Autonomous manoeuvre decision-making is essential for enhancing the survivability and operational effectiveness of unmanned aerial vehicles in high-risk and dynamic air combat scenarios. To address the limitations of traditional air combat decision-making methods in dealing with complex and rapidly changing environments, this paper proposes an autonomous air combat decision-making algorithm based on hybrid temporal difference error-reward prioritised experience replay with twin delayed deep deterministic policy gradient. This algorithm constructs a closed-loop learning system from environmental interaction to policy optimisation, addressing the key challenges of slow convergence and insufficient identification of critical tactical decisions in autonomous air combat. A hybrid priority metric leveraging reward backpropagation and temporal difference error filter is introduced to optimise the learning of high-value experiences while balancing sample diversity and the reuse of critical experiences. To reduce excessive trial and error in the initial phase, an integrated reward function combining task rewards and auxiliary guidance rewards is designed using the reward reshaping method to guide the agent on how to choose a manoeuvre strategy. Based on the established three-dimensional close-range air combat game model, simulation validations were conducted for both basic manoeuvre and expert system engagements. The results demonstrate that the proposed autonomous air combat manoeuvre decision-making algorithm exhibits higher learning efficiency and convergence stability. It can rapidly identify high-value manoeuvres and effectively formulate rational yet superior tactical strategies in the face of complex battlefield scenarios, demonstrating obvious benefits in enhancing combat effectiveness and tactical adaptability.

African swine fever (ASF) is a highly contagious animal disease caused by African swine fever virus (ASFV). It is listed by the World Organization for Animal Health (WOAH) as an animal disease subject to statutory reporting. ASFV, a large, enveloped double-stranded DNA virus with high genomic complexity, exhibits a case fatality rate of up to 100%, posing a significant threat to the global pig industry and food safety. To date, the absence of a safe commercial ASFV vaccine primarily stems from challenges in identifying immunogenic viral antigens, insufficient characterization of ASFV pathogenesis, and limited understanding of the virus’s immune evasion mechanisms. Here, we review the pathogenic characteristics (morphological structure, clinical symptoms, and epidemiological characteristics), molecular biological characteristics, and infection mechanism of ASFV, as well as the immune response mechanism, vaccine research, and the latest information on ASFV in other areas. This review will be in favour of understanding the current state of knowledge of ASF and developing effective vaccines to control this disease.

Shock-tube experiments are conducted to investigate the Atwood-number dependence of hydrodynamic instability induced by a strong shock with a Mach number exceeding 3.0. The compressible linear theory performs reliably under varying compressibility conditions. In contrast, the impulsive model significantly loses predictive accuracy at high shock intensities and Atwood numbers ($A_t$), particularly when specific heat ratio differences across the interface are pronounced. To address this limitation, we propose a modified impulsive model that offers favourable predictions over a wide range of compressibility conditions while retaining practical simplicity. In the nonlinear regime, increasing $A_t$ enhances both the shock-proximity and secondary-compression effects, which suppress bubble growth at early and late stages, respectively. Meanwhile, spike growth is promoted by the spike-acceleration and shock-proximity mechanisms. Several models reproduce spike growth across a wide range of $A_t$, whether physical or incidental. In contrast, no models reliably describe bubble evolution under all $A_t$ conditions, primarily due to neglecting compressibility effects that persist into the nonlinear regime. Building on these insights, we develop an empirical model that effectively captures bubble evolution over a wide $A_t$ range. Modal evolution is further shown to be strongly affected by compressibility-induced variations in interface morphology. The effect is particularly pronounced at moderate to high $A_t$, where it suppresses the fundamental mode growth while promoting higher-order harmonic generation.

The evolution mechanisms and suppression strategy of the Richtmyer–Meshkov instability (RMI) at heavy–light interfaces with varying Atwood numbers accelerated by two co-propagating shock waves are investigated through theoretical analysis and experimental evaluation. Existing models describing the complete evolution of once-shocked interfaces and the linear growth of twice-shocked interfaces are examined across low, moderate and high Atwood number regimes, and further refined based on detailed analyses of their limitations. Furthermore, an analytical model for describing the complete evolution of a twice-shocked interface (DS model) is developed through a comprehensive consideration of the shock-compression, start-up, linear and weakly nonlinear evolution processes. The combination of the refined models and DS model enables, for the first time, an accurate prediction of the complete evolution of interfaces subjected to two co-propagating shock waves. Building upon this, the parameter conditions required to manipulate the RMI with varying Atwood numbers are identified. Verification experiments confirm that suppressing the RMI growth at interfaces with various Atwood numbers via a same-side reshock is feasible and predictable. The present study may shed some light on strategies to suppress hydrodynamic instabilities in inertial confinement fusion through integrated adjustment of material densities and shock timings.

