Paddy fields are central to the origin and spread of rice agriculture and their development ultimately underpinned the formation of complex societies in Asia. Here, the authors report on the stratigraphy, radiocarbon dating and archaeobotanical record from Shiao, including one of the earliest and largest paddy fields yet identified (c. 6700 cal BP). As at nearby sites, paddy fields were successively overlaid with peat and marine sediments as sea level vacillated. With each iteration, the fields evolved from strip-like to ‘hash’-shaped configurations, representing growing labour input and, crucially, a corresponding increase in sustainable population size.

This work proposes a data-driven explicit algebraic stress-based detached-eddy simulation (DES) method. Despite the widespread use of data-driven methods in model development for both Reynolds-averaged Navier–Stokes (RANS) and large-eddy simulations (LES), their applications to DES remain limited. The challenge mainly lies in the absence of modelled stress data, the requirement for proper length scales in RANS and LES branches, and the maintenance of a reasonable switching behaviour. The data-driven DES method is constructed based on the algebraic stress equation. The control of RANS/LES switching is achieved through the eddy viscosity in the linear part of the modelled stress, under the $\ell ^2-\omega$ DES framework. Three model coefficients associated with the pressure–strain terms and the LES length scale are represented by a neural network as functions of scalar invariants of velocity gradient. The neural network is trained using velocity data with the ensemble Kalman method, thereby circumventing the requirement for modelled stress data. Moreover, the baseline coefficient values are incorporated as additional reference data to ensure reasonable switching behaviour. The proposed approach is evaluated on two challenging turbulent flows, i.e. the secondary flow in a square duct and the separated flow over a bump. The trained model achieves significant improvements in predicting mean flow statistics compared with the baseline model. This is attributed to improved predictions of the modelled stress. The trained model also exhibits reasonable switching behaviour, enlarging the LES region to resolve more turbulent structures. Furthermore, the model shows satisfactory generalization capabilities for both cases in similar flow configurations.

This paper investigates the aerodynamic and flow characteristics of a circular cylinder near the leading-edge separated flow of an elongated rectangular cylinder. The study varies the gap-to-diameter ratio (G/D) of 0 ≤ G/D ≤ 0.4 and distance-to-diameter ratio (L / D) of 0.6 ≤ L / D ≤ 5.8 in the subcritical Reynolds-number region. Here, D, G and L are the diameter of the circular cylinder, the gap between the two isomeric cylinders and the distance between the leading edge of the rectangular cylinder and the centre of the circular cylinder, respectively. Based on smoke-wire flow visualisations, particle image velocimetry test results, lift power spectral densities and pressure distributions, flow around the circular cylinder can be classified into three regimes, i.e. broadened body, body reattachment and co-shedding. In the broadened-body regime, gap flow is negligible, and the circular cylinder behaves as an extension of the rectangular cylinder. In the body-reattachment regime, the free shear layer separated from the rectangular cylinder’s leading edge reattaches to the circular cylinder forebody, significantly modifying its incoming flow. In the co-shedding regime, the free shear layer substantially alters the vortex shedding from the circular cylinder’s lower side, resulting in a distorted alternating vortex shedding from the circular cylinder. Both the drag and lift of the circular cylinder display distinct behaviours in the three flow regimes. Two primary flow modes are recognised through proper orthogonal decomposition analysis: an alternating vortex shedding mode and a one-sided shear flow mode, which result in two Strouhal numbers of 0.205 and 0.255, respectively.

