Construction properties of different soil profile constitutions in black soil of corn belt in Jilin were systemically studied.
以吉林省中部玉米带黑土为供试土壤，研究了黑土不同剖面构型的结构特性。
2
To simplified the designing, diagram presentation, construction and profile of helicoidal stair, the formation of helicoid is analyzed, and it's mathematical model is studied.
为简化旋转楼梯的设计、图示、施工及剖面形状，对螺旋面的形成进行了分析，建立了螺旋面的数学模型。
3
At present, domestic PVC plastic profile trades low-level construction is serious, the price war grows in intensity.