资讯

While there are examples of objects that exhibit more than one type of symmetry (for example a six-pointed star exhibits six lines of reflection and a point of 6-fold rotation), there are some ...
The two most basic kinds of symmetry are “reflective” and “rotational.” In the mathematical sense, an object has rotational symmetry if there is an axis around which you can spin it so ...
From basic solid state physics, these structures are only allowed to exhibit strict 2, 3, 4 or 6-fold rotational symmetry, i.e., upon rotation by a certain angle about a crystallographic axis ...
Researchers in the US have invented a new nanofabrication technique that can generate 2D patterns with very high rotational symmetries over large areas. Until now, only spatially repeating structures ...
Nature likes some symmetries, but dislikes others. Ordered solids often display a so-called 6-fold rotation symmetry. To achieve this kind of symmetry, the atoms in a plane surround themselves ...
A cube, for example, has 4-fold rotational symmetry – it will look identical from four angles during one full rotation. For a long time, the very definition of a crystal restricted them to 2-, 3 ...