Search Results (2,489)

To enhance the waterproofing performance of segment bolt holes in shield tunnels and ensure they meet the synergistic waterproofing requirements of segment joint sealing systems, a novel sealing gasket installed at the joint interface of the segment bolt hole has been designed. Numerical analysis was employed for a parametric study of factors influencing the waterproofing performance of the new gasket. Additionally, experimental research was conducted to evaluate its waterproofing capabilities. The study’s findings indicate that the hardness, height, and width of the novel bolt hole waterproof gasket significantly influence both the closure compression force and waterproofing performance. In contrast, the inner diameter primarily affects the closure compression force with a minimal impact on waterproofing performance. Compared to traditional water-swellable gaskets used for segment bolt holes, the novel EPDM (Ethylene Propylene Diene Monomer) waterproof gasket is more effective in mitigating the effects of manufacturing defects. For double-gasket segment joint sealing systems where the waterproofing strength of the bolt hole is critical, the adoption of this novel bolt hole waterproof gasket can better satisfy the synergistic waterproofing requirements between the two sealing gaskets, thereby effectively improving the overall waterproofing capacity of the segment joint sealing system. Full article

Peanut (Arachis hypogaea L.) is an important oil and cash crop, but its growth and productivity are severely constrained by low-temperature stress. Growth-regulating factors (GRFs) are plant-specific transcription factors involved in development and stress responses, yet their roles in peanut remain poorly understood. In this study, we identified AhGRF3b as a direct target of ahy-miR396 using degradome sequencing, which demonstrated precise miRNA-mediated cleavage sites within the AhGRF3b transcript. Expression profiling confirmed that ahy-miR396 suppresses AhGRF3b via post-transcriptional cleavage rather than translational repression. Functional analyses showed that overexpression of AhGRF3b in Arabidopsis thaliana promoted leaf expansion by enhancing cell proliferation. Specifically, leaf length, width, and petiole length increased by 104%, 22%, and 28%, respectively (p < 0.05). Under cold stress (0 °C for 7 days), transgenic lines (OE-2 and OE-6) exhibited significantly better growth than Col-0, with fresh weight increased by 158% and 146%, respectively (p < 0.05). Effect size analysis further confirmed these differences (Cohen’s d = 11.6 for OE-2 vs. Col-0; d = 6.3 for OE-6 vs. Col-0). Protein–protein interaction assays, performed using the yeast two-hybrid (Y2H) system and 3D protein–protein docking models, further supported that AhGRF3b interacts with Catalase 1 (AhCAT1), vacuolar cation/proton exchanger 3 (AhCAX3), probable polyamine oxidase 4 (AhPAO4), and ACT domain-containing protein 11 (AhACR11), which are involved in reactive oxygen species (ROS) scavenging and ion homeostasis. These interactions were associated with enhanced CAT and PAO enzymatic activities, reduced ROS accumulation, and upregulation of stress-related genes under cold stress. These findings suggest that the ahy-miR396/AhGRF3b module plays a potential regulatory role in leaf morphogenesis and cold tolerance, providing valuable genetic resources for breeding cold-tolerant peanut varieties. Full article

China is a global hotspot for amphibian biodiversity, yet under-explored montane regions harbor undiscovered cryptic species. Using integrative taxonomy, we describe a new salamandrid species, Pachytriton cheni sp. nov., from Qingliangfeng Nature Reserve, Anhui. Phylogenetic analyses of mitochondrial (ND2, cytb) and nuclear (RAG1, POMC) genes strongly support it as a monophyletic sister lineage to P. granulosus, with significant mitochondrial p-distances (4.39–10.22%) and unique nuclear haplotypes. Bayes factor species delimitation under the multispecies coalescent model (MSC) decisively rejects conspecificity with P. granulosus (2lnBF = 24.52). Morphologically, it is diagnosed by its small size; oval, narrow head (length > width); nearly black dorsum lacking bright orange spots; smooth skin; occipital V-shaped ridge; orange-red abdomen with brown markings; prominent neck folds; and minimal digit gap when limbs are adpressed. This discovery increases Pachytriton species to ten, highlights high-elevation montane ecosystems as key biodiversity refuges in East China, and underscores the need for further surveys to clarify the genus’s phylogeny. Full article

