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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 7045-7050 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Indiffusion profiles of sulfur in gallium arsenide were determined by secondary ion mass spectroscopy. In order to evaluate the shape of the profiles, a set of coupled reaction–diffusion equations was solved numerically. From the simulated nonequilibrium indiffusion profiles of sulfur, which diffuses into gallium arsenide via the kick-out mechanism, both the diffusion coefficient and the equilibrium concentration of arsenic self-interstitials were simultaneously determined. Transmission electron microscopy revealed that, due to an arsenic supersaturation, extrinsic dislocation loops have formed. The Fermi-level effect is more pronounced at lower diffusion temperatures and provides an additional driving force for the loop formation, agreeing well with the occurrence of larger faulted loops at a diffusion temperature of 950 °C rather than at 1100 °C. The complex behavior of the sulfur indiffusion can be quantitatively described by taking into account extended defects. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 3846-3854 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The atomic interface structure of implanted buried layers in (100) oriented Si substrates has been characterized by quantitative high-resolution transmission electron microscopy on cross-section specimens. The buried layers were produced by high-dose Co+ ion implantation [100 and 200 keV Co+ ions, (1–2)×1017 cm−2] at 350 °C and subsequent rapid thermal annealing at 750 and at 1150 °C. Planar interface regions of high perfection with domains of different atomic interface structures, and interface steps, frequently with {111} facets, were observed. Comparison with computer-simulated images for various interface models yields evidence for interface regions with six-fold and eight-fold coordination of the Co interface atoms. Furthermore, regions with interfaces showing a continuous transition as well as Co-rich interfaces were found. Measurements of the Schottky barrier heights have been performed and show smaller values for the upper CoSi2/n-Si(001) interfaces than for the lower ones. Possible correlations between the interface structures and the resulting electronic properties are discussed.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 2 (1990), S. 2764-2778 
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The growth rate of the ion-hose instability has been measured for a 2.5 MeV, 1 kA, 1 μsec electron beam following plasma channels of O2, N2, and H2 (in the ion-focused regime). The amplitude of transverse oscillations of a given beam segment was seen to grow, saturate, and damp as the segment traveled. The offset amplitude at saturation (dm) was seen to be an exponential function of the beam pulse duration (t): dm=dm,0 exp(2πGLt/tc), where tc is the time required for one channel oscillation and GL is the growth rate (for beam oscillations less than the channel radius). With beam radius equal to channel radius (rb=rc), and channel density equal to half the beam density, GL=0.75±0.15. Here GL was seen to scale with the square root of channel ion mass when data from channels of O2, N2, and H2 were compared. Also, GL was seen to increase as rb was increased (with the initial beam emittance kept the same). A fivefold decrease in growth rate was observed for t〉tc and dm〉rc. The decrease in growth rate may be due to the strongly anharmonic potential outside the channel or detuning from radial oscillations. Agreement was obtained between the data and models.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 76 (2000), S. 2677-2679 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Epitaxial Si/InAs/Si heterostructure grown on (001) Si substrate by molecular beam epitaxy and annealed at 800 °C was investigated by high resolution transmission electron microscopy. Extensive interdiffusion leads to the formation of an InAs solid solution in the Si cap layer. Additionally, InAs-enriched regions with extensions of ∼6 nm, which exhibit two kinds of ordering are observed. The ordering of InAs molecules has occurred, respectively, in (101) and (101¯) planes inclined and (110) and (11¯0) planes parallel to the [001] growth direction. It is attributed to the energy gain from the reduced number of mixed Si–As and Si–In bonds. The sample show photoluminescence in the 1.3 μm region, which is tentatively attributed to the recombination of excitons localized in the ordered regions. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 1536-1538 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The atomic structure of misfit dislocations at In0.2Ga0.8As/GaAs interfaces misoriented 2°–10° from (001) has been investigated by high-resolution electron microscopy. The misfit dislocations are predominantly dissociated 60° dislocations consisting of 90° and 30° Shockley partial dislocations and enclosed stacking faults. These dissociated 60° dislocations form increasingly asymmetrically on the different {111} glide planes as the misorientation increases. The 90° partial dislocations are not confined to the interface, but lie 0–100 A(ring) beneath it. The 30° partial dislocations, in turn, are pushed even further into the substrate.