Bibliothek

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
Filter
  • Digitale Medien  (10)
  • 1995-1999  (10)
Materialart
  • Digitale Medien  (10)
Erscheinungszeitraum
Jahr
  • 1
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 75 (1999), S. 1293-1295 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We describe an experiment aimed at testing the long term survivability of high temperature superconductors (HTSCs) in space. The experiment consists of a thin YBCO film integrated with a cryocooler. The experiment was launched into orbit aboard the TECHSAT II satellite in July 1998. Since then, the superconducting film was tested periodically, and has shown little or no degradation of its properties. Our experiment should provide the basic long term survivability data needed for advanced applications of HTSC in space, in the field of satellite communications. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 3763-3765 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We found unidirectional nanocracks in unidirectionally twinned films of YBa2Cu3O7−δ on NdGaO3 which are normal to the twin planes. In 70–250 nm thick films, transmission electron and atomic force microscopy show that these unidirectional nanocracks are found to be 1–2 μm apart and have 2–4 nm width. Microbridges that cross these nanocracks behave as natural Josephson junctions. They show Shapiro steps under microwave irradiation and suppression of the critical current Ic in magnetic fields. A very large in-plane anisotropy of the resistivities and Ic was observed and this was correlated with the nanocracks orientation, length, and film thickness. The observed anisotropy of Ic near Tc is shown to be consistent with a d+is wave symmetry of the order parameter in YBa2Cu3O7−δ. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 68 (1996), S. 705-707 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Using a stripline resonator technique, we measured the dependence on microwave current of the impedance of fabricated superconductor/normal-metal/superconductor Josephson junctions in YBa2Cu3O7 thin films. The results are compared with predictions of a resistively shunted junction model that yields good agreement at low and intermediate values of the microwave current. At high currents deviations from the model predictions are observed, which we propose are due to flux penetration into the junction. The results are consistent with previously proposed explanations of the rf power dependence of the high-Tc materials. © 1996 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 1769-1771 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We studied the proximity effect in a series of YBa2Cu2.7Fe0.3Oy/YBa2Cu3O7−δ bilayer film with varying YBa2Cu3O7−δ thickness. In a bilayer of isolated YBCO islands, a Tc of 72 K was observed, much higher than Tc of 32 K of the YBa2Cu2.7Fe0.3Oy film. Tc and Jc of thicker bilayers of continuous YBa2Cu3O7−δ films were found to decrease with decreasing YBCO thickness. This behavior of Tc and Jc can be explained by the Deutscher de Gennes theory for the proximity effect, provided one models the film as a series of grains whose lateral dimensions scale with the average film thickness. © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 5
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 74 (1999), S. 3392-3394 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Properties of oxygen-deficient edge junctions made of YBa2Cu3O6.6 as the superconductor and YBa2Cu3−xFexOy as the barrier are reported. These junctions show weak-link characteristics when the edge angle is 50°, while tunneling-like behavior is observed when the edge angle is 36°. In all junctions strong peaks in the conductivity are found, which depend on the specific junction geometry. Some series of peaks were identified as due to Tomasch oscillations in the cover electrode, which yield Δ=1.4±0.2 meV and vF′=(4.4±0.2)×107 cm/s. © 1999 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 6
    Digitale Medien
    Digitale Medien
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 73 (1998), S. 402-404 
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: We found that microcracks in thin Nd2/3Sr1/3MnO3 films create a series of intrinsic break junctions which are ideal for investigating tunneling phenomena in this system. A comparison of films with and without cracks, which have similar ferromagnetic Curie temperature (Tc) of 140–150 K, shows that the cracked film has a lower insulator to metal transition temperature TM (97 K vs 140 K), three orders of magnitude higher resistivity at TM, and two times larger magnetoresistance at 1 T near TM. At T〉TM we observed that ln ραT−1/4 in the uncracked film while in the cracked film a ln ραT−1/2 dependence was found. This indicates that the conductivity in the first case is due to variable range hopping in three dimension, while in the second case it is dominated by thermally activated tunneling across the insulating barriers (the microcracks). © 1998 American Institute of Physics.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 7