In the shale oil reservoirs, sandstone and shale often overlie each other. This significantly affects the vertical propagation of hydraulic fractures (HFs); however, the underlying mechanisms still remain unclear. This study employs Xsite software to investigate the influence of rock fracture toughness, tensile strength, elastic modulus, Poisson’s ratio, interlayer stress contrast, and the flow rate and viscosity of fracturing fluid on the propagation behaviour of HFs in sandstone–shale interbeds. As the type-I fracture toughness of the shale layer increases, the area of the vertical HF decreases and the average HF width becomes smaller. As the tensile strength of the sandstone layer increases, the distribution range of fluid pressure at the interface expands. The HF prefers to propagate in the softer rock rather than the harder one. A relatively narrower HF width is created in the layer with a higher elastic modulus resulting in a higher flow resistance to fracturing fluid. A shale layer with a high Poisson’s ratio is more likely to undergo a lateral expansion, causing stress at the fracture tip to be dispersed. When the effect of lithological interfaces is considered, an increasing interlayer stress contrast causes HFs to gradually transition from penetrating the interfaces to becoming confined between the two interfaces. When the influence of the lithological interface is not considered, an increasing interlayer stress contrast causes the HF to gradually transition from a penny-shaped fracture to a blade-shaped fracture. The HF penetrates the interfaces more easily at a higher injection rate and fluid viscosity, because most of the injected energy is used to create new fractures rather than leakoff into the interfaces. Understanding the influence of these factors on the HF propagation behaviour is of great significance for optimising hydraulic fracturing design. Full article

Solar-energy-driven membrane distillation provides a sustainable pathway to mitigate freshwater scarcity by utilizing an abundant renewable heat source. This study develops a two-dimensional axisymmetric computational fluid dynamics (CFD) model to simulate the transient performance of a hollow fiber water gap membrane distillation (HF-WGMD) module integrated with flat-plate solar collectors (FPCs). A lumped-parameter transient FPC model is coupled with the CFD framework to predict feed water temperature under time-varying solar irradiation, evaluated across four representative days in a Mediterranean city. The model is validated against experimental data, showing strong agreement. A comprehensive parametric analysis reveals that increasing the collector area from 10 to 50 m² enhances the average water flux by a factor of 6.4, reaching 10.9 kg/(m²h), while other parameters such as collector width, tube number and working fluid flow rate exert comparatively minor effects. The module flux strongly correlates with solar intensity, achieving a maximum instantaneous value of 18.4 kg/(m²h) with 35 m² collectors. Multistage HF-WGMD configurations are further investigated, demonstrating substantial reductions in solar energy demand due to internal thermal recovery by the cooling stream. A 40-stage system operating with only 10 m² of solar collectors achieves an average specific thermal energy consumption of 424 kWh/m³, while the overall solar desalination efficiency improves dramatically from 2.6% for a single-stage system with 50 m² collectors to 57.5% for the multistage configuration. The proposed system achieves a maximum freshwater productivity of 51.5 kg/day, highlighting the viability and optimization potential of solar-driven HF-WGMD desalination. Full article

The metal–dielectric hybrid tetramer metasurface has received a lot of attention in the field of optical sensing owing to the excellent refractive index sensing performance. However, achieving simultaneous high-quality Q-factor, polarization insensitivity, multi-band tunability across visible to near-infrared spectra, and ultra-narrow linewidth is an urgent problem to be solved. To overcome this challenge, we proposed a metal–dielectric yurt tetramer metasurface. The finite-difference time-domain method was used to simulate the sensing properties. We explored the physical mechanism of different resonance modes, optimized the structure parameters of the metasurface, and investigated the influence of incident light and environmental parameters on the sensing properties. The results show that the proposed structure not only possesses a high Q-factor but also exhibits excellent wavelength tunability in the visible to near-infrared band and has polarization insensitivity. By skillfully introducing the structural size perturbation, the surface plasmon resonance mode and two Fano resonance modes are successfully excited at the wavelengths of 737.43 nm, 808.99 nm, and 939.50 nm. The light–matter interaction at the Fano resonance frequencies is highly enhanced so that a maximum refractive index sensitivity, figures of merit (FOM), and Q-factor of 500.94 nm/RIU, 491.12 RIU⁻¹, and 793.13 are obtained. The narrowest full width at half maximum (FWHM) is 1.02 nm, respectively. This work provides a theoretical basis for the realization of a high-performance metasurface refractive index sensor. Full article

