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To improve the measurement accuracy of wood density and study the linear correlation between the drill feed resistance and wood density, a new micro drill instrument that can can simultaneously measure the rotation resistance and feed resistance of the drill needle was designed. The test wood samples included hardwood, softwood and conifer. The absolute dry density of each wood sample was measured. The drill resistance data was tested by using self-developed micro drill instrument and Resistogaph 650-SC. 4 linear models between drill resistance and the absolute dry density of wood . The results showed that: the statistical indicators of each model of the self-made micro drill resistance in-strument were better than the corresponding indicators of Resistogaph 650-SC; the coefficient of determination of the linear regression model between the feed resistance of the self-made micro drill resistance instrument and the absolute dry density of wood was 0.946; the statistical indicators of model including rotation resistance and feed resistance, were better than those of the model only including rotation resistance. Therefor, the design proposed in the article is reasonable, and increasing the feed resistance can improve the measurement accuracy of the micro drill resistance instrument for measuring wood density.

The mammalian Y chromosome offers a unique perspective on the male reproduction and paternal evolutionary histories. However, further understanding of the Y chromosome biology for most mammals is hindered by the lack of a Y chromosome assembly. This study presents an integrated in silico strategy for identifying and assembling the goat Y‐linked scaffolds using existing data. A total of 11.5 Mb Y‐linked sequences were clustered into 33 scaffolds, and 187 protein‐coding genes were annotated. We also identified high abundance of repetitive elements. A 5.84 Mb subset was further ordered into an assembly with the evidence from the goat radiation hybrid map (RH map). The existing whole‐genome resequencing data of 96 goats (worldwide distribution) were utilized to exploit the paternal relationships among bezoars and domestic goats. Goat paternal lineages were clearly divided into two clades (Y1 and Y2), predating the goat domestication. Demographic history analyses indicated that maternal lineages experienced a bottleneck effect around 2,000 YBP (years before present), after which goats belonging to the A haplogroup spread worldwide from the Near East. As opposed to this, paternal lineages experienced a population decline around the 10,000 YBP. The evidence from the Y chromosome suggests that male goats were not affected by the A haplogroup worldwide transmission, which implies sexually unbalanced contribution to the goat trade and population expansion in post‐Neolithic period., In this paper, we first assembled goat Y chromosome into 33 scaffolds totaling 11.5 Mb, and a subset of 5.84 Mb was further ordered into an assembly with the validation of goat radiation hybrid map. Then, we identified SNPs of 96 goat samples worldwide to exploit the paternal relationships among wild bezoars and domestic goats. The paternal lineages showed a clear division of bezoars and goats into two clades, and they were independent of goat domestication. Further demographical history of paternal and maternal lineages showed evident differences, with a bottleneck effect in mtDNA around 2,000 YBP, which may be related to the worldwide dispersal of goat in the post‐Neolithic period, implied the possibility of gender preference in goat domestication. Our research provided a new perspective of goat evolution history.

Gaillardia plants have been widely cultivated in China and have become an important component of garden landscaping. Different from the common ligulate ray floret, the cornflower-like (funnel-shaped) ray floret is a special phenotype variation in Gaillardia species. Previous studies revealed that CYC-like genes could shape the floret phenotype in Compositae. To reveal the molecular mechanism of the cornflower-like phenotype, we checked the capitulum transcriptomes of several cultivars of Gaillardia that possess different ray florets. As a result, we identified 11 CYC-like genes, of which five included complete coding region sequences. Phylogenetic analysis revealed that all five genes were CYC2-like genes. Relative expression analysis of RNA-resequencing reads, qRT-PCR comparison, and gene-silencing treatment all showed that the CYC2c gene is the main genetic mechanism responsible for the shaping of the cornflower-like ray floret phenotype in Gaillardia cultivars. This study expounded our understanding of flower morphology evolution and provides useful insights for improving Compositae breeding.

Traditional empirical mode decomposition (EMD) algorithm has drawback of mode mixing when dealing with complicative vibration signals, and this will reduce the accuracy of bearing fault diagnosis. By considering the superior performance of variational mode decomposition (VMD) in signal processing, this paper proposes a bearing fault diagnosis method based on EMD-VMD adjacent reconstruction and secondary decomposition algorithm. Firstly, the vibration signal is decomposed by EMD. Secondly, a mixed index normalized from kurtosis and root mean square is proposed to locate the sensitive IMF component. Then, an adjacent reconstruction method is designed by combining the obtained sensitive component and its neighbor IMFs. Finally, the modal component parameter of VMD is set by these IMFs used for new reconstructed signal, and bearing fault diagnosis is realized with Hilbert analysis. Simulation analysis experimental analysis results show that the proposed method has advantages in baring fault diagnosis compared with some traditional methods.