The Egg-Shaped Crystals That Should Not Be: A Brain-like Texture Combined with Single Crystallinity

We demonstrate here a unique metallo-organic material where the appearance and the internal crystal structure contradict. The egg-shaped (ovoid) crystals have a "brain-like" texture. Although these micro-sized crystals are monodispersed; like fingerprints the grainy surfaces are never alike. Remarkable, our X-ray and electron diffraction studies unexpectedly revealed that these structures are single crystals comprising a continuous coordination network of homochiral hexagonal and triangular channels. By applying different reaction condition, a series of isostructural and monodisperse crystals were obtained having a monodomain appearance. These results indicate that families of isostructural crystals following the established rules for crystal growth contain hidden gems to be discovered with fascinating multidomain morphologies.<br> <br>

The Egg-Shaped Crystals That Should Not Be: A Brain-like Texture Combined with Single Crystallinity

We demonstrate here a unique metallo-organic material where the appearance and the internal crystal structure contradict. The egg-shaped (ovoid) crystals have a "brain-like" texture. Although these micro-sized crystals are monodispersed; like fingerprints the grainy surfaces are never alike. Remarkable, our X-ray and electron diffraction studies unexpectedly revealed that these structures are single crystals comprising a continuous coordination network of homochiral hexagonal and triangular channels. By applying different reaction condition, a series of isostructural and monodisperse crystals were obtained having a monodomain appearance. These results indicate that families of isostructural crystals following the established rules for crystal growth contain hidden gems to be discovered with fascinating multidomain morphologies.<br> <br>

Lattice vibrations and disorder in crystalline benzoxazoles undergoing excited state intramolecular proton transfer: DFTB modeling

Structure and crystal lattice vibrations are calculated for 2-(2'-hydroxyphenyl)bezoxazole and bis-(2,5-benzoxazolyl)hydroquinone by density functional based tight-binding methods. Despite lowering of the molecular symmetry, structure parameters of the molecules in crystal and forms of the internal vibrations are similar to those of isolated molecules. Weak interaction between the molecules in the molecular crystals leads to appearance of the external vibrations, splitting and mixing of the vibrations of the isolated molecules into internal crystal vibrations. External and internal vibrations are not separated well; contribution of the translations and librations is noticeable in the region below 150 cm-1. The magnitude ofthe splitting does not exceed 4 cm-1 for the most vibrations. The internal vibrations that correspond to the out-of plane molecular vibrations demonstrate larger molecule-to-crystal frequency shift than in-plane modes, mostly to higher frequencies, whereas the modes involving torsion motion of the OH bond are shifted toward lower frequencies. Mixing occurs for the molecular vibrations with frequencies that are different by less than 16 cm-1. Calculations performed for model molecular clusters show that the defectcaused by different molecule orientation has lower energy than the defect related to the formation ofrotamers.

Paweł Hendrich’s Emergent Sound System

Paweł Hendrich’s compositions can be compared to macrocrystals - solids composed of numerous small and identical elements, constructed in accordance with a strict pattern. Importantly, the same internal crystal structure can produce forms highly diversified with regard to external shape. Similarly, this composer’s works are very precisely structured already on the level of individual sounds, but this structure is only a tool for the creation of very clear musical macroforms. The idea of emergence - of new values resulting from the combination of simple elements - is of key importance to this composer. The paper presents the principles of organising music material in the works of Paweł Hendrich. These are, among others: periodicity, multilayered structures, permutations and flexibility. These ideas are reflected in the musical work in many dimensions, both on the level of microand macro-structure. Their application exerts a major impact on the forms created by the composer. With the development of his musical language, the composer transforms his initial material more and more radically. Simple elements and processes that underlie the construction of his works become progressively more and more difficult to reconstruct, largely due to the application of a computer in the composition process. A comprehensive look at Paweł Hendrich’s entire output of compositions proves that his work is emergent as a whole. With each new piece, a new element is added, but all of them form a coherent system. No wonder, then, that one of the composer’s works bears the telling title of Emergon.

Study on the Infrared Radiation Properties of Different Tourmaline Species

Tourmaline is a kind of non-metal mineral, which has been applied widely in environmental protection, such as radiating infrared, producing ion negative and shielding electromagnetic radiation. It is proved that tourmaline has the properties of spontaneous electrode effect and weak magnetism. Tourmaline from different areas has some differences on internal crystal structure and chemical composition. This paper studied on the infrared radiation properties of four different kinds of tourmaline produced in Hebei Guangxi, Henan, Xinjiang. Our experiments indicated that different species of tourmaline has different rate of infrared radiation on the same condition, and infrared radiation rate changes with temperature and particle size.

The Influence of the Electromagnetic Field Power on the Solidification of the Casting

The electromagnetic stirring technique was used in the experiment to prepare the ingot casting. After comparing the conventional production by the means of ingot casting through electromagnetic field production, the results showed that the solidification of crystal was significantly influenced by the electromagnetic power. As the powers of the agitator increasesed from 0 KW to 20 KW, the refined grain size could be easily detected. That means, the length of the columnar crystal had shortened and isometric crystal had increased dramatically. From the phase transformation we can see that the pearlite and ferrite were distributed much more uniform than the original specimens. The results of the test showed that strengthening electromagnetic field is one of the most important methods to modify the internal crystal morphology. In conclusion, the electromagnetic stirring played a key role in ingot casting.