心包由两个不同的亚层组成：坚固的外纤维心包和内浆液心包。

The pericardium consists of two distinct sublayers: the sturdy outer fibrous pericardium and the inner serous pericardium.

youdao

有7种杜鹃生长于这种硬叶栎类林下亚层。

There are 7 species of Rhododendron occurs in the sub-stratum of this kind of forest.

youdao

星体亚层：一个星体层中内部的层面和组成部分。

Astral Sub - Planes: Internal levels and parts contained within a single astral plane.

youdao

So, let's take a look at one of these rows in more detail to think about why this might be happening, and it turns out the reason that these glitches occur are because the sub shell structure predominates in certain instances, and that's where these glitches take place.

那么，让我们仔细地看一看其中一行,想一想为什么会这样，结果是这些小偏差的出现,是因为在一定情况下,亚壳层结构会产生重要影响，这正发生在小偏差出现的地方。

麻省理工公开课 - 化学原理课程节选

And the reason is simply because the energy that Z we gain in terms of moving up in z, 5 so from going to z equals 4 to z equals 5, -- is actually outweighed by the energy it takes to go into this new shell, to go into this new sub shell.

原因很简单,就是因为我们通过提升，所得到的能量--从，Z，等于，4，到，Z，等于，事实上比填充到这个新的壳层,新的亚壳层，所消耗的能量更多。

麻省理工公开课 - 化学原理课程节选