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
    Fabrication of Bi-(Pb)-Sr-Ca-Cu-O mono- and multifilamentary superconductors and improvement in critical current density (1989)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 66 (1989), S. 2762-2764 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The Bi-(Pb)-Sr-Ca-Cu-O superconductor has been fabricated into tapes without sheathing and into multifilamentary wires and tapes with Ag sheathing. Metallurgical studies as well as measurements have been made for them. Tape specimens prepared by combination and repetition of cold work (or cold press) and sintering showed critical current density Jc as high as 5×103 A/cm2 at 77 K with good reproducibility and reliability, although these specimens are sufficiently thick (0.5–1.0 mm). (Generally, Jc at zero field is inversely proportional to thickness.) For these tape specimens (with Cu sheath), sintering and Jc measurement were performed after the Cu sheath was removed. X-ray analysis showed that most of these tape specimens consist purely of high-Tc phase (∼107 K). In these specimens, the c axis tends to align well. This c axis alignment as well as compacting effect may be a cause of the enhancement in Jc . On the other hand, the tape specimens cold-worked and sintered only once (not repeated) showed Jc as small as only 102 A/cm2 with the c axis showing no sign of alignment. A 1330-filament Bi-Pb-Sr-Ca-Cu-O wire with a Ag sheath has been successfully fabricated. This multifilamentary wire shows critical temperature Tc of ∼105 K. A multifilamentary tape specimen fabricated by a combination of cold work and sintering showed Jc of 1.05×103 A/cm2 at 77 K.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.344201
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    A study of the Hc2 enhancement due to the addition of Ti to the matrix of bronze-processed Nb3Sn superconductors (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 63 (1988), S. 2167-2170 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The measurements of ρn (the normal state resistivity), Tc, Hc2, and (dHc2/dt)T=Tc have been made for bronze-processed Nb3Sn wires with addition of Ti to the Cu-Sn matrix in order to study the mechanism of Hc2 enhancement due to the addition of Ti. The coefficient of electron specific heat, γ, has been derived by two independent methods: one using the Ginzburg–Landau–Abrikosov–Gor'kov (GLAG) theory and the measured values of ρn, Tc, and (dHc2/dT)T=Tc, and the other using the Kramer pinning theory and the gradient of J1/2cH1/4 -H curves. The ratios of γ/γ0 which have been derived by these two methods are in good agreement with each other. (γ0 is the value of γ for the specimen to which Ti is not added.) The upper critical fields given by the GLAG theory, H@B|c2 and Hc2, at 0 K increase rapidly with Ti concentration in the Nb3Sn layer up to 2 at. % and decrease slightly above 2 at. %. The rapid increase in ρnγTc caused by the addition of Ti is sufficient to explain the enhancement in Hc2, and among ρn, γ and Tc, only ρn shows a significant increase with increasing amounts of additional Ti, indicating that the main reason for the Hc2 enhancement is the increase in ρn.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.341079
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Comparison of Bi-system 2223 and 2212 thick superconducting tapes: Grain alignment, current density, and strain effects (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 1596-1599 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Bi-Sr-Ca-Cu-O (2212) and Bi-Pb-Sr-Ca-Cu-O (2223) superconductors were fabricated into silver-sheathed tapes by cold rolling and sintering. The resulting samples are compared in terms of microstructural alignment, critical current density, and strain dependence. Although both samples show good grain alignment, that of the 2212 phase is superior due to partial melting during heat treatment. This microstructural superiority is reflected in superior Jc as well. The single-filament and multifilament 2212 tapes have Jc (approximately-greater-than) 5 × 104 A/cm2 and Jc (approximately-greater-than) 1.5 × 104 A/cm2 at 20 T, respectively. Each material shows a similar dependence of Jc upon strain, with the 2223 phase exhibiting slightly more degradation. Furthermore, multifilamentary tapes were less affected by strain than single-filament tapes. A multifilamentary tape at 4.2 K, 0.5 T showed only a weak dependence upon strain, indicating that the strain dependence of the Bi system at low temperature may not be severe.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.349523
