A novel structure was observed below the smectic-A–smectic-C phase transition in a very thin open cell having an air interface above and enforced planar anchoring at the substrate below. The structure appears as periodic dark and light streaks running perpendicular to the oily streaks, which are present in the smectic-A phase [D. Coursault et al., Soft Matter, 2016, 12, 678]. These new streaks, which we call “soapy streaks”, form by extending from one oily streak to the next in discrete steps, eliminating optical evidence at visible wavelengths of the oily streaks. At lower temperatures the streaks can undulate and exhibit a sawtooth-like structure; such a structure is chiral in two dimensions. A possible scenario for the origin of these streaks is presented.

中文翻译：

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混合取向近晶C相条纹纹理的观察

在非常薄的开孔中，在近晶-A-近晶-C相变下方观察到一种新颖的结构，该结构具有上方的空气界面并在下方的基板上强制进行平面锚固。该结构表现为垂直于油性条纹的周期性深色和浅色条纹，这些条纹存在于近晶A相中[D.]。Coursault等。，软物质，2016年，12，678]。这些新的条纹，我们称为“肥皂状条纹”，是通过从一个油性条纹延伸到下一个离散的步骤而形成的，从而消除了在油性条纹可见波长处的光学证据。在较低的温度下，条纹会起伏并呈现出锯齿状的结构。这样的结构在二维上是手性的。提出了这些条纹起源的可能方案。