield ratios were converted to the angular momenta of primary fission fragments based on the statistical model. The deduced angular momenta were examined from various aspects. It is found that in general the angular momentum continuously increases with the fragment mass number including the region of symmetric mass division. However, there are some exceptions. For Sn isotopes the deduced angular momenta are quite small due to the spherical shape of the nuclear shell configuration. It is also concluded from the consideration of the charge distribution that the angular momentum of fission product scatters considerably within the narrow range of mass division. The dependence of the angular momentum on the available energy of fragments at scission point indicates that the individual fragment possesses a characteristic deformation at scission and/or the deduced angular momentum is seriously affected by the particle excitation after scission.
    Materialart: Digitale Medien
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