Gas turbine maintenance strategy relies heavily on accurate estimation of critical component life consumption of gas turbine engines during their operations. The equivalent operating hours (EOH) is a useful concept to measure the engine life consumption and support condition-based maintenance planning for gas turbine engines and their critical components. However, the current EOH calculation methods are mostly empirical and engine-specific, relying on vast operating data and experience. This paper introduces a novel physics-based method to estimate the EOH of the high-pressure turbine rotor blades of a gas turbine engine based on the damages caused by creep and low-cycle fatigue (creep-LCF) interactions. The method has been applied to a typical turbofan engine taking both 440-minute long-haul flight at one flight per day and 60-minute short-haul flight at two flights per day. A comparison of the predicted damages and life consumptions indicates that the creep EOH and also the creep damage of the engine of the short-haul aircraft is about 1.38 times that of the engine of the long-haul aircraft, the LCF equivalent operating cycles (EOC) and also the LCF damage of the engine of the short-haul aircraft is about 2.0 times that of the engine of the long-haul aircraft, and the total damages are more affected by the creep damage than the LCF damage with the creep damage being 6.78 times the LCF damage for the engine of the short-haul aircraft and 9.81 times for the engine of the long-haul aircraft. In addition, the total EOH or the total damage of the engine of the short-haul aircraft is about 1.44 times that of the engine of the long-haul aircraft. The proposed method shows a great potential to provide a quick estimate of the life consumption of gas turbine engines for condition monitoring, and it can be applied to other types of gas turbine engines.

This study presents a comprehensive analysis of the frequency response characteristics in a gas generator cycle liquid rocket engine, employing modular decomposition and linearised frequency-domain modeling to simulate dynamic behaviours under forced oscillations. The engine is dissected into key subsystems, including liquid pipelines, turbopump assembly, valves, flow regulation components, thrust chamber, gas generator and pyrotechnic starter, highlighting features such as centrifugal pump pressurisation, staged combustion and cavitation mitigation via venturis. Three oscillation scenarios are examined: supply system responses to thrust chamber pressure disturbances, combustion component responses to fluid disturbances and combustion component responses to pump speed disturbances. Simulations over 0–2000 Hz reveal acoustic-dominated traits in the thrust chamber with oxidiser pathway dominance, low-frequency emphasis in the gas generator driven by fuel disturbances, and heightened instability risks from pump pulsations. Parametric analyses demonstrate that increased pipeline lengths shift resonant frequencies downward, elevated injector pressure drops enhance stability margins by 1.6% with a 20% pressure drop increase, and chamber structural/gas parameter variations erode system stability. These insights, validated against benchmark models, inform strategies for mitigating combustion instability, optimising design parameters, and improving reliability in high-thrust propulsion applications.

Shanlan upland rice, as a unique local rice germplasm resource in Hainan comprises abundant genetic diversity. One hundred and sixty two Shanlan upland rice accessions collected from diverse ecological regions in Hainan were systematically characterized based on 11 agronomic traits. The rich genetic diversity was confirmed by phenotypic data from two consecutive years (2023 and 2024). Coefficient of variation ranged from 14.11% to 46.04% in 2023 and from 11.45% to 44.82% in 2024, with panicle-related traits (number of primary branches, grain number of primary branches, number of secondary branches, grain number of secondary branches and grain number per main panicle) exhibiting particularly high variation. Correlation analysis revealed highly significant synergistic effects among yield-related traits. Cluster analysis of the 162 accessions consistently classified them into five major groups across both growing seasons. Through grain number per main panicle and seed setting rate investigation, three excellent resources were selected that demonstrated stable and superior performance in both seasons. Notably, Line 69 exhibited outstanding “large panicles with high seed-setting rate,” producing 261.4 and 305 grains per main panicle in 2023 and 2024, respectively, with seed-setting rates reaching 93.79% and 90.07%. This study presents phenotypic data for Shanlan upland rice, offers high-quality breeding materials for subsequent research, and lays a theoretical groundwork for conserving and exploiting Hainan’s rice resources.