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    Metallurgical studies and optimization of sintering for the Bi-Sr-Ca-Cu-O superconductors (1988)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 64 (1988), S. 6392-6395 
    Details
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Metallurgical studies and optimization of sintering condition to obtain the maximum volume fraction of the high Tc phase (∼110 K) have been made for the Bi-Sr-Ca-Cu-O system. In the differential thermal analysis, double peaks of endothermic reaction at ∼870 and ∼910 °C were observed during the increase of temperature, and a weight loss accompanied each endothermic reaction. Optimum calcining and sintering conditions to obtain a large volume fraction of the high Tc phase were 820 °C×14 h+840 °C×6 h and 875 °C×100 to 200 h in air, respectively. As for the variation of Cu concentration, nominal composition of Bi1Sr1Ca1Cu2Ox gave the maximum volume fraction of the high Tc phase. (For these specimens, sintering time was varied up to 20 days.) Post annealing at 400 °C for 20 h in an oxygen atmosphere after the sintering at 875 °C for 100 to 470 h in air had little effect on the improvement of volume fraction of the high Tc phase. As for the specimen to which Pb is added, however, the post annealing at 400 °C for 20 h increased the volume fraction of the high Tc phase. Scanning electron microscopy showed that the Bi1Sr1Ca1Cu2Ox (nominal composition) specimens sintered at 875 °C for 100 to 470 h consist mostly of well-grown thin layers, while the specimen sintered at 875 °C for 14 h consists mostly of fine pieces of thin layers piling up at random. Electron probe microanalysis revealed that microstructure of the specimen sintered at 875 °C consists of Bi-poor regions and the matrix surrounding them, and that these Bi-poor regions are classified into Cu-rich regions and Ca-rich regions. The superconducting phases of this material are considered to exist in the matrix region. We identified the Cu-rich regions and Ca-rich regions as (Sr0.45, Ca0.55 )3 Cu5 Ox and (Sr0.08, Ca0.92 )2 CuOx, respectively. The average size of these regions increased with increasing time of sintering, although total volume fraction of these regions did not increase.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.342052
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Fabrication of multifilamentary Y-Ba-Cu-O oxide superconductors (1988)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 52 (1988), S. 2261-2262 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Workability of Y-Ba-Cu-O composite wires with a Ag sheath has been studied and multifilamentary Y-Ba-Cu-O superconductors with a Ag matrix have been successfully fabricated. Observations of the wires with a scanning electron microscope reveal that as the areal reduction ratio R increases, the average Y-Ba-Cu-O grain size decreases. The study on the workability of the composite wires reveals that composite wires consisting of the Y-Ba-Cu-O powder and a Ag matrix can be rolled or drawn to any extent by a cold-work process with intermediate annealings at 150 °C for R=∼10. Based on this study, we have succeeded in fabricating a 252 filament Y-Ba-Cu-O wire which shows a Tc (onset) of ∼95 K.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.99770
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Magnetization and critical current density of the Bi-(Pb)-Sr-Ca-Cu-O tapes in magnetic fields (1989)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2772-2774 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The Bi-(Pb)-Sr-Ca-Cu-O superconductor was fabricated into tapes with a Cu sheath. Measurements of magnetization and critical current density Jc in magnetic fields up to 23 T were made for them. The magnetization measurement revealed that, at 4.2 K, these tape specimens had excellent Jc -H(magnetic field) characteristics, while at 77 K, the flux pinning force in them was reduced to zero above 0.3 T due to the flux creep. In the resistive Jc measurement at 4.2 K, these tape specimens showed Jc of ∼7000 A/cm2 at 23. The Jc -H curve showed a slight peak effect, indicating the peak over 30 T.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.101950
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Increased gastric acid secretion after Helicobacter pylori eradication may be a factor for developing reflux oesophagitis (2001)
