We report the experimental results of the commissioning phase in the 10 PW laser beamline of the Shanghai Superintense Ultrafast Laser Facility (SULF). The peak power reaches 2.4 PW on target without the last amplifying during the experiment. The laser energy of 72 ± 9 J is directed to a focal spot of approximately 6 μm diameter (full width at half maximum) in 30 fs pulse duration, yielding a focused peak intensity around 2.0 × 1021 W/cm2. The first laser-proton acceleration experiment is performed using plain copper and plastic targets. High-energy proton beams with maximum cut-off energy up to 62.5 MeV are achieved using copper foils at the optimum target thickness of 4 μm via target normal sheath acceleration. For plastic targets of tens of nanometers thick, the proton cut-off energy is approximately 20 MeV, showing ring-like or filamented density distributions. These experimental results reflect the capabilities of the SULF-10 PW beamline, for example, both ultrahigh intensity and relatively good beam contrast. Further optimization for these key parameters is underway, where peak laser intensities of 1022–1023 W/cm2 are anticipated to support various experiments on extreme field physics.

In this paper, we show that each element in the convex hull of the rotation set of a compact invariant chain transitive set is realized by a Birkhoff solution, which is an improvement of the fundamental lemma of T. Zhou and W.-X. Qin [Pseudo solutions, rotation sets, and shadowing rotations for monotone recurrence relations. Math. Z. 297 (2021), 1673–1692] in the study of rotation sets for monotone recurrence relations. We then investigate the properties of rotation sets assuming the system has zero topological entropy. The rotation set for a Birkhoff recurrence class is a singleton and the forward and backward rotation numbers are identical for each solution in the same Birkhoff recurrence class. We also show the continuity of rotation numbers on the set of non-wandering points. If the rotation set is upper-stable, then we show that each boundary point is a rational number, and we also obtain a result of bounded deviation.

Continuous hBN films have been grown by means of a radio-frequency-sputtering technology, and their material properties have been investigated. The prepared hBN films can achieve good smoothness in a large area. The surface morphologies and compositions of the hBN films on Si substrate and Al film have been characterized, indicating that there is no difference. The 101-phase peak of hBN film is the strongest, and the optical band gap of the fabricated film is 5.84 eV. An attempt on the fabrication of the hBN based resistive switching (RS) device has been made by using an Ag/hBN/Al structure, leading to the observation of a clear and stable RS behavior. The device exhibits a resistance window (high-resistivity state/low-resistivity state) of around 102, and the RS behaviors of hBN film prepared by sputtering were first observed. It has been found that the opening voltage for the device is changed when a different cycle voltage is applied because of the built-in electric field increasing with the increase of applied cycle voltage. The mechanism of the RS behavior has been analyzed, which lay a foundation for the application of hBN as RS material in resistive random access memory to improve the storage density.

Resistant starch (RS) was recently approved to exert a powerful influence on gut health, but the effect of RS on the caecal barrier function in meat ducks has not been well defined. Thus, the effect of raw potato starch (RPS), a widely adopted RS material, on microbial composition and barrier function of caecum for meat ducks was determined. A total of 360 Cherry Valley male ducks of 1-d-old were randomly divided and fed diets with 0 (control), 12, or 24 % RPS for 35 d. Diets supplemented with RPS significantly elevated villus height and villus height:crypt depth ratio in the caecum. The 16S rRNA sequence analysis indicated that the diet with 12 % RPS had a higher relative abundance of Firmicutes and the butyrate-producing bacteria Faecalibacterium, Subdoligranulum, and Erysipelatoclostridium were enriched in all diets. Lactobacillus and Bifidobacterium were significantly increased in the 24 % RPS diet v. the control diet. When compared with the control diet, the diet with 12 % RPS was also found to notably increase acetate, propionate and butyrate contents and up-regulated barrier-related genes including claudin-1, zonula occludens-1, mucin-2 and proglucagon in the caecum. Furthermore, the addition of 12 % RPS significantly reduced plasma TNF-α, IL-1β and endotoxin concentrations. These data revealed that diets supplemented with 12 % RPS partially improved caecal barrier function in meat ducks by enhancing intestinal morphology and barrier markers expression, modulating the microbiota composition and attenuating inflammatory markers.

The three-dimensional microstructures of two conventional 316L stainless steels and a grain boundary (GB)-engineered version of the same steel have been characterized by using serial sectioning and electron backscatter diffraction mapping. The morphologies, area fractions, and number fractions of twin boundaries (TBs) were measured and compared, and the random boundary connectivity was evaluated. Although two-dimensional observations suggest that TBs are planar, occluded twin-grains and tunnel-shaped TBs were also observed. In addition, some large and morphologically complex TBs were observed in the GB-engineered sample, and these TBs were responsible for the increase in the twin area fraction that has been reported in past studies. While GB engineering increased the boundary area fraction, the TB number fraction was almost unchanged. Because the GB engineering process changed only the area fraction and not the number fraction, the connectivity of random boundaries was not disrupted.

Grain boundary engineering (GBE) has been carried out in nickel-based Alloy 690 with different initial grain sizes. The microstructure evolution during GBE-processing is characterized using electron backscatter diffraction to study the initial grain size effects on the grain boundary network (GBN). The microstructures of the partially recrystallized samples revealed that the GBE-processing is a strain-recrystallization process, during which each grain-cluster is formed by “multiple twinning” starting from a single recrystallization nucleus. Taking into consideration the coincidence site lattices (CSLs) and ∑, which is defined as the reciprocal density of coincidence sites, a high proportion of low-∑ CSL grain boundaries (GBs) and large grain-clusters are found to be the features of GBE-processed GBN. The initial grain size has a combined effect on the low-∑ CSL GBs proportion. A large initial grain size reduces the number of recrystallization nuclei that form, increasing the cluster size, but decreasing twin boundary density. On the other hand, smaller initial grain sizes increase the density of twin boundary after recrystallization, while decreasing grain-cluster size. Neither the grain-cluster size nor the twin boundary density is the sole factor influencing the proportion of low-∑ CSL GBs. The ratio of the grain cluster size over the grain size governs the proportion of low-∑ CSL GBs.