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 55 (1999), S. 1-6 
    ISSN: 1432-1041
    Schlagwort(e): Key words Deferiprone ; Iron overloaded patients ; Meta-analysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Notizen: Abstract Objective: To summarize efficacy and effectiveness in iron overloaded patients treated with the orally active iron chelator deferiprone also known as L1 or, using meta-analysis of the literature. Methods: We reviewed the literature, searching Medline and Embase databases, as well as reviews and other literature on the topic. Inclusion criteria were: original clinical trials reporting results for serum ferritin concentration (SF), hepatic iron concentration or urinary iron excretion (UIE). Efficacy data had to have been reported after ≥3 months of treatment. Data were combined using a random effects model (Cochrane) modified for use with single groups to produce a point estimate and a 95% confidence interval. To summarize the clinical effectiveness, overall proportion of patients where deferiprone was able to reduce serum ferritin was calculated. We also examined average (mg · l−1) serum ferritin levels over the reported time (mean) and absolute decrease from the baseline after therapy. To summarize efficacy, success was defined as the proportion of patients who achieved UIE of 25 mg per day or 0.5 mg · kg−1 · day−1, which equals the average amount received from monthly blood transfusions. We also calculated the overall average level (mg per day) of UIE over the reported time of therapy (mean). As part of a sensitivity analysis, data were analyzed for two ranges of deferiprone dosage: ≤50 mg · kg−1 · day−1 and ≥75 mg · kg−1 · day−1. Results: Of 83 identified references, nine clinical trials met our inclusion criteria, providing data for 129 iron overloaded patients. After a mean of 16 months of therapy (range 6.4–36 months) with 66.4 mg · kg−1 · day−1 (mean) of deferiprone, 75.5% of highly iron overloaded patients had a decrease in serum ferritin from baseline. The average drop in serum ferritin of 0.8 mg · l−1 was 23.5% from baseline. The overall average UIE for therapy was 28.8 mg per day in patients receiving ≥75 mg · kg−1 · day−1 over 8.5 months of therapy. At the same dosage, more than half of the patients (51.8%) achieved negative iron balance. When studies with patients receiving lower dosage (≤50 mg · kg−1 · day−1) were included, the success rate was 45.1%. Conclusion: Overall, deferiprone has clinical efficacy in achieving negative iron balance and reducing body iron burden in highly iron overloaded patients. After an average of 16 months of deferiprone in doses ≥75 mg · kg−1 · day−1, most patients had a decrease in ferritine concentration.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 8
    Digitale Medien
    Digitale Medien
    Springer
    European journal of clinical pharmacology 50 (1996), S. 147-148 
    ISSN: 1432-1041
    Schlagwort(e): Key words Felodipine ; Children; pharmacokinetics
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Medizin
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 9
    ISSN: 1432-1998
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Long-term prostaglandin (PG) therapy has recently been associated with gastric mucosal hyperplasia. We reviewed the clinical and radiologic (especially sonographic) records of eight patients with complex congenital heart disease who were on PG therapy. Feeding problems, vomiting, and abdominal distension were present in six patients. Barium meal revealed antral narrowing in three patients, suggestive of hypertrophic pyloric stenosis in two. Sonography showed a variable degree of increased gastric mucosal lobulation often accompanied by a marked polypoid or lobular appearance. Cortical hyperostosis related to PG therapy was seen in three patients. PG-associated gastric mucosal hyperplasia can cause feeding problems and pronounced gastric lobulation.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 10
    Digitale Medien
    Digitale Medien
    Springer
    Journal of low temperature physics 106 (1997), S. 243-248 
    ISSN: 1573-7357
    Schlagwort(e): 85.25. Cp ; 74.50.+r ; 85.70.-w
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The quasiparticle tunneling (QPT) in YBa2Cu3O7−δ (YBCO), Bi2Sr2CaCu2O8+x (BSCCO), Nd1.85Ce0.15CuOx (NCCO) and La1.85Sr0.15CuO4−δ (LSCO) grain boundary Josephson junctions (GBJs) has been studied. At voltages above the gap voltage V9, the measured conductance vs. voltage, G(V), curves show a temperature independent parabolic shape allowing the determination of the effective height and thickness of the insulating grain boundary barrier. At |V|〈Vg, the G(V)-curves are well fitted by a BCS density of states and temperature dependence of the energy gap, if a large broadening parameter Γ is assumed for the gap. The large Γ value most likely is related to the high density of localized states within the grain boundary barrier. Furthermore, a zero-bias conductance anomaly is observed which can be analyzed in terms of spin-flip and Kondo-type scattering at the interface (Anderson-Appelbaum model).
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...