a series of

According to the deformation compatibility con di tions of bottom chord bar and bridge floor system the axial force ratio formula between longitudinal girder in the first system of steel truss composite girder and bottom chord bar is derived.

根据下弦杆和桥面系的变形协调条件 ,推导了钢桁结合梁第一系统纵梁轴力与下弦杆轴力比值的公式。

Utilization and fixation of the distant heterosis in rice by one line method has been an exploratory work in rice breeding with great enticement and difficulty.

通过一系法利用和固定水稻的远缘杂种优势是一项具有极大诱惑力但难度颇大的科研难题。