充分必要条件

• A necessary and sufficient condition for the existence of positive solutions to singular boundary value problems
  一类奇异边值问题正解存在的充分必要条件
• A necessary and sufficient condition for the existence of positive solutions of fourth - order singular boundary value problems
  四阶奇异边值问题正解存在的充分必要条件
• A necessary and sufficient condtion for the existence of positive solutions of singular superlinear boundary value problems
  超线性奇异边值问题正解存在的充分必要条件
• Necessary and sufficient conditions for the existence of a positive definite solution of the matrix equation x a x - 2 a i
  矩阵方程x a x - 2 a i有对称正定解的充分必要条件矩阵方程
• Necessary and sufficient conditions for every closed maximal linear subspace to be strongly orthogonally complemented in banach spaces
  空间上闭线性子空间强正交可补的充分必要条件
• Theorem 1 ( bounded sum test ) a series of nonnegative terms converges if and only if it ' s partial sums are bounded above
  定理1正项级数收敛的充分必要条件是：它的部分和数列有上界。
• A necessary and sufficient condidtion for existence of positive solutions to singular superlinear boundary value problems at nonresonance
  非共振奇异超线性边值问题正解存在的充分必要条件
• The sufficient and necessary conditions of the centre - focus criterion for a class of cubic differential system are given
  摘要给出了一类三次多项式微分系统中心焦点判定的充分必要条件。
• A necessary and sufficient condition for theexistence of positive solutions for a nonlinear forth order three - point boundary walue problem
  一类四阶三点奇异边值问题正解存在的充分必要条件
• It is proved that an equivalent characterization , which two generalized frames are q equivalent if and only if they are near
  。 。是h6两个厂义框架，则八和k是q等价的充分必要条件是h和k是接近的