The dearth of nonpositive studies in the orthopaedic literature is of concern, and may be due largely to investigator-based factors. 骨科文献中非阳性结果的缺乏是令人担忧的,可能大部分是研究者本身的因素。
On the Sign Pattern Matrices with Nonpositive k-power k次幂非正的符号模式矩阵
P-Harmonic maps for simply connected manifolds with nonpositive curvature 单连通非正曲率流形的p-调和映照
THE NUMBER OF NEGATIVE ENTRIES IN THE SQUARE OF A SIGN PATTERN MATRIX WITH NONPOSITIVE SQUARE 平方非正的符号矩阵的平方中负元个数
The Lower Bound of the Number of Negative Entries of a Nonpositive Sign Pattern Matrix A~2 非正符号矩阵A~2中负元个数的下界