Search Results (1,094)

Sitka spruce (Picea sitchensis (Bong.) Carr.) is among the most commercially important tree species in European and North American forestry, and genetic improvement programmes are therefore essential for promoting its productivity and sustainability. This research emphasises the significance of the breeding programmes. The primary objective of this study was to provide more reliable information on family selection for the improvement programme of Sitka spruce by accounting for competition and environmental heterogeneity effects. Analyses in the present study were carried out on historical inventory data of height (HT) and diameter at breast height (DBH) from a half-sib progeny trial of Sitka spruce in Ireland. Tree measurement data were collected at ages 6, 12, 15 and 20 years. A mixed linear model incorporating spatial and competition terms was applied to estimate genetic parameters of the Sitka spruce population. The direct genetic effects of each family on its own phenotypes and the competition effect on its neighbour’s phenotype were examined over time. The study demonstrated an analytical approach for assessing both genetic as well as environmental aspects of competition in a Sitka spruce progeny trial. The combined model integrating competition and spatial terms (model CS) improved model fit compared with the basic model, which only included the random effects of genetic and experimental design factors (model B), with an AIC difference of up to 3609 between them. Residual error obtained from model CS was usually smaller than from model B, with the greatest reduction of 85%. Furthermore, model CS generally improved the estimation of heritability for growth traits, by up to 241, when compared with model B. In addition, genetic differences in competitive ability among families were also observed. Families with favourable combinations of direct genetic and competitive breeding values were suggested for selection in subsequent cycles of the breeding programme, i.e., families with relatively high direct genetic breeding value but low and consistent competitive breeding value over time. This work develops a practical framework to inform future family selection for Sitka spruce improvement programmes. Full article

To study the wind load characteristics of the construction steel platform of the high-rise core tube, considering the influence of safety net permeability and core tube interference, a large eddy simulation was used for unsteady numerical simulation. The pressure jump method was used to model the safety net, and the entrance turbulence was generated through the synthesis turbulence method to obtain the wind field distribution, wind pressure coefficient, and shape coefficient of the construction steel platform. The results indicate that there is a sudden drop in internal wind pressure at the entrance of the construction steel platform, and there are strong shear vortices and vortex shedding downstream of the platform. At 0° wind direction, the net wind pressure coefficient reaches a maximum of 1.3 at the center of the windward side, and a maximum negative value of −1.2 appears at the corners; as the wind direction angle increases, the maximum wind pressure coefficient decreases from 6.4 to about 5.3. The body shape coefficients of the windward side under three different wind directions are 0.563, 0.378, and 0.153, respectively. This indicates that the ventilation of the safety net reduces the wind load on the construction steel platform, resulting in a result lower than the standard value, and the standard value is conservative. The results of this study can provide data support and engineering reference for wind resistant design and structural optimization of construction steel platform structures. Full article

In this paper, an adaptive-weight model predictive control (AW-MPC) strategy is proposed to address the trajectory tracking problem of a lower-limb rehabilitation exoskeleton robot. First, based on human motion analysis, the dynamics of the lower-limb rehabilitation exoskeleton are established, and the nonlinear dynamic model is transformed into a linear model. Second, a MPC objective function is formulated to minimize the tracking error, yielding the optimal control input. Then, on the basis of conventional MPC, a weight-tuning scheme is developed: a weighting function is constructed according to the evolution of the tracking error to adaptively adjust the MPC weighting coefficients, and the closed-loop stability of the control system is proven via a Lyapunov-based analysis. Finally, the proposed method is validated on a lower-limb rehabilitation exoskeleton experimental platform, with a PID controller designed as a baseline for comparison. The experimental results demonstrate that, compared with the PID controller, the proposed AW-MPC achieves faster convergence of the tracking error, higher tracking accuracy, and enhanced robustness. Full article

The puncture force during sewing is a critical factor affecting sewing quality. In this study, the puncture process is divided into five stages, a mechanical model of the puncture process is established, and a quantitative expression is achieved. Using the ANSYS Explicit Dynamics method, a finite element analysis model of the penetration process was developed to investigate the influence of fabric structure (thickness and warp and weft density) and needle geometric parameters (point height, taper angle, and shank diameter) on penetration force. The results indicate the following: Two distinct force peaks occur during needle penetration—one at the instant of fabric piercing and another when the needle shaft enters the fabric. Increasing fabric thickness causes the former peak to rise significantly, while the latter peak increases more gradually. Puncture force decreases significantly with reduced warp and weft density. When density decreased from 85 × 85 TPI to 80 × 80 TPI, the first peak decreased by 18.5% and the second peak by 67.4%. A further decrease in warp and weft density to 75 × 75 TPI resulted in peak reductions of 58.48% and 20.64%, respectively. Additionally, the needle tip cone angle and tip height are critical parameters affecting the peak penetration force. The comparative analysis of improved standard needle tip cone angles and tip heights demonstrates that the modified machine needles exhibit lower peak penetration forces, confirming the effectiveness of the needle improvement methods proposed in this study. The research methodology and results presented herein provide an effective numerical simulation-based approach for needle selection and penetration force evaluation in fabric piercing and sewing. Full article

