Magnetic relaxation and three-dimensional critical fluctuations in B-doped Q-carbon – a high-temperature superconductor

Nanoscale ◽  
2018 ◽  
Vol 10 (26) ◽  
pp. 12665-12673 ◽  
Author(s):  
Anagh Bhaumik ◽  
Ritesh Sachan ◽  
Jagdish Narayan
Keyword(s):  
High Temperature ◽  
Magnetic Relaxation ◽  
High Speed ◽  
High Temperature Superconductor ◽  
Electronic Devices ◽  
Three Dimensional ◽  
Critical Fluctuations

Three-dimensional critical fluctuations and Anderson–Kim logarithmic magnetic relaxations in B-doped Q-carbon high-temperature superconductor will lead to multifunctional high-speed electronic devices.

The effect analysis of an engine jet on an aircraft blast deflector

2018 ◽  
Vol 41 (4) ◽  
pp. 990-1001
Author(s):  
Song Ma ◽  
Jianguo Tan ◽  
Xiankai Li ◽  
Jiang Hao
Keyword(s):  
High Temperature ◽  
Flow Field ◽  
High Speed ◽  
Deflection Angle ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Aircraft Engine ◽  
Experimental Results ◽  
Exhaust Gases ◽  
The Impact

This paper establishes a novel mathematical model for computing the plume flow field of a carrier-based aircraft engine. Its objective is to study the impact of jet exhaust gases with high temperature, high speed and high pressure on the jet blast deflector. The working condition of the nozzle of a fully powered on engine is first determined. The flow field of the exhaust jet is then numerically simulated at different deflection angle using the three-dimensional Reynolds averaged Navier–Stokes equations and the standard [Formula: see text]-[Formula: see text] turbulence method. Moreover, infra-red temperature tests are further carried out to test the temperature field when the jet blast deflector is at the [Formula: see text] deflection angle. The comparison between the simulation results and the experimental results show that the proposed computation model can perfectly describe the system. There is only 8–10% variation between them. A good verification is achieved. Moreover, the experimental results show that the jet blast deflector plays an outstanding role in driving the high-temperature exhaust gases. It is found that [Formula: see text] may be the best deflection angle to protect the deck and the surrounding equipment effectively. These data results provide a valuable basis for the design and layout optimization of the jet blast deflector and deck.

A New Method to Obtain U(J) Relationship in High Temperature Superconductor

1997 ◽  
Vol 11 (06) ◽  
pp. 753-765 ◽  
Author(s):  
M. J. Qin ◽  
X. Jin ◽  
X. X. Yao ◽  
Y. X. Fu ◽  
X. S. Rong ◽  
...  
Keyword(s):  
High Temperature ◽  
Magnetic Relaxation ◽  
High Temperature Superconductor ◽  
High Temperature Superconductors ◽  
Usual Method ◽  
New Method ◽  
Relaxation Data ◽  
J Curve ◽  
Different Temperatures

An implicit expression for the time dependence of the current density J(t) is derived without the constant assumption of dU/dJ or <dU/dJ>, based on which a new method to extract U(J) relationship from magnetic relaxation data in high temperature superconductors is described. This method is applied to a melt textured growth YBa2Cu3O6+x sample and we obtain U(J)~ J-μ with μ=0.90 for H‖c, which is in accordance with that derived by the usual method suggested by Malery et al.(μ=0.87). Moreover, both methods give the same value of the constant C, which implies that the determination of C by the requirement of continuity of the U(J) curve at different temperatures is reliable. And the results U(J)~ J-μ by both methods are evidence for the collective pinning or the vortex glass theory.

scholarly journals Ta-Doped Sb2Te Allows Ultrafast Phase-Change Memory with Excellent High-Temperature Operation Characteristics

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Yuan Xue ◽  
Shuai Yan ◽  
Shilong Lv ◽  
Sannian Song ◽  
Zhitang Song
Keyword(s):  
High Temperature ◽  
Phase Change ◽  
High Speed ◽  
Elevated Temperatures ◽  
Phase Change Memory ◽  
Three Dimensional ◽  
Amorphous Structure ◽  
Material System ◽  
Operation Speed ◽  
Change Memory

AbstractPhase-change memory (PCM) has considerable promise for new applications based on von Neumann and emerging neuromorphic computing systems. However, a key challenge in harnessing the advantages of PCM devices is achieving high-speed operation of these devices at elevated temperatures, which is critical for the efficient processing and reliable storage of data at full capacity. Herein, we report a novel PCM device based on Ta-doped antimony telluride (Sb2Te), which exhibits both high-speed characteristics and excellent high-temperature characteristics, with an operation speed of 2 ns, endurance of > 106 cycles, and reversible switching at 140 °C. The high coordination number of Ta and the strong bonds between Ta and Sb/Te atoms contribute to the robustness of the amorphous structure, which improves the thermal stability. Furthermore, the small grains in the three-dimensional limit lead to an increased energy efficiency and a reduced risk of layer segregation, reducing the power consumption and improving the long-term endurance. Our findings for this new Ta–Sb2Te material system can facilitate the development of PCMs with improved performance and novel applications.

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