The interactions between PM2.5 and meteorological factors play a crucial role in air pollution analysis. However, previous studies that have researched the relationships between PM2.5 concentration and meteorological conditions have been mainly confined to a certain city or district, and the correlation over the whole of China remains unclear. Whether spatial and seasonal variations exist deser...

High speed gas flows occur during the movement of aircrafts, rockets, and descent vehicles, as well in combustion chambers, nozzles, many other technological applications [...]

there are different methods to reduce drag in high speed hulls. one of these methods is a change in the shape of the body by adding longitudinal side tunnels. in this paper it has been attempted to determine the influence of the tunnel height on hydrodynamic characteristics of the hull to achieving an optimum shape for the tunnel. to achieve this purpose, numerical simulation of the problem has...

high speed trains are an indispensable part of rapid transportation systems in many countries. as the fastest means of transport on the ground, these trains are extremely sensitive to the terrain and track conditions. geometrical irregularities and mechanical characteristics of the track, together with inconsistencies in the lane (including bridges that support the track) are considered importa...