Peppermint (Mentha spp.) produces bioactive metabolites under stress. Light spectrum and methyl jasmonate (MeJA) are important factors influencing growth, physiology, and antioxidant defense. In this study, peppermint was cultivated under different light spectra and foliar MeJA concentrations in a controlled environment. Plants exposed to a balanced RGB (1:1:1) spectrum showed the greatest morphological development, with plant height (35.99 cm), canopy width (21.24 cm), and chlorophyll content (29.64 SPAD) significantly higher than those in other treatments. Foliar application of MeJA produced concentration-dependent effects: 2.0 mM increased photosynthetic rate to 6.49 µmol m⁻² s⁻¹ compared with 4.52 µmol m⁻² s⁻¹ in the control, 2.5 mM resulted in the highest fresh and dry biomass (24.82 g/plant and 2.42 g/plant, respectively), and 1.5 mM yielded the highest total phenolics (20.22 mg GAE/g DW) and antioxidant activity (60.97%). These findings demonstrate that peppermint responses to MeJA are strongly dose dependent and that light quality modulates growth by reducing stress compared with monochromatic spectra. Overall, the results suggest that integrating balanced light spectra with optimized MeJA concentrations can improve both biomass and secondary metabolite accumulation, supporting peppermint production under controlled conditions. Full article

Functioning as a critical ecotone between terrestrial and aquatic ecosystems, riparian zones exhibit soil enzyme activities that serve as key biomarkers of their nutrient cycling processes. However, despite considerable focus on riparian soil properties, the dynamics and underlying drivers of these enzymatic activities are not yet fully characterized. To this end, soils were systematically sampled across varying widths and depths from three representative riparian zones to quantify the driving forces of physicochemical properties on enzyme activity dynamics. The results showed that the soil enzyme activity was highest in the forest riparian zone and lowest in the farmland riparian zone, with average enzyme activities of 37.95 (μmol·g⁻¹·h⁻¹) and 26.85 (μmol·g⁻¹·h⁻¹), respectively. The width of the riparian zone changes the spatial distribution of soil enzyme activity. The soil enzyme activity is higher in the land edge area far from the river (profile-1) and lower in the water edge area near the river (profile-4), with average enzyme activities of 47.4384 (μmol·g⁻¹·h⁻¹) and 17.0017 (μmol·g⁻¹·h⁻¹), respectively. Moreover, soil water content (SWC) has a strong impact on enzyme activity changes. The increase in soil depth reduces soil enzyme activity, with enzyme activity in the 0–20 cm soil layer being 1.5 times higher than in the 20–50 cm soil layer. Meanwhile, the primary factors influencing changes in soil enzyme activity have gradually shifted from total nitrogen (TN), nitrate nitrogen (NO₃-N), and soil organic carbon (SOC) to the sole control of SOC. Research has shown that human influence strongly interferes with soil enzyme activity in riparian zones. The width of the riparian zone and soil depth serve as key drivers of the spatial distribution of soil enzyme activity by modulating soil environmental factors. The patterns revealed in this study indicate that maintaining appropriate riparian zone width and reducing anthropogenic disturbances can enhance nutrient cycling dynamics at the micro-scale by increasing soil enzyme activity. This process is crucial for strengthening the riparian zone’s macro-level ecosystem services, particularly by effectively enhancing its capacity to sequester and transform nutrients like nitrogen and phosphorus from agricultural nonpoint sources, thereby safeguarding downstream water quality. Consequently, soil enzyme activity serves as a key indicator, providing essential scientific basis for assessing riparian health and guiding ecological restoration efforts. Full article

In this paper, we study the line-shape (LS), which indicates the amount of absorbed energy, and the line-width (LW), which indicates the scattering factor, according to the vibrational direction of the externally applied energy in the electron–phonon potential interaction system of representative semiconductor bonding types, group II–VI (ZnO) and group III–V (GaN) bonded compound semiconductors and pure group IV (Si) bonded semiconductors. One of the two systems receives the externally applied energy of right-handed circular polarization vibration, and the other receives the externally applied energy of left-handed circular polarization vibration. To analyze the quantum transport, we first employ quantum transport theory (QTR) for an electron system confined within a square-well potential, where the projected Liouville equation is addressed using the balanced-average projection method. In analyzing quantum transitions, phonon emission is linked to the transition line-width (LW), whereas phonon absorption is evaluated through the transition line-shape (LS), highlighting its sensitivity to temperature and magnetic field variations. As a result of analyzing the line-width (LW), which is a quantum scattering coefficient, and the line-shape (LS), which represents the absorbed power, the absorbed power and scattering coefficient were higher for the left circularly polarized vibration under the influence of the external magnetic field. In contrast, the right polarization produced smaller values. In addition, the scattering coefficient (LW) and the absorbed power according to the bonding type of the semiconductor were the largest in Si, a group IV bonded semiconductor, followed by group III–V (GaN) and group II–VI (ZnO) bonded semiconductors. Full article

