中文摘要：

考虑了一类奇摄动二阶线性边值问题,在一阶导数的系数具有一个零点,即转向点的情形 下,分析了在转向点处可能出现角层现象的条件,然后利用中间变量匹配法构造出在整个区间上的 复合展开式的零次近似.

英文摘要：

Some singularly perturbed second order linear boundary value problems are considered. Corner layer phenomena which may be occur are analyzed under the case of the coefficient of first derivative with a zero, i. e. , a turning point. A composite expansion that is uniformly valid over the whole interval is constructed and a zero-order approximation solution of the problem is obtained using the immediate variable matching procedure.