No abstract

No abstract

It was shown that tin has two types of memory: 1) "memory of the structure" about of the event when it was in the α configuration, and 2) "memory of recognition (discern)" whereby tin recognises that an object with which it in contact, was previously in contact with substances of a particular type ("infection"). Transformations of metallic white tin into the grey semiconductor occur with the help of either small pieces of grey tin or other substances isomorphous with grey tin [1] [2] [3]. These pieces (when pressed into white tin) initiate phase transition (by "infection") from white tin into grey tin. Once the tin is transformed into its grey form, it retains a "memory" about this after it is transferred back into white tin. Thus, for second and subsequent phase transformations, there is no need for external initiators to be used. The tin has the "memory of recognition" too-when the tin can recognises that an object with which it is in contact, was previously in contact with the "infection". This phenomenon is concerned with the aging of tin: firstly, with the loss of "memory of the structure" of tin of the event when it was in the grey tin configuration, and, secondly, with the loss of "memory of recognition" of tin whereby the tin recognises that an object with which it is in contact, was previously in contact with substances of a particular type. Factors that effect the aging of tin has been studied in detail and an explanation of the mechanism of action of these factors has been suggested.

A new approach is proposed for preparing shaped α -Sn crystals. The key feature of this approach is that the phase transformation of β -Sn to α -Sn occurs in ice used as a shaper. α -Sn nucleates at a contact between β -Sn and a seed as water freezes in a closed system. The pressure exerted by the expanding ice minimizes the amount of α -Sn nuclei and reduces the growth rate. Water Sn sample Seed Stopper Fig. 1. Reactor for growing shaped α -Sn crystals.

No abstract