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Lack of soil moisture and phosphorus deficiency limits wheat grain yield in dryland areas. However, the moisture-conserving effect of straw mulching combined with phosphor fertilization on fertile florets per spike (FFS) and grain yield remains unclear. During the 2020–2021 and 2021–2022 growing seasons, we investigated the combined effects of straw mulching (0 and 8000 kg ha−1) and phosphorus fertilization (0, 75, and 120 kg P2O5 ha−1) on spike development, assimilates' availability, and the photosynthetic properties of flag leaves by conducting a field experiment. Compared with no straw mulch control, straw mulching increased fertile spike, grain number per spike (15.6%), and grain yield (22.6%), and grain number per spike was the most important contribution to increasing wheat grain yield (46%). An increase in grain number per spike is associated with FFS. Compared with no straw mulch control, straw mulching increased FFS by 19.5%, and it increased with increasing phosphorus fertilization levels. Moreover, straw mulching combined with phosphorus fertilization promoted the light compensation point (LCP), light saturation point (LSP), net photosynthetic rate (Pn), Chl b, and the maximal photochemical efficiency of photosystem II (Fv/Fm) of flag leaves to produce carbohydrates. Our study has shown that the primary factor for the divergence in FFS under straw mulching and phosphorus application was the efficiency of assimilate utilization in the spike, which ultimately led to increased grain number per spike and grain yield. [ABSTRACT FROM AUTHOR]

To analyze the absolute line intensities, as well as the coefficients of air‐ and self‐broadening of water vapor, 31 transition lines were measured using an external‐cavity diode laser (ECDL) in the range of 9090–9750 cm−1. A multispectrum fitting (MSF) program was used in conjunction with a quadratic speed‐dependent Voigt profile (qSDVP) and a Voigt profile (VP) to extract the line intensities and self‐ and air‐broadening coefficients. Values at room temperature (296 K) were then compared with the HITRAN2016 and HITRAN2020 database. The analysis results show that the line intensities and air‐broadening coefficients are more consistent with the database while also verifying that the self‐broadening coefficients obtained based on qSDVP are larger than those based on VP. [ABSTRACT FROM AUTHOR]

A compact photoacoustic gas sensor based on variable diameter T‐shaped cell for trace gas detection was developed. The acoustic pressure distribution in the variable diameter T‐shaped cell and conventional T‐shaped photoacoustic cell with the same size were simulated by COMSOL Multiphysics software, which indicated that at the first resonance frequency, the acoustic pressure at the end of the resonance tube of the designed photoacoustic cell is significantly stronger than that at the same position of the conventional T‐shaped cell. The performance of the sensor based on the variable diameter T‐shaped and conventional one were evaluated by detection of water vapor in atmospheric environment, the comparison shows that the signal‐to‐noise ratio of the variable diameter T‐shaped cell is about 1.6 times greater than that of the conventional one and a detection limit of 6.4 ppmv for water vapor detection was obtained. [ABSTRACT FROM AUTHOR]

To examine the characteristic of denitrification in Frankia, a symbiotic nitrogen-fixing microbe associated with non-leguminous plants, and its role as a N2 O source or sink, Casuarina root nodule endophyte Frankia was isolated using sectioning method, which was then purely cultured to investigate the denitrification process under NO3-addition. The results showed that after addition of NO3-to the medium under anaerobic condition, the concentration of NO3-decreased with time, while the concentrations of NO2-and N2 O initially increased and then decreased over time. Key denitrification genes and nitrogenase gene were detected at 26 h, 54 h and 98 h during incubation. Abundances of these genes significantly delivered among each other, and their dynamics were asynchronous. Redundancy analysis of the effect of NO3-, NO2-, N2O concentrations on abundances of denitrification genes and nitrogenase gene indicated that 81.9% of' the total variation in gene abundances could be explained by the first two axes. Frankia had a denitrifying activity under anaerobic condition, with denitrification genes, including nitrous oxide reductase gene (nosZ), being identified. Our results suggested that Frankia possessed a complete denitrification pathway and the ability of N2O reduction under anaerobic condition. [ABSTRACT FROM AUTHOR]

In order to solve the problems of low hardness and poor wear resistance of titanium alloy, laser cladding technology was used to prepare NiCrBSi coatings with different amounts of B4C on the surface of Ti-6Al-4V alloy. The effects of B4C content on the microstructure evolution, hardness, fracture toughness, and wear resistance of NiCrBSi coatings were investigated. The results showed that with an increase of B4C addition, the size and number of ceramic phases TiB2, TiC, and CrB in the coating increased, and the ceramic phases were dispersed in the coating. The average microhardness of the coating with 9 wt.% B4C addition was the highest, reaching 1250.3 HV0.2, which is 15% higher than that of the coating without B4C addition. After adding B4C, the fracture toughness of the coating increased. When the addition of B4C was 3 wt.%, the fracture toughness of the coating was the highest, reaching 1.42 MPa m1/2, which is 178.4% higher than that of the coating without B4C. With the increase of the addition of B4C, the wear loss of the coating decreased and the wear resistance increased. [ABSTRACT FROM AUTHOR]