Soil salinity severely constrains strawberry production by disrupting ion homeostasis and provoking oxidative injury. This study investigated whether soluble silicon (Si) and activated carbon (AC) act to enhance salt tolerance in strawberry (Fragaria × ananassa). Under NaCl stress, plants showed pronounced growth inhibition, increased Na⁺ accumulation and a deteriorated K⁺/Na⁺ balance, accompanied by elevated reactive oxygen species (ROS) and lipid peroxidation. In contrast, combined AC + Si treatment consistently provided the strongest protection, improving seedling vigor and survival. Relative to NaCl alone, AC + Si increased shoot and root fresh weight by 67.5% and 78.5%, reduced shoot Na⁺ by 59.1%, and lowered shoot H₂O₂ and MDA by 62.6% and 66.5%, respectively, indicating marked improvement in ion–redox homeostasis. Beyond plant responses, AC-containing treatments alleviated salt-induced increases in soil electrical conductivity, coinciding with a clear restructuring of the rhizosphere bacterial community and enrichment of putatively beneficial taxa. Transcriptome profiling further supported coordinated reprogramming of ion transport, redox control and stress-responsive signaling pathways under the AC + Si regime. Collectively, the results indicated that Si and AC co-application enhances strawberry salt tolerance through an integrated soil–plant–microbiome mechanism that stabilizes ion homeostasis and reinforces redox homeostasis. Full article

Heavy metal pollution poses a serious threat to water resource security and ecological health, due to its high toxicity, persistence, and bioaccumulation. Accordingly, it is crucial to develop efficient, low-cost, and environmentally friendly adsorption materials. Biomass-based materials, as a widely available, renewable, and low-cost natural organic resource, exhibit significant advantages for water pollutant adsorption and removal due to their unique porous structures and abundant active functional groups. This review systematically summarizes the classification strategies, fabrication methodologies, and adsorption performances of biomass-based materials for aqueous heavy metal ion removal. Key factors governing adsorption behavior, including solution pH, temperature, initial ion concentration, and adsorbent dosage, are critically analyzed to elucidate structure–property–performance correlations. Particular emphasis is placed on the underlying adsorption mechanisms, encompassing physical adsorption, surface complexation, ion exchange, electrostatic interactions, and synergistic interfacial effects. By integrating recent advances in material design and mechanistic understanding, this review provides a comprehensive framework bridging fundamental research and practical implementation, and highlights future opportunities for engineering next-generation sustainable biomass adsorbents toward efficient heavy metal ion decontamination. Full article

As a representative next-generation probiotic, Akkermansia muciniphila (A. muciniphila) produces a variety of functional proteins that play critical roles in the prevention and treatment of multiple diseases, including metabolic disorders, inflammatory diseases, neurological disorders, and cancer. This review summarizes the disease-associated proteins of A. muciniphila reported to date, including the outer membrane proteins Amuc_1100 and Amuc_1098, as well as the secreted proteins P9 (Amuc_1631), P5, Amuc_1409, Amuc_1434, and Amuc_2109. These proteins exert their biological effects by activating multiple signaling pathways, such as Toll-like receptor 2 (TLR2), ICAM-2, and Wnt/β-catenin, thereby regulating physiological processes including glucagon-like peptide-1 (GLP-1) secretion, serotonin biosynthesis, lipid metabolism, and intestinal stem cell proliferation. This review provides a theoretical foundation and future perspectives for in-depth research investigation and clinical application of A. muciniphila disease-related proteins. Full article

Although halide solid electrolytes (HSEs) demonstrate a higher voltage window and superior interfacial stability toward Li-rich layered oxides (LLOs) compared to sulfide systems, HSE-based all-solid-state lithium batteries (HSE-ASSLBs) still face a fundamental trade-off between achieving high capacity and maintaining cycling stability. To resolve this issue, a rational adjustment of the depth-of-discharge (DOD) via discharge cut-off voltage control is proposed. Analysis of dQ/dV profiles and post-cycled electrodes indicates that excessive DOD (lower cut-off voltages) aggravates structural degradation and interfacial side reactions, whereas insufficient DOD (higher cut-off voltage) fails to fully utilize the compensatory capacity from low-voltage redox couples. Notably, an optimized cut-off voltage of 2.6 V activates a stable low-voltage redox reaction centered around 2.85 V, which effectively offsets high-voltage capacity loss while suppressing unfavorable interfacial evolution. As a result, the ASSLB configured with a Li_1.2Ni_0.13Mn_0.54Co_0.13O₂ cathode and a Li_2.75In_0.75Zr_0.25Cl₆ HSE delivers an initial discharge capacity of 281.6 mAh g⁻¹ at 1C and achieves significantly improved capacity retention from 71.8% to 86.1% over 300 cycles. This study confirms that DOD regulation offers a simple and effective electrochemical protocol for enabling durable high-capacity output in LLO-based ASSLBs. Full article

