Controlling phase and morphology of inorganic nanostructures originated from the internal crystal structure

2009 ◽  
pp. 5943 ◽  
Author(s):  
Changzheng Wu ◽  
Yi Xie
2015 ◽  
Vol 12 (1) ◽  
pp. 116-126
Author(s):  
Paweł Hendrich ◽  
Krzysztof Stefański

Abstract 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.


2021 ◽  
Author(s):  
vivek singh ◽  
Lothar Houben ◽  
linda shimon ◽  
Sidney Cohen ◽  
Ofra Golani ◽  
...  

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>


2021 ◽  
Author(s):  
vivek singh ◽  
Lothar Houben ◽  
linda shimon ◽  
Sidney Cohen ◽  
Ofra Golani ◽  
...  

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>


2014 ◽  
Vol 490-491 ◽  
pp. 1536-1541
Author(s):  
Qi Lu ◽  
Feng Bai ◽  
Ni Wang

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.


Author(s):  
Douglas L. Dorset ◽  
Anthony J. Hancock

Lipids containing long polymethylene chains were among the first compounds subjected to electron diffraction structure analysis. It was only recently realized, however, that various distortions of thin lipid microcrystal plates, e.g. bends, polar group and methyl end plane disorders, etc. (1-3), restrict coherent scattering to the methylene subcell alone, particularly if undistorted molecular layers have well-defined end planes. Thus, ab initio crystal structure determination on a given single uncharacterized natural lipid using electron diffraction data can only hope to identify the subcell packing and the chain axis orientation with respect to the crystal surface. In lipids based on glycerol, for example, conformations of long chains and polar groups about the C-C bonds of this moiety still would remain unknown.One possible means of surmounting this difficulty is to investigate structural analogs of the material of interest in conjunction with the natural compound itself. Suitable analogs to the glycerol lipids are compounds based on the three configurational isomers of cyclopentane-1,2,3-triol shown in Fig. 1, in which three rotameric forms of the natural glycerol derivatives are fixed by the ring structure (4-7).


Author(s):  
George G. Cocks ◽  
Louis Leibovitz ◽  
DoSuk D. Lee

Our understanding of the structure and the formation of inorganic minerals in the bivalve shells has been considerably advanced by the use of electron microscope. However, very little is known about the ultrastructure of valves in the larval stage of the oysters. The present study examines the developmental changes which occur between the time of conception to the early stages of Dissoconch in the Crassostrea virginica(Gmelin), focusing on the initial deposition of inorganic crystals by the oysters.The spawning was induced by elevating the temperature of the seawater where the adult oysters were conditioned. The eggs and sperm were collected separately, then immediately mixed for the fertilizations to occur. Fertilized animals were kept in the incubator where various stages of development were stopped and observed. The detailed analysis of the early stages of growth showed that CaCO3 crystals(aragonite), with orthorhombic crystal structure, are deposited as early as gastrula stage(Figuresla-b). The next stage in development, the prodissoconch, revealed that the crystal orientation is in the form of spherulites.


Author(s):  
F.-R. Chen ◽  
T. L. Lee ◽  
L. J. Chen

YSi2-x thin films were grown by depositing the yttrium metal thin films on (111)Si substrate followed by a rapid thermal annealing (RTA) at 450 to 1100°C. The x value of the YSi2-x films ranges from 0 to 0.3. The (0001) plane of the YSi2-x films have an ideal zero lattice mismatch relative to (111)Si surface lattice. The YSi2 has the hexagonal AlB2 crystal structure. The orientation relationship with Si was determined from the diffraction pattern shown in figure 1(a) to be and . The diffraction pattern in figure 1(a) was taken from a specimen annealed at 500°C for 15 second. As the annealing temperature was increased to 600°C, superlattice diffraction spots appear at position as seen in figure 1(b) which may be due to vacancy ordering in the YSi2-x films. The ordered vacancies in YSi2-x form a mesh in Si plane suggested by a LEED experiment.


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