Critical current studies on metal clad R1Ba2Cu3O7−x wires

Transport and magnetic critical current in superconducting MgB2 wires

Direct comparison of the magnetic and transport critical current density (Jc) for the same pieces of copper-sheathed MgB2 wires shows a large discrepancy in magnitude and field dependence of the two. The value of magnetic Jc can differ from the value of transport Jc by a factor of 10 or more. This discrepancy does not occur merely because of the difference in the voltage at which the magnetic a...

Critical-current reduction in thin superconducting wires due to current crowding

Influence of Preparation Process on Microstructure, Critical Current Density and Tc of MgB2/Fe/Cu Wires

The powder-in-tube MgB2 wires were prepared by high energy milling of Mg and B powder. The powder was not mechanically alloyed for 2h short milling time. However, the MgB2 grains in wires are very small (20 100nm) and resembled to the dimple after post-heat treatment. The clear evidence for transcrystlline fracture is observed. It indicated that the grain connection was greatly improved and the...

ترجمه بخشی از کتاب "critical readings in translation studies"

چکیده در دنیای پیچیده ی امروز، تغییرات زیادی در زندگی بشری در حال وقوع اند و شاهد رقابت های بسیار فشرده ی جوامع در دستیابی به فناوری برتر و قدرت بیشترهستیم. به نظر می رسد که فرد وجامعه مجبورند به طریقی در وضعیت خویش دگرگونی ایجاد کنند تا از قافله ی علم، فناوری، و پیشرفت عقب نمانند. رشته مطالعات ترجمه نیز از این قاعده مستثنا نیست. علی رغم وسعت روز افزون پژوهش در این حوزه و میان رشته ای بودن مطال...

پیشرفتهای اخیر در زمینه ساخت سیم و نوار ابررسانای MgB2

 MgB2 wire and tape were prepared using the powder in tube and reaction in-situ technique. All samples were characterized using the XRD, SEM, TEM, as well as transport and magnetic measurements. High transport and magnetic critical current density values have been obtained for metal-clad wires and tapes. Different sheath materials have been examined, but Fe appears to be the best sheath for MgB...