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In order to explore the influence of oxidants on the fractal characteristics of coal pores, samples of low-rank coal from Qianqiu Mine, medium-rank coal from Shaqu Mine and high-rank coal from Zhongma Mine were collected, and coal samples of different coal ranks were pretreated with chlorine dioxide and ammonium persulfate. The pore structure of coal samples before and after oxidant treatment was analyzed, and the pore fractal dimension was calculated. At the same time, the relationship between fractal dimension and tortuosity and porosity was analyzed. The results show that as the coal rank increases, the pore fractal dimension gradually decreases; after treatment with oxidant, the coal sample pore fractal dimension, tortuosity and porosity all increase in different degrees, indicating that the oxidant can increase the complexity of coal pores. At the same time, it is conducive to the desorption and transport of coalbed methane, and the promotion effect of chlorine dioxide is more obvious than that of ammonium persulfate; as the pore fractal dimension increases, the tortuosity decreases first and then increases. The pore fractal dimension D=2.80 is approximate the turning point of the trend line, and the porosity shows a downward trend.

In this paper, seven half‐scale specimens are used to investigate the effects of the beam–column width ratio, concrete strength, and axial load on the seismic performance of wide exterior beam–column joints. The test results show that all the specimens undergo bending damage at the beam end. The concrete damage in the core column is not significant, meeting the seismic requirements of strong column–weak beams and strong joint–weak members. For specimens with small beam widths, the increase in axial load can effectively reduce the damage to the concrete in the outer joint and increase the strength of the specimen. Increasing the beam width and concrete strength reduces the ductility of the specimen while increasing the strength of the specimen. The bonding performance of the longitudinal bars anchored outside the core column is poor, as bond–slip with the concrete is observed during the test. In addition, compared with ACI 318‐19, GB 50011‐2010 is more conservative for calculating the shear strength of exterior wide beam–column joints. Finally, a corresponding finite element model is established by MSC Marc and verified based on the experimental results. [ABSTRACT FROM AUTHOR]

Invasive plants often alter biological soil conditions to increase their own competitiveness. Through indoor simulated nitrogen deposition culture experiments, we investigated the differences in growth indicators and nutrient content levels between the invasive plant Cenchrus spinifex Cav. and the native symbiotic plant Agropyron cristatum (L.) Gaertn. under diverse nitrogen application modes and planting-competition ratios. Furthermore, we examined the alterations in key microbial communities involved in soil nitrogen cycling of C. spinifex. The results indicated that the invasion of C. spinifex could inhibit the growth of native plants, and in fact altered the accumulation and transformation processes related to soil nitrogen, resulting in reduced rates of soil nitrogen transformation. The overarching aim of this research was to construct a theoretical foundation for the scientific comprehension of the invasion mechanisms of C. spinifex, in order to better prevent the further spread of this invasive plant and mitigate its pernicious impact on the current environment. [ABSTRACT FROM AUTHOR]

Seed germination and dispersal have an important impact on the establishment and spread of invasive plants. Understanding the extent of intraspecific seed trait variations can enhance our understanding of how invasive plants respond to environmental change after introduction and help predict the dynamic of invasive species under future environmental conditions. However, less attention has been given to the variation in seed traits within species as opposed to among species. We compared seed production, seed morphological traits, dispersal ability, and seedling performance of Chromolaena odorata from 10 introduced populations in Asia and 12 native populations in America in a common garden. The results showed that range (introduced vs. native) and climate affected these traits. Compared with the native population, the introduced populations had higher seed numbers per capitula, lighter seeds, and higher potential dispersal ability seeds (lower terminal velocity) but lower germination rates and seedling lengths. Climatic clines in seed numbers per capitula and pappus length were observed; however, the clines in pappus length differed between the introduced and native populations. Trait covariation patterns were also different between both ranges. In the native populations, there was a trade-off between seed numbers per capitula and seed mass, while this relationship was not found for the introduced populations. These results indicate that C. odorata alters the ecological strategy of seed following invasion, which facilitates its establishment and fast dispersal and contributes to successful invasion in the introduced ranges. [ABSTRACT FROM AUTHOR]

Nitrate (NO3−) is a significant inorganic nitrogen source in soil, playing a crucial role in influencing crop productivity. As sessile organisms, plants have evolved complex mechanisms for nitrate uptake and response to varying soil levels. Recent advancements have enhanced our understanding of nitrate uptake and signaling pathways. This mini‐review offers a comparative analysis of nitrate uptake mechanisms in Arabidopsis and rice. It also examines nitrate signal transduction, highlighting the roles of AtNRT1.1 and AtNLP7 as nitrate receptors and elucidating the OsNRT1.1B‐OsSPX4‐OsNLP3 cascade. Additionally, it investigates nuclear transcriptional networks that regulate nitrate‐responsive genes, controlled by various transcription factors (TFs) crucial for plant development. By integrating these findings, we highlight mechanisms that may help to enhance crop nitrogen utilization. [ABSTRACT FROM AUTHOR]

The intensive raising model for meat duck production has widely adopted cascading cages. However, investigations on low-protein diets for Pekin ducks under this model are scarce. Thus, a 3 × 6 factorial experiment was conducted using six dietary crude protein (CP) levels (17.61%, 16.25%, 15.34%, 14.55%, 13.38%, and 12.64%, analyzed) and three cage layers (lower, middle, and upper). The study aimed to examine the effects of dietary CP reduction with crystalline amino acid supplementation on growth performance, carcass traits, and apparent nutrient digestibility in growing Pekin ducks from 21 to 42 days of age housed at different cage layers. A total of 1620 21-day-old Pekin ducks were randomly divided into 18 groups, each with six replicates of 15 ducks per replicate. Ducks were distributed across different cage layers and were fed one of six experimental diets, respectively, each varying in dietary CP levels but maintaining similar dietary energy and amino acid profiles. The results showed that the reduction in dietary CP levels affected growth performance (p < 0.05), while weight gain, feed intake, and feed/gain of Pekin ducks had no difference among 17.61%, 16.25%, and 15.34% CP groups (p > 0.05). As dietary CP decreased, abdominal fat yield increased (p < 0.05), but breast and leg meat yields were unaffected (p > 0.05). CP intake, nitrogen intake, and nitrogen excretion decreased linearly (p < 0.05) with decreasing dietary CP levels, while apparent nutrient digestibility in Pekin ducks increased proportionally (p < 0.05). Additionally, body weight, weight gain, feed intake, CP intake, nitrogen intake, and nitrogen excretion of Pekin ducks decreased (p < 0.05) due to different cage layers, while carcass characteristics remained unaffected by cage layer (p > 0.05). In summary, it is feasible to reduce the dietary CP level with crystalline amino acid supplementation in growing Pekin ducks from 21 to 42 days of age housed in cascading cages, while the cage layers affected growth performance of ducks. Based on broken-line models, it was determined that the optimal dietary CP requirement for achieving maximum weight gain and feed efficiency in growing Pekin ducks is approximately 15%. [ABSTRACT FROM AUTHOR]