Search

The high strength joining of carbon fiber reinforced nylon 6 composites (CF/PA6) to TWIP980 steel was achieved by resistance element welding (REW). A 304 stainless steel rivet was used as an assistant element. The effect of welding current and welding time on the joint mechanical property was studied. Four joint failure modes with different strengths were identified, and the microstructures of joints, and the interfaces between CF/PA6 and the steel were analyzed. As the melting point and thermal conductivity of CF/PA6 are lower than those of the high-strength steel, it is prone to overheat and decompose during welding. While ensuring the formation of a certain size of weld nugget, avoiding or reducing the decomposition of CF/PA6 is the key to the successful implementation of CF/PA6 high-strength steel REW. By using a hard welding process such as high welding current and short welding time, high strength joints can be obtained while reducing the decomposition of CF/PA6. Based on the failure load of the joint, the weld lobe under the conditions of this study was determined. The process is sensitive to the change of welding time, and the allowable welding time range is narrow. The decomposition of CF/PA6 cannot be avoided completely even when the welding parameters in the weld lobe are employed. Therefore, it is necessary to conduct further research on the temperature field and the nugget formation mechanism of the REW process.

The YABBY gene family, specific to seed plants, encodes a class of transcription factors in the lamina maintenance and development of lateral organs. Magnoliids are sisters to the clade-containing eudicots and monocots, which have rapidly diversified among the common ancestors of these three lineages. However, prior to this study, information on the function of the YABBY genes in magnoliids was extremely limited to the third major clades and the early diverging lineage of Mesangiospermae. In this study, the sum of 55 YABBY genes including five genes in INO, six in CRC, eight in YAB2, 22 in YAB5, and 14 in FIL clade were identified from seven magnoliid plants. Sequence analysis showed that all encoded YABBY protein sequences possess the highly conserved YABBY domain and C2C2 zinc-finger domain. Gene and protein structure analysis indicates that a certain number of exons were highly conserved and similar in the same class, and YABBY genes encode proteins of 71–392 amino acids and an open reading frame of 216–1179 bp in magnoliids. Additionally, the predicted molecular weight and isoelectric point of YABBY proteins in three species ranged from 7689.93 to 43578.13 and from 5.33 to 9.87, respectively. Meanwhile, the YABBY gene homolog expression of Litsea was detected at a temporal and spatial level during various developmental stages of leaf and reproductive tissues. This research could provide a brief overview of YABBY gene family evolution and its differential expression in magnoliids. Therefore, this comprehensive diversification analysis would provide a new insight into further understanding of the function of genes in seven magnoliids. [ABSTRACT FROM AUTHOR]