Coconut oil, extracted from coconut kernels, is a rich source of medium-chain fatty acids (MCFAs), including lauric acid, capric acid and caprylic acid. This experiment aimed to investigate the protective effect of coconut oil against intestinal injury induced by lipopolysaccharide (LPS) challenge in piglets. A total of 24 piglets were used in a 2 × 2 factorial experiment with dietary treatment (3% soybean oil vs 3% coconut oil) and LPS challenge (saline vs LPS). After 28 days of the experiment, piglets were injected intraperitoneally with LPS (100 μg/kg body weight) or saline. Piglets were slaughtered and sampled for testing. Pigs fed coconut oil had higher average daily gain and body weight during the entire study. Supplementation with coconut oil improved intestinal morphology and barrier function, indicated by increased jejunal villus height, as well as enhanced protein expression of ZO-1 and Occuldin. Furthermore, coconut oil supplementation improved plasma antioxidant capacity indicated by enhanced glutathione peroxidase (GSH-Px) activity and decreased malondialdehyde (MDA) concentration. Moreover, Coconut oil ameliorated the LPS-induced release of pro-inflammatory cytokines, as indicated by decreased IL-1β expression in the jejunum. Coconut oil also alleviated the up-regulation of the expression of necroptosis protein receptor-interacting protein kinase 3 (RIPK3) and mixed lineage kinase-like protein (MLKL) in the jejunum of piglets stimulated by LPS. In conclusion, dietary supplementation of coconut oil can improve the growth performance of piglets, and alleviate LPS-induced intestinal injury and inflammation by inhibiting necroptosis signaling pathway.

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.

Diastasis of rectus abdominis (DRA) is a common pathological condition in postpartum rehabilitation, but with limited treatment strategies. This study aimed to explore the effect of using a trunk-wearable neuromuscular electrical stimulation (NMES) device on postpartum women with moderate and severe DRA. A total of 84 postpartum women with an inter-rectus distance (IRD) of ≥3 cm were randomly assigned to two equal groups. The treatment group received a trunk-wearable NMES device and exercise therapy, whereas the control group received exercise only. We measured IRD and calculated treatment response proportion, improvement of trunk muscle strength, and low-back pain in both groups. Additionally, we evaluated quality of life (QoL) using the SF-36 questionnaire and Hernia-related Quality of Life Survey (HerQLes). Statistical analysis was performed using SAS 9.4. After 8-week treatment, the IRD of the umbilical (M3) sector showed a greater reduction in the treatment group (−10.6 [−17.9 to −3.3]%, p < 0.05). Patients in the treatment group had higher treatment response proportions (p = 0.0031 and p = 0.0010, W2 and W3, respectively). Additionally, the treatment group had higher Janda assessment scores and greater reduction in low-back pain (both p < 0.0001). QoL evaluation indicated greater improvements in the SF-36 questionnaire (pain and role-emotional scales,p < 0.05) and HerQLes (p < 0.0001) in the treatment group. The application of a trunk-wearable NMES device on DRA patients, accompanied by exercise therapy, significantly reduced IRD and increased the treatment response proportion. Moreover, we observed positive improvements in trunk muscle strength, low-back pain, and QoL.

Politicization is one of the most fundamental characteristics of Chinese society, manifested in the direct and comprehensive control of society by the Chinese Communist Party (CCP). Methods include soft control through ideology and coercive control through campaigns. Based on the varying degrees of the CCP’s social control, the trajectory of China’s regime politicization can be divided into four periods: (1) the politicized regime of 1949–1965, (2) the hyper-politicized regime of 1966–1978, (3) the de-politicized regime of 1979–2012, and (4) the re-politicized regime of 2013–2023. We established an annual politicization index for the years 1949 to 2023 through a content analysis of two million articles in the People’s Daily, validating the trajectory of politicization changes in China. We use a model analysis of CCP membership attainment to demonstrate the applicability of the index in assessing how regime dynamics affect Party membership across the four periods.

