400,257 research outputs found
Detecting and diagnosing faults in dynamic stochastic distributions using a rational b-splines approximation to output PDFs
Describes the process of detecting and diagnosing faults in dynamic stochastic distributions using a rational b-splines approximation to output PDFs
Macroporous materials: microfluidic fabrication, functionalization and applications
This article provides an up-to-date highly comprehensive overview (594 references) on the state of the art of the synthesis and design of macroporous materials using microfluidics and their applications in different fields
Thermal spin current and spin accumulation at ferromagnetic insulator/nonmagnetic metal interface
Spin current injection and spin accumulation near a ferromagnetic insulator
(FI)/nonmagnetic metal (NM) bilayer film under a thermal gradient is
investigated theoretically. Using the Fermi golden rule and the Boltzmann
equations, we find that FI and NM can exchange spins via interfacial
electron-magnon scattering because of the imbalance between magnon emission and
absorption caused by either non-equilibrium distribution of magnons or
non-equilibrium between magnons and electrons. A temperature gradient in FI
and/or a temperature difference across the FI/NM interface generates a spin
current which carries angular momenta parallel to the magnetization of FI from
the hotter side to the colder one. Interestingly, the spin current induced by a
temperature gradient in NM is negligibly small due to the nonmagnetic nature of
the non-equilibrium electron distributions. The results agree well with all
existing experiments.Comment: 8 pages, 2 figure
Time-dependent 2.2 MeV and 0.5 MeV lines from solar flares
The time dependences of the 2.2 MeV and 0.51 MeV gamma ray lines from solar flares are calculated and the results are compared with observations of the 1972, August 4 and 7 flares. Time lag between the nuclear reactions and the formation of these two lines are caused, respectively, by capture of the neutrons, and by deceleration of the positrons and decay of the radioactive nuclei. Results show that the calculation is consistent with the observed rise of the 2.2 MeV line on August 4, and it does not require different time dependences for the accelerated protons and electrons in the flare region. The above lags can explain the delayed gamma ray emission observed on August 7. Positrons of energies greater than about 10 MeV could be detected in interplanetary space following large solar flares
Breaking the current density threshold in spin-orbit-torque magnetic random access memory
Spin-orbit-torque magnetic random access memory (SOT-MRAM) is a promising
technology for the next generation of data storage devices. The main bottleneck
of this technology is the high reversal current density threshold. This
outstanding problem of SOT-MRAM is now solved by using a current density of
constant magnitude and varying flow direction that reduces the reversal current
density threshold by a factor of more than the Gilbert damping coefficient. The
Euler-Lagrange equation for the fastest magnetization reversal path and the
optimal current pulse are derived for an arbitrary magnetic cell. The
theoretical limit of minimal reversal current density and current density for a
GHz switching rate of the new reversal strategy for CoFeB/Ta SOT-MRAMs are
respectively of the order of A/cm and A/cm far below
A/cm and A/cm in the conventional strategy. Furthermore,
no external magnetic field is needed for a deterministic reversal in the new
strategy
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