The prefix “nano” specifically means a measure of 10−9 units. Although it is widely accepted that the prefix “nano” specifically refers to 10−9units, in the context of nano-sized and nanocrystalline materials, the units should only be those of dimensions, rather than of any other unit of the scientific measurements. Besides, for practical purposes, it appears to be unrealistic to consider the prefix “nano” to solely and precisely refer to 10−9 m, just as it is not considered that “micro” specifically and solely concerns something with a dimension of precisely 10−6 m [89]. Currently, there is a general agreement that the subject of nanoscience and nanotechnology started after the famous talk: “There’s plenty of room at the bottom” given by the Nobel Prize winner in physics Prof. Richard P. Feynman on December 26, 1959, at the annual meeting of the American Physical Society held at California Institute of Technology. This well-known talk has been widely published in various media (e.g., [90]).