Stress–velocity cross-spectra provide critical insights into the wall turbulence dynamics, where second-order cross-spectra have been used to characterise the amplitude modulation of large-scale motions on smaller scales. Here, we investigate the higher-order stress–velocity cross-spectra. Through theoretical analysis, we derive an exact relationship demonstrating that the difference in convection velocity between streamwise Reynolds normal stress fluctuations ($r$) and streamwise velocity fluctuations ($u$) – termed the $r{-}u$ convection velocity difference – is governed jointly by the second- and fourth-order cross-spectra. A new ‘coherence similarity’ (CS) model is proposed, which reveals an approximate similarity between higher-order and second-order cross-spectra. As a result, the $r{-}u$ convection velocity difference can be explained in terms of second-order cross-spectral properties. Numerical validation confirms that the CS model predicts higher-order cross-spectra and the convection velocity difference accurately. Furthermore, the contours of stress–velocity cross-spectra undergo a structural transition from single-lobe to triple-lobe patterns with increasing wall distance, suggesting the presence of complex space–time coupling between $r$ and $u$.

In this work we propose a neural operator-based coloured-in-time forcing model to predict space–time characteristics of large-scale turbulent structures in channel flows. The resolvent-based method has emerged as a powerful tool to capture dominant dynamics and associated spatial structures of turbulent flows. However, the method faces the difficulty in modelling the coloured-in-time nonlinear forcing, which often leads to large predictive discrepancies in the frequency spectra of velocity fluctuations. Although the eddy viscosity has been introduced to enhance the resolvent-based method by partially accounting for the forcing colour, it is still not able to accurately capture the decay rate of the time-correlation function. Also, the uncertainty in the modelled eddy viscosity can significantly limit the predictive reliability of the method. In view of these difficulties, we propose using the neural operator based on the DeepONet architecture to model the stochastic forcing as a function of mean velocity and eddy viscosity. Specifically, the DeepONet-based model is constructed to map an arbitrary eddy-viscosity profile and corresponding mean velocity to stochastic forcing spectra based on the direct numerical simulation data at $Re_\tau =180$. Furthermore, the learned forcing model is integrated with the resolvent operator, which enables predicting the space–time flow statistics based on the eddy viscosity and mean velocity from the Reynolds-averaged Navier–Stokes (RANS) method. Our results show that the proposed forcing model can accurately predict the frequency spectra of velocity in channel flows at different characteristic scales. Moreover, the model remains robust across different RANS-provided eddy viscosities and generalises well to $Re_\tau =550$.

We introduce a natural boundary value problem for a triholomorphic map $u$ from a compact almost hyper-Hermitian manifold $M$ with smooth boundary $\partial M$ into a closed hyperKähler manifold $N$ with free boundary $u(\partial M)\subset \Gamma$ lying on some geometrically natural closed supporting submanifold $\Gamma\subset N$, called tri-isotropic submanifold. We establish partial regularity theory and energy quantization result in this boundary setting under some additional assumption on the $W^{2,1}$ norm of the weakly converging sequences.

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.

Appropriate soil water and nitrogen (N) management strategies are critical for achieving sustainable agricultural development in drylands. Straw mulching has been used to improve crop yield and water use efficiency (WUE), but N management strategies may need to be adjusted from conventional practice. The current study investigated the interactive effects of N application rate (conventional and high N rate), N application frequencies (single, and split N in 2 – 3 applications) and seasonal conditions on wheat population density dynamics, yield, harvest index (HI), grain protein content, water- and N-use efficiency, and residual soil N under straw mulching on the Loess Plateau of China. Nitrogen rate had no effect on yield, HI, WUE and grain protein content, but high N rate resulted in lower grain weight and nitrogen partial factor productivity (PFPN), and higher soil N residue. Splitting N applications significantly improved grain yield (7%), HI (9%), grain protein content (5%), PFPN and N harvest index, along with a reduction in soil N residue, compared to single application. However, there was no difference in above traits between split-N in 2 and 3 applications. Conventional N rate (vs. high N rate) and split N application (vs. single application) both alleviated the negative correlation between grain yield and grain protein content, and split N application increased grain N removal per unit yield compared to single N application. It is concluded that conventional N rate combined with split application in two doses, is suitable for straw mulching in drylands of the Loess Plateau, China.

