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Based on the Weibull random distribution of the micro-unit strength of fiber reinforced concrete, the parameters are introduced to describe the micro-unit strength of concrete reasonably, and it is used to establish a damage-softening constitutive model that can reflect the whole process of fiber reinforced concrete damage with the Drucker-Prager yield criterion. On this basis, according to the stress-strain curves of concrete with different palm fiber content and cement content, the functional relationship is discussed among the parameters with palm fiber content and cement content of concrete damage-softening model based on Weibull distribution, then a more realistic concrete damage- softening constitutive model is established with the modified model parameters. To consider the dynamic characteristics of micro-elements in palm fiber concrete during loading-unloading, a modified linear regression model parameter solving method is proposed. By comparing the experimental results with the calculated values, the rationality of the constitutive model and the parameter solution method is verified. The constitutive model proposed in this paper can well reflect the stress-strain relationship and damage evolution process of plam fiber reinforced concrete under different mix ratios, which can provide reference for the engineering application of brown fiber concrete.

The spatiotemporal accuracy of precipitation products is critical for their application in watershed hydrology, meteorology and drought monitoring. This study introduces a novel, multi-scale assessment framework to evaluate the accuracy of four widely used precipitation products [the Global Precipitation Measurement Integrated Multi-Satellite Retrievals (GPM IMERG), the Multi-Source Weighted Ensemble Precipitation (MSWEP), the China Meteorological Forcing Dataset, and the long-term, gauge-based gridded precipitation dataset for the Chinese mainland (CHM_PRE)]. A key innovation is the integration of precipitation zoning, achieved by applying the Rotated Empirical Orthogonal Function method to delineate the upper and middle reaches of the Hanjiang River Basin (UMHRB) into distinct precipitation zones. We then systematically assessed the performance within these zones in terms of daily statistical accuracy, capacity to capture spatiotemporal evolution, and skill in detecting precipitation events and extremes. This study validates the applicability of dividing the study area into five precipitation zones, as determined from observed data (1975–2018). A key finding is CHM_PRE is recommended as the most reliable product across all zones. In terms of precipitation event probability, MSWEP excels at reproducing the probability density distribution across various intensities, whereas CHM_PRE tends to overestimate the frequency of non-precipitation events (< 0.1 mm/d). Critically, a major discrepancy emerges in extreme precipitation detection: although all products show high capability at the watershed scale, their performance deteriorates markedly at the zonal scale. This was most pronounced for MSWEP, whose Kling–Gupta Efficiency for Rx1day dropped to as low as 0.07 in Zone 5 and 0.09 in Zone 3, indicating a failure to effectively capture extremes in these regions. This multi-faceted, zoning-level assessment provides a nuanced understanding of product performance, offering valuable insights for the informed selection of appropriate datasets tailored to specific hydrological and meteorological applications.

The coupled combustion of biomass and organic solid wastes including oil sludge has attracted much attention. Although the optimal mixing ratio of different coal types and biomass has been extensively studied, little attention has been paid to oil sludge that has undergone co-combustion. In this study, the combustion characteristics of blended fuel for coal, biomass and oil sludge under different mixing ratios are studied via a thermogravimetric test and differential thermal analysis. Kinetic analysis of tri-fuel is performed using the Flynn–Wall–Ozawa (FWO) and Dolye methods. The results show that the bituminous coal combustion process mainly involves the combustion of fixed carbon (236.0–382.0 °C). Wood pellet combustion (383.0–610.0 °C) has two processes involving the combustion of compound carbon and fixed carbon. Blending wood pellets effectively enhances combustion efficiency. Wood pellets from Korla (KOL) have the most obvious effect on reducing the ignition temperature. The blending combustion of bituminous coal (SC), wood pellets from Hutubi (HTB) and oil sludge (OS) have significant synergistic effects. As the OS mixing ratio increases from 10% to 20% with 45% HTB, Ti and Th decrease from 354.9 and 514.3 °C to 269.8 and 452.7 °C, respectively. In addition, f(α) is [−ln(1 − α)]2 for tri-fuel in most mixing ratios when α < 0.5, while f(α) becomes [−ln(1 − α)]3 at α > 0.5. At a high-HTB-level mixing ratio, increasing the OS content causes a decrease in activation energy to 35.87 kJ mol−1. The moderate blending of oil sludge improves the pre-finger factor and the combustion performance.

