[en] Chemical and physical adsorption of a H₂O molecule on a Zr (0 0 0 1) surface is studied by first principle calculations. A surface zirconium atom is substituted by a metal element atom in the 4th and 5th period of the periodic table to investigate the doping effect on the water adsorption. Doping elements Ge, Sn, Sb, Zn, Ga, Ru, Rh, Pd, Ag, Cr, Mn, Fe, Co, Ni, Cu, Nb, and Mo can increase the oxidation resistance. This strategy can be used to design high oxidation resistance cladding material for light water reactor

[en] Highlights: • The model couples outer aerodynamic heating and inner impingement cooling together. • Cooling effectiveness of helium impingement-cooled TPS is significant. • Thermal and mechanical performances of the TPS with different materials are tested. • Operating requirements and limitations for the actively-cooled TPS are probed. - Abstract: This paper presents numerical studies on a typical actively-cooled thermal protection system (TPS) which turns out to be a potential candidate for the leading edge thermal management. The leading edge is cooled by the impingement jet of gaseous helium. The external aerodynamic heating and radiation, the heat conduction in solid wall, and the internal impingement cooling are coupled in a unified computational fluid dynamics system by using a quasi-coupling method. The thermal-hydraulic performance of internal impingement cooling is particularly highlighted. Four metal alloys are tested in order to find out the impact of the material property on the TPS’s cooling performance. Results show that the reduction of leading edge temperature is remarkable with the impingement cooling scheme and the maximum temperature can be controlled far below the materials’ melting point. However, the thermal stress does not significant decrease and is still a barrier for the application of the actively-cooled TPS. The operation limits of various materials are demonstrated, which may benefit to the future material selection work. Besides, the coolant flow rate requirements for safely operating the TPS under various flight conditions are ascertained.

[en] The existing problems of settling tank with mechanical agitation in uranium mills were analyzed. The designed structure of this equipment and operating parameters which influenced the quality and recovery rate of uranium were optimized. A favorable effect was obtained by improving the structural form and size of the tank, method of mother liquor separation, type of agitation impeller, rotational speed and motor power. (authors)

[en] The problems needed to pay attention to in the physical design of packed moving bed adsorption column were presented. The design of key parts such as the inlet and outlet of liquid phase and gas phase were improved. The expected effect was achieved by the improvement. (author)

[en] Graphical abstract: Cycle stability and coulombic efficiency curves of the Li/CPE/LiCoO₂ cell with 10% Si/Ti molecular sieve at different C-rates, where the insert shows the constructional diagrams of the assembled Li/CPE/LiCoO₂ cell. - Abstract: The mesoporous Si/Ti molecular sieve was successfully synthesized from tetrabutyl titanate, tetraethoxysilane and EO₂₀PO₇₀EO₂₀ by sol-gel combined with following pyrolysis processes and confirmed by XRD and TEM. The poly (vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP))-based composite polymer electrolyte (CPE) membranes doped with Si/Ti molecular sieve were fabricated by phase inversion method and the desirable CPEs were obtained after being activated in liquid electrolytes, which are investigated by SEM, XRD, TG, LSV and EIS measurements. The results show that the CPE doped with 10% Si/Ti molecular sieve (vs P(VDF-HFP) in weight) presents the most uniform surface with abundant interconnected micro-pores and possesses excellent mechanical tensile strength with high decomposition temperature about 400 °C and wide electrochemical working window about 4.7 V; adding Si/Ti molecular sieve into the system can significantly decrease the crystallinity and improve the ionic conductivity of the as-prepared CPEs, in which the ionic conductivity and lithium ion transference number at room temperature are up to 3.263 mS cm⁻¹ and 0.4292, respectively, and the reciprocal temperature dependence of ionic conductivity follows Vogel-Tamman-Fulcher relation. Furthermore, the anti-shrinkage rate of the as-prepared CPE membrane distinctly outperforms the commercial polyolefin membrane at 120 °C about 2 h. The interfacial resistance of the assembled Li/CPE/Li simulated cell can rapidly increase to a steady value about 548 Ω from the initial value about 362 Ω at 30 °C during 5 days storage, and the assembled Li/CPE/LiCoO₂ coin cell with the electrolyte also show excellent rate and cycle performance, which indicates that this kind of CPE is an exciting potential candidate as polymer electrolyte for the lithium ion battery.

[en] Highlights: • The spray-drying method is a simple and energy-saving method to prepare LATP. • The compounds with single phase structure of LATP were synthesized at 700–900 °C. • The ionic conductivity of the prepared LATP was maximized at 0.622 mS cm"−"1 at 800 °C. - Abstract: Solid state electrolyte Li_1_._3Al_0_._3Ti_1_._7(PO_4)_3 is synthesized by spray-drying and post-calcining method. X-ray diffraction is employed to characterize the powders calcined in the range of 700–900 °C for 2 h, which indicates powders are well crystallized. FTIR shows trivalent cation Al"3"+ is substituted by Ti"4"+. The composite material appears as 2–5 μm spherical particle. TG–DTA results confirm that the thermal decomposition of precursors obtained by spray-drying method occurred at lower temperature compares with solid phase synthesis method and sol–gel method. The ionic conductivity of the pellets reaches a maximum of 0.622 mS cm"−"1 at calcining temperature of 800 °C

[en] Moessbauer spectroscopy of ⁵⁷Fe was used to study the content and structure of precipitates in different thermal-treated Zircaloy-4 specimens. The spectra of Zircaloy-4 have two sets of peaks. One of them can be ascribed to precipitates of intermetallic compound Zr(Cr,Fe)₂. The structure of the specimen is changed by thermal treatment. The area of the Moessbauer peak is also changed. Content of Zr(Cr,Fe)₂ in a water quenched sample is the same as that in an as-received (50% cold worked) sample. The content of alloying element-iron in matrix between precipitates is not an important factor which has an influence on corrosion resistance of Zircaloy-4. (orig.)

[en] We applied the X-ray standing wave method to the determination of the Sb position in atomic-layer-doped Si crystal. From the fitting of the calculated with the experimental results, an extension of 0.03 and a coherent ratio of 86 % were obtained. (author)

[en] The geometric properties and stabilities of 3d transition metal-doped silicon clusters have been investigated by the density functional theory (DFT). And also the adiabatic electron affinities (AEAs), the vertical ionization potentials (VIPs), the distances in metal dimers and the spin magnetic moments of the M₂ @Si₂₀ (M = Sc-Zn) clusters have been investigated. The calculations show that the dodecahedron fullerene cage Si₂₀ can be fully stabilized by encapsulating a metal dimmer of Sc, Ti, V, Mn and the stability of the silicon cage has been enhanced by doped with metal atoms. But as the number of d electrons increases, the embedded fullerene configuration is partially distorted. (authors)

[en] An experimental station using an X-ray source of an in-vacuum undulator was constructed in the TRISTAN accumulation ring at the National Laboratory for High Energy Physics. The physical experiments have been carried out using this pulsed and highly brilliant radiation. The photon flux density, the beam size and other beam characteristics at the station are described, and some experiments which have been performed in this station are also explained. (author)