    Oxford UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 15 (2001), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: The role of acid secretion in reflux oesophagitis which may develop after H. pylori eradication is not well known.〈section xml:id="abs1-2"〉〈title type="main"〉Aim:To investigate the participation of altered gastric acid secretion and the presence of hiatal hernia in the development of reflux oesophagitis after eradication therapy for H. pylori.〈section xml:id="abs1-3"〉〈title type="main"〉Subjects and Methods:A total of 105 patients with H. pylori infection, but without reflux oesophagitis at the time of eradication therapy, were followed prospectively for 7 months after the clearance of this microorganism. Gastric acid secretion was assessed by endoscopic gastrin test, and the presence of hiatal hernia by endoscopy.〈section xml:id="abs1-4"〉〈title type="main"〉Results:Reflux oesophagitis developed in 11 out of 105 (10.5%) patients when examined at 7 months after the eradication therapy. The incidence was correlated significantly with the increase in gastric acid secretion after the eradication of H. pylori, and was significantly higher in the patients with hiatal hernia (20%) than in those without it (0%).〈section xml:id="abs1-5"〉〈title type="main"〉Conclusions:Increased acid secretion after H. pylori eradication is an important risk factor of reflux oesophagitis, especially in patients with hiatal hernia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2036.2001.00988.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Long-term effect of 〈fr〉Helicobacter pylori〈/fr〉 eradication on the reversibility of acid secretion in profound hypochlorhydria (2004)
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 19 (2004), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background : Although profound hypochlorhydria is considered to be an important risk factor for development of gastric cancer, long-term effect of Helicobacter pylori eradication on its reversibility remains uncertain.Aim : To clarify the change in acid secretion after eradication in a long-term follow-up over 5 years in patients with profound hypochlorhydria.Methods : Twenty-three H. pylori-positive patients with hypochlorhydria (〈0.6 mmol/10 min) were enrolled prospectively. Assessment of gastrin-stimulated acid output and histologic evaluation of biopsy specimens were performed prior to, and 1, 7 months after eradication. Subsequently, gastric acid secretion was assessed for long-term period over 5 years after eradication in 12 patients.Results : Gastric acid secretion was reversed to normal range in nine of 23 patients (39%) at 7 months after eradication. In the long-term follow-up, gradual and significant recovery in gastric acid secretion was observed up to 2 years post-therapy. However, there was no additional increase during the last 3 years of 5-year follow-up period, leaving the acid secretory levels subnormal in the majority of the patients.Conclusions : This long-term follow-up study suggests that the pathologic process has already progressed to an irreversible stage in the majority of H. pylori-positive patients with marked body atrophy and profound hypochlorhydria.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2036.2004.01948.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    The Presence of Anti-Protein A Antibodies in Patients with Rheumatoid Arthritis (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Scandinavian journal of immunology 33 (1991), S. 0 
    Details
    ISSN: 1365-3083
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Sixteen patients with rheumatoid arthritis (RA) were examined for the presence of anti-protein A antibodies. The F(ab′)2 preparations from five RA patients showed significant binding lo IgG-free protein A on ELISA. The protein A binding was further examined by immunoblotting. The F(ab′)2 preparations of high protein A-binding protein gave A specific reaction with IgG-free protein A on nitrocellulose paper. This demonstrates the presence of anti-protein A antibodies in patients with RA. Those RA patients with anti-protein A antibodies had more active disease as judged by the Lansbury's activity index. The level of serum rheumatoid factor (RAHA) was significantly higher in patients with anti-protein A antibodies than in those without anti-protein A antibodies.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-3083.1991.tb02530.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Proton MR Spectroscopy in Solvent Abusers (1996)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 801 (1996), S. 0 
    Details
    ISSN: 1749-6632
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Allgemeine Naturwissenschaft
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1749-6632.1996.tb17466.x
    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...