In such case, it is proved that, for the unique existence of solution, there must be given in addition the principalvector and the principal moment of the external forces on each boundary contour.
在这种情况下，为了解的唯一性，证明了必须另外给出每一边界围线上外力的主矢量与主力矩。
2
The principal objective of vector control is the reduction of malaria morbidity and mortality by reducing the levels of transmission.
媒介控制的主要目标是通过降低传播水平来降低发病率和死亡率。
3
The principal component analysis in multivariate statistic analysis is a method of compressing the dimension of vector data by extracting principal typical components from sample data set.