Asparagus (Asparagus officinalis L.) is a highly nutritious vegetable rich in various bioactive compounds. Ensuring both yield improvement and quality preservation is a shared goal for producers and researchers. As novel green yield-enhancing technologies in facility agriculture, electrostatic fields and elevated CO2 application hold significant potential. This study investigated the effects of the interaction between electrostatic fields and elevated CO2 on the growth and physiological characteristics of asparagus. The results demonstrated that the combined treatment of electrostatic fields and elevated CO2 significantly increased total yield, tender stem number, and single tender stem weight of asparagus, while also shortening the harvesting period and promoting rapid shoot growth. Additionally, the treatment markedly enhanced the total chlorophyll content in asparagus leaves, improving photosynthetic capacity. By boosting antioxidant enzyme activities (e.g., SOD, APX) and reducing malondialdehyde (MDA) levels, the treatment maintained the redox homeostasis of asparagus shoots, effectively mitigating oxidative damage. In terms of nutrient accumulation, the interaction between electrostatic fields and elevated CO2 significantly promoted the synthesis and accumulation of key nutrients, including soluble sugars, reducing sugars, soluble proteins, total phenolics, total flavonoids, and ascorbic acid, thereby substantially improving the nutritional quality of asparagus. Comprehensive analysis using fuzzy membership functions revealed that the combined treatment of electrostatic fields and elevated CO2 outperformed individual treatments in enhancing asparagus growth and physiological characteristics. This study provides important theoretical insights and technical support for the efficient and sustainable cultivation of asparagus in facility agriculture.

In this study, the co-combustion of coal and biomass, and the tri-combustion of coal, biomass, and oil sludge in a 130 t h−1 circulating fluidized bed (CFB) boiler are investigated via the computational particle fluid dynamics (CPFD) approach. Furthermore, the effect of biomass feeding position is also comprehensively evaluated. The results show that for the co-combustion of coal and biomass, the O2 mole fraction at the furnace outlet rises from 0.0541 to 0.0640 as the biomass blending ratio enhances from 40% to 100%, while the CO2 mole fraction reduces from 0.1357 to 0.1267. The mole fraction of NOx and SO2 at the furnace outlet decreases from 4.5867 × 10−5 to 3.9096 × 10−5 and 2.8253 × 10−4 to 4.6635 × 10−5, respectively. For the tri-combustion of three fuels, the average NOx mole fraction initially grows quickly and then declines gradually, ranging from 4.1173 × 10−5 to 4.2556 × 10−5. The mole fraction of SO2 at the furnace outlet increases from 3.5176 × 10−4 to 4.7043 × 10−4 when the ratio of oil sludge rises from 10% to 20%. The uniformity of temperature and gas components distribution is “new inlet > secondary air inlet > feed inlet”. As for the three inlet positions, the mole fractions of NOx at the furnace outlet are between 3.9096 × 10−5 and 5.1537 × 10−5, while those for SO2 are between 2.5978 × 10−4 and 2.5278 × 10−4.

Celery (Apium graveolens L.) is a widely cultivated leafy vegetable of significant agronomic and nutritional importance. Owing to its high nutritional value, global demand for celery has steadily increased. However, under natural cultivation conditions, uncontrolled light exposure often prolongs the seedling stage and impairs celery growth quality. Improving the nutritional quality of celery through artificial regulation of the light environment has therefore become an important research focus. This work aimed to elucidate the impact of varying light–dark cycles on the growth characteristics and nutritional attributes of celery. Six light–dark cycle treatments (4 h/2 h, 8 h/4 h, 16 h/8 h, 24 h/12 h, 32 h/16 h, and 40 h/20 h) were applied, using ‘Oster Ziyu Xiangqin’ as the plant material under a constant light intensity of 400 μmol·m−2·s−1. The results revealed that the 24 h/12 h light–dark treatment significantly enhanced plant height, total fresh weight, and root vigor and showed superior performance in photosynthetic and chlorophyll fluorescence parameters. The 32 h/16 h treatment significantly enhanced the accumulation of soluble sugars, proteins, total phenolic compounds, and flavonoids, as well as the activities of antioxidant enzymes, while reducing nitrate-nitrogen levels. In conclusion, the 24 h/12 h light–dark cycle was most conducive to the growth and photosynthetic performance of celery, whereas the 32 h/16 h treatment optimally enhanced its nutritional quality and antioxidant capacity.

