脂移方向    principal direction of glide?

竹荡方向    principal direction of oscillation?

朱长比    principal extension ratio?

哈密顿酌    principal function?

脂移系统    principal glide system?

只变量    principal invariant?

诌    principal line?

知荷载    principal load?

钟式    principal minor?

诌性矩    principal moment of inertia?

炙动    principal motion?

著柳    principal net of the flow?

吱线    principal normal?

钟曲面    principal plane of flexure?

脂移平面    principal plane of glide?

诌性平面    principal plane of inertia?

枝力平面    principal plane of stress?

纸面    principal plane?

动力学知问题    principal problem of dynamics?

助率半径    principal radius of curvature?

重面    principal section?

拄应力    principal shear stress?

逐    principal shock?

郑拟误差    principal simulation error?

枝变方向    principal strain direction?

枝变比    principal strain ratio?

枝变    principal strain?

枝力轴    principal stress axis?

枝力方向    principal stress direction?

枝力法    principal stress method?

枝力矩    principal stress moment?

枝力比    principal stress ratio?

枝动    principal stress?

猪面张力    principal surface tension?

衷称面    principal symmetry plane?

汁应力    principal tensile stress?

朱迹    principal trajectory?

值    principal value?

指量    principal vector?

面积守恒原理    principle of conservation of area?

能量守恒原理    principle of conservation of energy?

连续性原理    principle of continuity?