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Objective The delayed lateral displacement of elastic wheels occurs in a certain type of tram during servive, significantly affecting the safe operation and maintenance of the vehicle. Method Experimental research is conducted using methods such as quality inspection of elastic wheels, train mainline testing, and simulation calculations to analyze the causes of delayed lateral displacement of wheels in depth. Result & Conclusion The analysis results indicate that the inherent product performance of elastic wheels meets the standards and service requirements, with high stability and reliability. The vibration level of trains in small curve sections is higher than that in straight sections, with a root mean square value of vertical vibration reaching 2.77g. Moreover, there is a vibration dominant frequency of 300 to 450 Hz in curve sections, matching the natural modal frequency of the elastic wheels at 340.37 Hz, resulting in coupling resonance between the wheels and the rai in this section. Therefore, it is recommended that in the operation and maintenance of the wheel-rail railway lubrication operations should be strengthened on one hand and the inspection frequency of rail corrugation in small curve sections be increased on the other hand to reduce the wheel-rail friction coefficient and improve the operating environment for wheel maintenance.

Long non-coding RNAs (lncRNAs) play important roles in response to various biotic and abiotic stresses. So far, systematic identification and characterization of lncRNAs have been reported in a few model plant species and major crops, but their roles in abiotic stress response have not yet been reported in common wild rice (Oryza rufipogon). Dongxiang wild rice (DXWR) possesses a high degree of drought resistance and has been well recognized as a precious genetic resource for drought resistant rice breeding. We presented the reference catalog of 1 655 novel lncRNA transcripts in DXWR using strand-specific RNA sequencing and bioinformatics approaches. Meanwhile, a total of 1 092 lncRNAs were determined as differentially expressed lncRNAs under drought stress. Quantitative real-time PCR results exhibited a high concordance with RNA sequencing data, which confirmed that the expression patterns of lncRNAs based on RNA sequencing were highly reliable. Furthermore, 8 711 transcripts were predicted as target genes of the differentially expressed lncRNAs. Functional annotation analysis based on Gene Ontology and Kyoto Encyclopedia of Genes and Genomes databases showed that the target genes were significantly enriched in cellular and metabolic processes, cell part, binding and plant hormone signal transduction, as well as many other terms related to abiotic stress resistance. These results expanded our understanding of lncRNA biology and provided candidate regulators for genetic improvement of drought resistance in rice cultivars. Keywords: Dongxiang wild rice, Drought stress, Long non-coding RNA, Systematic characterization

MicroRNAs (miRNAs) are non-coding small RNAs, which play important regulatory roles in response to biotic and abiotic stresses. Dongxiang wild rice (Oryza rufipogon, DXWR) can survive in extreme drought environment, but its molecular mechanism of drought resistance is still largely unknown. To further explore miRNA regulatory mechanisms involved in drought resistance, we identified 138 novel miRNAs in DXWR using small RNA sequencing and bioinformatics approaches, and found that the expression levels of 67 novel miRNAs were significantly affected by drought stress. In total, 200 candidate target genes were predicted and annotated for the drought stress-responsive novel miRNAs. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways suggested that most of the target genes were related to metabolism. Stem-loop quantitative real-time PCR (qRT-PCR) results exhibited high concordance with sequencing data, which confirmed that miRNA expression patterns based on small RNA sequencing in the present study were reliable. Meanwhile, qRT-PCR validated the inverse expression patterns between several miRNAs and their target genes. These results will enhance our understanding of miRNA regulatory mechanisms in response to drought stress in DXWR, and can serve as an important reference for the protection and utilization of this valuable genetic resource. Keywords: Dongxiang wild rice, drought stress, genetic resource, novel microRNA, small RNA sequencing