Fibers have been widely applied to improve the mechanical properties of natural soil and traditional cemented soils, but rarely investigated in substrates for slope eco-protection. Vegetation-growing concrete (VC) substrate is a kind of ecological cemented soil and has very wide popularization and application prospects. In this study, unconsolidated-undrained (UU) triaxial compression tests were conducted on the control specimens of VC substrate containing three cement contents and the palm fiber reinforced specimens manufactured by adding four fiber contents. The control specimens were shown to possess increasing yield strength, ultimate strength, yield strain and shear modulus with cement content, which resulted from the cemented texture improved by the hydrate products as recognized previously. Instead of inextensible reinforcement provided by cement, the palm fibers were found to provide extensible reinforcement, through which the obvious softening behavior of VC substrate could transfer to elasto-plasticity. Attributed to the unique ductility, the fibers added could bring with considerable increase in ductility of reinforced substrate, except for additional increases in yield strength, ultimate strength and yield strain.

The substrate for vegetation concrete is a new type of plant substrate used for slope protection. While it has demonstrated good performance in slope protection and a greening effect, the sustainability of ecological restoration projects is difficult and there are significant construction risks in areas with frequent earthquakes. In this study, a new type of substrate for vegetation concrete was developed for areas with frequent earthquakes, and a shaking table test was performed to evaluate the seismic performance. The test results indicated that the proposed substrate of the vegetation concrete displayed good stability under seismic excitation at earthquake intensities of V, VI, VII, and VIII. A comparison of several different reinforcement methods under seismic conditions indicated that wavy laying of a flexible net was the best reinforcement method. Through observation of the displacement time history curve and macroscopic phenomenon, the failure process of the substrate layer was obtained and consisted of the following three stages: cracking between substrate layer and bedrock, internal cracking of the substrate layer, and vibration crushing. Ultimately, the research results have significant reference value for ecological restoration projects using substrates for vegetation concrete in areas with frequent earthquakes.

Vegetation-growing Concrete (VC), as a new type of cemented soil, is usually used for plants growing on the surface of high and steep rocky slopes. With the widespread application of VC substrate, a pressing problem arises to ensure its durability under wetting and drying conditions. To explore the greatest possible impact on the mechanical properties and microstructure features of VC substrate, an experimental program including triaxial test, SEM analysis, and ultrasonic testing was implemented. The results showed that wetting and drying cycles can significantly decrease more than 40-percent of peak strength, 60-percent of residual strength, and 50-percent of cohesion for VC substrate under ultimate conditions. The fundamental cause of reduction in mechanical performance was found to be the weakening of the bond between soil particles. And it was discovered that structural damage increased as the number of wetting and drying cycles increased but at a slower rate. Based on the tested results, linear functions between the loss extent parameters of mechanical performance and the structural damage variable were established for the VC substrate. Finally, the action mechanisms of wetting and drying cycles for VC substrate were discussed, and the main influential factors were proposed.

Vegetated concrete substrate (VCS) is a kind of ecological cemented soil, which has very wide application prospect in high and steep rock slope eco-protection. Cement is an important component of VCS, but it has high energy consumption and environmental pollution. Fiber reinforcement plays an positive role in improving the mechanical properties of soil, and its use as a substitute for cement content in VCS under the condition of equal strength is rarely investigated. In this study, the unconsolidated-undrained (UU) triaxial compression test of unreinforced substrate as blank control samples (BCS) and reinforced substrate as fiber reinforced samples (FRS) were carried out. The test results showed that the stress-strain curve of VCS can be divided into compaction stage, elastic stage, plastic stage and strain hardening stage. The average peak strength increased by 34.3kPa, 53.6kPa, 218kPa and 81.8kPa as cement content of VCS was 0%,4%, 6% and 8%, respectively. The relationship between the peak strength and cement content of VCS could be better fit by Boltzmann function. The mathematical model of fiber instead of cement in VCS under the condition of equal strength was established. It is found that there is a critical point of cement content according to the mathematical model. The cement of VCS can be completely replaced by plam fiber as the cement content is less than the critical point. While the cement content is higher than the critical point, the cement of VCS can be partially replaced by plam fiber. The decrease of average cement content was 17.23%, 19.00%, 24.27% and 25.34% with 0.2%, 0.4%, 0.6% and 0.8% fiber content in reinforced substrate, respectively. The theoretical method and interpolation method for fiber substitute cement content of VCS under equal strength condition were proposed, which can provide technical guidance for ecological slope protection engineering practice of vegetated concrete.