上导数 meaning in English

upper derivative
upper differential coefficient

Then in section 2 we discuss the elliptic problem which has time derivative on the boundary condition and obtain the corresponding regularity estimate which is quoted in chapter 3
第二节讨论边界条件含有时间方向上导数的椭圆问题，并且得到相关的正则性估计，其结果在第三章中被引用。
Under the existence of barrier strips , the existence theorem is established for the following boundary value problem on time scales by using properties of derivative on time scales
在存在障碍带的假设下，建立了时间尺度上的边值问题解的存在性定理其证明依赖于时间尺度上导数自身的性质