15,465 research outputs found
Electron-doped phosphorene: A potential monolayer superconductor
We predict by first-principles calculations that the electron-doped
phosphorene is a potential BCS-like superconductor. The stretching modes at the
Brillouin-zone center are remarkably softened by the electron-doping, which
results in the strong electron-phonon coupling. The superconductivity can be
introduced by a doped electron density () above
cm, and may exist over the liquid helium temperature when cm. The maximum critical temperature is predicted to be
higher than 10 K. The superconductivity of phosphorene will significantly
broaden the applications of this novel material
An Improved NSGA-II and its Application for Reconfigurable Pixel Antenna Design
Based on the elitist non-dominated sorting genetic algorithm (NSGA-II) for multi-objective optimization problems, an improved scheme with self-adaptive crossover and mutation operators is proposed to obtain good optimization performance in this paper. The performance of the improved NSGA-II is demonstrated with a set of test functions and metrics taken from the standard literature on multi-objective optimization. Combined with the HFSS solver, one pixel antenna with reconfigurable radiation patterns, which can steer its beam into six different directions (θDOA = ± 15°, ± 30°, ± 50°) with a 5 % overlapping impedance bandwidth (S11 < − 10 dB) and a realized gain over 6 dB, is designed by the proposed self-adaptive NSGA-II
First principles calculation of lithium-phosphorus co-doped diamond
We calculate the density of states (DOS) and the Mulliken population of the
diamond and the co-doped diamonds with different concentrations of lithium (Li)
and phosphorus (P) by the method of the density functional theory, and analyze
the bonding situations of the Li-P co-doped diamond thin films and the impacts
of the Li-P co-doping on the diamond conductivities. The results show that the
Li-P atoms can promote the split of the diamond energy band near the Fermi
level, and improve the electron conductivities of the Li-P co-doped diamond
thin films, or even make the Li-P co-doped diamond from semiconductor to
conductor. The effect of Li-P co-doping concentration on the orbital charge
distributions, bond lengths and bond populations is analyzed. The Li atom may
promote the split of the energy band near the Fermi level as well as may
favorably regulate the diamond lattice distortion and expansion caused by the P
atom.Comment: 14 pages, 11 figure
Photographic observations of 10 artificial meteors
Photographic observation of artificial meteo
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