Aerothermal issues in hypersonic transitional swept shock wave/boundary-layer interactions (SBLIs) are critical for the structural safety of high-speed vehicles but remain poorly understood. In this work, previously scarce, high-resolution heat transfer distributions of the hypersonic transitional swept SBLIs, are obtained from fast-responding temperature-sensitive paint (fast TSP) measurements. A series of $34^\circ$ compression ramps with sweep angles ranging from $0^\circ$ to $45^\circ$ are tested in a Mach 12.1 shock tunnel, with a unit Reynolds number of 3.0 $\times$ 10$^{6}$ m$^{-1}$. The fast TSP provides a global view of the three-dimensional aerothermal effects on the ramps, allowing in-depth analysis on the sweep effects and the symmetry of heat transfer. The time-averaged results reveal that the heat flux peak near reattachment shifts upstream with decreasing amplitude as the sweep angle increases, and a second peak emerges in the $45^\circ$ swept ramp due to a type V shock–shock interaction. Downstream of reattachment, the heat flux streaks induced by Görtler-like vortices weaken with increasing sweep angle, whereas their dominant projected wavelengths show little dependence on sweep angle or spanwise location. Away from the ramp’s leading side, the transition onset of the reattached boundary layer gradually approaches the reattachment point. Finally, a general quasi-conical aerothermal symmetry is identified upstream of reattachment, although spanwise variations in transition onset, shock–shock interaction and heat flux streaks are found to disrupt this symmetry downstream of reattachment with varying degrees.

This study evaluated the effect of different medium-chain to long-chain fatty acid (MCFA:LCFA, M:L) ratios on growth performance, intestinal function, antioxidant capacity and gut microbiota in piglets. A total of 250 piglets were randomly assigned to five groups with five replicates, each containing ten pigs. The diets, containing varying amounts of MCFA-rich coconut oil and LCFA-rich soyabean oil, resulted in M:L ratios of 0, 2·1, 4·2, 8·8 and 33·8 %. Results showed that both final body weight and average daily weight gain increased as the M:L ratio increased (P < 0·05), while the 8·8 % M:L ratio diet exhibited the lowest feed:gain ratio (P < 0·05). As the M:L ratio increased, the contents of superoxide dismutase and glutathione peroxidase were increased, and MDA was decreased in serum (P < 0·05). The 8·8 and 33·8 % M:L diets improved ileal and jejunal morphology (P < 0·05), as indicated by greater villus height and villus height:crypt depth ratios. Furthermore, increasing M:L ratios from 0 to 33·8 % increased expression of tight junction proteins occludin and ZO-1 in the jejunum (P < 0·05). The 33·8 % M:L ratio reduced microbial α-diversity (P < 0·05), while 8·8 % M:L diet significantly increased the abundance of beneficial bacteria (e.g. Lactobacilli, Prevotella) and decreased harmful bacteria (e.g. Escherichia-Shigella, Enterococcus) in the cecum (P < 0·05). In summary, our study found that 8·8 % of dietary M:L ratios significantly improved growth performance, likely through modulating intestinal function, antioxidant activity and gut microbial composition.

We aimed to investigate the association between plasma advanced glycation end products (AGE) level and fat, skeletal muscle-related body composition parameters in middle-aged and elderly Chinese participants. A total of 1139 participants aged over 40 years were included in a cross-sectional study. Body composition including BMI, waist:hip ratio (WHR), fat mass index (FMI), percentage of body fat (PBF), the ratio of trunk fat to legs fat (trunk fat/legs fat), fat free mass (FFM), fat free mass index (FFMI) and skeletal muscle index (SMI) was measured using a bioelectrical impedance analyser. Plasma free and combined AGE were measured by ultra-high performance liquid chromatography-tandem MS. Multiple linear regression and weighted quantile sum regression models were used to examine the association between AGE and body composition parameters. Total exposure of plasma advanced glycation end products (AGE) was positively associated with BMI (β (95 % CI): 0·381 (0·037, 0·724), P = 0·030), FMI (β (95 % CI): 0·521 (0·241, 0·800), P = 0·001), PBF (β (95 % CI): 1·996 (1·160, 2·832), P < 0·0001), trunk fat/legs fat (β (95 % CI): 0·058 (0·036, 0·080), P < 0·001); while it was negatively associated with FFM (β (95 % CI): −1·075 (–2·028, –0·122), P = 0·027), FFMI (β (95 % CI): −0·687 (–1·076, –0·297), P = 0·001) and SMI (β (95 % CI): −1·264 (–1·767, –0·761), P < 0·001). The associations between plasma AGE and FFM and FFMI were more pronounced in those aged less than 61 years and female participants. This study provides evidence on the associations between plasma AGE and fat and skeletal muscle parameters, suggesting their potential role in the development of obesity and skeletal muscle loss.