The digital transformation of Chinese companies offers a new frontier for organizational research. Widespread use of workplace platforms creates rich archives of unobtrusive data, providing continuous, real-time insights into organizational life that traditional surveys cannot capture. The central challenge for scholars is turning this data abundance into meaningful theory. This special issue highlights three studies that meet this challenge by using innovative methods to convert granular data into valuable knowledge. The papers employ digital-context experiments, real-time behavioral tracking, and machine-learning-assisted theory building to study phenomena from interpersonal dynamics to crisis productivity. Looking ahead, we explore the potential of unstructured multimodal data and new AI tools to make complex analysis more accessible. We conclude with a research agenda calling for methodological rigor, interdisciplinary collaboration, and a firm balance between technological innovation and theoretical depth.

Recent research on zoonotic diseases has increasingly focused on tick-borne illnesses due to their high prevalence in northwestern China. This study aimed to determine the prevalence of tick-borne pathogens in yaks (Bos grunniens) within Qinghai Province. A total of 299 blood samples were collected from yaks in Xining City of Qinghai Province and analysed using polymerase chain reaction. Results indicated the absence of several significant zoonotic pathogens, including Borrelia burgdorferi sensu lato, Anaplasma spp. and Coxiella burnetii. However, rickettsiae were detected in the sampled yaks. The overall prevalence of spotted fever group rickettsiae was 46·5%, with a significant difference between females (68·3%) and males (9·09%). Age was also identified as a significant factor influencing infection rates. Furthermore, sequencing analysis revealed that the obtained rickettsial sequences shared 99·04–100% nucleotide identity with Rickettsia raoultii, a species endemic to Qinghai, China. Phylogenetic analysis based on the ompA and gltA genes confirmed that these sequences clustered within the R. raoultii clade. This study demonstrates a high prevalence of R. raoultii infection in yaks from Qinghai. Consequently, the implementation of preventive and therapeutic measures for yaks is recommended to mitigate the risk of transmission. This study did not collect tick samples simultaneously, so the transmission vector cannot be identified. Additionally, uneven sample distribution across some age groups may affect the representativeness of the results.

Butachlor is a herbicide extensively employed in rice (Oryza sativa L.) cultivation but historically under-investigated for its toxicological impacts on terrestrial vegetation. This study examines the dose-dependent effects of butachlor on the germination and antioxidant defense mechanisms in the seeds of Asian tape grass [Vallisneria natans (Lour.) H. Hara], an important submerged plant species widely distributed in the agricultural ponds. In a hydroponic setup, seeds were exposed to four concentrations of butachlor (0, 20, 200, and 2,000 μg ai L−1), and cultivated under controlled light conditions to quantify germination rates and assess oxidative stress responses. Our findings showed that butachlor concentrations up to 20 μg L−1 had no effect on the germination rate of V. natans seeds, while germination rates decreased by 6.0% and 8.7% at 200 and 2,000 μg L−1, respectively. At 2,000 μg L−1, malondialdehyde (MDA) content increased by 5.7 nmol g−1 FW, and catalase (CAT) activity declined by 21%, indicating oxidative damage. Additionally, the antioxidants proline (Pro) and glutathione (GSH) were upregulated under 20 μg L−1 butachlor treatment after 12 h, contributing to reactive oxygen species (ROS) scavenging and cellular stability. This study highlights the nuanced interactions between butachlor exposure and the antioxidant defenses in V. natans, providing valuable insights into the ecological impacts of herbicide pollution. Understanding these interactions is crucial for development of sustainable agricultural practices and management of herbicide resistance in aquatic systems.

