垂直面直接曝辐量
direct solar radiation on perpendicular plane
平面直线调整法
level linearity adjustment
平面直线图
planar straight-line graph
曲线直线化
approximate nonlinear method
异面直线
Skew lines
straight lines in differenf planes
crossover line
general position lines
异面直线公垂线中点
mid-point of vertical line in crossover lines
永磁直线直流无刷电动机
linear permanent magnet brushless DC motor