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The utilization of hydrogen-enriched liquefied petroleum gas (LPG) is an effective means of reducing carbon emissions, but the special physical and chemical properties of hydrogen have raised concerns among the public. To delve into the intricate chemical kinetic mechanisms governing the inhibitory effect of CO2 on the explosion of hydrogen-enriched LPG, this study systematically investigated the influence of varying CO2 concentrations (3%, 6%, and 9%) on the explosion characteristics of hydrogen-enriched LPG (hydrogen ratio ranging from 0 to 0.5) within a 20 L spherical explosion chamber. Subsequently, a chemical kinetic analysis was conducted, focusing on the explosion reaction dynamics of the H2/LPG/CO2/Air mixture, encompassing temperature sensitivity assessments and the production rates of key free radicals. The findings reveal that although hydrogen incorporation does not significantly alter the maximum explosion pressure of LPG, it markedly accelerates the explosion reaction rate, posing a challenge for CO2 in effectively inhibiting the explosion of hydrogen-enriched LPG. CO2 functions as a stabilizing third body within the reaction system, diminishing the collision frequency among free radicals, hydrogen molecules, hydrocarbon molecules, and oxygen molecules, thereby slowing down the reaction rate. As the proportion of hydrogen increases, the concentration of ·H radicals, known for their high reactivity, escalates, rapidly completing the propagation phase of the chain reaction and intensifying the overall generation rates of critical free radicals, including ·H, ·O, and ·OH. Notably, the key reaction H + O 2 ⇋ O + O H , which governs the reaction temperature, undergoes significant enhancement, further accelerating the explosion reaction rate and ultimately diminishing the inhibitory efficacy of CO2 against the hydrogenated LPG explosion. Furthermore, as the amount of hydrogen added increases, hydrogen's competitiveness for oxygen within the reaction system markedly improves, attenuating the oxidation of hydrocarbons. Concurrently, the alkane recombination reaction, exemplified by C 3 H 6 + C H 3 (+ M) ⇋ s C 4 H 9 (+ M) , is strengthened. These insights provide valuable understanding of the complex interactions and mechanisms during the explosion of hydrogen-enriched LPG in the presence of CO2, with implications for the safe application of hydrogen-enriched LPG. [ABSTRACT FROM AUTHOR]

Fusarium head blight (FHB), caused by the Fusarium graminearum species complex, causes significant losses in grain yield and quality of wheat (Triticum aestivum) by inducing floret sterility. Grains become contaminated with mycotoxins, especially deoxynivalenol (DON), making them unsuitable for consumption. To clarify the impact of wheat cultivar resistance, infection level, and climate after anthesis on the efficacy of a fungicide for the control of FHB, we treated two moderately susceptible cultivars and 11 susceptible cultivars with fungicide (48% phenamacril + tebuconazole) at anthesis over two years. FHB incidence (INC), disease severity index (DSI), Fusarium-damaged kernels, DON contamination, thousand-kernel weight, and yield were evaluated under artificially inoculated and naturally infected field trials in 2018 and 2021. The results of multi-factor variance analysis show that the control efficacy with respect to INC and DSI is affected by cultivar, fungicide, infection level, and climatic conditions including the average daily temperature, average daily relative humidity, and total rainfall from anthesis to 21 days after anthesis (p < 0.01). Notably, cultivar resistance (deviance = 13.34, 9.55, and 11.22) is more important than fungicide (deviance = 5.77, 6.66, and 6.69) to control the efficacy of INC, DSI, and DON. The results also suggest that infection level appears to be more important than cultivars and fungicide to control the efficacy of INC, and more important than fungicide to control the efficacy of DSI. Total rainfall is more important than other climatic factors. Our results reveal that fungicide is more effective in moderately susceptible cultivars ('Zhengmai 9023' and 'Xinong 979', 89.5%~98.9%) and some susceptible cultivars than in other susceptible cultivars ('Zhengmai 7698' and 'Zhoumai 27', 51.9%~67.2%). Thus, integrating cultivar resistance with fungicide application can be an effective strategy for the management of FHB and DON in winter wheat in the Huang-huai-hai Plain of China. [ABSTRACT FROM AUTHOR]

CSMSFC (Calcium Sulphoaluminate Cement-based Micro Steel Fiber Concrete) possesses the advantages of early strength, high strength, exceptional toughness, minimal shrinkage, and excellent bond performance with bars. When applied to NLSB (Non-contact Lap Splice of Bars) in prefabricated structures, CSMSFC enhances mechanical performance while preventing shrinkage cracking and reducing seismic damage. Additionally, it shortens construction periods for prefabricated structures and achieves a comprehensive improvement in seismic performance and construction efficiency. However, there is a lack of systematic testing of factors influencing the bond strength between CSMSFC and NLSB and the effect of CSMSFC on the force transfer performance between NLSB. Therefore, the axial tensile tests of NLSB were conducted on 51 non-contact lapping specimens to investigate the bond properties and force transfer mechanism between lapping bars and CSMSFC. The effects of lapping length, volume fraction of steel fibers, spacing of bars, and concrete cover thickness on the lapping characteristics were examined, and the comparison with OPMSFC (Ordinary Portland Cement-based Micro Steel Fiber Concrete) was also considered. The experimental results demonstrate that the bond strength between bars and CSMSFC increased by 36.8%, 42.3%, and 43.3% respectively, with volume fractions of steel fiber at 1.5%, 3%, and 4.5% compared to the absence of steel fiber. The bonding effect between CSMSFC and bars is similar to that of OPMSFC and bars. The bond strength between CSMSFC and the bars improved by 4.3% and 6.6% with the increases of the spacing of bars from 0 to 20 mm and the concrete cover thickness from 10 to 30 mm. Conversely, with the increases of the lapping length from 50 mm to 100 mm, 200 mm, and 300 mm, the bond strength decreased by 46.8%, 72.2%, and 82.0%, respectively. Finally, based on the force transmission mechanism of the non-contact lapping bars, a calculation model is proposed for determining the lapping length while considering the reinforcing effect of steel fiber "stirrups." A formula is derived from the model to calculate the minimum lapping length of HRB400 bars in CSMSFC, considering the volume fraction of steel fibers, which can assist in designing the minimum lap length of NLSB in practical applications. [ABSTRACT FROM AUTHOR]