Due to the presence of stray current in the subway environment, the durability issues of subway structures differ from those of general structures. This study simulates the combined effects of chloride ions and stray current in the subway environment through electrochemical corrosion experiments, thereby analyzing the corrosion morphology and mechanical property degradation of steel strands and the corrosion-induced cracking of concrete. The experimental results indicate that stray current affects the strength and ductility of steel strands as well as the cracking of concrete. The corrosion difference coefficient μ_c at different positions is greater than 1.6 and the average corrosion degree η_ave is less than 7%. The corrosion morphology gradually changes from non-uniform to uniform corrosion until the η_ave is greater than 12%. The concrete crack width under a stray current of 60 mA is 10.67 times that of cracks under 20 mA after 42 days, which is approximately linearly related to the current intensity. Based on the experimental results, a corrosion-induced crack prediction model for prestressed concrete under stray current is proposed, with the main influencing factors being current intensity, concrete tensile strength, and protective layer thickness. These findings can provide valuable references for the durability analysis of subway structures. Full article

To solve the problems of large root damage and incomplete seedling blocks (SBs) in rice machine transplanting, this study numerically optimized the root blanket-cutting device for rice blanket seedling cutting and throwing transplanters based on the discrete element method (DEM) and multi-body dynamics (MBD) coupling method. A longitudinal sliding cutter (LSC)–substrate–root interaction model was established. Based on the simulation tests of Center Composite Design and response surface analysis, the sliding angle and cutter shaft speed of the LSCs arranged at the circumferential angles (CAs) of 0°, 30°, and 60° were optimized. The simulation results indicated that the LSC arrangement CA significantly affected the cutting performance, with the optimal configuration achieved at a CA of 60°. Under the optimal parameters (sliding angle of 57°, cutter shaft speed of 65.3 r/min), the average deviation between the simulated and physical tests was less than 11%, and the reliability of the parameters was verified. A seedling needle–substrate–root interaction model was established. The Box–Behnken Design method was applied to conduct simulation tests and response surface optimization, focusing on the picking angle, needle width, and rotary gearbox speed. The simulation results showed that the picking angle was the key influencing factor. Under the optimal parameters (picking angle of 20°, seedling needle width of 15 mm, rotary gearbox speed of 209 r/min), the average deviation between the simulated and physical tests was less than 10%, which met the design requirements. This study provides a new solution for reducing root injury, improving SB integrity, and reducing energy consumption in rice transplanting, and provides theoretical and technical references for optimizing transplanting machinery structure and selecting working parameters. Full article

Conventional ridging and mulching machines struggle to perform effectively in yellow sand substrates due to their loose texture, high collapsibility, and strong fluidity, which compromise ridge stability and operational quality. To address these challenges, this study proposes the development of an integrated rotary tillage, ridging, and film-mulching machine specifically designed to meet the agronomic requirements of tomato cultivation in greenhouse environments with yellow sand substrate. Based on theoretical analysis and parameter calculations, a soil transportation model was established, and the key structural parameters—such as blade arrangement and helical shaft geometry—were determined. A discrete element method (DEM) simulation was employed to construct a contact model for the yellow sand–slag mixed substrate. A combination of single-factor experiments and Box–Behnken response surface methodology was used to investigate the effects of forward speed, shaft rotational speed, and tillage depth on ridge stability and operational performance. The simulation results indicated that a forward speed of 0.82 m·s⁻¹, shaft speed of 260 rpm, and tillage depth of 150 mm yielded the highest ridge stability, with an average of 95.7%. Field trials demonstrated that the ridge top width, base width, height, and spacing were 598.6 mm, 802.3 mm, 202.4 mm, and 1002.8 mm, respectively, with an average ridge stability of 94.3%, differing by only 1.4 percentage points from the simulated results. However, a quantitative traction/energy comparison with conventional equipment was not collected in this study, and we report this as a limitation. The energy consumption is estimated based on power usage and effective field capacity (EFC) under similar operating conditions. Soil firmness reached 152.1 kPa, fully satisfying the agronomic requirements for tomato cultivation. The proposed machine significantly improves operational adaptability and ridge stability in yellow sand substrate conditions, providing robust equipment support for efficient greenhouse farming. Full article