Excellent products often contain profound cultural connotations. To improve the quality of cultural products, it is important to study how typical cultural carriers can be more promptly and efficiently identified and incorporated into products through a detailed and easy-to-use design process. In this article, we propose an approach from three different levels to assist designers in incorporating cultural features into products, including: (1) the integrated framework of the composition and division of cultural carriers, (2) the extraction and translation model from cultural carriers, cultural elements to cultural features and (3) the cultural product design process. The proposed approach was applied in a large and complex cultural product case, that is, inter-city train design. The evaluation of the recognition of culture features indicated that the approach contributed to conferring culture on products through thoughtful design and could ensure that the product schemes reflect cultural features as well as interesting cultural connotations.

In this paper, a wideband reconfigurable reflectarray antenna (RRA) using 1-bit resolution for beam scanning with two-dimensional (2D) capability is presented at Ku-band. A 1-bit RRA element with a rectangular patch embedded with slots is proposed for broadband operation. Each element is equipped with a single PIN diode, allowing for resonance tuning while ensuring low cost and minimal power consumption. According to the simulation results, the proposed element is capable of 1-bit phase resolution with a phase difference of ${180^\circ \pm 20^\circ}$ stability from 11.27 to 13.74 GHz, which corresponds to an approximate bandwidth of 19.75%. To demonstrate its capabilities, we developed, fabricated, and tested a wideband electronically RRA with ${14 \times 14}$ elements. The experimental results demonstrate that the realized maximum gain in the broadside direction is 21.1 dB with a peak aperture efficiency of 20.9%. 2D beam scanning within ${\pm50^\circ}$ angular range are obtained and the scan gain reduction is 1.88 dB for ${-50^\circ}$ scanned beam in E-plane while 2.21 dB for ${50^\circ}$ scanned beam in H-plane. The 1-dB gain bandwidth of the RRA is 15.1%.

Flapping-wing robots, inspired by natural flyers, have gained significant attention for surveillance and environmental monitoring applications. This study presents the design and analysis of a bat-inspired flapping-wing robot with foldable wings, aiming to enhance flight efficiency and maneuverability. The robot features silicone-based, stretchable membrane wings, with a wingspan of 1.4 m and a total mass of 620 g. A one-degree-of-freedom (DOF) revolute-spherical-spherical-revolute mechanism is used to reproduce the flapping motion, while a one-DOF Watt six-bar linkage mechanism enables dynamic wing folding, allowing adaptive wing shape modulation during flight. Explicit solutions for joint angle of the wing were expressed through analytical method. Flight tests were conducted to validate the effectiveness of the flapping-folding mechanism. Results show that the robot successfully replicates bat wing kinematics, with folding during the upstroke and unfolding during the downstroke. This research offers insights into bio-inspired wing designs for next-generation flapping-wing robots.

Aiming at the issues of more difficult to solve and lower precision of six-axis robotic arm in inverse kinematics (IK) solution, a multi-strategy improved dung beetle optimization algorithm (ECDBO) is proposed. It improves performance in four aspects: population initiation, global search capability, search direction perturbation and jumping out of local optima. Sobol sequence strategy was introduced to initialize the dung beetle population, resulting in a more even distribution of individual dung beetles and increasing the diversity of initial population. Boundary optimization strategy is adopted to balance the requirements on search capability at different times. This approach enhances global search capability at the beginning and local search capability at the end of an iteration. Propose hybrid directional perturbation strategy to change the search direction of rolling dung beetles and stealing dung beetles. It allows for more detailed exploration and improves convergence accuracy. The Levy flight strategy is incorporated to perturb current optimal solution, enhancing algorithm’s ability to jump out of the local optimum. In order to verify performance of ECDBO algorithm, CEC2017 function tests and robotic arm IK solving experiments were conducted and compared with other algorithms. ECDBO ranked first on 21 functions in the 30 dimensions tested in CEC2017 and on 27 functions in the 100 dimensions. ECDBO performs well in the IK solving experiments of two robotic arms with better accuracy than other algorithms. The experimental results show that the ECDBO algorithm significantly improves the convergence and accuracy, and also performs excellently on the IK solving problem.

