projections投影图projectionn.投影；投射；规划；发射；凸出物；预测；放映projection chamber投影火花室Projection mapping投影算子projection aligner投影式光刻机projectional angle投射角Projection grating投影光栅projection stepper步进式投影曝光装置projection grinder光学曲线磨床projection welding凸焊,凸出焊接projection formula投影式projection pursuit投影寻踪