The objective of this study was to propose a correlation model of the damage class and deformation of reinforced concrete (RC) beams damaged by earthquakes with a focus on columns and walls. For this purpose, a series of full-scale RC beam specimens with different shear strength margins were tested under cyclic lateral loading to examine their deformation performance and damage states. Then, the damage class and seismic capacity reduction factor of RC beams were evaluated based on the test results. The results showed that the tendency of shear failure, such as shear crack pattern and shear deformation component, of specimens with small shear strength margins was more remarkable, and its maximum residual crack widths tended to be slightly larger and dominated by shear cracks. The results also indicated that the effect of the shear strength margin on the seismic capacity reduction factor which represents the residual seismic performance of RC beams was limited, whereas the specimen with a smaller shear strength margin exhibited lower ultimate deformation capacity. In addition, there was a difference in the boundary value of the lateral drift angle which classifies the damage class of specimens with different shear strength margins. Finally, correlation models between the damage class and deformation of RC beams with different deformation capacities were proposed. Full article

Quasi-two-dimensional (Q2D) perovskite films have garnered significant attention as novel gain media for lasers due to their tunable bandgap, narrow linewidth, and solution processability. Q2D perovskites endowed with intrinsic quantum well structures demonstrate remarkable potential as gain media for cost-effective miniaturized lasers, owing to their superior ambient stability and enhanced photon confinement capabilities. However, the mixed-phase distribution within Q2D films constitutes a critical determinant of their optical properties, exhibiting pronounced sensitivity to specific fabrication protocols and processing parameters, including annealing temperature, duration, antisolvent volume, injection timing, and dosing rate. These factors frequently lead to broad phase distribution in Q2D perovskite films, thereby inducing incomplete exciton energy transfer and multiple emission peaks, while simultaneously making the fabrication processes intricate and reducing reproducibility. Here, we report a novel annealing-free and antisolvent-free method for the preparation of Q2D perovskite films fabricated in ambient atmosphere. By constructing a tailored mixed-solvent vapor atmosphere and systematically investigating its regulatory effects on the nucleation and growth processes of film via in situ photoluminescence spectra, we successfully achieved the fabrication of Q2D perovskite films with large n narrow phase distribution characteristics. Due to the reduced content of small n domains, the incomplete energy transfer from small n to large n phases and the carriers’ accumulation in small n can be greatly suppressed, thereby suppressing the trap-assistant nonradiative recombination and Auger recombination. Ultimately, the Q2D perovskite film showed a single emission peak at 519 nm with the narrow full width at half maximum (FWHM) of 21.5 nm and high photoluminescence quantum yield (PLQY) of 83%. And based on the optimized Q2D film, we achieved an amplified spontaneous emission (ASE) with a low threshold of 29 μJ·cm⁻², which was approximately 60% lower than the 69 μJ·cm⁻² of the control film. Full article

Additive manufacturing has promising potential for the development of 3D-printed protective structures such as stab-resistant body armor. However, no research to date has examined the impact of 3D printing parameters on the protective performance of such 3D-printed structures manufactured using fused filament fabrication technology. This study, therefore, investigates the effects of five key printing parameters: layer thickness, print speed, print temperature, infill density (Id), and layer width, on the mechanical and protective performance of 3D-printed polycarbonate (PC) armor. A Taguchi L₂₇ matrix was employed to systematically analyze these parameters, with toughness, stab penetration depth, and armor panel weight as the primary responses. ANOVA results, along with the Taguchi approach, demonstrated that Id was the most influential factor across all print parameters. This is because a higher Id led to denser structures, reduced voids and porosities, and enhanced energy absorption, significantly increasing toughness while reducing penetration depth. Morphological analysis supported the statistical findings regarding the role of Id on the performance of such structures. With optimized printing parameters, no penetration to the armor panels was recorded, outperforming the UK body armor standard of a maximum permitted knife penetration depth of 8 mm. Moreover, an artificial neural network (ANN) utilizing the 5-14-12-3 topology was created to predict the toughness, stab penetration depth, and armor panel weight of 3D-printed armors. The ANN model demonstrated better prediction performance for stab penetration depth compared to the Taguchi method, confirming the successful application of such an approach. These findings provide a critical foundation for the development of high-performance 3D-printed protective structures. Full article