5 请问NV_D是什么意思，能否举个例子

NV_D(wind_v, =, C_U(c, t), C_V(c, t), C_W(c, t)); NV_D(rain_v, =, C_UDSI(c, t, RS_ALP + 1), C_UDSI(c, t, RS_ALP + 2), C_UDSI(c, t, RS_ALP + 3))谢谢