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Bulk W-0.5 wt%ZrC (W-ZrC), W-1 wt%Re-0.5 wt%ZrC (W-1Re-ZrC), and W-3 wt%Re-0.5 wt%ZrC (W-3Re-ZrC) alloys were prepared and exposed to He2+ ion irradiation with an incident energy of 500 keV at 400 °C. Post-irradiation analysis revealed the formation of He bubbles, with consistent number density and average size across all alloys. However, the W-3Re-ZrC alloy exhibited a notably higher density of dislocation loops within grain interiors compared to W-ZrC and W-1Re-ZrC. This led to a significant increase in the hardening rate of W-3Re-ZrC to 61.5 %, nearly twice that of the other alloys. By considering the binding energies of He-vacancy, He-He, and Re-He, the formation and growth behavior of irradiation-induced defects, including He bubbles and dislocation loops, were also discussed. This work provides valuable insight into the relationships among Re alloying, He-induced defects, and irradiation hardening in Re-alloyed W materials, thus offering valuable guidance for the design of W-based plasma-facing materials.

ABSTRACT: Milk proteins can be used as encapsulation walls to increase the bioavailability of active compounds because they can bind hydrophobic, hydrophilic, and charged compounds. The objective of this study was to investigate the effects of astaxanthin (ASTA) encapsulation and the functional properties of milk protein and ASTA nanocomposites by an ultrasound-assisted pH-shifting treatment of different milk proteins, including milk protein concentrate (MPC), micellar casein (MCC), and whey protein isolate (WPI). The ultrasound-assisted pH-shifting treatment of milk protein helped to improve the encapsulation rate of ASTA. Therein, MCC showed great improvement of encapsulating ASTA after co-treatment with the raised encapsulated rate of 5.11%, followed by WPI and MPC. Furthermore, the nanocomposites of ASTA with milk protein exhibit improved bioavailability, antioxidant capacity, and storage stability. By comparison, MCC-encapsulated ASTA has the best storage stability, followed by MPC, and WPI-encapsulated ASTA has the least stability over a 28-d storage period. The results of intrinsic fluorescence and surface hydrophobicity showed that milk protein underwent fluorescence quenching after binding to ASTA, which was due to the hydrophobic sites of the protein being occupied by ASTA. In general, the nanocomposites of milk protein and ASTA fabricated by using an ultrasound-assisted pH-shifting treatment have the potential to be better nano-delivery systems for ASTA in functional foods, especially MCC, which showed excellent performance in encapsulation after treatment technique.

9Cr-F/M−xSi (x = 0–1.0 wt%) steels were fabricated through vacuum induction melting technique and processed by hot forging, hot rolling, normalizing and tempering, subsequently. Their microstructure and mechanical properties were characterized using OM, SEM, TEM, Vickers hardness tester and tensile tester. The steel has a typical ferrite/martensitic structure, with M23C6 and MX phases precipitated at the martensite lath boundary or in the lath. With Si content increasing, the average ultimate tensile strength (UTS) and hardness of 9Cr-F/M−xSi increase simultaneously from 678 MPa and 235 HV for 9Cr-F/M−0Si steel to 788 MPa and 265 HV for 9Cr-F/M−1.0Si steel, respectively, while the total elongation kept almost constant at 22.5%. The main strengthening mechanism is the solid solution strengthening due to silicon addition and the change in the carbide precipitation behavior caused no remarkable hardening contribution. These results can provide a reference for the composition design of structural materials for nuclear reactors.

Interface engineering is a significant strategy to develop structural materials with good properties. In this study, bulk V/Cu nano-multilayers with different layer thicknesses were fabricated by cross accumulative roll bonding (CARB). Interface stability of V/Cu nano-multilayers with different layer thicknesses and their effects on thermal conductivity and helium irradiation have been explored. The microstructure analysis, tensile and hardness tests result show that V/Cu nano-multilayers maintain high mechanical properties and good thermal stability after annealing at 500 °C for 1 h. However, the strength drastically degrades after higher-temperature annealing because of microstructure instability, which is closely related to the aspect ratio of grains. Furthermore, spheroidization occurring in multilayer during the annealing process promotes efficient electron transportation and weakens electron scattering, which benefits the increase of thermal conductivity. The irradiation response of V/Cu nano-multilayers was explored by helium bombardment with a fluence of 1 × 1017 ions/cm2 at room temperature and 500 °C, respectively. Helium bubbles transform to gas cavities with increasing irradiated temperature, and different morphology of cavities at heterointerface, newly formed grain boundaries and triple junctions is attributed to the defect diffusion preference combined with thermal-induced interfaces migration.

