scholarly journals Selective synthesis and structural transformation between a molecular ring-in-ring architecture and an abnormal trefoil knot

2020 ◽  
Vol 11 (30) ◽  
pp. 8013-8019 ◽  
Author(s):  
Li-Long Dang ◽  
Xiang Gao ◽  
Yue-Jian Lin ◽  
Guo-Xin Jin
Keyword(s):  
Structural Transformation ◽  
Solvent Effects ◽  
Chemical Reactivity ◽  
Structural Transformations ◽  
Selective Synthesis ◽  
Trefoil Knot ◽  
Ring Architecture

The chemical reactivity of Ag+ ions and solvent effects induce reversible structural transformations between an abnormal trefoil knot, a tetranuclear macrocycle and a ring-in-ring architecture.

Structural Transformation of a Germanium Σ=13 (510) [001] Tilt Grain Boundary under the Electron Beam

1990 ◽  
Vol 48 (1) ◽  
pp. 52-53 ◽  
Author(s):  
Jean-Luc Rouvière ◽  
Alain Bourret
Keyword(s):  
Electron Microscopy ◽  
High Resolution ◽  
Grain Boundary ◽  
Structural Transformation ◽  
Mirror Symmetry ◽  
High Resolution Electron Microscopy ◽  
Structural Transformations ◽  
Covalent Bonds ◽  
Resolution Electron ◽  
Tilt Grain Boundary

The possible structural transformations during the sample preparations and the sample observations are important issues in electron microscopy. Several publications of High Resolution Electron Microscopy (HREM) have reported that structural transformations and evaporation of the thin parts of a specimen could happen in the microscope. Diffusion and preferential etchings could also occur during the sample preparation.Here we report a structural transformation of a germanium Σ=13 (510) [001] tilt grain boundary that occurred in a medium-voltage electron microscopy (JEOL 400KV).Among the different (001) tilt grain boundaries whose atomic structures were entirely determined by High Resolution Electron Microscopy (Σ = 5(310), Σ = 13 (320), Σ = 13 (510), Σ = 65 (1130), Σ = 25 (710) and Σ = 41 (910), the Σ = 13 (510) interface is the most interesting. It exhibits two kinds of structures. One of them, the M-structure, has tetracoordinated covalent bonds and is periodic (fig. 1). The other, the U-structure, is also tetracoordinated but is not strictly periodic (fig. 2). It is composed of a periodically repeated constant part that separates variable cores where some atoms can have several stable positions. The M-structure has a mirror glide symmetry. At Scherzer defocus, its HREM images have characteristic groups of three big white dots that are distributed on alternatively facing right and left arcs (fig. 1). The (001) projection of the U-structure has an apparent mirror symmetry, the portions of good coincidence zones (“perfect crystal structure”) regularly separate the variable cores regions (fig. 2).

The Eventfulness of Social Reproduction

2011 ◽  
Vol 29 (4) ◽  
pp. 294-314 ◽  
Author(s):  
Adam Moore
Keyword(s):  
Structural Transformation ◽  
Social Reproduction ◽  
Social Life ◽  
Structural Transformations ◽  
Social Structures ◽  
Stability And Change ◽  
Theoretical Assumptions

The work of William Sewell and Marshall Sahlins has led to a growing interest in recent years in events as a category of analysis and their role in the transformation of social structures. I argue that tying events solely to instances of significant structural transformation entails problematic theoretical assumptions about stability and change and produces a circumscribed field of events, undercutting the goal of developing an “eventful” account of social life. Social continuity is a state that is achieved just as much as are structural transformations, and events may be constitutive of processes of reproduction as well as change.

Physical Analysis of Structural Transformation in Ge-Incorporated a-SbxSe100-x System

2011 ◽  
Vol 316-317 ◽  
pp. 45-53 ◽  
Author(s):  
Sunanda Sharda ◽  
Neha Sharma ◽  
Pankaj Sharma ◽  
Vineet Sharma
Keyword(s):  
Structural Transformation ◽  
Chalcogenide Glasses ◽  
Theoretical Study ◽  
Far Infrared ◽  
Structural Transformations ◽  
Physical Parameters ◽  
Physical Analysis ◽  
Melt Quenching ◽  
Structural Environment ◽  
Rigidity Percolation

Chalcogenide glasses are suitable for far-infrared and imaging applications. In the present study, Sb10Se90-xGex (x=0, 19, 21, 23, 25, 27) system has been chosen to study structural transformations via physical parameters. Bulk samples with x = 0, 19, 21, 23, 25 and 27 have been prepared using the melt-quenching technique. A theoretical study of the ternary glass system revealed that there was a significant change in the structural environment of the system due to rigidity percolation, which took place as Se was replaced by Ge, and hence resulted in changes in other physical parameters of the system.

Multiple structural transformations coupled with switchable magnetic and dielectric responses in an amphidynamic crystal of 4′-tert-butylbenzylpyridinium bis(maleonitriledithiolate)nickelate

2015 ◽  
Vol 3 (30) ◽  
pp. 7906-7915 ◽  
Author(s):  
Wei-Hua Ning ◽  
Lu Zhai ◽  
Jian-Lan Liu ◽  
Xiao-Ming Ren ◽  
Katsuya Ichihashi ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Structural Transformation ◽  
Magnetic Phase ◽  
Structural Transformations ◽  
Magnetic Phase Transitions

An amphidynamic crystal shows a two-step structural transformation; the steps are coupled to both hysteretic magnetic phase transitions and dielectric anomalies.

Inclusion of cyclodextrins in a metallosupramolecular framework via structural transformations

CrystEngComm ◽  
2021 ◽  
Author(s):  
Supattra Somsri ◽  
Naoto Kuwamura ◽  
Tatsuhiro Kojima ◽  
Nobuto Yoshinari ◽  
Apinpus Rujiwatra ◽  
...  
Keyword(s):  
Structural Transformation ◽  
Structural Transformations ◽  
Porous Framework ◽  
Site Selective ◽  
Complex Anions

A 3D porous framework composed of D-penicillaminato AuI3CoIII2 complex anions and aqua sodium(I) cations underwent a solvent-mediated structural transformation to generate a multilayer framework, including α-CD as cyclic trimers. Site-selective...

SOLVENT EFFECTS ON CHEMICAL REACTIVITY

2014 ◽  
pp. 753-810
Author(s):  
WOLFGANG LINERT ◽  
MARKUS HOLZWEBER ◽  
ROLAND SCHMID
Keyword(s):  
Solvent Effects ◽  
Chemical Reactivity
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