To do that, a new concept of metal artifact classification is devised using linear interpolation in the virtual projection domain. The proposed method reduces severe artifacts very quickly and effectively and has good performance to keep the detailed body structure preserved. Results of qualitative and quantitative comparisons with other representative algorithms such as LIMAR and NMAR support the excellence of the proposed algorithm. Thanks to the nature of reducing artifacts in the image itself and its low computational cost, the proposed algorithm can function as an initial image generator for other MAR algorithms, as well as being integrated in the modalities under limited computation power such as mobile CT scanners.Substrates have strong effects on optoelectronic properties of two-dimensional (2D) materials, which have emerged as promising platforms for exotic physical phenomena and outstanding applications. To reliably interpret experimental results and predict such effects at 2D interfaces, theoretical methods accurately describing electron correlation and electron-hole interaction such as first-principles many-body perturbation theory are necessary. In our previous work (2020Phys. Rev. B102205113), we developed the reciprocal-space linear interpolation method that can take into account the effects of substrate screening for arbitrarily lattice-mismatched interfaces at the GW level of approximation. In this work, we apply this method to examine the substrate effect on excitonic excitation and recombination of 2D materials by solving the Bethe-Salpeter equation. We predict the nonrigid shift of 1s and 2s excitonic peaks due to substrate screening, in excellent agreements with experiments. We then reveal its underlying physical mechanism through 2D hydrogen model and the linear relation between quasiparticle gaps and exciton binding energies when varying the substrate screening. At the end, we calculate the exciton radiative lifetime of monolayer hexagonal boron nitride with various substrates at zero and room temperature, as well as the one of WS2where we obtain good agreement with experimental lifetime. Our work answers important questions of substrate effects on excitonic properties of 2D interfaces.We studied the structural, electronic, and optical characters of SiS2, a new type of group IV-VI two-dimensional semiconductor, in this article. We focused on monolayer SiS2 and its characteristic changes when different strains are applied on it. Results reveal that the monolayer SiS2 is dynamically stable when no strain is applied. In terms of electronic properties, it remains a semiconductor under applied strain within the range from -10% to 10%. Besides, its indirect band-gap is altered regularly after applying a strain, whereas different strains lead to various changing trends. Simufilam As for its optical properties, it exhibits remarkable transparency for infrared and most visible light. Its main absorption and reflection regions lie in the blue and ultraviolet areas. The applied uniaxial strain causes its different optical properties along the armchair direction and zigzag direction. Moreover, the tensile strain could tune its optical properties more effectively than the compressive strain. When different strains are applied, the major changes are in blue and ultraviolet regions, but only minor changes can be found in infrared and visible regions. So its optical properties reveal good stability in infrared and visible regions. Therefore, SiS2 has a promising prospect in nano-electronic and nano-photoelectric devices.Perovskite solar cells (PSCs) are important candidates for next generation thin-film photovoltaic technology due to their superior performance in energy harvesting. At present, their photoelectric conversion efficiencies (PCEs) are comparable to those of silicon-based solar cells. PSCs have usually multi-layer structure. Therefore, they face the problem that the energy levels between adjacent layers often mismatch to each other. Meanwhile, large amount of defects are often introduced due to the solution preparation procedures. What's more, the perovskite is prone to degradation under ultraviolet (UV) irradiation. These problems could degrade the efficiency and stability of PSCs. In order to solve these problems, quantum dots (QDs), a kind of low-dimensional semiconductor material, have been recently introduced into PSCs as charge transport materials, interfacial modification materials, dopants and luminescent down shifting materials. By these strategies, the energy alignment and interfacial conditions are improved, the defects are efficiently passivated, and the instability of perovskite under UV irradiation is suppressed. So the device efficiency and stability are both improved. In this paper, we overview the recent progress of QDs' utilizations in PSCs.For use in electron paramagnetic resonance (EPR) dosimetry with tooth enamel, in the present study, very detailed mesh-type tooth models composed of 198 individual tooth models (i.e. newborn 20, 1 year 28, 5 years 48, 10 years 38, 15 years 32, and adult 32) for each gender were developed. The developed tooth models were then implanted in the ICRP pediatric and adult mesh-type reference computational phantoms (MRCPs) and used to calculate tooth enamel doses, by Monte Carlo simulations with Geant4, for external photon exposures in several idealized irradiation geometries. The calculated dose values were then compared to investigate the dependency of the enamel dose on the age and gender of the phantom and the sites of the teeth. The results of the present study generally show that if the photon energy is low (i.e. 3 MeV, moderate differences were observed (i.e. up to a factor of two), due to the existence of dose build-up in the head of the phantom for high energy photons. The calculated dose values were also compared with those of the previous studies where voxel and mathematical models were used to calculate the enamel doses. The results again showed significant differences at low energies, e.g. up to ~3500 times at 0.015 MeV, which are mainly due to the differences in the level of tooth-modeling detailedness.