High-concentrate diets are commonly used to enhance lamb growth performance; however, their long-term impacts on metabolic health, particularly fat deposition and liver function, remain a challenge. This study utilized an integrative multi-omics approach to explore the role of keystone rumen microbiota in modulating the rumen-liver-tail adipose axis under high-concentrate diets. Keystone rumen bacterial taxa, including Ruminococcus_gauvreauii, Syntrophococcus, Solobacterium, Bifidobacterium, and Ruminococcaceae_UCG-010, were identified as critical mediators linking dietary changes to tail fat deposition. Liver transcriptomic analysis revealed disrupted folate biosynthesis, regulated by key members of the AKR1C3 family (AKR1C23, AKR1C1, and PGFS), which played a pivotal role in glucose and fatty acid metabolism through the action of tetrahydrobiopterin. In tail adipose tissue, pathways associated with vitamin B6 metabolism and fatty acid elongation were significantly enriched, with pyridoxal 5’-phosphate and elongation-related genes (ELOVL3, HSD17B12, and FADS2) contributing to lipid biosynthesis and deposition. These findings establish a mechanistic framework for the rumen-liver-tail adipose axis, highlighting the influence of keystone rumen microbiota on host metabolism. This study offers novel insights into dietary interventions and microbial strategies to improve ruminant healthy production efficiency and meat quality.

Plant-based diets may improve mental health among older adults by alleviating depression and improving life satisfaction. This study aimed to explore the associations between plant-based dietary pattern trajectories (PDPT), depression and life satisfaction in Chinese older adults. Data of participants from the 2008–2018 Chinese Longitudinal Healthy Longevity Survey were analysed. We utilised group-based trajectory modelling to identify the PDPT. Logistic and linear regression models were used to analyse the associations between PDPT, depression and life satisfaction. In total, 1835 participants were divided into three groups based on plant-based dietary index (PDI), healthy plant-based dietary index (HPDI) or unhealthy plant-based dietary index (UPDI) trajectories, respectively, and the PDPT were maintained at stable levels. PDI trajectory was not significantly associated with depression or life satisfaction. HPDI trajectory had no significant association with depression. However, compared with low HPDI trajectory, participants in the high (β = 0·185, 95 % CI: 0·032, 0·337) HPDI trajectories had higher life satisfaction. Compared with the low UPDI trajectory, participants in the high UPDI trajectory groups were associated with a higher risk of depression (OR = 1·793, 95 % CI: 1·124, 2·861). Further, the medium (β = −0·145, 95 % CI: −0·273, −0·018) and high (β = −0·335, 95 % CI: −0·478, −0·191) UPDI trajectory were associated with poor life satisfaction. Dietary interventions should be prioritised to address the persistent unhealthy dietary habits among Chinese older adults, with particular emphasis on reducing UPDI to enhance mental health by promoting intake of healthy plant-based and animal-based foods while avoiding unhealthy plant-based foods.

Cyber breaches pose a significant threat to both enterprises and society. Analyzing cyber breach data is essential for improving cyber risk management and developing effective cyber insurance policies. However, modeling cyber risk is challenging due to its inherent characteristics, including sparsity, heterogeneity, heavy tails, and dependence. This work introduces a cluster-based dependence model that captures both temporal and cross-group dependencies, providing a more accurate representation of multivariate cyber breach risks. The proposed framework employs a cluster-based kernel approach to model breach severity, effectively handling heterogeneity and extreme values, while a copula-based method is used to capture multivariate dependence. Our findings, validated through both empirical and synthetic studies, demonstrate that the proposed model effectively captures the statistical characteristics of multivariate cyber breach risks and outperforms commonly used models in predictive accuracy. Furthermore, we show that our approach can enhance cyber insurance pricing by generating more profitable insurance contracts.