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With the rapid development of multimedia services and smart devices, 360-degree video has enhanced the user viewing experience, ushering in a new era of immersive human–computer interaction. These technologies are increasingly integrating everyday life, including gaming, education, and healthcare. However, the uneven spatiotemporal distribution of wireless resources presents significant challenges for the transmission of ultra-high-definition 360-degree video streaming. To address this issue, this paper proposes a multi-layer non-uniform coding-based adaptive transmission method for 360° video (MNCATM). This method optimizes video caching and transmission by dividing non-uniform tiles and leveraging users' dynamic field of view (FoV) information and the multi-bitrate characteristics of video content. First, the video transmission process is formalized and modeled, and an adaptive transmission optimization framework for a non-uniform video is proposed. Based on this, the optimization problem required by the paper is summarized, and an algorithm is proposed to solve the problem. Simulation experiments demonstrate that the proposed method, MNCATM, outperforms existing transmission schemes in terms of bandwidth utilization and user quality of experience (QoE). MNCATM can effectively utilize network bandwidth, reduce latency, improve transmission efficiency, and maximize user experience quality. [ABSTRACT FROM AUTHOR]

In this study, fracture behaviors of base metal and weld metal of ferritic steel welded joint in the thick wall pipeline for hydrogen transportation were investigated and the effects of hydrogen and specimen thickness (B) on fracture toughness were comprehensively considered in detail. A series of single edge notched tensile (SENT) tests for base metal and weld metal with B/W (width) ratio of 0.5, 1 and 2 were conducted with and without pre-electrochemical hydrogen charging, and crack tip opening displacement (CTOD) of δ m value was obtained by the double clip gauges method. It was found that fracture toughness (δ m) of base metal and weld metal decreased with increasing specimen thickness or hydrogenating, and δ m of hydrogenating specimen with B/W ratio of 2 was smallest. It was believed that large specimen thickness decreased fracture toughness by constraining plastic deformation at crack tip and restricting dislocations movement, while hydrogen promoted embrittlement by reducing cohesive energy of fracture. In the hydrogenating specimen with larger thickness, there was lower dislocation density near crack tip, leading to a decrease in trapped hydrogen and intensifying the cohesive energy reduction effect, which resulted in reduced δ m and the worse fracture toughness, and it means that hydrogen and specimen thickness synergistically affected fracture toughness. In addition, effect of thickness and hydrogen on decreasing fracture toughness was more pronounced for weld metal than base metal, which could be attributed to poorer plastic deformation ability of weld metal and lower dislocation density at crack tip. It is concluded that the hydrogen and thickness effects should be taken into account for the structural integrity evaluation of welded joint in hydrogen transportation pipeline. • Hydrogen coupled with specimen thickness severely deteriorated fracture toughness of base metal and weld metal. • Significant hydrogen embrittlement in thicker specimen was due to hydrogen, plastic deformation and dislocation interaction. • The hydrogen embrittlement effect was more pronounced for weld metal than base metal. • Structural integrity evaluation for welded pipelinemust take hydrogen and thickness into account. [ABSTRACT FROM AUTHOR]

The interactions between displacement cascades and three types of structures, dislocations, dislocation loops and grain boundaries, in BCC-Fe are investigated through molecular dynamics simulations. Wigner–Seitz analysis is used to calculate the number of point defects induced in order to illustrate the effects of three special structures on the displacement cascade. The displacement cascades in systems interacting with all three types of structure tend to generate more total defects compared to bulk Fe. The surviving number of point defects in the grain boundary case is the largest of the three types of structures. The changes in the atomic structures of dislocations, dislocation loops and grain boundaries after displacement cascades are analyzed to understand how irradiation damage affects them. These results could reveal irradiation damage at the microscale. Varied defect production numbers and efficiencies are investigated, which could be used as the input parameters for higher scale simulation. [ABSTRACT FROM AUTHOR]

The combined application of manure and chemical fertiliser has major effects on soil physico-chemical and biological properties, and it increases crop yields. A 4-year study was conducted to study the effects of the application of high (HM 22 500 kg/ha), medium (MM 15 000 kg/ha), and low (LM 7500 kg/ha) rates of manure in combination with conventional chemical fertiliser. We evaluated the effects on soil properties, nutrient use, and crop yield in a continuouscropping maize system. We also compared the three manure treatments with chemical fertiliser-only (CF-only) and no fertiliser (NF) treatments during 2007-2010 in semi-arid conditions. Compared with CF-only and NF, manure combined with chemical fertiliser produced a lower soil bulk density and significantly increased the >0.25-mm water-stable aggregate content, which was higher with increasing manure application rates. The duration of increased soil enzyme activity after manure application depended on the manure application rate; HM produced a significantly higher increase in soil enzyme activity than CF-only and NF during 2007-2010. Manure combined with chemical fertiliser significantly increased crop yield and nitrogen (N) content of the crop organs, showing that this treatment enhanced the use of N fertiliser. Soil properties may be conserved by the MM treatment, which improved soil properties while increasing crop yield, because there was no significant difference in the residual level of N with the MM and CF-only treatments. Therefore, the MM treatment may be an appropriate soil fertiliser treatment for dryland maize farming. Additional keywords: maize yield, manure, nutrient use, organic matter, soil bulk density, soil enzyme activity, water- stable aggregate., Introduction Problems associated with conventional agricultural management (i.e. frequent conventional tillage and excessive inorganic fertiliser application) have led to land degradation, soil organic matter loss, and structure deterioration, which affect [...]