Pudong White (PDW) pigs, historically originating from Shanghai, are the only Chinese indigenous pigs characterised by their completely white coats, with the exception of Rongchang pigs. However, there is limited information concerning their overall genetic structure or relationship with other breeds, especially the East Chinese (ECN) and European pigs. To uncover the genetic structure, selection signatures, and potential exotic introgression in PDW pigs, we sampled 15 PDW pigs using whole-genome sequencing (~20×). We then conducted in-depth population genetic analyses in 320 pigs from 27 global pig groups, namely, European wild boars, Chinese wild boars, and outgroup. Neighbour-joining tree and principal component analysis confirmed that PDW pigs belonged to the ecotype of ECN pigs. Both f3, D-statistics, and structure analysis showed that PDW pigs shared apparent alleles with Large White (LW) pigs. Three statistics, rIBD, a haplotype heat map and copy number variation, further indicated that PDW pigs shared apparent alleles with LW pigs at the KIT Proto-Oncogene, Receptor Tyrosine Kinase (KIT) and PARG-MARCHF8 loci, suggesting that the lineage of European pigs in PDW originated from LW pigs. After further detecting the KIT mutations in different pig breeds, PDW was confirmed to have the same duplication region 1, duplication region 2, and the splicing mutation on intron 17 of KIT as LW pigs that determine the white coat colour phenotype in European white pigs. We hypothesised that LW pigs were imported to China ∼110–160 years ago according to the admixture time estimate and then crossed with ECN pigs, resulting in the introgression of the KIT alleles that produce the white coat colour phenotype in the PDW pig breed. To our knowledge, this study presents the first thorough description of the genetic structure of PDW pigs via whole-genome resequencing data; moreover, the results provide a basis for the national project for the conservation of this unique Chinese local population.

Tungsten is considered as the most promising material for plasma facing components (PFCs) in the magnetic confinement fusion devices, due to its high melting temperature, high thermal conductivity, low swelling, low tritium retention and low sputtering yield. However, the brittleness, poor machinability and low strength at high-temperatures of tungsten limits its application. Focusing on this issue, various W alloys with enhanced mechanical properties have been developed over recent decades. Among them, the W-ZrC alloys exhibit high strength, high ductility, low ductile-to-brittle transition temperature, good high-temperature stability, excellent resistance to thermal shock and low H/He plasma etching, making it one of the most promising candidate plasma facing materials (PFMs) for the future fusion devices. Therefore, the R&D experience of W-ZrC materials for PFCs, including the design idea, optimization of composition, fabrication technology (from powder metallurgy processing to hot working, from small specimen to large-sized bulk material), microstructure and performance (mechanical properties, thermal conductivity, resistance to thermal shocks and to H/He irradiation, H isotope retention behaviors) were reviewed in this paper. Key words: Plasma-facing materials, Tungsten, ZrC, Microstructure, Mechanical property

Tungsten materials with high ductility/strength are highly desirable for a wide range of critical applications. Fine-grained W-0.5 wt.% TaC alloys were produced by an optimized multi-step process, consisting of high-energy ball milling, hot press sintering and subsequent hot rolling. Grain refinement induced improvement in mechanical properties is achieved with ultimate tensile strength (UTS) of 982 MPa and total elongation (TE) as large as ∼12.0% at 200 °C. UTS values are over 570 MPa at all tested temperature ranging from RT to 500 °C and the TE increases to ∼40.5% at 400 °C. These good mechanical properties are attributed to advanced process routes. Hydrogen atmosphere during the fabrication reduces oxygen impurity contents and then decreases the amount of submicron oxide particles. The multi-step process routes generate optimal microstructures with nanometric TaC particles uniformly distributed in the submicron subgrains interior. Nano-sized particles could hinder grain boundary migration, reduce grain growth rate and thus keep microstructure stability, improving low-temperature strength and ductility of W-TaC alloys. The optimized fabrication routes for such refractory alloys offer a general pathway for manufacturing bulk dispersion-strengthened materials with both good mechanical properties and thermal stability.

He-charged FeCrNi films were prepared by radio frequency (RF) magnetron sputtering technique, and helium desorption behavior, growth process and evolution mechanism of helium bubbles in FeCrNi film were studied by thermal desorption spectroscopy (TDS) spectra combined with microstructure analysis under different annealing treatments. Three different He desorption peaks were observed in TDS spectra, which can be related to the release of interstitial helium atoms from the near-surface regions, helium-vacancy clusters with different sizes in FeCrNi film. TEM analysis showed that helium bubbles can be uniformly distributed in He-charged FeCrNi nanocrystalline films. Under annealing treatments at different temperatures, the size of helium bubbles obviously increases with increasing annealing temperature, corresponding to the significantly decrease in the number density of helium bubbles in FeCrNi films, and the growth mechanism of helium bubbles was suggested to originate from the migration and coalescence (MC) mechanism. Key words: Magnetron sputtering, FeCrNi film, Thermal desorption, He bubbles

In this paper, bulk W-0.2 wt% ZrC and W-0.8 wt% ZrC (hereafter abbreviated as WZC02, WZC08, respectively) plates were fabricated by ball milling, sintering and multi-step hot rolling technology. The microstructure, mechanical properties and thermal stability were studied to demonstrate the influence of ZrC contents. The results of Vickers hardness and tensile tests show that the WZC08 alloy has a higher hardness, larger tensile strength but lower ductility than that of the WZC02 alloy. The ductile brittle transition temperature (DBTT) of both WZC02 and WZC08 alloys are about 300 °C. The recrystallization temperature of the as-rolled WZC08 is between 1500 °C and 1600 °C, which is 200 °C higher than that of the as-rolled WZC02. The EBSD results indicate that there are strong [101] texture in both rolled WZC02 and WZC08 alloys. Microstructural analysis shows that the ZrC dispersion particles in as-rolled WZC02 have smaller particle sizes and uniform distributions but lower number densities than that in WZC08. By comparing with the pure W and WZC05, an optimal ZrC content is proposed to achieve a better comprehensive property including high tensile strength, good ductility and high thermal stability. Key words: Tungsten, ZrC content, Microstructure, Mechanical property, Thermal stability