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Aiming to address the problems of low working efficiency and high damage rate of high and low roller peeling equipment in the process of fresh corn harvesting in China, this paper theoretically analyzes the mechanical motion process between the peeling device and the corn ear, and a high–low roll peeling structure is proposed. This structure incorporates elastomeric rubber material, a roller segmentation design, and an adjustable spiral frame, and the selection of relevant parameters is given. To determine the optimal operating parameters for the fresh-corn-peeling device, a three-factor, three-level orthogonal test was conducted using the Box–Behnken central grouping method in Design-Expert 12 software. The test factors were peeling roller speed, peeling roller tilt angle, and vibrating plate frequency. The evaluation indices considered were the bract peeling rate (BPR) and the grain breaking rate (GBR). Based on the theoretical analysis results, a test bench for the fresh-corn-ear-peeling device was established and the parameter combination for optimal peeling quality was determined according to the actual work situation. The results show that the impact on the BPR and GBR, from large to small, is in the following order: peeling roller speed, peeling roller tilt angle, and frequency vibration plate. The optimization module was used to optimize the operating parameters and used the following integers to obtain the optimal operating parameter combination: the peeling roller speed was 480 r·min−1; the peeling roller tilt angle was 8°; the vibrating plate frequency was 260 times·min−1; the corresponding BPR was 91.75%, which was 0.66% points lower than the optimal value; and the GBR was 1.55%, which was 0.08% points higher than the optimal value. Notably, this fresh-corn-peeling equipment exhibited superior performance in terms of peeling fracture results compared with standard peeling equipment. Therefore, this study provides valuable technical support for the optimal design and selection of fresh-corn-peeling equipment.

Moso bamboo is an economically and ecologically important nontimber forestry species. Here, the authors analyze 427 genomes collected from 15 representative geographic areas, and identify genes under balancing selection, putative patterns of historic demography, and candidate genes associated with important traits.

The existence of positive periodic solutions of the Rayleigh equations $ x''+f(x')+g(x) = e(t) $ with singularities is investigated in this paper. Based on the continuation theorem of coincidence degree theory and the method of upper and lower solutions, the multiple periodic solutions of the singular Rayleigh equations can be determined under the weak conditions of the term $ g $. We discuss both the repulsive singular case and the attractive singular case. Some results in the literature are generalized and improved. Moreover, some examples and numerical simulations are given to illustrate our theoretical analysis.

NAC (NAM, ATAF, and CUC) transcription factors (TFs) are implicated in the transcriptional regulation of diverse processes and have been characterized in a number of plant species. However, NAC TFs are still not well understood in bamboo, especially their potential association with the secondary cell wall (SCW). Here, 94 PeNACs were identified and characterized in moso bamboo (Phyllostachys edulis). Based on their gene structures and conserved motifs, the PeNACs were divided into 11 groups according to their homologs in Arabidopsis. PeNACs were expressed variously in different tissues of moso bamboo, suggesting their functional diversity. Fifteen PeNACs associated with the SCW were selected for co-expression analysis and validation. It was predicted that 396 genes were co-expressed with the 15 PeNACs, in which 16 and 55 genes were involved in the lignin catabolic process and cellulose biosynthetic process respectively. As the degree of lignification in the growing bamboo shoots increased, all 15 PeNACs were upregulated with a trend of rising first and then decreasing except PeNAC37, which increased continuously. These results indicated that these PeNACs might play important roles in SCW biosynthesis and lignification in bamboo shoots. Seven of 15 PeNACs had been found positively co-expressed with seven PeMYBs, and they had similar expression patterns with those of the PeMYBs in bamboo shoots. The targeted sites of miR164 were found in 16 PeNACs, of which three PeNACs associated with SCW were validated to have an opposite expression trend to that of miR164 in growing bamboo shoots. In addition, three PeNACs were selected and verified to have self-activation activities. These results provide comprehensive information of the NAC gene family in moso bamboo, which will be helpful for further functional studies of PeNACs to reveal the molecular regulatory mechanisms of bamboo wood property.