First-principle Studies on Ferromagnetism of Fe-doped AlN Diluted Magnetic Semiconductors

We have studied the electronic structures and magnetic properties of Fe-doped AlN by first-principles calculations within density functional theory. The calculated results show that AlN crystals doped by double Fe atoms display ferromagnetic properties, and the total magnetic moment is 10.0 μB per 72-atom supercell (3 × 3 × 2). The calculated energy differences between the antiferromagnetic (AFM) and ferromagnetic (FM) phases are 207 meV, which means FM state is a stable state. It is also found that the 3d-states of Fe dopants and the 2p-states of N atoms bonding to Fe dopants are the main contributors to the density of states at the Fermi level

Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite

As China's first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band (1-250 keV) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 MeV. It was designed to perform pointing, scanning and gamma-ray burst (GRB) observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed. Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Comment: 29 pages, 40 figures, 6 tables, to appear in Sci. China-Phys. Mech. Astron. arXiv admin note: text overlap with arXiv:1910.0443

Schema of the proposed method.

<p>The solid line path summarizes the training process of MAs detection, and the dashed line path summarizes the test process.</p

The results of the proposed method and the DRSCREEN approach on the DRDB database.

<p>The results of the proposed method and the DRSCREEN approach on the DRDB database.</p

An example of color fundus image containing MAs.

<p>(A) The color fundus image. (B) The corresponding enlarged part of (A) in green channel with indicated MAs (diamond: regular MA, circle: subtle MA, triangle: irregular MA, square: clustered MAs, pentagon: MA close to vessel). Reprinted from [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0161556#pone.0161556.ref008" target="_blank">8</a>] under a CC BY license, with permission from Dr. Yalin Zheng, original copyright 2012.</p