The moulting of birds creates different trailing-edge gaps in their wings, which inspires the handling of damaged wings in micro-air vehicles. The effects of the moult gap on aerodynamic performance are investigated by employing a bird-inspired flapping wing model. The aerodynamic performance is evaluated by numerically solving the Navier–Stokes equations for incompressible flows. Moult-gapped wings with different gap widths and positions are compared with the original intact wing in terms of aerodynamic forces and vortex structures. It is found that the decrease in the average lift is slower than that expected from the classical aerodynamic model. The moult gap results in three-dimensional gap vortices, which interact with leading-edge vortices and tip vortices. The interaction generates a pair of parallelly arranged vortex loops on each wing. The downwash momentum associated with this pair of vortex loops is enhanced by the gap vortices. The gap-vortices-enhanced downwash compensates for the loss in the lifting surface, increasing the aerodynamic force per unit area. A composite actuator disk model is proposed based on the vortex loops. The proposed model accounts for not only the finite-span wing effects but also the vortex compensation effects, while the previous quasi-steady model only accounts for the finite-span wing effects.

To explore the longitudinal associations between a Chinese healthy diet and the progression of cardiometabolic multimorbidity (CMM) development among Chinese adults. A prospective analysis was conducted utilising data from 18 720 participants in the China Health and Nutrition Survey, spanning from 1997 to 2018. Dietary data were collected by three consecutive 24-h dietary recalls combined with the weighing method. A Chinese healthy diet score was developed by assigning scores to various food components. CMM was defined as the coexistence of two or more cardiometabolic diseases (CMD), including myocardial infarction, stroke and type 2 diabetes, diagnosed through blood indicators and clinical diagnosis. We employed a multistate model to examine the associations between the Chinese healthy diet and the longitudinal progression from being free of CMD to first CMD and then to CMM. Quantile G-computation was utilised to evaluate the relative contribution of each food component. Over a median follow-up period of 7·3 years, 2214 (11·8 %) participants developed first CMD, and 156 (0·83 %) progressed to CMM. Comparing participants in the highest quintile of dietary scores with those in the lowest, we observed a 55 % lower risk of transitioning from baseline to CMM (HR = 0·45, 95 % CI: 0·23, 0·87) and a 60 % lower risk of transition from first CMD to CMM (HR = 0·40, 95 % CI: 0·20, 0·81). Fresh fruits contributed to 42·8 and 43·0 % for delaying CMM and transition from first CMD to CMM, respectively. Our study revealed that greater adherence to the Chinese healthy diet is negatively associated with the risk of CMM.

Differential item functioning (DIF) screening has long been suggested to ensure assessment fairness. Traditional DIF methods typically focus on the main effects of demographic variables on item parameters, overlooking the interactions among multiple identities. Drawing on the intersectionality framework, we define intersectional DIF as deviations in item parameters that arise from the interactions among demographic variables beyond their main effects and propose a novel item response theory (IRT) approach for detecting intersectional DIF. Under our framework, fixed effects are used to account for traditional DIF, while random item effects are introduced to capture intersectional DIF. We further introduce the concept of intersectional impact, which refers to interaction effects on group-level mean ability. Depending on which item parameters are affected and whether intersectional impact is considered, we propose four models, which aim to detect intersectional uniform DIF (UDIF), intersectional UDIF with intersectional impact, intersectional non-uniform DIF (NUDIF), and intersectional NUDIF with intersectional impact, respectively. For efficient model estimation, a regularized Gaussian variational expectation-maximization algorithm is developed. Simulation studies demonstrate that our methods can effectively detect intersectional UDIF, although their detection of intersectional NUDIF is more limited.