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 2798-2800 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The influence of substrate misorientation on the structure and morphology of In0.2Ga0.8As layers grown by molecular beam epitaxy on vicinal, near (001), GaAs substrates was investigated by transmission electron microscopy. The substrates were tilted at angles between 0° and 10° in 〈100〉, 〈110〉, and 〈120〉 directions. In layers which exceeded the critical thickness, networks of 60° dislocations running along the intersections of the four {111} planes with the interface were observed. Growth uniformity and anisotropy of strain relaxation were shown to depend on the type of growth steps introduced by a particular tilting direction.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 61 (1992), S. 2545-2547 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: InP was found to be semi-insulating after Cu diffusion. This conversion of both n-InP and p-InP was ascribed to the presence of Cu-In precipitates that act as buried Schottky barriers. The thermal stability of both the precipitates and the electrical properties of InP:Cu were studied after high temperature annealing treatments. Atomic resolution microscopy was used to determine the structure of these precipitates. Diffraction studies of some of these inclusions show that they have the structure of the metallic hexagonal compound Cu16In9. The concentration of Cu-In precipitates was found to be comparable with what our calculations show would achieve intrinsic behavior due to the effect of the metallic inclusions.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Anaesthesia 59 (2004), S. 0 
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Allergy 48 (1993), S. 0 
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Eosinophil cationic protein (ECP) is a cationic protein secreted by eosinophils with toxic properties for the respiratory epithelium. Sputum-ECP levels have been shown to correlate inversely with airflow obstruction in asthma. In the present study we investigated whether ECP concentrations are different between asthmatic patients and patients with chronic bronchitis. Sputum-ECP concentrations from seven patients with bronchial asthma and seven patients with chronic bronchitis matched for FEV, were compared (FEV, 66.1 f 29.0% of predicted; FEV, Chronic Bronchitis: 65.2 33.3% of predicted; p = n.s.). Furthermore, sputum-ECP levels in 4 asthmatic patients with severe airflow obstruction and in 1 patient with chronic bronchitis were measured before and after initiation of a 7-day oral therapy with methylprednisolone 20 mg BID. Changes in sputum-ECP values were compared with changes in FEV, in these 5 patients. Sputum-ECP levels and pulmonary function were measured as previously described (Am Rev Respir Dis 1992: 145: 604). Sputum-ECP levels from asthmatics were significantly elevated compared with patients with chronic bronchitis: asthma: 893.4 f346.2 pg/l per g sputum; chronic bronchitis: 30.0 f 8.5 pg/l per g sputum (p = 0.002). The degree of airway obstruction correlated with the sputum-ECP levels in asthmatics (r = -0.76, p = 0.05). but not in the patients with chronic bronchitis (r = 0.24, p = n.s.). In a separate group of 4 patients with asthma, elevated sputum-ECP levels prior to initiation of systemic corticosteroid therapy were associated with a marked improvement in FEV, after treatment, though this was not observed in one patient with chronic bronchitis and low sputum-ECP levels. We conclude that airflow obstruction in bronchial asthma, but not chronic bronchitis, is associated with elevated sputum-ECP concentrations. Furthermore, preliminary data suggest that elevated sputum-ECP levels predict reversibility of airflow obstruction with systemic corticosteroid therapy. Hence, sputum-ECP levels might be helpful in the differential diagnosis and treatment strategies of bronchial asthma and chronic bronchitis, especially in those patients who lack significant peripheral blood- or sputum-eosinophilia.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Journal of molecular medicine 68 (1990), S. 880-885 
    ISSN: 1432-1440
    Keywords: Wegener's granulomatosis ; Granulomatous giant cell myocarditis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 28-year-old male patient suffering from Wegener's granulomatosis died suddenly with signs of cardiac failure after clinical symptoms had basically subsided under chemotherapy. Autopsy revealed pulmonary granulomata, necrotizing vasculitis of the lungs and kidneys, focal and segmental necrotizing glomerulonephritis, and diffuse granulomatous and necrotizing giant cell myocarditis. Histological confirmation of inflammation of the heart in Wegener's disease has rarely been reported. Although cardiac involvement in Wegener's granulomatosis sometimes is suspected, it is usually thought to have no major impact on the course of the disease. By its dramatic clinical and morphologic presentation this case illustrates that the heart, in addition to the lungs and kidneys, may determine the outcome of the idiopathic granulomatous vasculitis of Wegener.
    Type of Medium: Electronic Resource
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