Ice cliffs and supraglacial ponds are key drivers of mass loss on debris-covered glaciers. However, the relationship between melt ponds and adjacent ice cliffs has not been fully explored. We investigated the seasonal drainage patterns of a melt pond on the debris-covered Zhuxi Glacier in southeast Tibet and estimated the mass loss of its adjacent ice cliff during 2023–24. Using hourly time-lapse photogrammetry, we built a series of high-resolution point clouds to quantify the evolution of the ice cliff-pond system. Our findings indicate that subaerial melting and undercutting were the primary mechanisms of ice cliff mass loss during summer. In winter when the pond water level dropped, ice cliff calving became the dominant mode of ice loss. As the water level rose in spring, calving and subaerial melting occurred simultaneously and ice loss from calving accounted for approximately 19.5% of total ice loss from February to July 2024. Our results reveal the transitional state of this ice cliff-pond system, exhibiting characteristics of both melt hotspots and lake-terminating calving fronts, and highlight the interplay between seasonal drainage-refill pond and differing modes of ice loss on adjacent ice cliff. Future research should focus on additional high-resolution monitoring of similar systems and incorporation of ice cliff-pond dynamics in glacier-scale numerical models.

For a planar analytic Hamiltonian system, which has a period annulus limited by a nilpotent center and a homoclinic loop to a nilpotent singularity, we study its analytic perturbation to obtain the number of limit cycles bifurcated from the periodic orbits inside the period annulus. By characterizing the coefficients and their properties of the high-order terms in the expansion of the first-order Melnikov function near the loop, we provide a new way to find more limit cycles. Moreover, we apply these general results to concrete systems, for instance, an $(m+1)$th-order generalized Liénard system, and an mth-order near-Hamiltonian system with a hyperelliptic Hamiltonian of degree $6$.

In this paper, we study the existence of solutions to the following Hartree equation

\begin{align*}\begin{cases}-\Delta u+\lambda V(x) u+\mu u=\left(\int_{\mathbb{R}^N}\frac{|u|^p}{|x-y|^{N-\alpha}}\right)|u|^{p-2}u,\ \text{in}\ \mathbb{R}^N,\\\int_{\mathbb{R}^N}|u|^2=\omega,\end{cases}\end{align*}

Where $N\geq 3$, $\omega,\lambda \gt 0$, $p\in \left(\frac{N+\alpha}{N}, \frac{N+\alpha}{N-2}\right)\setminus\left\{\frac{N+\alpha+2}{N}\right\}$ and µ will appear as a Lagrange multiplier. We assume that $0\leq V\in L^{\infty}_{loc}(\mathbb{R}^N)$ has a bottom $int V^{-1}(0)$ composed of $\ell_0$ $(\ell_{0}\geq1)$ connected components $\{\Omega_i\}_{i=1}^{\ell_0}$, where $int V^{-1}(0)$ is the interior of the zero set $V^{-1}(0)=\{x\in\mathbb{R}^N| V(x)=0\}$ of V. It is worth pointing out that the penalization technique is no longer applicable to the local sublinear case $p\in \left(\frac{N+\alpha}{N},2\right)$. Therefore, we develop a new variational method in which the two deformation flows are established that reflect the properties of the potential. Moreover, we find a critical point without introducing a penalization term and give the existence result for $p\in \left(\frac{N+\alpha}{N}, \frac{N+\alpha}{N-2}\right)\setminus\left\{\frac{N+\alpha+2}{N}\right\}$. When ω is fixed and satisfies $\omega^{\frac{-(p-1)}{-Np+N+\alpha+2}}$ sufficiently small, we construct a $\ell$-bump $(1\leq\ell\leq \ell_{0})$ positive normalization solution, which concentrates at $\ell$ prescribed components $\{\Omega_i\}^{\ell}_{i=1}$ for large λ. We also consider the asymptotic profile of the solutions as $\lambda\rightarrow\infty$ and $\omega^{\frac{-(p-1)}{-Np+N+\alpha+2}}\rightarrow 0$.

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.

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.