Systematic experimental data on local extreme velocities and unsteady features in high-Reynolds-number deep-cavity flows remain limited. In this study, two-component particle image velocimetry (PIV) measurements were performed to investigate the flow characteristics of an incoming-flow-driven deep cavity with $L/D$ = $1/3$ at Re = 2.55 × 105. Three streamwise $xy$ planes ($z/W$ = 0.10, 0.25, 0.50) and three spanwise yz planes ($x/L$ = 0.10, 0.25, 0.50) were measured systematically. The time-averaged velocity, root mean square velocity fluctuations, in-plane turbulent kinetic energy (TKE), instantaneous maximum velocity, and higher-order statistics including skewness and kurtosis were analysed. The results show that the vertical velocity fluctuation on the intermediate streamwise plane ($z/W$ = 0.25) reaches peak value approximately $v$rms/Ulid = 0.072 (where Ulid is the characteristic inflow velocity above the cavity), indicating the strongest local vertical unsteady response among the measured streamwise planes. On the near-wall plane ($z/W$ = 0.10), the instantaneous maximum velocity exhibits skewness 1.23 and kurtosis 7.47, reflecting pronounced local intermittent extreme events, whereas the extreme events on the middle plane ($z/W$ = 0.50) are weaker and closer to a Gaussian-like distribution. The spanwise planes also demonstrate clear non-Gaussian features, with high-fluctuation and high in-plane TKE regions primarily concentrated in areas associated with the interaction between the shear layer and recirculation structures, revealing significant spatial anisotropy in the flow. These results suggest that shear-layer development, primary recirculation, sidewall confinement and downstream flow turning jointly modulate local extreme events and intermittent velocity fluctuations. This study provides systematic experimental quantification of spatial non-uniformity and extreme-event characteristics in a high-Reynolds-number deep cavity using multi-plane PIV, offering useful experimental references for turbulence model validation and complex cavity-flow control.

The optics roughness in Öffner stretchers has been widely identified as a major cause of temporal contrast degradation at tens of picoseconds before the main pulse. However, we find that amplifier-induced noise may become the decisive factor for temporal contrast deterioration at a similar time window with the increase of the B-integral in chirped-pulse amplification systems. Even employing a high-precision convex mirror with root-mean-square roughness values better than 0.2 nm, the experimental measurements show that amplifier-induced noise generates asymmetric profiles under nonlinear effects – exhibiting an obvious pre-pedestal growth proportional to the accumulated B-integral. Analogous to post-to-pre-pulse conversion dynamics, the numerical simulations demonstrate the impact of the B-integral on the pre-pedestal, especially when the pulse peak power scales from the terawatt level to the petawatt level.

Exhumation-induced stress triggers natural hydraulic fracturing, governing fluid overpressure limits in deeply buried strata. In the Sichuan Basin (South China), the geomechanical response of Lower Cambrian shale to multi-phase differential exhumation remains poorly quantified. We integrated apatite and zircon thermochronology, vitrinite reflectance, residual stratal thickness, and Skempton’s poroelastic model to reconstruct the exhumation and pore pressure history of the Qiongzhusi Formation. Results reveal a four-stage, northwestward-migrating exhumation since the Cretaceous, featuring severe uplift (3000–4000 m) along basin margins and the Weiyuan anticline, versus moderate uplift (2000–2500 m) in the Ziyang intra-basin area. This differential exhumation halted thermal evolution, establishing a spatial thermal maturity distribution (VR = 3.2%–4.0%) and a lower boundary at ∼5500 m, below which graphitization degrades rock properties. Crucially, differential exhumation magnitude and varying initial pore pressures at maximum burial (∼7000 m) governed stress trajectories during uplift. Driven by higher initial pressure, the moderately exhumed Ziyang area reached the natural fracturing threshold at 4100 m, significantly deeper than the heavily exhumed Weiyuan area (3250 m). These critical failure depths mechanistically define the upper limits for overpressure preservation, demonstrating that differential exhumation and poroelastic relaxation fundamentally control the vertical boundaries of overpressured shale compartments.

Passive exoskeletons offer several advantages, including lightweight design, simple structure, and inherent energy efficiency. Most existing passive exoskeletons rely on clutch mechanisms to control spring-based energy storage and release, typically focusing only on recovering biomechanical energy during the stance phase of gait. In this study, we propose and analyze a lightweight passive ankle exoskeleton capable of harvesting and releasing energy during both the stance and swing phases of walking. The device aims to enhance gait assistance while maintaining structural simplicity and minimizing weight. By integrating the optimal stiffness ratio between the stance and swing phases, derived from musculoskeletal model simulations, with previously established optimal stance-phase stiffness parameters, we determined a suitable stiffness coefficient for the swing-phase spring. To validate the design, we conducted comparative experiments on participants walking with exoskeletons configured with different stiffness coefficients. Spatiotemporal parameters, metabolic energy cost, and muscle activation patterns were analyzed to evaluate performance. The results demonstrate that the proposed exoskeleton effectively reduces Soleus muscle activation while increasing tibialis anterior activity, leading to a 6.84% reduction in walking energy cost compared to a nonassistive condition. Furthermore, energy recovery during the swing phase alone contributes an additional 1.67% reduction in energy expenditure, improving overall walking efficiency. The proposed design also eliminates complex clutch components, significantly simplifying manufacturing and reducing costs, thereby enhancing the applicability of passive exoskeletons in daily mobility and rehabilitation scenarios.

