When a metro train passes through the shaft, it will lead to severe pressure fluctuations on surfaces of tunnel and train due to the sudden change of tunnel cross section. Based on the three-dimensional, compressible and unsteady N-S equation method, this paper simulates aerodynamic problems caused by trains when they pass through the airshafts at the speed of 140 km/h by the means of constructing four middle shaft models, one is the real shaft, the other three are the simplifications. Time delays generated on trains' surfaces after trains pass through shafts in the three simplifications' model, but on tunnels' surfaces from entering portals for the different corridor sizes. The tendency of max pressure, min pressure and pressure amplitude at trains' and tunnels' surfaces is consistent in four kinds of models. But the different area of shafts' corridor sizes cause the most used model gets the maximum pressure amplitude, the real model gets the minimum pressure amplitude, and the two simplifications' are the middle.

Litsea coreana var. lanuginose is a perennial, indeciduous, and broad-leaved tree used as an essential medicinal and edible plant. In addition, this species is well-known for its leaves are rich in aromatic oil. In this study, we firstly assembled and characterized the complete chloroplast genome of L. coreana var. lanuginose using Illumina pair-end sequencing and performed a phylogenetic analysis with other 13 species in Lauraceae. The results revealed that its chloroplast genome was 152,859 bp in total length with 39% of GC content, containing a pair of inverted repeats of 20,084 bp (IRA and IRB), separated by a large single-copy (LSC) region of 93,795 bp and a small single-copy (SSC) region of 18,896 bp. The plastid genome of L. coreana var. lanuginose encoded 125 genes, including 81 protein-coding genes, 36 transfer RNA (tRNA), and eight ribosomal RNA (rRNA) genes. The phylogenetic analysis suggested that L. coreana var. lanuginose was closely related to the clade of Litsea monopetala , Litsea garrettii , and Litsea elongate in Lauraceae family.