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This paper utilised computational fluid dynamics (CFD) technology to calculate the resistance of a novel high-speed quadramaran in calm water using the Navier‒Stokes (N‒S) equation, analysed the total resistance, frictional resistance, and residual resistance characteristics of this novel high-speed quadramaran at different length Froude numbers, and compared them with the results of a conventional high-speed catamaran with the same displacement. The results showed that the total resistance of the quadramaran had a significant hump at the Froude number of 0.6, due to the complexity of the wave interference among the four demihulls, and the hump value was about 1.6 times that of the catamaran. Above the hump speed, the total resistance of the quadramaran decreased with the increase of the Froude number, until reaching the Froude number of 1.06, when the curve became flat, and it showed a maximum resistance reduction of 40% at the Froude number of 1.66 compared with the catamaran, where the total resistance curve was steep. The frictional resistance of the quadramaran increased gradually with the growth of the Froude number, which was basically consistent with the change trend of the catamaran. The residual resistance of the quadramaran first rose and then reduced with the rising Froude number, the curve showed a large hump due to the adverse wave interference, and the hump value was about 1.7 times that of the catamaran. Above the Froude number of 1.06, as the wave interference changed from adverse to favourable, the quadramaran had lower residual resistance than the catamaran. The bow and stern demihulls of the quadramaran were also analysed for their resistance characteristics. The total resistance of the bow demihulls increased gradually with the increase of the Froude number, the curve had a small hump at the Froude number of 0.7, and above the hump speed, the curve was steep. The total resistance of the stern demihulls first increased and then decreased with the growth of the Froude number, the hump value at the Froude number of 0.85 was significant and was about 2 times that of the bow demihulls, and the curve became flat above the Froude number of 1.51.

Abstract Toughened gadolinium- and lead-containing plexiglasses (GLCPs) were prepared via copolymerization using ethoxylated bisphenol A dimethacrylate (BPAxEODMA, x = 2, 4, 10) as comonomer and network regulator. As-obtained modified GLCPs [...]

In watermelon (Citrullus lanatus), lesion mimic is a rare, valuable trait that can be used by breeders for selection at early growth stages. In this study, we tested a seven-generation family to determine the inheritance and genetic basis of this trait. As revealed by analysis of the lesion mimic mutant clalm, this trait is controlled by a single dominant gene. Whole genome resequencing–bulked segregant analysis demonstrated that this gene is located on chromosome 4 from 3,760,000 bp to 7,440,000 bp, a region corresponding to a physical distance of 3.68 Mb encompassing approximately 72 annotated genes. There are 6 genes with non-synonymous mutation SNP sites. The predicted target gene, ClCG04G001930, encodes a Phytoalexin deficient 4 (PAD4), a protein that plays an important regulatory role in leaf senescence in many plant species. According to quantitative real-time PCR analysis, the expression level of ClCG04G001930 was significantly higher in the clalm mutant than in normal watermelon. Twenty-five SNPs were identified in the ClCG04G001930 gene of F2 individuals of the clalm mutant. Overexpression the ClCG04G001930 gene, designated as ClPAD4, yielded transgenic lines whose leaves gradually developed chlorotic lesions over 3 weeks. RNA interference of the ClPAD4 yielded transgenic lines whose cotyledon prone to diseased over 2 weeks. Our results suggest that ClPAD4 might be the candidate gene responsible for lesion mimic in the clalm mutant. Our findings may serve as a foundation for elucidating the mechanism underlying the molecular metabolism of programmed cell death and should be useful for marker-assisted selection breeding in watermelon. [ABSTRACT FROM AUTHOR]

[Objective] The coupling relationships and change mechanisms between rural land consolidation projects and rural beautification construction were studied in order to provide a theoretical basis for implementing plans for land consolidation projects in the context of rural beautification construction. [Methods] Eleven rural land consolidation projects at Jingbian County of Shaanxi Province were selected as cases. An evaluation index system for rural land consolidation projects and an evaluation system for rural beautification construction were established. The entropy weight method was used to determine the index weight. The relative coefficient evaluation method was used to process the basic data and to calculate index scores. A correlation analysis curve was determined using Sigmaplot 10.0 software to estimate a regression model in order to explore the coupling relationship between rural land consolidation projects and rural beautification construction. [Results] ① Coupling relationships between economic benefit and village appearance, living standard, rural civilization, and production development followed the order of living standard > production development > rural civilization > village appearance. The coupling relationship between economic benefits and village appearance was not significant; ② Coupling relationships between grain production capacity and village appearance, living standard, rural civilization, and production development followed the order of production development > living standard > rural civilization > village appearance. As grain production capacity increased, village appearance score initially increased, then decreased, and finally increased, but the fluctuation range was narrow (between 50 and 70). The change trend between grain production capacity and both living standard and rural civilization increased with increasing grain production capacity score, and living standard initially decreased and then increased. ③ The coupling relationships between cultivated land grade and village appearance, living standard, rural civilization, and production development followed the order of production development > living standard > rural civilization > village appearance. The relationships between cultivated land grade and village appearance, rural civilization, and production development initially decreased, then increased, and finally decreased. The fluctuation ranges were 50—70, 20—80, and 30—80 points, respectively. The coupling relationship between cultivated land grade and village appearance was the lowest. [Conclusion] Through the analysis of the coupling function curve and the correlation coefficient, it can be concluded that for rural land consolidation, economic benefits, grain production capacity, and cultivated land have good coupling relationships with living standard and production development for the evaluation index of rural beautification construction, followed by the relationship with rural civilization. The coupling relationship with village appearance needs to be further improved to provide new solutions for subsequent land consolidation project innovations and system innovations that will ultimately achieve mutual benefits between the two systems.

To study the performance of partial air cushion-supported catamaran (PACSCAT), which is sailing with a flexible air seal in waves, this paper uses the model tests, and research the motion characteristics of PACSCAT at different wavelengths, by monitoring the boundaries of heave, pitch, acceleration, air cushion pressure. Firstly this paper introduces the test situation of PACSCAT in the towing tank and introduces the test method, equipment, and test conditions. Second, this paper extracts the test data, analyzes the features of heave, pitch, acceleration, and air cushion pressure, and studies their linear and nonlinear changes in regular waves. Thirdly this paper analyzes the nonlinear air leakage flow of the bow of PACSCAT in detail under the test conditions and studies the internal and external free liquid surface under different conditions.