Low-protein (LP) diets are increasingly adopted in poultry production to improve nitrogen efficiency. While their effects on the utilization of trace minerals have been demonstrated, the optimal supplementation strategies for these minerals remain insufficiently explored. This study investigated the interactive effects of dietary iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn) supplementation in laying hens fed a 15% crude protein LP diet using a uniform design approach. A total of 1,008 Hy-Line Brown laying hens (49–60 weeks of age) were randomly allocated to 12 dietary treatments with graded combinations of the four trace elements. Production performance, egg quality, apparent nutrient digestibility, fecal mineral excretion, and duodenal metal ion transporters were assessed. Trace minerals supplementation did not affect laying performance (P > 0.05). However, significant interactions among minerals influenced egg quality, ash digestibility, and fecal mineral excretion (P < 0.05). Antagonistic interactions were observed for Cu × Zn and Fe × Zn, while Mn × Zn showed synergism (P < 0.05). Regression analyses demonstrated that optimal trace minerals combinations varied depending on the specific response variables. Given that production performance remained stable across minerals treatments, minimizing total mineral excretion was prioritized as the optimization objective. The optimization results indicate that no additional supplementation of Cu, Mn, and Zn is required, whereas 33 mg/kg of Fe represents the optimal level for minimizing total mineral excretion. These findings suggest that basal diet Cu, Mn, and Zn concentrations may largely meet the requirements of laying hens from 49 to 60 weeks of age in terms of production performance and mineral utilization. Overall, this study provides an effective approach for identifying key influencing factors and developing precision trace minerals supplementation strategies that maintain production performance while substantially reducing mineral excretion, thereby supporting environmentally sustainable poultry production.

Dyslipidaemia is associated with chronic low-grade inflammation and immune dysfunction, but the immunological effects of dietary phytosterols in humans remain unclear. We conducted a secondary analysis of an outcome-assessor-blinded, randomised controlled feeding trial to evaluate the effects of a high-phytosterol (HPS) diet, using phytosterol-enriched corn–wheat germ blended oil (CWGO), compared with a low-phytosterol (LPS) diet using peanut oil, on systemic inflammatory markers, humoural immune markers and peripheral blood lymphocyte subsets in Chinese adults with dyslipidaemia. After a 2-week run-in period, 104 participants were randomised to the HPS group (n 52) or the LPS group (n 52) for 12 weeks. In intention-to-treat analyses, the HPS group had a higher CD4+:CD8+ ratio at 12 weeks than the LPS group (adjusted mean difference: 0·561; 95 % CI 0·060, 1·063; P = 0·03) and a lower CD8+ T-cell count (adjusted mean difference: −116·315 cells/μl; 95 % CI −215·781, –16·849; P = 0·02). No significant between-group differences were observed for systemic inflammatory markers, humoral immune markers or most other lymphocyte subset outcomes. In per-protocol analyses, the difference in CD4+:CD8+ ratio remained significant, whereas the reduction in CD8+ T-cell count was attenuated. These exploratory findings suggest that a 12-week phytosterol-enriched CWGO intervention may be associated with changes in T-cell subset balance in adults with dyslipidaemia, although the results should be interpreted cautiously given the exploratory nature of this secondary analysis.

Cavitation bubble collapse near a wall is investigated by employing a recently developed laser–fluid computational framework to simulate the complete lifecycle of a wall-detached laser-induced bubble, including the water breakdown phase. The model couples compressible multiphase Euler equations, a radiative transport equation and a latent heat reservoir formulation for phase transition. A wide range of nine stand-off ratios $\gamma \in [0.79,\ 2.14]$ is investigated and directly compared with recent experimental measurements. The simulations reproduce the interfacial dynamics of bubbles with excellent accuracy. Moreover, the computations are capable of reidentifying the three experimentally observed collapse regimes, i.e. purely torus, mixed tip-and-torus and purely tip collapse, and correctly identify the collapse as the dominant source of the peak wall pressure rather than jet impact. A sensitivity analysis shows that only the mixed tip-and-torus regime exhibits strong dependence on the laser absorption coefficient. The simulations give access to the details on pressure, density, temperature and velocity fields inside the bubble and demonstrate that the vapour remains in average thermodynamic equilibrium during most of lifetime. The results reveal significantly different time scales between thermodynamic fields where the gas pressure becomes quasi-uniform inside the bubble during expansion and collapse, whereas the temperature remains strongly non-uniform with persistent spatial gradients. This study provides the most complete numerical reproduction to date of experimental laser-induced bubble collapse near a wall, and offers new physical insight into the coupling between bubble–wall interaction, laser-induced thermodynamics and collapse regimes.