Stellite alloys are widely used in the aerospace field owing to their excellent high-temperature strength and thermal fatigue resistance. However, with the rapid development of the aerospace industry, there is an urgent demand to further enhance the mechanical properties and thermal fatigue resistance of Stellite alloys. In the present study, we prepared a conventional CoCrW alloy (classified as a Stellite alloy) and a novel CoCrWAlNi alloy, which was formulated by introducing aluminum and nickel into the CoCrW matrix, using the direct laser deposition technique. Their microstructural characteristics, mechanical properties, and thermal fatigue performance were systematically investigated. The results indicated that the additions of aluminum and nickel contribute to stabilizing the γ-Co phase. Compared with the CoCrW alloy, the CoCrWAlNi alloy exhibited higher elongation at fracture. In situ observation was employed to study the initiation and propagation of thermal fatigue cracks. Meanwhile, the effects of oxidation on thermal fatigue resistance were analyzed through experimental tests and theoretical calculations based on the Huntz model. Finally, an optimized thermal fatigue mechanism tailored for cobalt-based alloys was established, which yields deeper insights into the failure mechanisms of these alloys under complex thermal-cycling fatigue conditions. Full article

With the increasing demand for earth observation and communication missions, semi-rigid airships have emerged as critical aerial platforms due to their long endurance and high payload capacity. However, high-precision dynamic modeling and robust autonomous flight control remain challenging because of large hull volume and strong aerodynamic nonlinearities. This study proposes an integrated framework combining computational fluid dynamics (CFD) aerodynamic modeling with full-envelope gain scheduling control. First, nonlinear aerodynamic characteristics over wide ranges of angles of attack and sideslip are identified via CFD simulation, and a six-degree-of-freedom (6-DOF) nonlinear dynamic model incorporating added-mass effects is established. Subsequently, a gain scheduling linear quadratic regulator (LQR) controller is then designed using airspeed, climb rate, and yaw rate as scheduling variables, enabling coordinated control allocation between low-speed thrust vectoring and high-speed aerodynamic surfaces. Simulation results demonstrate improved three-dimensional (3D) path following performance and smooth flight mode transitions. The mean absolute errors (MAEs) in altitude, airspeed, and heading are limited to 0.711 m, 0.028 m/s, and 2.377°, respectively. Furthermore, the system’s robustness is validated under composite wind disturbances, confirming effectiveness of the proposed approach across the full flight envelope. Full article

Coping serves as a protective function in students’ responses to school bullying. Previous studies have proposed several models to explain how victims cope with school bullying, but most of these frameworks were developed in Western contexts. Grounded in these frameworks, this qualitative study explores how victims cope with different developmental stages of school bullying within the Chinese cultural context. Using grounded theory and constant comparative analysis, we analyzed retrospective self-reports from 67 Chinese university students who described bullying experiences from elementary to high school. The analysis identified four key coping categories: emotional response, endurance and avoidance, cognitive reconstruction, and action-oriented resistance. Based on these coping strategies, we developed a Victims’ Coping Strategies Model structured along two axes: engagement–disengagement and a cognitive–emotional to cognitive–behavioral continuum. By capturing the complex interplay of internal and external strategies influenced by Chinese sociocultural norms, the model demonstrates the developmental and context-dependent nature beyond static classifications of coping strategies. The findings contribute to cultural and developmental understandings of victim responses and inform practical implications for intervention. Full article

