[en] The thermodynamic behavior of the Ga-Li system is analyzed using the calculation of phase diagram technique. The liquid phase is modeled with the Redlich-Kister equation. The ordered intermetallic compound GaLi is thermodynamically described by a two sublattice model. The other compounds are treated as stoichiometric compounds. A set of self-consistent thermodynamic parameters is obtained

[en] Thermodynamic properties and phase diagram data for the Li-N system are calculated by employing the CALPHAD (CALculation of PHAse Diagrams) method. This modeling is focussed on the liquidus curve and the Li-Li₃N system is described in terms of a simple eutectic phase diagram. The eutectic reaction occurs at 0.052 mol.% N and 180.3 deg. C. All the calculated thermodynamic properties agree well with the critically evaluated experimental data

[en] The thermal stability of GaN single crystals obtained by Li-based flux was investigated by DTA-TG, XRD, Raman and infrared spectroscopy. The results evidence that pure GaN becomes unstable above 900 deg. C under N₂ of 0.1 MPa. The specific heat of GaN was determined at temperatures ranging from 1.9 K to 80 K. Its electronic specific heat coefficient is 0.47 mJ K^-2 mol^-1 and the Debye temperature is 278 K

[en] The periodic microfringe structures were induced on the front silicon surface by pulsed CO₂ laser irradiation with the existence of a painting or coating layer on the bottom surface of silicon substrate. The microfringes were formed under single pulse irradiation due to the laser induced periodic surface structure (LIPSS) effect. The nanodot were self-organized in chains under cumulative laser pulse irradiation, and located along the microfringe ridges. The silicon surface was patterned with a nanocone array of two different average sizes at even higher laser intensity. The larger cones distributed in rows, and the smaller cones scattered between the two adjacent rows of the larger cones. The far-infrared absorption of silicon is promoted by the increase of free carrier concentration and thermal energy resulting from the laser interaction with the coating/painting materials at the substrate bottom surface

[en] Highlights: • The sub-5-μm microstructures on commercial pure titanium are creatively obtained based on cracks growth under 10 ns laser irradiation. • The distribution modification of laser energy induced by cambered microstructures was theoretically analyzed to produce nanostructures. • The sharp micro-nano structures under combined action of crack growth and hot-melt are obtained. - Abstract: This study reported on the formation of sub-5-μm microstructures covered on titanium by cracks growth under 10-ns laser radiation at the wavelength of 532 nm and its induced light modification for production of nanostructures. The electric field intensity and laser power density absorbed by commercial pure titanium were computed to investigate the self-trapping introduced by cracks and the effect of surface morphology on laser propagation characteristics. It is found that nanostructures can form at the surface with the curvature radius below 20 μm. Meanwhile, variable laser fluences were applied to explore the evolution of cracks on commercial pure titanium with or without melt as spot overlap number increased. Experimental study was first performed at the peak laser fluence of 1.063 J/cm"2 to investigate the microstructures induced only by cracks growth. The results demonstrated that angular microstructures with size between 1.68 μm and 4.74 μm was obtained and no nanostructure covered. Then, at the peak laser fluence of 2.126 J/cm"2, there were some nanostructures covered on the melt-induced curved microstructured surface. However, surface molten material submerged in the most of cracks at the spot overlap number of 744, where the old cracks disappeared. The results indicated that there was too much molten material and melting time at the peak laser fluence of 2.126 J/cm"2, which was not suitable for obtainment of perfect micro-nano structures. On this basis, peak laser fluence was reduced down to 1.595 J/cm"2 and the sharp sub–5 μm microstructures with nanostructures covered was obtained at spot overlap number of 3720.

[en] Experimental results on fine-structure transitions occurring in collisional redistribution of far--off-resonant radiation are presented. Measurements on Na-Ar atomic collisions illustrate that electronically nonadiabatic transitions occurring in the final state, following absorption, are important for describing the redistribution process. The results also provide details of the fine-structure transition process that are not obtainable from the usual resonant scattering experiments

No abstract available

[en] Single-crystal tantalum sheets were implanted by 110 keV nitrogen ions to a dose of 5 x 10¹⁷ ions/cm² at a temperature less than 100 C. The structural changes and the concentration depth profiles of the implanted layers were characterized by glancing-angle X-ray diffraction (GXRD), selected area diffraction (SAD) and Auger electron spectroscopy (AES), respectively. The microhardness, the friction coefficient and the wear rate of the specimens against hardened GCr15 steel balls were also determined before and after the implantation. Scanning electron microscopy (SEM) and electron probe micro-analyzer (EPMA) were used to analyze the wear tracks. The results showed that there exist deviations between the characterization results of AES and GXRD or SAD. The AES measurement suggests the formation of the tantalum nitrides with a maximum N/Ta ratio of 1/2, while the GXRD and SAD reveal the formation of bcc Ta(N), fcc TaN and a trace amount of hcp Ta₂N. This can be explained by considering the inhomogeneous distribution of nitrogen atoms in micro-regions: the enrichment of nitrogen atoms in local micro-regions leads to the formation of fcc TaN; however, the unfavorable structural compatibility between bcc Ta and hcp Ta₂N hinders the formation of hcp Ta₂N in the regions where the N/Ta ratio reaches 1/2. The detected trace amount of the hcp Ta₂N phase in the implanted layers can be considered as an after effect of nitrogen loss from the originally formed nitrides. The results also showed that the tribological properties of the Ta surfaces were improved due to the implantation. It is believed that the implantation-induced Ta(N), fcc TaN, and hcp Ta₂N phases are responsible for this improvement. (orig.)

[en] A method is described in this paper, which introduces some slots in the C type dipole pole and some conductors can be put inside these slots. These conductors can control the flow of the magnetic flux by adjusting its trim current, thus that can improve the magnetic field distribution at the median plane of this dipole. The effect of the trim current for low field was investigated using OPERA-2D and 3D, some results will be present in this paper. Furthermore, the fabricating technology of this C type dipole and some magnetic field measurement results will be discussed in this paper as well

[en] The EAST tungsten divertor was designed and manufactured in 2012-2014 shut down. First commissioning is during EAST 2014 plasma summer operation due May to July. Some weak points exposed and brought damages on some divertor modules. Reasons were analyzed and optimization was made. Around half year spent for analysis, divertor modules structure optimized manufacturing and reconstruction. The optimized divertor operated during 2015 summer plasma operation and demonstrate optimizations are efficiency. There is no issue for tungsten divertor during operation. EAST plasma heating power increased step by step and will up to 20MW in 2015 winter campaign plasma operation and will validate tungsten divertor heat exhausting capability. (author)