In this study, the Mach reflection of a detonation wave in 2H$_2$ + O$_2$ + 2Ar over a concave double wedge was experimentally investigated. Three Mach reflection configurations could be observed successively, namely, Mach reflection of a Chapman–Jouguet detonation over the first surface, Mach reflection of an overdriven detonation wave over the second surface, and Mach reflection after the interaction of two triple points. The experimental results indicated that the classical reactive theories based on the straight Mach stem assumption are unable to accurately predict the behaviours of the latter two Mach reflections. The asymptotic triple-point trajectory angle of the secondary Mach reflection, $\chi _2$, is significantly smaller than the theoretical prediction. A curved model for the Mach stem $m_1$ is constructed, introducing a curved Mach stem near the triple point. The Mach stem has a concave curvature, implying a lower overdrive degree and a smaller incident angle, which consequently leads to a reduction in $\chi _2$. Based on the curved Mach stem model, an equivalent wedge angle $\varPhi$ and an equivalent overdrive degree $\overline {\alpha }$ are introduced to predict the value of $\chi _2$. An analytical model for solving the interaction of two triple points was developed. Two different wave structures after the interaction – namely, downward-travelling shock–shock and downward-travelling centred shock–expansion – were determined using gas dynamic and shock dynamic methods. The curved Mach stem $m_1$ can result in the variation of the wave structure.

During World War II, the Japanese Kwantung Army’s Unit 731 secretly conducted large-scale, inhumane, and unethical human experimentation in China, culminating in one of the most heinous medical atrocities, crimes against humanity, and war crimes in the Asia-Pacific theatre of the war. Despite the gravity of the subject matter and its historical significance, research on Unit 731 has, for a long time, been rather limited, but has gradually increased in recent decades. In this article, we identify several important characteristics and trends in research activities related to Unit 731, with a view to providing a general overview of the existing scholarship and to providing recommendations for future research.

From the 1950s to the 1970s, academic research started to accumulate. The second stage was one of rapid development from the 1980s to the 1990s. During this period, research efforts in Japan had a far-reaching influence and began to spread to China, Europe, and the U.S. Scholars from scientific, medical, and educational communities began participating in Unit 731 research successively. The third stage of multi-dimensional development began at the onset of the twenty-first century. Research expanded into comparative inquiries of Japanese medical atrocities and their Nazi counterpart; at the same time, research on many topics in diverse disciplines was also deepened and intensified. In addition to focusing on pragmatic issues such as reflections and actions of modern society and reconciliation, researchers have also been concerned with historical writing and collective memory.

In this work, we demonstrate a high-energy regenerative amplifier based on a single Yb:CaGdAlO4 (Yb:CALGO) crystal, delivering a pulse energy of 11.2 mJ at a 1 kHz repetition rate. To the best of our knowledge, this represents the highest pulse energy directly obtained from an Yb:CALGO single-crystal regenerative amplifier to date. To mitigate the severe gain narrowing typically associated with high-energy amplification, a specially designed polarization-spectral filter was integrated into the system to pre-shape the seed spectrum, enabling an amplified full width at half maximum spectral bandwidth of 10.1 nm. As a result, the amplified pulses were able to be compressed to a pulse duration of 198 fs without any pedestal. The output power stability, measured over 200 minutes, exhibited a root mean square fluctuation of 0.27%, and the beam quality factors were Mx2 = 1.08 and My2 = 1.17.

The characteristically low flowback recovery in shale reservoirs stems from spontaneous imbibition, a governing mechanism for fluid retention and hydrocarbon production. Despite extensive research, the fundamental processes underlying aqueous-phase transport in shales remain poorly understood. This review synthesises recent findings by characterising imbibition as a dynamic, cross-scale transport phenomenon driven by the coupling of capillary suction, chemical potential gradients and clay hydration. Unlike traditional static descriptions of this process, this review highlight how imbibition induces continuous pore-network evolution via hydration-triggered microfracture propagation and mineral-scale blockage. Geological attributes, fluid chemistry and operational parameters are systematically evaluated. We further examine the methodological transition from macroscopic monitoring to in situ visualisation, and from classical analytical solutions to multiphysics numerical frameworks. Lastly, we conclude by identifying critical knowledge gaps and outlining future perspectives in high-pressure high-temperature in situ measurements, multiscale predictive correlations and intelligent fluid systems.