A coil curl is arranged in an inverted V-shaped fender of a front wheel whose wheel frame is provided with an electromagnet.

This will tend to preserve the internal valve, avoiding disruption of the dorsal aesthetic lines, and inverted V deformity, and airway compromise.

The different planting years grassland in Maqin, biomass carbon content showed inverted v shaped distribution, and biomass carbon of mixed planting grassland 6a is largest.