We experimentally and theoretically examine the maximum spreading of viscous droplets impacting ultra-smooth solid surfaces, where viscosity plays a dominant role in governing droplet spreading. For low-viscosity droplets, viscous dissipation occurs mainly in a thin boundary layer near the liquid–solid interface, whereas for high-viscosity droplets, dissipation is expected to extend throughout the droplet bulk. Incorporating these dissipation mechanisms with energy conservation principles, two distinct theoretical scaling laws for the maximum spreading factor ($\beta _m$) are derived: $\beta _m \sim ({\textit{We}}/ {\textit{Oh}})^{1/6}$ for low-viscosity regimes (${\textit{Oh}} \lesssim 0.1$) and $\beta _m \sim \textit{Re}^{1/5}$ for high-viscosity regimes (${\textit{Oh}} \gt 1$), where $\textit{We}$, $\textit{Re}$ and $\textit{Oh}$ are the Weber, Reynolds and Ohnesorge numbers, respectively. Both scaling laws show good agreement with the experimental data for their respective validity ranges of $\textit{Oh}$. Furthermore, to better model experimental data at vanishing $\textit{Re}$, we introduce a semi-empirical scaling law, $\beta _m \sim (A + {\textit{We}}/ {\textit{Oh}})^{1/6}$, where $A$ is a fitting parameter accounting for finite spreading ($\beta _m \approx 1$) at negligible impact velocities. This semi-empirical law provides an effective description of $\beta _m$ for a broad experimental range of $10^{-3} \leqslant {\textit{Oh}} \leqslant 10^0$ and $10^1 \leqslant {\textit{We}} \leqslant 10^3$.

High gain greater than 106 is crucial for the preamplifiers of joule-class high-energy lasers. In this work, we present a specially designed compact amplifier using 0.5%Nd,5%Gd:SrF2 and 0.5%Nd,5%Y:SrF2 crystals. The irregular crystal shape enhances the gain length of the laser beam and helps suppress parasitic oscillations. The amplified spontaneous emission (ASE) induced by the high gain is analyzed through ray tracing. The balance between gain and ASE is estimated via numerical simulation. The gain spectral characteristics of the two-stage two-pass amplifier are examined, demonstrating the advantages of using different crystals, with bandwidths up to 8 nm and gains over 106. In addition, the temperature and stress distributions in the Nd,Gd:SrF2 crystal are simulated. This work is expected to contribute to the development of high-peak-power ($\ge$terawatt-class) high-energy (joule-class) laser devices.

Effective performance of oil-based drilling fluids (OBFs) in demanding high-temperature environments hinges on the stability of their rheological properties. However, conventional organoclays (OCs) utilized to control these properties often exhibit thermal degradation at elevated temperatures, necessitating the development of more robust alternatives. Therefore, the present study aimed to develop a high-temperature-resistant OC to enhance OBF rheological stability. To address the thermal instability issues of conventional quaternary organo-montmorillonites (OMts), which manifest as interlayer structural collapse and particle aggregation, an innovative dual modification strategy was developed through the synergistic combination of quaternary ammonium intercalation and silane grafting. Montmorillonite (Mnt) was modified with dioctadecyl dimethyl ammonium chloride (1821) and stearyl dimethyl benzyl ammonium chloride (1827) at a mass ratio of 2:1 to yield 1821+1827-OMt, which was subsequently further modified with dodecyl trimethoxy silane (DTMS) to form 1821+1827+DTMS-OMt. Comparison of the properties of 1821+1827-OMt and 1821+1827+DTMS-OMt after high temperatures revealed the following. (1) Thermogravimetric (TG) and derivative thermogravimetric (DTG) analysis and gel volume tests demonstrated that the Si–O–Si bonds in 1821+1827+DTMS-OMt were thermally stable up to ~440°C, and the gel volume of the 1821+1827+DTMS-OMt suspension remained stable at 100 mL following high-temperature aging treatments. (2) X-ray diffraction and elemental analysis revealed that 1821+1827+DTMS-OMt exhibited a larger basal spacing and larger nitrogen content compared with ungrafted 1821+1827-OMt. (3) The suspension containing 1821+1827+DTMS-OMt demonstrated enhanced thermal stability at 260°C, evidenced by its narrower rheological parameter ranges of apparent viscosity (6–12 mPa s), plastic viscosity (5–9 mPa s), and yield point (1–3 Pa), compared with those of the suspension containing 1821+1827-OMt. (4) Optical microscopy demonstrated that 1821+1827+DTMS-OMt exhibited greater resistance to agglomeration at high temperatures than 1821+1827-OMt. The high-temperature-resistant OC developed in this study overcomes the thermal instability of traditional OCs, providing a robust approach for enhancing the efficiency and reliability of oil-based drilling fluids in high-temperature drilling applications.