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Direct-drive spherical implosions can be used to access high-energy-density plasma conditions for inertial confinement fusion (ICF). In this paper, the effects of carbon impurity due to ICF capsule compression by a laser pulse on the process of D / 3 He thermonuclear plasma burning are studied in an ICF cycle. The effect of carbon impurity concentrations on the effective ignition parameters, the plasma heating rate caused by energy deposition of reaction products, and energy loss rates in the process of burning plasma have also been analyzed in the ICF process. The results obtained show that during the ICF spherical implosions of the D / 3 He fuel, the ignition temperature, T (ig) , and the confinement parameter, ρ R , in the hot spot are approximately equal to 58 keV and 5 g/cm 2 , respectively. These values are increased by the presence of impurity. [ABSTRACT FROM AUTHOR]

Pyrite is a mineral often associated with coal in coal seams and is a major source of sulfur in coal. Coal–pyrite is widely distributed, easily available, low-cost, and non-toxic, and has high light absorption coefficient. So, it shows potential for various applications. In this paper, the density-functional theory (DFT + U) is used to construct coal–pyrite with carbon doped in the sulfur and iron vacancies of pyrite. The effects of different carbon defects, different carbon doping concentrations, and different doping distributions in the same concentration on the electronic structure and optical properties of coal–pyrite were studied. The results show that the absorption coefficient and reflectivity of coal–pyrite, when its carbon atom substitutes the iron and sulfur atoms in the sulfur and iron vacancies, are significantly higher than those of the perfect pyrite, indicating that coal–pyrite has potential for application in the field of photovoltaic materials. When carbon is doped in the sulfur vacancy, this impurity state reduces the width of the forbidden band; with the increase in the doping concentration, the width of the forbidden band decreases and the visible-light absorption coefficient increases. The distribution of carbon impurities impacts the band gap but has almost no effect on the light absorption coefficient, complex dielectric function, and reflectivity, indicating that the application of coal–pyrite to photovoltaic materials should mainly consider the carbon doping concentration instead of the distribution of carbon impurities. The research results provide a theoretical reference for the application of coal–pyrite in the field of photoelectric materials. [ABSTRACT FROM AUTHOR]

Abstract: This paper proposes a method of lossless micromagnetic detection in the geomagnetic field for detecting traces of carbon impurity defects in crystalline silicon. The magnetization tests show that crystalline silicon is a diamagnetic substance with a stronger relative permeability than carbon. Micromagnetic decay theory is gained according to the energy decay. When the geomagnetic field penetrates through the materials, the apparent magnetic susceptibility can be calculated and subsequently used to project the images. The resulting image clearly showed the location of the defects. Test results are proved by the metallographic phase and spectral analysis. New method and ideas are provided for effective detection of trace carbon impurity defects in the crystalline silicon. [Copyright &y& Elsevier]

Pyrite is a mineral often associated with coal in coal seams and is a major source of sulfur in coal. Coal–pyrite is widely distributed, easily available, low-cost, and non-toxic, and has high light absorption coefficient. So, it shows potential for various applications. In this paper, the density-functional theory (DFT + U) is used to construct coal–pyrite with carbon doped in the sulfur and iron vacancies of pyrite. The effects of different carbon defects, different carbon doping concentrations, and different doping distributions in the same concentration on the electronic structure and optical properties of coal–pyrite were studied. The results show that the absorption coefficient and reflectivity of coal–pyrite, when its carbon atom substitutes the iron and sulfur atoms in the sulfur and iron vacancies, are significantly higher than those of the perfect pyrite, indicating that coal–pyrite has potential for application in the field of photovoltaic materials. When carbon is doped in the sulfur vacancy, this impurity state reduces the width of the forbidden band; with the increase in the doping concentration, the width of the forbidden band decreases and the visible-light absorption coefficient increases. The distribution of carbon impurities impacts the band gap but has almost no effect on the light absorption coefficient, complex dielectric function, and reflectivity, indicating that the application of coal–pyrite to photovoltaic materials should mainly consider the carbon doping concentration instead of the distribution of carbon impurities. The research results provide a theoretical reference for the application of coal–pyrite in the field of photoelectric materials.

By introducing different dopants into the lattice, lanthanum sulfides with higher stability were prepared via the sulfurization of lanthanum oxides using CS gas at 1 000 °C. The sulfurizing time of 8 hours was optimized for La/Ca=2 at 1 000 °C and its sulfurization mechanism to form CaLaS was via the reaction of β-LaS with CaS. As the increase of the La/Ca and La/Na ratio, longer sulfurizing time was required to get cubic phase. The investigation indicates that Na ions were more effective to stabilize cubic structure comparing with Ca ions. [ABSTRACT FROM AUTHOR]

Using the ab initio VASP-PAW method with the generalized gradient approximation, the magnetic behavior of wurtzite-like beryllium oxide (BeO) without magnetic impurities has been predicted. Our results indicate the transformation of non-magnetic insulator BeO into magnetic half-metal at the substitution of oxygen atoms by carbon or in the presence of beryllium vacancy. [ABSTRACT FROM AUTHOR]

Kaolinite is a difficult-to-float clay existing in coal slurries which negatively impacts coal flotation. A better understanding of its adsorption behavior would improve coal-slurry processing. Carbon impurities in the kaolinite can affect this behavior. The appearance and elemental surface composition of the carbon impurities precipitated by kaolinite oxidative treatment were microscopically analyzed, and their chemical speciation and relative C and O contents were probed. The mechanisms of adsorption on the main kaolinite cleavage planes ((001) and (00 1) surfaces) for two carbon-impurity structural models, a phenolic hydroxyl unit (Ph–OH) and carbon hydroxyl unit (C–OH), were considered using density functional theory methods. The carbon impurities consisted mainly of C and O, with C present mostly as C–C, C–H, and C–O species, and O existing mainly in –OH and C–O structures. Both Ph–OH and C–OH units adsorbed stably on the kaolinite (001) and (00 1) surfaces through hydrogen bonding between the hydroxyl groups and surfaces. A strong electrostatic attraction occurred between the Ph–OH benzene ring and kaolinite surfaces, whereas the carbon ring in C–OH did not interact with either surface. Finally, for both units, adsorption on the kaolinite (001) surface was more stable than on the (00 1) surface. [ABSTRACT FROM AUTHOR]