scholarly journals Stabilization and self-passivation of symmetrical grain boundaries by mirror symmetry breaking

2019 ◽  
Vol 3 (1) ◽  
Author(s):  
Ji-Sang Park
Keyword(s):  
Symmetry Breaking ◽  
Grain Boundaries ◽  
Mirror Symmetry

High Resolution Electron Microscopy of internal interfaces in layered materials

1990 ◽  
Vol 48 (4) ◽  
pp. 320-321
Author(s):  
Yoichi Ishida ◽  
Hideki Ichinose ◽  
Yutaka Takahashi ◽  
Jin-yeh Wang
Keyword(s):  
Grain Boundaries ◽  
Mirror Symmetry ◽  
Functional Materials ◽  
High Resolution Electron Microscopy ◽  
Layered Materials ◽  
Plane Boundary ◽  
Chemical Information ◽  
Layer Plane ◽  
High Tc ◽  
Cubic Metals

Layered materials draw attention in recent years in response to the world-wide drive to discover new functional materials. High-Tc superconducting oxide is one example. Internal interfaces in such layered materials differ significantly from those of cubic metals. They are often parallel to the layer of the neighboring crystals in sintered samples(layer plane boundary), while periodically ordered interfaces with the two neighboring crystals in mirror symmetry to each other are relatively rare. Consequently, the atomistic features of the interface differ significantly from those of cubic metals. In this paper grain boundaries in sintered high-Tc superconducting oxides, joined interfaces between engineering ceramics with metals, and polytype interfaces in vapor-deposited bicrystal are examined to collect atomic information of the interfaces in layered materials. The analysis proved that they are not neccessarily more complicated than that of simple grain boundaries in cubic metals. The interfaces are majorly layer plane type which is parallel to the compound layer. Secondly, chemical information is often available, which helps the interpretation of the interface atomic structure.

2,6-Dibromogallates as a new building block for controlling π-stacking, network formation and mirror symmetry breaking

2021 ◽  
Author(s):  
Ohjin Kwon ◽  
Xiaoqian Cai ◽  
Azhar Saeed ◽  
Feng Liu ◽  
Silvio Poppe ◽  
...  
Keyword(s):  
Symmetry Breaking ◽  
Building Block ◽  
Mirror Symmetry ◽  
Network Formation ◽  
Network Structures ◽  
Π Stacking ◽  
Bicontinuous Cubic ◽  
Substituted 1 ◽  
End Group

Achiral multi-chain (polycatenar) compounds based on the 2,7-diphenyl substituted [1]benzothieno[3,2-b]benzothiophene (BTBT) unit and a 2,6-dibromo-3,4,5-trialkoxybenzoate end group lead to materials forming bicontinuous cubic liquid crystaline phases with helical network structures...

Reply to “Mirror Symmetry Breaking” of the Centrosymmetric CaCO3 Crystals with Amino Acids

2008 ◽  
Vol 120 (20) ◽  
pp. 3741-3744
Author(s):  
Niklas Loges ◽  
Stephan E. Wolf ◽  
Martin Panthöfer ◽  
Lars Müller ◽  
Marc-Christopher Reinnig ◽  
...  
Keyword(s):  
Amino Acids ◽  
Symmetry Breaking ◽  
Mirror Symmetry

scholarly journals Entropic Analysis of Mirror Symmetry Breaking in Chiral Hypercycles

Life ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 28 ◽  
Author(s):  
David Hochberg ◽  
Josep Ribó
Keyword(s):  
Symmetry Breaking ◽  
Entropy Production ◽  
Mirror Symmetry ◽  
Flow Reactor ◽  
Evolutionary Selection ◽  
Replicator System ◽  
Stoichiometric Network Analysis ◽  
Underlying Mechanisms ◽  
The Individual ◽  
Origin Of Homochirality

Replicators are fundamental to the origin of life and evolvability. Biology exhibits homochirality: only one of two enantiomers is used in proteins and nucleic acids. Thermodynamic studies of chemical replicators able to lead to homochirality shed valuable light on the origin of homochirality and life in conformity with the underlying mechanisms and constraints. In line with this framework, enantioselective hypercyclic replicators may lead to spontaneous mirror symmetry breaking (SMSB) without the need for additional heterochiral inhibition reactions, which can be an obstacle for the emergence of evolutionary selection properties. We analyze the entropy production of a two-replicator system subject to homochiral cross-catalysis which can undergo SMSB in an open-flow reactor. The entropy exchange with the environment is provided by the input and output matter flows, and is essential for balancing the entropy production at the non-equilibrium stationary states. The partial entropy contributions, associated with the individual elementary flux modes, as defined by stoichiometric network analysis (SNA), describe how the system’s internal currents evolve, maintaining the balance between entropy production and exchange, while minimizing the entropy production after the symmetry breaking transition. We validate the General Evolution Criterion, stating that the change in the chemical affinities proceeds in a way as to lower the value of the entropy production.

scholarly journals Computing the Parameter Values for the Emergence of Homochirality in Complex Networks

Life ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 74
Author(s):  
Andrés Montoya ◽  
Elkin Cruz ◽  
Jesús Ágreda
Keyword(s):  
Symmetry Breaking ◽  
Heuristic Algorithm ◽  
Mirror Symmetry ◽  
Steady States ◽  
Chemical Mechanism ◽  
Reaction Networks ◽  
Nonlinear Character ◽  
Algorithmic Problems ◽  
Algorithmic Analysis ◽  
Parameter Values

The goal of our research is the development of algorithmic tools for the analysis of chemical reaction networks proposed as models of biological homochirality. We focus on two algorithmic problems: detecting whether or not a chemical mechanism admits mirror symmetry-breaking; and, given one of those networks as input, sampling the set of racemic steady states that can produce mirror symmetry-breaking. Algorithmic solutions to those two problems will allow us to compute the parameter values for the emergence of homochirality. We found a mathematical criterion for the occurrence of mirror symmetry-breaking. This criterion allows us to compute semialgebraic definitions of the sets of racemic steady states that produce homochirality. Although those semialgebraic definitions can be processed algorithmically, the algorithmic analysis of them becomes unfeasible in most cases, given the nonlinear character of those definitions. We use Clarke’s system of convex coordinates to linearize, as much as possible, those semialgebraic definitions. As a result of this work, we get an efficient algorithm that solves both algorithmic problems for networks containing only one enantiomeric pair and a heuristic algorithm that can be used in the general case, with two or more enantiomeric pairs.

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