The A* algorithm is widely used in path planning for Automated Guided Vehicles (AGVs), but the path it generates is prone to collision with random obstacles. To address this issue, this paper proposes a hybrid path planning algorithm integrating the improved A* algorithm with Dynamic Window Approach (DWA). Firstly, a global key point extraction strategy is adopted, and Bresenham’s line algorithm is used to eliminate redundant path points and turning inflection points, optimizing the conciseness and continuity of the path while redefining the child nodes of the current position. Secondly, in complex environments, the inflection points of the global path are taken as the target points of DWA to segment the path, and local dynamic planning is combined to achieve real-time obstacle avoidance. Simulation results show that compared with the traditional A* algorithm, the improved algorithm reduces the planning time by 24.19%, decreases the number of inflection points by 40.00%, and shortens the path length by 1.49%. In environments with random obstacles, the path generated by the hybrid algorithm is smoother, which can effectively enhance the local obstacle avoidance capability and improve the safety of path planning. Furthermore, physical experiments on an AGV platform with a distributed master-slave control architecture (STM32 microcontroller and Jetson embedded processor) verify the algorithm’s hardware compatibility and real-time computing performance, validating its engineering applicability in practical industrial scenarios. Full article

As a representative digital additive construction material, three-dimensional printed concrete (3DPC) imposes a synergistic rheological requirement on fresh cementitious mixtures, namely “pumpability–extrudability–buildability,” throughout the forming process. Rheological parameters and their temporal evolution not only govern the stability of the material during pumping, nozzle extrusion, and layer-by-layer deposition, but also directly determine interlayer interfacial integrity, geometric fidelity, and the development of macroscopic mechanical performance. This paper provides a systematic review of the regulation strategies and evolutionary characteristics of 3DPC rheology, with particular emphasis on how raw material composition, printing parameters, and multiscale evolution mechanisms influence yield stress, plastic viscosity, and thixotropic behavior. The time-dependent evolution of rheological properties is elucidated across multiple length scales, encompassing microscopic particle interactions and hydration-induced bridging, mesoscopic aggregate force-chain networks and particle migration, and macroscopic shear stimulation coupled with temperature–humidity effects. On this basis, it is further highlighted that existing models and characterization frameworks remain insufficient to capture the time-dependent structural evolution under realistic printing conditions. Therefore, the establishment of unified characterization standards, together with in situ rheological measurements and multiscale simulations, is urgently required to enable the coordinated optimization of material design and printing processes and to facilitate engineering-scale implementation. Full article

Disease resistance breeding is an important direction for the genetic improvement of Chinese cabbage. The traditional elite variety ‘Yutian Baojian’ Chinese cabbage is highly regarded for its tall cylindrical head with a pointed tip, tightly twisted wrapper leaves, and sweet taste. However, long-term cultivation has led to a significant decline in its resistance to clubroot caused by Plasmodiophora brassicae. To restore clubroot resistance while maintaining its desirable horticultural traits, this study used the clubroot-susceptible ‘Yutian Baojian’ as the recurrent parent and the resistant donor ‘Shaocai’, which carries the CRd resistance gene, to develop backcross populations. Using marker-assisted selection (MAS), plants were comprehensively screened based on foreground selection with markers tightly linked to the CRd gene, background selection with 73 genome-wide polymorphic markers, and phenotypic evaluation of horticultural traits, including plant height, plant spread, head shape, and soluble solids content. In the BC₁ population, three individuals showing high genetic similarity were selected. From the BC₂ population, four elite individuals were obtained, exhibiting 99.32% genetic similarity, stable clubroot resistance, and typical horticultural characteristics. Furthermore, three homozygous resistant inbred lines (BC₂S₂) with the ‘Yutian Baojian’ phenotype were developed. These results enrich the clubroot-resistant germplasm resources of Chinese cabbage and provide an effective MAS-based strategy for the precise improvement and germplasm innovation of local cultivars. Full article

Idesia polycarpa Maxim. is an important woody oilseed species and is dioecious; however, systematic evidence for sex-specific differences in leaf physico-chemical traits and their spectral responses remains limited. In this study, mature female and male trees were investigated. Leaves were sampled throughout the growing season (May–October), and FTIR-ATR spectra were acquired to derive peak height and peak area metrics for diagnostic bands. In parallel, leaf antioxidant enzyme activities (SOD, CAT, POD, and APX), biomass-related traits, leaf nutrient concentrations, and rhizosphere soil nutrient indices were measured. Differences between sexes, seasonal dynamics, and spectrum–trait coupling were evaluated using repeated-measures analysis and correlation analyses. The results showed that the positions of major absorption bands were largely consistent between sexes, indicating broadly similar chemical composition, whereas the male plants lacked an obvious band near 1671 cm⁻¹ in May. Several spectral peak parameters were significantly correlated with leaf pH, leaf dry matter content, total phosphorus, and APX activity. Female and male plants exhibited month-dependent differences in enzyme activities, dry matter content, and leaf N and K, and leaf–soil nutrient linkages were also detected, suggesting sex-specific resource allocation patterns. Overall, FTIR-ATR peak metrics provide a rapid means to characterize seasonal variation in leaf physico-chemical properties of I. polycarpa and offer supporting evidence for studies of sexual dimorphism. Full article